xref: /petsc/src/ts/interface/ts.c (revision 31152f8aa72e3d28c15275a27fd70dec1575434b)
1 
2 #include <petsc-private/tsimpl.h>        /*I "petscts.h"  I*/
3 #include <petscdmshell.h>
4 #include <petscdmda.h>
5 #include <petscviewer.h>
6 #include <petscdraw.h>
7 
8 /* Logging support */
9 PetscClassId  TS_CLASSID, DMTS_CLASSID;
10 PetscLogEvent TS_Step, TS_PseudoComputeTimeStep, TS_FunctionEval, TS_JacobianEval;
11 
12 const char *const TSExactFinalTimeOptions[] = {"STEPOVER","INTERPOLATE","MATCHSTEP","TSExactFinalTimeOption","TS_EXACTFINALTIME_",0};
13 
14 #undef __FUNCT__
15 #define __FUNCT__ "TSSetTypeFromOptions"
16 /*
17   TSSetTypeFromOptions - Sets the type of ts from user options.
18 
19   Collective on TS
20 
21   Input Parameter:
22 . ts - The ts
23 
24   Level: intermediate
25 
26 .keywords: TS, set, options, database, type
27 .seealso: TSSetFromOptions(), TSSetType()
28 */
29 static PetscErrorCode TSSetTypeFromOptions(TS ts)
30 {
31   PetscBool      opt;
32   const char     *defaultType;
33   char           typeName[256];
34   PetscErrorCode ierr;
35 
36   PetscFunctionBegin;
37   if (((PetscObject)ts)->type_name) defaultType = ((PetscObject)ts)->type_name;
38   else defaultType = TSEULER;
39 
40   if (!TSRegisterAllCalled) {ierr = TSRegisterAll();CHKERRQ(ierr);}
41   ierr = PetscOptionsFList("-ts_type", "TS method"," TSSetType", TSList, defaultType, typeName, 256, &opt);CHKERRQ(ierr);
42   if (opt) {
43     ierr = TSSetType(ts, typeName);CHKERRQ(ierr);
44   } else {
45     ierr = TSSetType(ts, defaultType);CHKERRQ(ierr);
46   }
47   PetscFunctionReturn(0);
48 }
49 
50 struct _n_TSMonitorDrawCtx {
51   PetscViewer   viewer;
52   PetscDrawAxis axis;
53   Vec           initialsolution;
54   PetscBool     showinitial;
55   PetscInt      howoften;  /* when > 0 uses step % howoften, when negative only final solution plotted */
56   PetscBool     showtimestepandtime;
57   int           color;
58 };
59 
60 #undef __FUNCT__
61 #define __FUNCT__ "TSSetFromOptions"
62 /*@
63    TSSetFromOptions - Sets various TS parameters from user options.
64 
65    Collective on TS
66 
67    Input Parameter:
68 .  ts - the TS context obtained from TSCreate()
69 
70    Options Database Keys:
71 +  -ts_type <type> - TSEULER, TSBEULER, TSSUNDIALS, TSPSEUDO, TSCN, TSRK, TSTHETA, TSGL, TSSSP
72 .  -ts_max_steps maxsteps - maximum number of time-steps to take
73 .  -ts_final_time time - maximum time to compute to
74 .  -ts_dt dt - initial time step
75 .  -ts_monitor - print information at each timestep
76 .  -ts_monitor_lg_timestep - Monitor timestep size graphically
77 .  -ts_monitor_lg_solution - Monitor solution graphically
78 .  -ts_monitor_lg_error - Monitor error graphically
79 .  -ts_monitor_lg_snes_iterations - Monitor number nonlinear iterations for each timestep graphically
80 .  -ts_monitor_lg_ksp_iterations - Monitor number nonlinear iterations for each timestep graphically
81 .  -ts_monitor_sp_eig - Monitor eigenvalues of linearized operator graphically
82 .  -ts_monitor_draw_solution - Monitor solution graphically
83 .  -ts_monitor_draw_solution_phase - Monitor solution graphically with phase diagram
84 .  -ts_monitor_draw_error - Monitor error graphically
85 .  -ts_monitor_solution_binary <filename> - Save each solution to a binary file
86 -  -ts_monitor_solution_vtk <filename.vts> - Save each time step to a binary file, use filename-%%03D.vts
87 
88    Developer Note: We should unify all the -ts_monitor options in the way that -xxx_view has been unified
89 
90    Level: beginner
91 
92 .keywords: TS, timestep, set, options, database
93 
94 .seealso: TSGetType()
95 @*/
96 PetscErrorCode  TSSetFromOptions(TS ts)
97 {
98   PetscBool              opt,flg;
99   PetscErrorCode         ierr;
100   PetscViewer            monviewer;
101   char                   monfilename[PETSC_MAX_PATH_LEN];
102   SNES                   snes;
103   TSAdapt                adapt;
104   PetscReal              time_step;
105   TSExactFinalTimeOption eftopt;
106   char                   dir[16];
107 
108   PetscFunctionBegin;
109   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
110   ierr = PetscObjectOptionsBegin((PetscObject)ts);CHKERRQ(ierr);
111   /* Handle TS type options */
112   ierr = TSSetTypeFromOptions(ts);CHKERRQ(ierr);
113 
114   /* Handle generic TS options */
115   ierr = PetscOptionsInt("-ts_max_steps","Maximum number of time steps","TSSetDuration",ts->max_steps,&ts->max_steps,NULL);CHKERRQ(ierr);
116   ierr = PetscOptionsReal("-ts_final_time","Time to run to","TSSetDuration",ts->max_time,&ts->max_time,NULL);CHKERRQ(ierr);
117   ierr = PetscOptionsReal("-ts_init_time","Initial time","TSSetTime",ts->ptime,&ts->ptime,NULL);CHKERRQ(ierr);
118   ierr = PetscOptionsReal("-ts_dt","Initial time step","TSSetTimeStep",ts->time_step,&time_step,&flg);CHKERRQ(ierr);
119   if (flg) {
120     ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
121   }
122   ierr = PetscOptionsEnum("-ts_exact_final_time","Option for handling of final time step","TSSetExactFinalTime",TSExactFinalTimeOptions,(PetscEnum)ts->exact_final_time,(PetscEnum*)&eftopt,&flg);CHKERRQ(ierr);
123   if (flg) {ierr = TSSetExactFinalTime(ts,eftopt);CHKERRQ(ierr);}
124   ierr = PetscOptionsInt("-ts_max_snes_failures","Maximum number of nonlinear solve failures","TSSetMaxSNESFailures",ts->max_snes_failures,&ts->max_snes_failures,NULL);CHKERRQ(ierr);
125   ierr = PetscOptionsInt("-ts_max_reject","Maximum number of step rejections before step fails","TSSetMaxStepRejections",ts->max_reject,&ts->max_reject,NULL);CHKERRQ(ierr);
126   ierr = PetscOptionsBool("-ts_error_if_step_fails","Error if no step succeeds","TSSetErrorIfStepFails",ts->errorifstepfailed,&ts->errorifstepfailed,NULL);CHKERRQ(ierr);
127   ierr = PetscOptionsReal("-ts_rtol","Relative tolerance for local truncation error","TSSetTolerances",ts->rtol,&ts->rtol,NULL);CHKERRQ(ierr);
128   ierr = PetscOptionsReal("-ts_atol","Absolute tolerance for local truncation error","TSSetTolerances",ts->atol,&ts->atol,NULL);CHKERRQ(ierr);
129 
130 #if defined(PETSC_HAVE_SAWS)
131   {
132   PetscBool set;
133   flg  = PETSC_FALSE;
134   ierr = PetscOptionsBool("-ts_saws_block","Block for SAWs memory snooper at end of TSSolve","PetscObjectSAWsBlock",((PetscObject)ts)->amspublishblock,&flg,&set);CHKERRQ(ierr);
135   if (set) {
136     ierr = PetscObjectSAWsSetBlock((PetscObject)ts,flg);CHKERRQ(ierr);
137   }
138   }
139 #endif
140 
141   /* Monitor options */
142   ierr = PetscOptionsString("-ts_monitor","Monitor timestep size","TSMonitorDefault","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
143   if (flg) {
144     ierr = PetscViewerASCIIOpen(PetscObjectComm((PetscObject)ts),monfilename,&monviewer);CHKERRQ(ierr);
145     ierr = TSMonitorSet(ts,TSMonitorDefault,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
146   }
147   ierr = PetscOptionsString("-ts_monitor_python","Use Python function","TSMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
148   if (flg) {ierr = PetscPythonMonitorSet((PetscObject)ts,monfilename);CHKERRQ(ierr);}
149 
150   ierr = PetscOptionsName("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",&opt);CHKERRQ(ierr);
151   if (opt) {
152     TSMonitorLGCtx ctx;
153     PetscInt       howoften = 1;
154 
155     ierr = PetscOptionsInt("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",howoften,&howoften,NULL);CHKERRQ(ierr);
156     ierr = TSMonitorLGCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
157     ierr = TSMonitorSet(ts,TSMonitorLGTimeStep,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
158   }
159   ierr = PetscOptionsName("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",&opt);CHKERRQ(ierr);
160   if (opt) {
161     TSMonitorLGCtx ctx;
162     PetscInt       howoften = 1;
163 
164     ierr = PetscOptionsInt("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",howoften,&howoften,NULL);CHKERRQ(ierr);
165     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
166     ierr = TSMonitorSet(ts,TSMonitorLGSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
167   }
168   ierr = PetscOptionsName("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",&opt);CHKERRQ(ierr);
169   if (opt) {
170     TSMonitorLGCtx ctx;
171     PetscInt       howoften = 1;
172 
173     ierr = PetscOptionsInt("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",howoften,&howoften,NULL);CHKERRQ(ierr);
174     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
175     ierr = TSMonitorSet(ts,TSMonitorLGError,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
176   }
177   ierr = PetscOptionsName("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",&opt);CHKERRQ(ierr);
178   if (opt) {
179     TSMonitorLGCtx ctx;
180     PetscInt       howoften = 1;
181 
182     ierr = PetscOptionsInt("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",howoften,&howoften,NULL);CHKERRQ(ierr);
183     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
184     ierr = TSMonitorSet(ts,TSMonitorLGSNESIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
185   }
186   ierr = PetscOptionsName("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",&opt);CHKERRQ(ierr);
187   if (opt) {
188     TSMonitorLGCtx ctx;
189     PetscInt       howoften = 1;
190 
191     ierr = PetscOptionsInt("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",howoften,&howoften,NULL);CHKERRQ(ierr);
192     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
193     ierr = TSMonitorSet(ts,TSMonitorLGKSPIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
194   }
195   ierr = PetscOptionsName("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",&opt);CHKERRQ(ierr);
196   if (opt) {
197     TSMonitorSPEigCtx ctx;
198     PetscInt          howoften = 1;
199 
200     ierr = PetscOptionsInt("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",howoften,&howoften,NULL);CHKERRQ(ierr);
201     ierr = TSMonitorSPEigCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
202     ierr = TSMonitorSet(ts,TSMonitorSPEig,ctx,(PetscErrorCode (*)(void**))TSMonitorSPEigCtxDestroy);CHKERRQ(ierr);
203   }
204   opt  = PETSC_FALSE;
205   ierr = PetscOptionsName("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",&opt);CHKERRQ(ierr);
206   if (opt) {
207     TSMonitorDrawCtx ctx;
208     PetscInt         howoften = 1;
209 
210     ierr = PetscOptionsInt("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",howoften,&howoften,NULL);CHKERRQ(ierr);
211     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
212     ierr = TSMonitorSet(ts,TSMonitorDrawSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
213   }
214   opt  = PETSC_FALSE;
215   ierr = PetscOptionsName("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",&opt);CHKERRQ(ierr);
216   if (opt) {
217     TSMonitorDrawCtx ctx;
218     PetscReal        bounds[4];
219     PetscInt         n = 4;
220     PetscDraw        draw;
221 
222     ierr = PetscOptionsRealArray("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",bounds,&n,NULL);CHKERRQ(ierr);
223     if (n != 4) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Must provide bounding box of phase field");
224     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,1,&ctx);CHKERRQ(ierr);
225     ierr = PetscViewerDrawGetDraw(ctx->viewer,0,&draw);CHKERRQ(ierr);
226     ierr = PetscDrawClear(draw);CHKERRQ(ierr);
227     ierr = PetscDrawAxisCreate(draw,&ctx->axis);CHKERRQ(ierr);
228     ierr = PetscDrawAxisSetLimits(ctx->axis,bounds[0],bounds[2],bounds[1],bounds[3]);CHKERRQ(ierr);
229     ierr = PetscDrawAxisSetLabels(ctx->axis,"Phase Diagram","Variable 1","Variable 2");CHKERRQ(ierr);
230     ierr = PetscDrawAxisDraw(ctx->axis);CHKERRQ(ierr);
231     /* ierr = PetscDrawSetCoordinates(draw,bounds[0],bounds[1],bounds[2],bounds[3]);CHKERRQ(ierr); */
232     ierr = TSMonitorSet(ts,TSMonitorDrawSolutionPhase,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
233   }
234   opt  = PETSC_FALSE;
235   ierr = PetscOptionsName("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",&opt);CHKERRQ(ierr);
236   if (opt) {
237     TSMonitorDrawCtx ctx;
238     PetscInt         howoften = 1;
239 
240     ierr = PetscOptionsInt("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",howoften,&howoften,NULL);CHKERRQ(ierr);
241     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
242     ierr = TSMonitorSet(ts,TSMonitorDrawError,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
243   }
244   opt  = PETSC_FALSE;
245   ierr = PetscOptionsString("-ts_monitor_solution_binary","Save each solution to a binary file","TSMonitorSolutionBinary",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
246   if (flg) {
247     PetscViewer ctx;
248     if (monfilename[0]) {
249       ierr = PetscViewerBinaryOpen(PetscObjectComm((PetscObject)ts),monfilename,FILE_MODE_WRITE,&ctx);CHKERRQ(ierr);
250       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
251     } else {
252       ctx = PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)ts));
253       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))NULL);CHKERRQ(ierr);
254     }
255   }
256   opt  = PETSC_FALSE;
257   ierr = PetscOptionsString("-ts_monitor_solution_vtk","Save each time step to a binary file, use filename-%%03D.vts","TSMonitorSolutionVTK",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
258   if (flg) {
259     const char *ptr,*ptr2;
260     char       *filetemplate;
261     if (!monfilename[0]) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
262     /* Do some cursory validation of the input. */
263     ierr = PetscStrstr(monfilename,"%",(char**)&ptr);CHKERRQ(ierr);
264     if (!ptr) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
265     for (ptr++; ptr && *ptr; ptr++) {
266       ierr = PetscStrchr("DdiouxX",*ptr,(char**)&ptr2);CHKERRQ(ierr);
267       if (!ptr2 && (*ptr < '0' || '9' < *ptr)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Invalid file template argument to -ts_monitor_solution_vtk, should look like filename-%%03D.vts");
268       if (ptr2) break;
269     }
270     ierr = PetscStrallocpy(monfilename,&filetemplate);CHKERRQ(ierr);
271     ierr = TSMonitorSet(ts,TSMonitorSolutionVTK,filetemplate,(PetscErrorCode (*)(void**))TSMonitorSolutionVTKDestroy);CHKERRQ(ierr);
272   }
273 
274   ierr = PetscOptionsString("-ts_monitor_dmda_ray","Display a ray of the solution","None","y=0",dir,16,&flg);CHKERRQ(ierr);
275   if (flg) {
276     TSMonitorDMDARayCtx *rayctx;
277     int                  ray = 0;
278     DMDADirection        ddir;
279     DM                   da;
280     PetscMPIInt          rank;
281 
282     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
283     if (dir[0] == 'x') ddir = DMDA_X;
284     else if (dir[0] == 'y') ddir = DMDA_Y;
285     else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
286     sscanf(dir+2,"%d",&ray);
287 
288     ierr = PetscInfo2(((PetscObject)ts),"Displaying DMDA ray %c = %D\n",dir[0],ray);CHKERRQ(ierr);
289     ierr = PetscNew(TSMonitorDMDARayCtx,&rayctx);CHKERRQ(ierr);
290     ierr = TSGetDM(ts,&da);CHKERRQ(ierr);
291     ierr = DMDAGetRay(da,ddir,ray,&rayctx->ray,&rayctx->scatter);CHKERRQ(ierr);
292     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)ts),&rank);CHKERRQ(ierr);
293     if (!rank) {
294       ierr = PetscViewerDrawOpen(PETSC_COMM_SELF,0,0,0,0,600,300,&rayctx->viewer);CHKERRQ(ierr);
295     }
296     rayctx->lgctx = NULL;
297     ierr = TSMonitorSet(ts,TSMonitorDMDARay,rayctx,TSMonitorDMDARayDestroy);CHKERRQ(ierr);
298   }
299   ierr = PetscOptionsString("-ts_monitor_lg_dmda_ray","Display a ray of the solution","None","x=0",dir,16,&flg);CHKERRQ(ierr);
300   if (flg) {
301     TSMonitorDMDARayCtx *rayctx;
302     int                 ray = 0;
303     DMDADirection       ddir;
304     DM                  da;
305     PetscInt            howoften = 1;
306 
307     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Malformed ray %s", dir);
308     if      (dir[0] == 'x') ddir = DMDA_X;
309     else if (dir[0] == 'y') ddir = DMDA_Y;
310     else SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Unknown ray direction %s", dir);
311     sscanf(dir+2, "%d", &ray);
312 
313     ierr = PetscInfo2(((PetscObject) ts),"Displaying LG DMDA ray %c = %D\n", dir[0], ray);CHKERRQ(ierr);
314     ierr = PetscNew(TSMonitorDMDARayCtx, &rayctx);CHKERRQ(ierr);
315     ierr = TSGetDM(ts, &da);CHKERRQ(ierr);
316     ierr = DMDAGetRay(da, ddir, ray, &rayctx->ray, &rayctx->scatter);CHKERRQ(ierr);
317     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&rayctx->lgctx);CHKERRQ(ierr);
318     ierr = TSMonitorSet(ts, TSMonitorLGDMDARay, rayctx, TSMonitorDMDARayDestroy);CHKERRQ(ierr);
319   }
320 
321   /*
322      This code is all wrong. One is creating objects inside the TSSetFromOptions() so if run with the options gui
323      will bleed memory. Also one is using a PetscOptionsBegin() inside a PetscOptionsBegin()
324   */
325   ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
326   ierr = TSAdaptSetFromOptions(adapt);CHKERRQ(ierr);
327 
328   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
329   if (ts->problem_type == TS_LINEAR) {ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);}
330 
331   /* Handle specific TS options */
332   if (ts->ops->setfromoptions) {
333     ierr = (*ts->ops->setfromoptions)(ts);CHKERRQ(ierr);
334   }
335 
336   /* process any options handlers added with PetscObjectAddOptionsHandler() */
337   ierr = PetscObjectProcessOptionsHandlers((PetscObject)ts);CHKERRQ(ierr);
338   ierr = PetscOptionsEnd();CHKERRQ(ierr);
339   PetscFunctionReturn(0);
340 }
341 
342 #undef __FUNCT__
343 #undef __FUNCT__
344 #define __FUNCT__ "TSComputeRHSJacobian"
345 /*@
346    TSComputeRHSJacobian - Computes the Jacobian matrix that has been
347       set with TSSetRHSJacobian().
348 
349    Collective on TS and Vec
350 
351    Input Parameters:
352 +  ts - the TS context
353 .  t - current timestep
354 -  U - input vector
355 
356    Output Parameters:
357 +  A - Jacobian matrix
358 .  B - optional preconditioning matrix
359 -  flag - flag indicating matrix structure
360 
361    Notes:
362    Most users should not need to explicitly call this routine, as it
363    is used internally within the nonlinear solvers.
364 
365    See KSPSetOperators() for important information about setting the
366    flag parameter.
367 
368    Level: developer
369 
370 .keywords: SNES, compute, Jacobian, matrix
371 
372 .seealso:  TSSetRHSJacobian(), KSPSetOperators()
373 @*/
374 PetscErrorCode  TSComputeRHSJacobian(TS ts,PetscReal t,Vec U,Mat *A,Mat *B,MatStructure *flg)
375 {
376   PetscErrorCode ierr;
377   PetscObjectState Ustate;
378   DM             dm;
379   DMTS           tsdm;
380   TSRHSJacobian  rhsjacobianfunc;
381   void           *ctx;
382   TSIJacobian    ijacobianfunc;
383 
384   PetscFunctionBegin;
385   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
386   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
387   PetscCheckSameComm(ts,1,U,3);
388   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
389   ierr = DMGetDMTS(dm,&tsdm);CHKERRQ(ierr);
390   ierr = DMTSGetRHSJacobian(dm,&rhsjacobianfunc,&ctx);CHKERRQ(ierr);
391   ierr = DMTSGetIJacobian(dm,&ijacobianfunc,NULL);CHKERRQ(ierr);
392   ierr = PetscObjectStateGet((PetscObject)U,&Ustate);CHKERRQ(ierr);
393   if (ts->rhsjacobian.time == t && (ts->problem_type == TS_LINEAR || (ts->rhsjacobian.X == U && ts->rhsjacobian.Xstate == Ustate))) {
394     *flg = ts->rhsjacobian.mstructure;
395     PetscFunctionReturn(0);
396   }
397 
398   if (!rhsjacobianfunc && !ijacobianfunc) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
399 
400   if (ts->rhsjacobian.reuse) {
401     ierr = MatShift(*A,-ts->rhsjacobian.shift);CHKERRQ(ierr);
402     ierr = MatScale(*A,1./ts->rhsjacobian.scale);CHKERRQ(ierr);
403     if (*A != *B) {
404       ierr = MatShift(*B,-ts->rhsjacobian.shift);CHKERRQ(ierr);
405       ierr = MatScale(*B,1./ts->rhsjacobian.scale);CHKERRQ(ierr);
406     }
407     ts->rhsjacobian.shift = 0;
408     ts->rhsjacobian.scale = 1.;
409   }
410 
411   if (rhsjacobianfunc) {
412     ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,*A,*B);CHKERRQ(ierr);
413     *flg = DIFFERENT_NONZERO_PATTERN;
414     PetscStackPush("TS user Jacobian function");
415     ierr = (*rhsjacobianfunc)(ts,t,U,A,B,flg,ctx);CHKERRQ(ierr);
416     PetscStackPop;
417     ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,*A,*B);CHKERRQ(ierr);
418     /* make sure user returned a correct Jacobian and preconditioner */
419     PetscValidHeaderSpecific(*A,MAT_CLASSID,4);
420     PetscValidHeaderSpecific(*B,MAT_CLASSID,5);
421   } else {
422     ierr = MatZeroEntries(*A);CHKERRQ(ierr);
423     if (*A != *B) {ierr = MatZeroEntries(*B);CHKERRQ(ierr);}
424     *flg = SAME_NONZERO_PATTERN;
425   }
426   ts->rhsjacobian.time       = t;
427   ts->rhsjacobian.X          = U;
428   ierr                       = PetscObjectStateGet((PetscObject)U,&ts->rhsjacobian.Xstate);CHKERRQ(ierr);
429   ts->rhsjacobian.mstructure = *flg;
430   PetscFunctionReturn(0);
431 }
432 
433 #undef __FUNCT__
434 #define __FUNCT__ "TSComputeRHSFunction"
435 /*@
436    TSComputeRHSFunction - Evaluates the right-hand-side function.
437 
438    Collective on TS and Vec
439 
440    Input Parameters:
441 +  ts - the TS context
442 .  t - current time
443 -  U - state vector
444 
445    Output Parameter:
446 .  y - right hand side
447 
448    Note:
449    Most users should not need to explicitly call this routine, as it
450    is used internally within the nonlinear solvers.
451 
452    Level: developer
453 
454 .keywords: TS, compute
455 
456 .seealso: TSSetRHSFunction(), TSComputeIFunction()
457 @*/
458 PetscErrorCode TSComputeRHSFunction(TS ts,PetscReal t,Vec U,Vec y)
459 {
460   PetscErrorCode ierr;
461   TSRHSFunction  rhsfunction;
462   TSIFunction    ifunction;
463   void           *ctx;
464   DM             dm;
465 
466   PetscFunctionBegin;
467   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
468   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
469   PetscValidHeaderSpecific(y,VEC_CLASSID,4);
470   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
471   ierr = DMTSGetRHSFunction(dm,&rhsfunction,&ctx);CHKERRQ(ierr);
472   ierr = DMTSGetIFunction(dm,&ifunction,NULL);CHKERRQ(ierr);
473 
474   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
475 
476   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
477   if (rhsfunction) {
478     PetscStackPush("TS user right-hand-side function");
479     ierr = (*rhsfunction)(ts,t,U,y,ctx);CHKERRQ(ierr);
480     PetscStackPop;
481   } else {
482     ierr = VecZeroEntries(y);CHKERRQ(ierr);
483   }
484 
485   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
486   PetscFunctionReturn(0);
487 }
488 
489 #undef __FUNCT__
490 #define __FUNCT__ "TSComputeSolutionFunction"
491 /*@
492    TSComputeSolutionFunction - Evaluates the solution function.
493 
494    Collective on TS and Vec
495 
496    Input Parameters:
497 +  ts - the TS context
498 -  t - current time
499 
500    Output Parameter:
501 .  U - the solution
502 
503    Note:
504    Most users should not need to explicitly call this routine, as it
505    is used internally within the nonlinear solvers.
506 
507    Level: developer
508 
509 .keywords: TS, compute
510 
511 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
512 @*/
513 PetscErrorCode TSComputeSolutionFunction(TS ts,PetscReal t,Vec U)
514 {
515   PetscErrorCode     ierr;
516   TSSolutionFunction solutionfunction;
517   void               *ctx;
518   DM                 dm;
519 
520   PetscFunctionBegin;
521   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
522   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
523   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
524   ierr = DMTSGetSolutionFunction(dm,&solutionfunction,&ctx);CHKERRQ(ierr);
525 
526   if (solutionfunction) {
527     PetscStackPush("TS user solution function");
528     ierr = (*solutionfunction)(ts,t,U,ctx);CHKERRQ(ierr);
529     PetscStackPop;
530   }
531   PetscFunctionReturn(0);
532 }
533 #undef __FUNCT__
534 #define __FUNCT__ "TSComputeForcingFunction"
535 /*@
536    TSComputeForcingFunction - Evaluates the forcing function.
537 
538    Collective on TS and Vec
539 
540    Input Parameters:
541 +  ts - the TS context
542 -  t - current time
543 
544    Output Parameter:
545 .  U - the function value
546 
547    Note:
548    Most users should not need to explicitly call this routine, as it
549    is used internally within the nonlinear solvers.
550 
551    Level: developer
552 
553 .keywords: TS, compute
554 
555 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
556 @*/
557 PetscErrorCode TSComputeForcingFunction(TS ts,PetscReal t,Vec U)
558 {
559   PetscErrorCode     ierr, (*forcing)(TS,PetscReal,Vec,void*);
560   void               *ctx;
561   DM                 dm;
562 
563   PetscFunctionBegin;
564   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
565   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
566   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
567   ierr = DMTSGetForcingFunction(dm,&forcing,&ctx);CHKERRQ(ierr);
568 
569   if (forcing) {
570     PetscStackPush("TS user forcing function");
571     ierr = (*forcing)(ts,t,U,ctx);CHKERRQ(ierr);
572     PetscStackPop;
573   }
574   PetscFunctionReturn(0);
575 }
576 
577 #undef __FUNCT__
578 #define __FUNCT__ "TSGetRHSVec_Private"
579 static PetscErrorCode TSGetRHSVec_Private(TS ts,Vec *Frhs)
580 {
581   Vec            F;
582   PetscErrorCode ierr;
583 
584   PetscFunctionBegin;
585   *Frhs = NULL;
586   ierr  = TSGetIFunction(ts,&F,NULL,NULL);CHKERRQ(ierr);
587   if (!ts->Frhs) {
588     ierr = VecDuplicate(F,&ts->Frhs);CHKERRQ(ierr);
589   }
590   *Frhs = ts->Frhs;
591   PetscFunctionReturn(0);
592 }
593 
594 #undef __FUNCT__
595 #define __FUNCT__ "TSGetRHSMats_Private"
596 static PetscErrorCode TSGetRHSMats_Private(TS ts,Mat *Arhs,Mat *Brhs)
597 {
598   Mat            A,B;
599   PetscErrorCode ierr;
600 
601   PetscFunctionBegin;
602   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
603   if (Arhs) {
604     if (!ts->Arhs) {
605       ierr = MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&ts->Arhs);CHKERRQ(ierr);
606     }
607     *Arhs = ts->Arhs;
608   }
609   if (Brhs) {
610     if (!ts->Brhs) {
611       if (A != B) {
612         ierr = MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&ts->Brhs);CHKERRQ(ierr);
613       } else {
614         ts->Brhs = ts->Arhs;
615         ierr = PetscObjectReference((PetscObject)ts->Arhs);CHKERRQ(ierr);
616       }
617     }
618     *Brhs = ts->Brhs;
619   }
620   PetscFunctionReturn(0);
621 }
622 
623 #undef __FUNCT__
624 #define __FUNCT__ "TSComputeIFunction"
625 /*@
626    TSComputeIFunction - Evaluates the DAE residual written in implicit form F(t,U,Udot)=0
627 
628    Collective on TS and Vec
629 
630    Input Parameters:
631 +  ts - the TS context
632 .  t - current time
633 .  U - state vector
634 .  Udot - time derivative of state vector
635 -  imex - flag indicates if the method is IMEX so that the RHSFunction should be kept separate
636 
637    Output Parameter:
638 .  Y - right hand side
639 
640    Note:
641    Most users should not need to explicitly call this routine, as it
642    is used internally within the nonlinear solvers.
643 
644    If the user did did not write their equations in implicit form, this
645    function recasts them in implicit form.
646 
647    Level: developer
648 
649 .keywords: TS, compute
650 
651 .seealso: TSSetIFunction(), TSComputeRHSFunction()
652 @*/
653 PetscErrorCode TSComputeIFunction(TS ts,PetscReal t,Vec U,Vec Udot,Vec Y,PetscBool imex)
654 {
655   PetscErrorCode ierr;
656   TSIFunction    ifunction;
657   TSRHSFunction  rhsfunction;
658   void           *ctx;
659   DM             dm;
660 
661   PetscFunctionBegin;
662   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
663   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
664   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
665   PetscValidHeaderSpecific(Y,VEC_CLASSID,5);
666 
667   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
668   ierr = DMTSGetIFunction(dm,&ifunction,&ctx);CHKERRQ(ierr);
669   ierr = DMTSGetRHSFunction(dm,&rhsfunction,NULL);CHKERRQ(ierr);
670 
671   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
672 
673   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
674   if (ifunction) {
675     PetscStackPush("TS user implicit function");
676     ierr = (*ifunction)(ts,t,U,Udot,Y,ctx);CHKERRQ(ierr);
677     PetscStackPop;
678   }
679   if (imex) {
680     if (!ifunction) {
681       ierr = VecCopy(Udot,Y);CHKERRQ(ierr);
682     }
683   } else if (rhsfunction) {
684     if (ifunction) {
685       Vec Frhs;
686       ierr = TSGetRHSVec_Private(ts,&Frhs);CHKERRQ(ierr);
687       ierr = TSComputeRHSFunction(ts,t,U,Frhs);CHKERRQ(ierr);
688       ierr = VecAXPY(Y,-1,Frhs);CHKERRQ(ierr);
689     } else {
690       ierr = TSComputeRHSFunction(ts,t,U,Y);CHKERRQ(ierr);
691       ierr = VecAYPX(Y,-1,Udot);CHKERRQ(ierr);
692     }
693   }
694   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
695   PetscFunctionReturn(0);
696 }
697 
698 #undef __FUNCT__
699 #define __FUNCT__ "TSComputeIJacobian"
700 /*@
701    TSComputeIJacobian - Evaluates the Jacobian of the DAE
702 
703    Collective on TS and Vec
704 
705    Input
706       Input Parameters:
707 +  ts - the TS context
708 .  t - current timestep
709 .  U - state vector
710 .  Udot - time derivative of state vector
711 .  shift - shift to apply, see note below
712 -  imex - flag indicates if the method is IMEX so that the RHSJacobian should be kept separate
713 
714    Output Parameters:
715 +  A - Jacobian matrix
716 .  B - optional preconditioning matrix
717 -  flag - flag indicating matrix structure
718 
719    Notes:
720    If F(t,U,Udot)=0 is the DAE, the required Jacobian is
721 
722    dF/dU + shift*dF/dUdot
723 
724    Most users should not need to explicitly call this routine, as it
725    is used internally within the nonlinear solvers.
726 
727    Level: developer
728 
729 .keywords: TS, compute, Jacobian, matrix
730 
731 .seealso:  TSSetIJacobian()
732 @*/
733 PetscErrorCode TSComputeIJacobian(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat *A,Mat *B,MatStructure *flg,PetscBool imex)
734 {
735   PetscErrorCode ierr;
736   TSIJacobian    ijacobian;
737   TSRHSJacobian  rhsjacobian;
738   DM             dm;
739   void           *ctx;
740 
741   PetscFunctionBegin;
742   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
743   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
744   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
745   PetscValidPointer(A,6);
746   PetscValidHeaderSpecific(*A,MAT_CLASSID,6);
747   PetscValidPointer(B,7);
748   PetscValidHeaderSpecific(*B,MAT_CLASSID,7);
749   PetscValidPointer(flg,8);
750 
751   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
752   ierr = DMTSGetIJacobian(dm,&ijacobian,&ctx);CHKERRQ(ierr);
753   ierr = DMTSGetRHSJacobian(dm,&rhsjacobian,NULL);CHKERRQ(ierr);
754 
755   if (!rhsjacobian && !ijacobian) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
756 
757   *flg = SAME_NONZERO_PATTERN;  /* In case we're solving a linear problem in which case it wouldn't get initialized below. */
758   ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,*A,*B);CHKERRQ(ierr);
759   if (ijacobian) {
760     *flg = DIFFERENT_NONZERO_PATTERN;
761     PetscStackPush("TS user implicit Jacobian");
762     ierr = (*ijacobian)(ts,t,U,Udot,shift,A,B,flg,ctx);CHKERRQ(ierr);
763     PetscStackPop;
764     /* make sure user returned a correct Jacobian and preconditioner */
765     PetscValidHeaderSpecific(*A,MAT_CLASSID,4);
766     PetscValidHeaderSpecific(*B,MAT_CLASSID,5);
767   }
768   if (imex) {
769     if (!ijacobian) {  /* system was written as Udot = G(t,U) */
770       ierr = MatZeroEntries(*A);CHKERRQ(ierr);
771       ierr = MatShift(*A,shift);CHKERRQ(ierr);
772       if (*A != *B) {
773         ierr = MatZeroEntries(*B);CHKERRQ(ierr);
774         ierr = MatShift(*B,shift);CHKERRQ(ierr);
775       }
776       *flg = SAME_PRECONDITIONER;
777     }
778   } else {
779     Mat Arhs = NULL,Brhs = NULL;
780     MatStructure flg2;
781     if (rhsjacobian) {
782       ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
783       ierr = TSComputeRHSJacobian(ts,t,U,&Arhs,&Brhs,&flg2);CHKERRQ(ierr);
784     }
785     if (Arhs == *A) {           /* No IJacobian, so we only have the RHS matrix */
786       ts->rhsjacobian.scale = -1;
787       ts->rhsjacobian.shift = shift;
788       ierr = MatScale(*A,-1);CHKERRQ(ierr);
789       ierr = MatShift(*A,shift);CHKERRQ(ierr);
790       if (*A != *B) {
791         ierr = MatScale(*B,-1);CHKERRQ(ierr);
792         ierr = MatShift(*B,shift);CHKERRQ(ierr);
793       }
794     } else if (Arhs) {          /* Both IJacobian and RHSJacobian */
795       MatStructure axpy = DIFFERENT_NONZERO_PATTERN;
796       if (!ijacobian) {         /* No IJacobian provided, but we have a separate RHS matrix */
797         ierr = MatZeroEntries(*A);CHKERRQ(ierr);
798         ierr = MatShift(*A,shift);CHKERRQ(ierr);
799         if (*A != *B) {
800           ierr = MatZeroEntries(*B);CHKERRQ(ierr);
801           ierr = MatShift(*B,shift);CHKERRQ(ierr);
802         }
803       }
804       ierr = MatAXPY(*A,-1,Arhs,axpy);CHKERRQ(ierr);
805       if (*A != *B) {
806         ierr = MatAXPY(*B,-1,Brhs,axpy);CHKERRQ(ierr);
807       }
808       *flg = PetscMin(*flg,flg2);
809     }
810   }
811 
812   ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,*A,*B);CHKERRQ(ierr);
813   PetscFunctionReturn(0);
814 }
815 
816 #undef __FUNCT__
817 #define __FUNCT__ "TSSetRHSFunction"
818 /*@C
819     TSSetRHSFunction - Sets the routine for evaluating the function,
820     where U_t = G(t,u).
821 
822     Logically Collective on TS
823 
824     Input Parameters:
825 +   ts - the TS context obtained from TSCreate()
826 .   r - vector to put the computed right hand side (or NULL to have it created)
827 .   f - routine for evaluating the right-hand-side function
828 -   ctx - [optional] user-defined context for private data for the
829           function evaluation routine (may be NULL)
830 
831     Calling sequence of func:
832 $     func (TS ts,PetscReal t,Vec u,Vec F,void *ctx);
833 
834 +   t - current timestep
835 .   u - input vector
836 .   F - function vector
837 -   ctx - [optional] user-defined function context
838 
839     Level: beginner
840 
841 .keywords: TS, timestep, set, right-hand-side, function
842 
843 .seealso: TSSetRHSJacobian(), TSSetIJacobian()
844 @*/
845 PetscErrorCode  TSSetRHSFunction(TS ts,Vec r,PetscErrorCode (*f)(TS,PetscReal,Vec,Vec,void*),void *ctx)
846 {
847   PetscErrorCode ierr;
848   SNES           snes;
849   Vec            ralloc = NULL;
850   DM             dm;
851 
852   PetscFunctionBegin;
853   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
854   if (r) PetscValidHeaderSpecific(r,VEC_CLASSID,2);
855 
856   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
857   ierr = DMTSSetRHSFunction(dm,f,ctx);CHKERRQ(ierr);
858   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
859   if (!r && !ts->dm && ts->vec_sol) {
860     ierr = VecDuplicate(ts->vec_sol,&ralloc);CHKERRQ(ierr);
861     r    = ralloc;
862   }
863   ierr = SNESSetFunction(snes,r,SNESTSFormFunction,ts);CHKERRQ(ierr);
864   ierr = VecDestroy(&ralloc);CHKERRQ(ierr);
865   PetscFunctionReturn(0);
866 }
867 
868 #undef __FUNCT__
869 #define __FUNCT__ "TSSetSolutionFunction"
870 /*@C
871     TSSetSolutionFunction - Provide a function that computes the solution of the ODE or DAE
872 
873     Logically Collective on TS
874 
875     Input Parameters:
876 +   ts - the TS context obtained from TSCreate()
877 .   f - routine for evaluating the solution
878 -   ctx - [optional] user-defined context for private data for the
879           function evaluation routine (may be NULL)
880 
881     Calling sequence of func:
882 $     func (TS ts,PetscReal t,Vec u,void *ctx);
883 
884 +   t - current timestep
885 .   u - output vector
886 -   ctx - [optional] user-defined function context
887 
888     Notes:
889     This routine is used for testing accuracy of time integration schemes when you already know the solution.
890     If analytic solutions are not known for your system, consider using the Method of Manufactured Solutions to
891     create closed-form solutions with non-physical forcing terms.
892 
893     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
894 
895     Level: beginner
896 
897 .keywords: TS, timestep, set, right-hand-side, function
898 
899 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetForcingFunction()
900 @*/
901 PetscErrorCode  TSSetSolutionFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
902 {
903   PetscErrorCode ierr;
904   DM             dm;
905 
906   PetscFunctionBegin;
907   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
908   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
909   ierr = DMTSSetSolutionFunction(dm,f,ctx);CHKERRQ(ierr);
910   PetscFunctionReturn(0);
911 }
912 
913 #undef __FUNCT__
914 #define __FUNCT__ "TSSetForcingFunction"
915 /*@C
916     TSSetForcingFunction - Provide a function that computes a forcing term for a ODE or PDE
917 
918     Logically Collective on TS
919 
920     Input Parameters:
921 +   ts - the TS context obtained from TSCreate()
922 .   f - routine for evaluating the forcing function
923 -   ctx - [optional] user-defined context for private data for the
924           function evaluation routine (may be NULL)
925 
926     Calling sequence of func:
927 $     func (TS ts,PetscReal t,Vec u,void *ctx);
928 
929 +   t - current timestep
930 .   u - output vector
931 -   ctx - [optional] user-defined function context
932 
933     Notes:
934     This routine is useful for testing accuracy of time integration schemes when using the Method of Manufactured Solutions to
935     create closed-form solutions with a non-physical forcing term.
936 
937     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
938 
939     Level: beginner
940 
941 .keywords: TS, timestep, set, right-hand-side, function
942 
943 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetSolutionFunction()
944 @*/
945 PetscErrorCode  TSSetForcingFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
946 {
947   PetscErrorCode ierr;
948   DM             dm;
949 
950   PetscFunctionBegin;
951   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
952   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
953   ierr = DMTSSetForcingFunction(dm,f,ctx);CHKERRQ(ierr);
954   PetscFunctionReturn(0);
955 }
956 
957 #undef __FUNCT__
958 #define __FUNCT__ "TSSetRHSJacobian"
959 /*@C
960    TSSetRHSJacobian - Sets the function to compute the Jacobian of F,
961    where U_t = G(U,t), as well as the location to store the matrix.
962 
963    Logically Collective on TS
964 
965    Input Parameters:
966 +  ts  - the TS context obtained from TSCreate()
967 .  Amat - (approximate) Jacobian matrix
968 .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
969 .  f   - the Jacobian evaluation routine
970 -  ctx - [optional] user-defined context for private data for the
971          Jacobian evaluation routine (may be NULL)
972 
973    Calling sequence of func:
974 $     func (TS ts,PetscReal t,Vec u,Mat *A,Mat *B,MatStructure *flag,void *ctx);
975 
976 +  t - current timestep
977 .  u - input vector
978 .  Amat - (approximate) Jacobian matrix
979 .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
980 .  flag - flag indicating information about the preconditioner matrix
981           structure (same as flag in KSPSetOperators())
982 -  ctx - [optional] user-defined context for matrix evaluation routine
983 
984    Notes:
985    See KSPSetOperators() for important information about setting the flag
986    output parameter in the routine func().  Be sure to read this information!
987 
988    The routine func() takes Mat * as the matrix arguments rather than Mat.
989    This allows the matrix evaluation routine to replace A and/or B with a
990    completely new matrix structure (not just different matrix elements)
991    when appropriate, for instance, if the nonzero structure is changing
992    throughout the global iterations.
993 
994    Level: beginner
995 
996 .keywords: TS, timestep, set, right-hand-side, Jacobian
997 
998 .seealso: SNESComputeJacobianDefaultColor(), TSSetRHSFunction(), TSRHSJacobianSetReuse()
999 
1000 @*/
1001 PetscErrorCode  TSSetRHSJacobian(TS ts,Mat Amat,Mat Pmat,TSRHSJacobian f,void *ctx)
1002 {
1003   PetscErrorCode ierr;
1004   SNES           snes;
1005   DM             dm;
1006   TSIJacobian    ijacobian;
1007 
1008   PetscFunctionBegin;
1009   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1010   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
1011   if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
1012   if (Amat) PetscCheckSameComm(ts,1,Amat,2);
1013   if (Pmat) PetscCheckSameComm(ts,1,Pmat,3);
1014 
1015   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1016   ierr = DMTSSetRHSJacobian(dm,f,ctx);CHKERRQ(ierr);
1017   if (f == TSComputeRHSJacobianConstant) {
1018     /* Handle this case automatically for the user; otherwise user should call themselves. */
1019     ierr = TSRHSJacobianSetReuse(ts,PETSC_TRUE);CHKERRQ(ierr);
1020   }
1021   ierr = DMTSGetIJacobian(dm,&ijacobian,NULL);CHKERRQ(ierr);
1022   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1023   if (!ijacobian) {
1024     ierr = SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1025   }
1026   if (Amat) {
1027     ierr = PetscObjectReference((PetscObject)Amat);CHKERRQ(ierr);
1028     ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1029 
1030     ts->Arhs = Amat;
1031   }
1032   if (Pmat) {
1033     ierr = PetscObjectReference((PetscObject)Pmat);CHKERRQ(ierr);
1034     ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1035 
1036     ts->Brhs = Pmat;
1037   }
1038   PetscFunctionReturn(0);
1039 }
1040 
1041 
1042 #undef __FUNCT__
1043 #define __FUNCT__ "TSSetIFunction"
1044 /*@C
1045    TSSetIFunction - Set the function to compute F(t,U,U_t) where F() = 0 is the DAE to be solved.
1046 
1047    Logically Collective on TS
1048 
1049    Input Parameters:
1050 +  ts  - the TS context obtained from TSCreate()
1051 .  r   - vector to hold the residual (or NULL to have it created internally)
1052 .  f   - the function evaluation routine
1053 -  ctx - user-defined context for private data for the function evaluation routine (may be NULL)
1054 
1055    Calling sequence of f:
1056 $  f(TS ts,PetscReal t,Vec u,Vec u_t,Vec F,ctx);
1057 
1058 +  t   - time at step/stage being solved
1059 .  u   - state vector
1060 .  u_t - time derivative of state vector
1061 .  F   - function vector
1062 -  ctx - [optional] user-defined context for matrix evaluation routine
1063 
1064    Important:
1065    The user MUST call either this routine, TSSetRHSFunction().  This routine must be used when not solving an ODE, for example a DAE.
1066 
1067    Level: beginner
1068 
1069 .keywords: TS, timestep, set, DAE, Jacobian
1070 
1071 .seealso: TSSetRHSJacobian(), TSSetRHSFunction(), TSSetIJacobian()
1072 @*/
1073 PetscErrorCode  TSSetIFunction(TS ts,Vec res,TSIFunction f,void *ctx)
1074 {
1075   PetscErrorCode ierr;
1076   SNES           snes;
1077   Vec            resalloc = NULL;
1078   DM             dm;
1079 
1080   PetscFunctionBegin;
1081   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1082   if (res) PetscValidHeaderSpecific(res,VEC_CLASSID,2);
1083 
1084   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1085   ierr = DMTSSetIFunction(dm,f,ctx);CHKERRQ(ierr);
1086 
1087   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1088   if (!res && !ts->dm && ts->vec_sol) {
1089     ierr = VecDuplicate(ts->vec_sol,&resalloc);CHKERRQ(ierr);
1090     res  = resalloc;
1091   }
1092   ierr = SNESSetFunction(snes,res,SNESTSFormFunction,ts);CHKERRQ(ierr);
1093   ierr = VecDestroy(&resalloc);CHKERRQ(ierr);
1094   PetscFunctionReturn(0);
1095 }
1096 
1097 #undef __FUNCT__
1098 #define __FUNCT__ "TSGetIFunction"
1099 /*@C
1100    TSGetIFunction - Returns the vector where the implicit residual is stored and the function/contex to compute it.
1101 
1102    Not Collective
1103 
1104    Input Parameter:
1105 .  ts - the TS context
1106 
1107    Output Parameter:
1108 +  r - vector to hold residual (or NULL)
1109 .  func - the function to compute residual (or NULL)
1110 -  ctx - the function context (or NULL)
1111 
1112    Level: advanced
1113 
1114 .keywords: TS, nonlinear, get, function
1115 
1116 .seealso: TSSetIFunction(), SNESGetFunction()
1117 @*/
1118 PetscErrorCode TSGetIFunction(TS ts,Vec *r,TSIFunction *func,void **ctx)
1119 {
1120   PetscErrorCode ierr;
1121   SNES           snes;
1122   DM             dm;
1123 
1124   PetscFunctionBegin;
1125   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1126   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1127   ierr = SNESGetFunction(snes,r,NULL,NULL);CHKERRQ(ierr);
1128   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1129   ierr = DMTSGetIFunction(dm,func,ctx);CHKERRQ(ierr);
1130   PetscFunctionReturn(0);
1131 }
1132 
1133 #undef __FUNCT__
1134 #define __FUNCT__ "TSGetRHSFunction"
1135 /*@C
1136    TSGetRHSFunction - Returns the vector where the right hand side is stored and the function/context to compute it.
1137 
1138    Not Collective
1139 
1140    Input Parameter:
1141 .  ts - the TS context
1142 
1143    Output Parameter:
1144 +  r - vector to hold computed right hand side (or NULL)
1145 .  func - the function to compute right hand side (or NULL)
1146 -  ctx - the function context (or NULL)
1147 
1148    Level: advanced
1149 
1150 .keywords: TS, nonlinear, get, function
1151 
1152 .seealso: TSSetRhsfunction(), SNESGetFunction()
1153 @*/
1154 PetscErrorCode TSGetRHSFunction(TS ts,Vec *r,TSRHSFunction *func,void **ctx)
1155 {
1156   PetscErrorCode ierr;
1157   SNES           snes;
1158   DM             dm;
1159 
1160   PetscFunctionBegin;
1161   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1162   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1163   ierr = SNESGetFunction(snes,r,NULL,NULL);CHKERRQ(ierr);
1164   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1165   ierr = DMTSGetRHSFunction(dm,func,ctx);CHKERRQ(ierr);
1166   PetscFunctionReturn(0);
1167 }
1168 
1169 #undef __FUNCT__
1170 #define __FUNCT__ "TSSetIJacobian"
1171 /*@C
1172    TSSetIJacobian - Set the function to compute the matrix dF/dU + a*dF/dU_t where F(t,U,U_t) is the function
1173         you provided with TSSetIFunction().
1174 
1175    Logically Collective on TS
1176 
1177    Input Parameters:
1178 +  ts  - the TS context obtained from TSCreate()
1179 .  Amat - (approximate) Jacobian matrix
1180 .  Pmat - matrix used to compute preconditioner (usually the same as Amat)
1181 .  f   - the Jacobian evaluation routine
1182 -  ctx - user-defined context for private data for the Jacobian evaluation routine (may be NULL)
1183 
1184    Calling sequence of f:
1185 $  f(TS ts,PetscReal t,Vec U,Vec U_t,PetscReal a,Mat *Amat,Mat *Pmat,MatStructure *flag,void *ctx);
1186 
1187 +  t    - time at step/stage being solved
1188 .  U    - state vector
1189 .  U_t  - time derivative of state vector
1190 .  a    - shift
1191 .  Amat - (approximate) Jacobian of F(t,U,W+a*U), equivalent to dF/dU + a*dF/dU_t
1192 .  Pmat - matrix used for constructing preconditioner, usually the same as Amat
1193 .  flag - flag indicating information about the preconditioner matrix
1194           structure (same as flag in KSPSetOperators())
1195 -  ctx  - [optional] user-defined context for matrix evaluation routine
1196 
1197    Notes:
1198    The matrices Amat and Pmat are exactly the matrices that are used by SNES for the nonlinear solve.
1199 
1200    The matrix dF/dU + a*dF/dU_t you provide turns out to be
1201    the Jacobian of F(t,U,W+a*U) where F(t,U,U_t) = 0 is the DAE to be solved.
1202    The time integrator internally approximates U_t by W+a*U where the positive "shift"
1203    a and vector W depend on the integration method, step size, and past states. For example with
1204    the backward Euler method a = 1/dt and W = -a*U(previous timestep) so
1205    W + a*U = a*(U - U(previous timestep)) = (U - U(previous timestep))/dt
1206 
1207    Level: beginner
1208 
1209 .keywords: TS, timestep, DAE, Jacobian
1210 
1211 .seealso: TSSetIFunction(), TSSetRHSJacobian(), SNESComputeJacobianDefaultColor(), SNESComputeJacobianDefault()
1212 
1213 @*/
1214 PetscErrorCode  TSSetIJacobian(TS ts,Mat Amat,Mat Pmat,TSIJacobian f,void *ctx)
1215 {
1216   PetscErrorCode ierr;
1217   SNES           snes;
1218   DM             dm;
1219 
1220   PetscFunctionBegin;
1221   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1222   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
1223   if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
1224   if (Amat) PetscCheckSameComm(ts,1,Amat,2);
1225   if (Pmat) PetscCheckSameComm(ts,1,Pmat,3);
1226 
1227   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1228   ierr = DMTSSetIJacobian(dm,f,ctx);CHKERRQ(ierr);
1229 
1230   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1231   ierr = SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1232   PetscFunctionReturn(0);
1233 }
1234 
1235 #undef __FUNCT__
1236 #define __FUNCT__ "TSRHSJacobianSetReuse"
1237 /*@
1238    TSRHSJacobianSetReuse - restore RHS Jacobian before re-evaluating.  Without this flag, TS will change the sign and
1239    shift the RHS Jacobian for a finite-time-step implicit solve, in which case the user function will need to recompute
1240    the entire Jacobian.  The reuse flag must be set if the evaluation function will assume that the matrix entries have
1241    not been changed by the TS.
1242 
1243    Logically Collective
1244 
1245    Input Arguments:
1246 +  ts - TS context obtained from TSCreate()
1247 -  reuse - PETSC_TRUE if the RHS Jacobian
1248 
1249    Level: intermediate
1250 
1251 .seealso: TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
1252 @*/
1253 PetscErrorCode TSRHSJacobianSetReuse(TS ts,PetscBool reuse)
1254 {
1255   PetscFunctionBegin;
1256   ts->rhsjacobian.reuse = reuse;
1257   PetscFunctionReturn(0);
1258 }
1259 
1260 #undef __FUNCT__
1261 #define __FUNCT__ "TSLoad"
1262 /*@C
1263   TSLoad - Loads a KSP that has been stored in binary  with KSPView().
1264 
1265   Collective on PetscViewer
1266 
1267   Input Parameters:
1268 + newdm - the newly loaded TS, this needs to have been created with TSCreate() or
1269            some related function before a call to TSLoad().
1270 - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
1271 
1272    Level: intermediate
1273 
1274   Notes:
1275    The type is determined by the data in the file, any type set into the TS before this call is ignored.
1276 
1277   Notes for advanced users:
1278   Most users should not need to know the details of the binary storage
1279   format, since TSLoad() and TSView() completely hide these details.
1280   But for anyone who's interested, the standard binary matrix storage
1281   format is
1282 .vb
1283      has not yet been determined
1284 .ve
1285 
1286 .seealso: PetscViewerBinaryOpen(), TSView(), MatLoad(), VecLoad()
1287 @*/
1288 PetscErrorCode  TSLoad(TS ts, PetscViewer viewer)
1289 {
1290   PetscErrorCode ierr;
1291   PetscBool      isbinary;
1292   PetscInt       classid;
1293   char           type[256];
1294   DMTS           sdm;
1295   DM             dm;
1296 
1297   PetscFunctionBegin;
1298   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1299   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1300   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1301   if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
1302 
1303   ierr = PetscViewerBinaryRead(viewer,&classid,1,PETSC_INT);CHKERRQ(ierr);
1304   if (classid != TS_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Not TS next in file");
1305   ierr = PetscViewerBinaryRead(viewer,type,256,PETSC_CHAR);CHKERRQ(ierr);
1306   ierr = TSSetType(ts, type);CHKERRQ(ierr);
1307   if (ts->ops->load) {
1308     ierr = (*ts->ops->load)(ts,viewer);CHKERRQ(ierr);
1309   }
1310   ierr = DMCreate(PetscObjectComm((PetscObject)ts),&dm);CHKERRQ(ierr);
1311   ierr = DMLoad(dm,viewer);CHKERRQ(ierr);
1312   ierr = TSSetDM(ts,dm);CHKERRQ(ierr);
1313   ierr = DMCreateGlobalVector(ts->dm,&ts->vec_sol);CHKERRQ(ierr);
1314   ierr = VecLoad(ts->vec_sol,viewer);CHKERRQ(ierr);
1315   ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1316   ierr = DMTSLoad(sdm,viewer);CHKERRQ(ierr);
1317   PetscFunctionReturn(0);
1318 }
1319 
1320 #include <petscdraw.h>
1321 #if defined(PETSC_HAVE_SAWS)
1322 #include <petscviewersaws.h>
1323 #endif
1324 #undef __FUNCT__
1325 #define __FUNCT__ "TSView"
1326 /*@C
1327     TSView - Prints the TS data structure.
1328 
1329     Collective on TS
1330 
1331     Input Parameters:
1332 +   ts - the TS context obtained from TSCreate()
1333 -   viewer - visualization context
1334 
1335     Options Database Key:
1336 .   -ts_view - calls TSView() at end of TSStep()
1337 
1338     Notes:
1339     The available visualization contexts include
1340 +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
1341 -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
1342          output where only the first processor opens
1343          the file.  All other processors send their
1344          data to the first processor to print.
1345 
1346     The user can open an alternative visualization context with
1347     PetscViewerASCIIOpen() - output to a specified file.
1348 
1349     Level: beginner
1350 
1351 .keywords: TS, timestep, view
1352 
1353 .seealso: PetscViewerASCIIOpen()
1354 @*/
1355 PetscErrorCode  TSView(TS ts,PetscViewer viewer)
1356 {
1357   PetscErrorCode ierr;
1358   TSType         type;
1359   PetscBool      iascii,isstring,isundials,isbinary,isdraw;
1360   DMTS           sdm;
1361 #if defined(PETSC_HAVE_SAWS)
1362   PetscBool      isams;
1363 #endif
1364 
1365   PetscFunctionBegin;
1366   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1367   if (!viewer) {
1368     ierr = PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ts),&viewer);CHKERRQ(ierr);
1369   }
1370   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1371   PetscCheckSameComm(ts,1,viewer,2);
1372 
1373   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1374   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);
1375   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1376   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1377 #if defined(PETSC_HAVE_SAWS)
1378   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&isams);CHKERRQ(ierr);
1379 #endif
1380   if (iascii) {
1381     ierr = PetscObjectPrintClassNamePrefixType((PetscObject)ts,viewer);CHKERRQ(ierr);
1382     ierr = PetscViewerASCIIPrintf(viewer,"  maximum steps=%D\n",ts->max_steps);CHKERRQ(ierr);
1383     ierr = PetscViewerASCIIPrintf(viewer,"  maximum time=%G\n",ts->max_time);CHKERRQ(ierr);
1384     if (ts->problem_type == TS_NONLINEAR) {
1385       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solver iterations=%D\n",ts->snes_its);CHKERRQ(ierr);
1386       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solve failures=%D\n",ts->num_snes_failures);CHKERRQ(ierr);
1387     }
1388     ierr = PetscViewerASCIIPrintf(viewer,"  total number of linear solver iterations=%D\n",ts->ksp_its);CHKERRQ(ierr);
1389     ierr = PetscViewerASCIIPrintf(viewer,"  total number of rejected steps=%D\n",ts->reject);CHKERRQ(ierr);
1390     ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1391     ierr = DMTSView(sdm,viewer);CHKERRQ(ierr);
1392     if (ts->ops->view) {
1393       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1394       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1395       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1396     }
1397   } else if (isstring) {
1398     ierr = TSGetType(ts,&type);CHKERRQ(ierr);
1399     ierr = PetscViewerStringSPrintf(viewer," %-7.7s",type);CHKERRQ(ierr);
1400   } else if (isbinary) {
1401     PetscInt    classid = TS_FILE_CLASSID;
1402     MPI_Comm    comm;
1403     PetscMPIInt rank;
1404     char        type[256];
1405 
1406     ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
1407     ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
1408     if (!rank) {
1409       ierr = PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);CHKERRQ(ierr);
1410       ierr = PetscStrncpy(type,((PetscObject)ts)->type_name,256);CHKERRQ(ierr);
1411       ierr = PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR,PETSC_FALSE);CHKERRQ(ierr);
1412     }
1413     if (ts->ops->view) {
1414       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1415     }
1416     ierr = DMView(ts->dm,viewer);CHKERRQ(ierr);
1417     ierr = VecView(ts->vec_sol,viewer);CHKERRQ(ierr);
1418     ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1419     ierr = DMTSView(sdm,viewer);CHKERRQ(ierr);
1420   } else if (isdraw) {
1421     PetscDraw draw;
1422     char      str[36];
1423     PetscReal x,y,bottom,h;
1424 
1425     ierr   = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1426     ierr   = PetscDrawGetCurrentPoint(draw,&x,&y);CHKERRQ(ierr);
1427     ierr   = PetscStrcpy(str,"TS: ");CHKERRQ(ierr);
1428     ierr   = PetscStrcat(str,((PetscObject)ts)->type_name);CHKERRQ(ierr);
1429     ierr   = PetscDrawBoxedString(draw,x,y,PETSC_DRAW_BLACK,PETSC_DRAW_BLACK,str,NULL,&h);CHKERRQ(ierr);
1430     bottom = y - h;
1431     ierr   = PetscDrawPushCurrentPoint(draw,x,bottom);CHKERRQ(ierr);
1432     if (ts->ops->view) {
1433       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1434     }
1435     ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr);
1436 #if defined(PETSC_HAVE_SAWS)
1437   } else if (isams) {
1438     PetscMPIInt rank;
1439     const char  *name;
1440 
1441     ierr = PetscObjectGetName((PetscObject)ts,&name);CHKERRQ(ierr);
1442     ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
1443     if (!((PetscObject)ts)->amsmem && !rank) {
1444       char       dir[1024];
1445 
1446       ierr = PetscObjectViewSAWs((PetscObject)ts,viewer);CHKERRQ(ierr);
1447       ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time_step",name);CHKERRQ(ierr);
1448       PetscStackCallSAWs(SAWs_Register,(dir,&ts->steps,1,SAWs_READ,SAWs_INT));
1449       ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time",name);CHKERRQ(ierr);
1450       PetscStackCallSAWs(SAWs_Register,(dir,&ts->ptime,1,SAWs_READ,SAWs_DOUBLE));
1451     }
1452     if (ts->ops->view) {
1453       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1454     }
1455 #endif
1456   }
1457 
1458   ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1459   ierr = PetscObjectTypeCompare((PetscObject)ts,TSSUNDIALS,&isundials);CHKERRQ(ierr);
1460   ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1461   PetscFunctionReturn(0);
1462 }
1463 
1464 
1465 #undef __FUNCT__
1466 #define __FUNCT__ "TSSetApplicationContext"
1467 /*@
1468    TSSetApplicationContext - Sets an optional user-defined context for
1469    the timesteppers.
1470 
1471    Logically Collective on TS
1472 
1473    Input Parameters:
1474 +  ts - the TS context obtained from TSCreate()
1475 -  usrP - optional user context
1476 
1477    Level: intermediate
1478 
1479 .keywords: TS, timestep, set, application, context
1480 
1481 .seealso: TSGetApplicationContext()
1482 @*/
1483 PetscErrorCode  TSSetApplicationContext(TS ts,void *usrP)
1484 {
1485   PetscFunctionBegin;
1486   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1487   ts->user = usrP;
1488   PetscFunctionReturn(0);
1489 }
1490 
1491 #undef __FUNCT__
1492 #define __FUNCT__ "TSGetApplicationContext"
1493 /*@
1494     TSGetApplicationContext - Gets the user-defined context for the
1495     timestepper.
1496 
1497     Not Collective
1498 
1499     Input Parameter:
1500 .   ts - the TS context obtained from TSCreate()
1501 
1502     Output Parameter:
1503 .   usrP - user context
1504 
1505     Level: intermediate
1506 
1507 .keywords: TS, timestep, get, application, context
1508 
1509 .seealso: TSSetApplicationContext()
1510 @*/
1511 PetscErrorCode  TSGetApplicationContext(TS ts,void *usrP)
1512 {
1513   PetscFunctionBegin;
1514   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1515   *(void**)usrP = ts->user;
1516   PetscFunctionReturn(0);
1517 }
1518 
1519 #undef __FUNCT__
1520 #define __FUNCT__ "TSGetTimeStepNumber"
1521 /*@
1522    TSGetTimeStepNumber - Gets the number of time steps completed.
1523 
1524    Not Collective
1525 
1526    Input Parameter:
1527 .  ts - the TS context obtained from TSCreate()
1528 
1529    Output Parameter:
1530 .  iter - number of steps completed so far
1531 
1532    Level: intermediate
1533 
1534 .keywords: TS, timestep, get, iteration, number
1535 .seealso: TSGetTime(), TSGetTimeStep(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSSetPostStep()
1536 @*/
1537 PetscErrorCode  TSGetTimeStepNumber(TS ts,PetscInt *iter)
1538 {
1539   PetscFunctionBegin;
1540   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1541   PetscValidIntPointer(iter,2);
1542   *iter = ts->steps;
1543   PetscFunctionReturn(0);
1544 }
1545 
1546 #undef __FUNCT__
1547 #define __FUNCT__ "TSSetInitialTimeStep"
1548 /*@
1549    TSSetInitialTimeStep - Sets the initial timestep to be used,
1550    as well as the initial time.
1551 
1552    Logically Collective on TS
1553 
1554    Input Parameters:
1555 +  ts - the TS context obtained from TSCreate()
1556 .  initial_time - the initial time
1557 -  time_step - the size of the timestep
1558 
1559    Level: intermediate
1560 
1561 .seealso: TSSetTimeStep(), TSGetTimeStep()
1562 
1563 .keywords: TS, set, initial, timestep
1564 @*/
1565 PetscErrorCode  TSSetInitialTimeStep(TS ts,PetscReal initial_time,PetscReal time_step)
1566 {
1567   PetscErrorCode ierr;
1568 
1569   PetscFunctionBegin;
1570   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1571   ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
1572   ierr = TSSetTime(ts,initial_time);CHKERRQ(ierr);
1573   PetscFunctionReturn(0);
1574 }
1575 
1576 #undef __FUNCT__
1577 #define __FUNCT__ "TSSetTimeStep"
1578 /*@
1579    TSSetTimeStep - Allows one to reset the timestep at any time,
1580    useful for simple pseudo-timestepping codes.
1581 
1582    Logically Collective on TS
1583 
1584    Input Parameters:
1585 +  ts - the TS context obtained from TSCreate()
1586 -  time_step - the size of the timestep
1587 
1588    Level: intermediate
1589 
1590 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1591 
1592 .keywords: TS, set, timestep
1593 @*/
1594 PetscErrorCode  TSSetTimeStep(TS ts,PetscReal time_step)
1595 {
1596   PetscFunctionBegin;
1597   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1598   PetscValidLogicalCollectiveReal(ts,time_step,2);
1599   ts->time_step      = time_step;
1600   ts->time_step_orig = time_step;
1601   PetscFunctionReturn(0);
1602 }
1603 
1604 #undef __FUNCT__
1605 #define __FUNCT__ "TSSetExactFinalTime"
1606 /*@
1607    TSSetExactFinalTime - Determines whether to adapt the final time step to
1608      match the exact final time, interpolate solution to the exact final time,
1609      or just return at the final time TS computed.
1610 
1611   Logically Collective on TS
1612 
1613    Input Parameter:
1614 +   ts - the time-step context
1615 -   eftopt - exact final time option
1616 
1617    Level: beginner
1618 
1619 .seealso: TSExactFinalTimeOption
1620 @*/
1621 PetscErrorCode  TSSetExactFinalTime(TS ts,TSExactFinalTimeOption eftopt)
1622 {
1623   PetscFunctionBegin;
1624   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1625   PetscValidLogicalCollectiveEnum(ts,eftopt,2);
1626   ts->exact_final_time = eftopt;
1627   PetscFunctionReturn(0);
1628 }
1629 
1630 #undef __FUNCT__
1631 #define __FUNCT__ "TSGetTimeStep"
1632 /*@
1633    TSGetTimeStep - Gets the current timestep size.
1634 
1635    Not Collective
1636 
1637    Input Parameter:
1638 .  ts - the TS context obtained from TSCreate()
1639 
1640    Output Parameter:
1641 .  dt - the current timestep size
1642 
1643    Level: intermediate
1644 
1645 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1646 
1647 .keywords: TS, get, timestep
1648 @*/
1649 PetscErrorCode  TSGetTimeStep(TS ts,PetscReal *dt)
1650 {
1651   PetscFunctionBegin;
1652   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1653   PetscValidRealPointer(dt,2);
1654   *dt = ts->time_step;
1655   PetscFunctionReturn(0);
1656 }
1657 
1658 #undef __FUNCT__
1659 #define __FUNCT__ "TSGetSolution"
1660 /*@
1661    TSGetSolution - Returns the solution at the present timestep. It
1662    is valid to call this routine inside the function that you are evaluating
1663    in order to move to the new timestep. This vector not changed until
1664    the solution at the next timestep has been calculated.
1665 
1666    Not Collective, but Vec returned is parallel if TS is parallel
1667 
1668    Input Parameter:
1669 .  ts - the TS context obtained from TSCreate()
1670 
1671    Output Parameter:
1672 .  v - the vector containing the solution
1673 
1674    Level: intermediate
1675 
1676 .seealso: TSGetTimeStep()
1677 
1678 .keywords: TS, timestep, get, solution
1679 @*/
1680 PetscErrorCode  TSGetSolution(TS ts,Vec *v)
1681 {
1682   PetscFunctionBegin;
1683   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1684   PetscValidPointer(v,2);
1685   *v = ts->vec_sol;
1686   PetscFunctionReturn(0);
1687 }
1688 
1689 /* ----- Routines to initialize and destroy a timestepper ---- */
1690 #undef __FUNCT__
1691 #define __FUNCT__ "TSSetProblemType"
1692 /*@
1693   TSSetProblemType - Sets the type of problem to be solved.
1694 
1695   Not collective
1696 
1697   Input Parameters:
1698 + ts   - The TS
1699 - type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1700 .vb
1701          U_t - A U = 0      (linear)
1702          U_t - A(t) U = 0   (linear)
1703          F(t,U,U_t) = 0     (nonlinear)
1704 .ve
1705 
1706    Level: beginner
1707 
1708 .keywords: TS, problem type
1709 .seealso: TSSetUp(), TSProblemType, TS
1710 @*/
1711 PetscErrorCode  TSSetProblemType(TS ts, TSProblemType type)
1712 {
1713   PetscErrorCode ierr;
1714 
1715   PetscFunctionBegin;
1716   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1717   ts->problem_type = type;
1718   if (type == TS_LINEAR) {
1719     SNES snes;
1720     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1721     ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);
1722   }
1723   PetscFunctionReturn(0);
1724 }
1725 
1726 #undef __FUNCT__
1727 #define __FUNCT__ "TSGetProblemType"
1728 /*@C
1729   TSGetProblemType - Gets the type of problem to be solved.
1730 
1731   Not collective
1732 
1733   Input Parameter:
1734 . ts   - The TS
1735 
1736   Output Parameter:
1737 . type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1738 .vb
1739          M U_t = A U
1740          M(t) U_t = A(t) U
1741          F(t,U,U_t)
1742 .ve
1743 
1744    Level: beginner
1745 
1746 .keywords: TS, problem type
1747 .seealso: TSSetUp(), TSProblemType, TS
1748 @*/
1749 PetscErrorCode  TSGetProblemType(TS ts, TSProblemType *type)
1750 {
1751   PetscFunctionBegin;
1752   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1753   PetscValidIntPointer(type,2);
1754   *type = ts->problem_type;
1755   PetscFunctionReturn(0);
1756 }
1757 
1758 #undef __FUNCT__
1759 #define __FUNCT__ "TSSetUp"
1760 /*@
1761    TSSetUp - Sets up the internal data structures for the later use
1762    of a timestepper.
1763 
1764    Collective on TS
1765 
1766    Input Parameter:
1767 .  ts - the TS context obtained from TSCreate()
1768 
1769    Notes:
1770    For basic use of the TS solvers the user need not explicitly call
1771    TSSetUp(), since these actions will automatically occur during
1772    the call to TSStep().  However, if one wishes to control this
1773    phase separately, TSSetUp() should be called after TSCreate()
1774    and optional routines of the form TSSetXXX(), but before TSStep().
1775 
1776    Level: advanced
1777 
1778 .keywords: TS, timestep, setup
1779 
1780 .seealso: TSCreate(), TSStep(), TSDestroy()
1781 @*/
1782 PetscErrorCode  TSSetUp(TS ts)
1783 {
1784   PetscErrorCode ierr;
1785   DM             dm;
1786   PetscErrorCode (*func)(SNES,Vec,Vec,void*);
1787   PetscErrorCode (*jac)(SNES,Vec,Mat*,Mat*,MatStructure*,void*);
1788   TSIJacobian    ijac;
1789   TSRHSJacobian  rhsjac;
1790 
1791   PetscFunctionBegin;
1792   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1793   if (ts->setupcalled) PetscFunctionReturn(0);
1794 
1795   if (!((PetscObject)ts)->type_name) {
1796     ierr = TSSetType(ts,TSEULER);CHKERRQ(ierr);
1797   }
1798 
1799   if (!ts->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call TSSetSolution() first");
1800 
1801   ierr = TSGetAdapt(ts,&ts->adapt);CHKERRQ(ierr);
1802 
1803   if (ts->rhsjacobian.reuse) {
1804     Mat Amat,Pmat;
1805     SNES snes;
1806     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1807     ierr = SNESGetJacobian(snes,&Amat,&Pmat,NULL,NULL);CHKERRQ(ierr);
1808     /* Matching matrices implies that an IJacobian is NOT set, because if it had been set, the IJacobian's matrix would
1809      * have displaced the RHS matrix */
1810     if (Amat == ts->Arhs) {
1811       ierr = MatDuplicate(ts->Arhs,MAT_DO_NOT_COPY_VALUES,&Amat);CHKERRQ(ierr);
1812       ierr = SNESSetJacobian(snes,Amat,NULL,NULL,NULL);CHKERRQ(ierr);
1813       ierr = MatDestroy(&Amat);CHKERRQ(ierr);
1814     }
1815     if (Pmat == ts->Brhs) {
1816       ierr = MatDuplicate(ts->Brhs,MAT_DO_NOT_COPY_VALUES,&Pmat);CHKERRQ(ierr);
1817       ierr = SNESSetJacobian(snes,NULL,Pmat,NULL,NULL);CHKERRQ(ierr);
1818       ierr = MatDestroy(&Pmat);CHKERRQ(ierr);
1819     }
1820   }
1821 
1822   if (ts->ops->setup) {
1823     ierr = (*ts->ops->setup)(ts);CHKERRQ(ierr);
1824   }
1825 
1826   /* in the case where we've set a DMTSFunction or what have you, we need the default SNESFunction
1827    to be set right but can't do it elsewhere due to the overreliance on ctx=ts.
1828    */
1829   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1830   ierr = DMSNESGetFunction(dm,&func,NULL);CHKERRQ(ierr);
1831   if (!func) {
1832     ierr =DMSNESSetFunction(dm,SNESTSFormFunction,ts);CHKERRQ(ierr);
1833   }
1834   /* if the SNES doesn't have a jacobian set and the TS has an ijacobian or rhsjacobian set, set the SNES to use it.
1835      Otherwise, the SNES will use coloring internally to form the Jacobian.
1836    */
1837   ierr = DMSNESGetJacobian(dm,&jac,NULL);CHKERRQ(ierr);
1838   ierr = DMTSGetIJacobian(dm,&ijac,NULL);CHKERRQ(ierr);
1839   ierr = DMTSGetRHSJacobian(dm,&rhsjac,NULL);CHKERRQ(ierr);
1840   if (!jac && (ijac || rhsjac)) {
1841     ierr = DMSNESSetJacobian(dm,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1842   }
1843   ts->setupcalled = PETSC_TRUE;
1844   PetscFunctionReturn(0);
1845 }
1846 
1847 #undef __FUNCT__
1848 #define __FUNCT__ "TSReset"
1849 /*@
1850    TSReset - Resets a TS context and removes any allocated Vecs and Mats.
1851 
1852    Collective on TS
1853 
1854    Input Parameter:
1855 .  ts - the TS context obtained from TSCreate()
1856 
1857    Level: beginner
1858 
1859 .keywords: TS, timestep, reset
1860 
1861 .seealso: TSCreate(), TSSetup(), TSDestroy()
1862 @*/
1863 PetscErrorCode  TSReset(TS ts)
1864 {
1865   PetscErrorCode ierr;
1866 
1867   PetscFunctionBegin;
1868   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1869   if (ts->ops->reset) {
1870     ierr = (*ts->ops->reset)(ts);CHKERRQ(ierr);
1871   }
1872   if (ts->snes) {ierr = SNESReset(ts->snes);CHKERRQ(ierr);}
1873 
1874   ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1875   ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1876   ierr = VecDestroy(&ts->Frhs);CHKERRQ(ierr);
1877   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
1878   ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
1879   ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
1880   ierr = VecDestroyVecs(ts->nwork,&ts->work);CHKERRQ(ierr);
1881 
1882   ts->setupcalled = PETSC_FALSE;
1883   PetscFunctionReturn(0);
1884 }
1885 
1886 #undef __FUNCT__
1887 #define __FUNCT__ "TSDestroy"
1888 /*@
1889    TSDestroy - Destroys the timestepper context that was created
1890    with TSCreate().
1891 
1892    Collective on TS
1893 
1894    Input Parameter:
1895 .  ts - the TS context obtained from TSCreate()
1896 
1897    Level: beginner
1898 
1899 .keywords: TS, timestepper, destroy
1900 
1901 .seealso: TSCreate(), TSSetUp(), TSSolve()
1902 @*/
1903 PetscErrorCode  TSDestroy(TS *ts)
1904 {
1905   PetscErrorCode ierr;
1906 
1907   PetscFunctionBegin;
1908   if (!*ts) PetscFunctionReturn(0);
1909   PetscValidHeaderSpecific((*ts),TS_CLASSID,1);
1910   if (--((PetscObject)(*ts))->refct > 0) {*ts = 0; PetscFunctionReturn(0);}
1911 
1912   ierr = TSReset((*ts));CHKERRQ(ierr);
1913 
1914   /* if memory was published with SAWs then destroy it */
1915   ierr = PetscObjectSAWsViewOff((PetscObject)*ts);CHKERRQ(ierr);
1916   if ((*ts)->ops->destroy) {ierr = (*(*ts)->ops->destroy)((*ts));CHKERRQ(ierr);}
1917 
1918   ierr = TSAdaptDestroy(&(*ts)->adapt);CHKERRQ(ierr);
1919   ierr = SNESDestroy(&(*ts)->snes);CHKERRQ(ierr);
1920   ierr = DMDestroy(&(*ts)->dm);CHKERRQ(ierr);
1921   ierr = TSMonitorCancel((*ts));CHKERRQ(ierr);
1922 
1923   ierr = PetscHeaderDestroy(ts);CHKERRQ(ierr);
1924   PetscFunctionReturn(0);
1925 }
1926 
1927 #undef __FUNCT__
1928 #define __FUNCT__ "TSGetSNES"
1929 /*@
1930    TSGetSNES - Returns the SNES (nonlinear solver) associated with
1931    a TS (timestepper) context. Valid only for nonlinear problems.
1932 
1933    Not Collective, but SNES is parallel if TS is parallel
1934 
1935    Input Parameter:
1936 .  ts - the TS context obtained from TSCreate()
1937 
1938    Output Parameter:
1939 .  snes - the nonlinear solver context
1940 
1941    Notes:
1942    The user can then directly manipulate the SNES context to set various
1943    options, etc.  Likewise, the user can then extract and manipulate the
1944    KSP, KSP, and PC contexts as well.
1945 
1946    TSGetSNES() does not work for integrators that do not use SNES; in
1947    this case TSGetSNES() returns NULL in snes.
1948 
1949    Level: beginner
1950 
1951 .keywords: timestep, get, SNES
1952 @*/
1953 PetscErrorCode  TSGetSNES(TS ts,SNES *snes)
1954 {
1955   PetscErrorCode ierr;
1956 
1957   PetscFunctionBegin;
1958   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1959   PetscValidPointer(snes,2);
1960   if (!ts->snes) {
1961     ierr = SNESCreate(PetscObjectComm((PetscObject)ts),&ts->snes);CHKERRQ(ierr);
1962     ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
1963     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->snes);CHKERRQ(ierr);
1964     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->snes,(PetscObject)ts,1);CHKERRQ(ierr);
1965     if (ts->dm) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
1966     if (ts->problem_type == TS_LINEAR) {
1967       ierr = SNESSetType(ts->snes,SNESKSPONLY);CHKERRQ(ierr);
1968     }
1969   }
1970   *snes = ts->snes;
1971   PetscFunctionReturn(0);
1972 }
1973 
1974 #undef __FUNCT__
1975 #define __FUNCT__ "TSSetSNES"
1976 /*@
1977    TSSetSNES - Set the SNES (nonlinear solver) to be used by the timestepping context
1978 
1979    Collective
1980 
1981    Input Parameter:
1982 +  ts - the TS context obtained from TSCreate()
1983 -  snes - the nonlinear solver context
1984 
1985    Notes:
1986    Most users should have the TS created by calling TSGetSNES()
1987 
1988    Level: developer
1989 
1990 .keywords: timestep, set, SNES
1991 @*/
1992 PetscErrorCode TSSetSNES(TS ts,SNES snes)
1993 {
1994   PetscErrorCode ierr;
1995   PetscErrorCode (*func)(SNES,Vec,Mat*,Mat*,MatStructure*,void*);
1996 
1997   PetscFunctionBegin;
1998   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1999   PetscValidHeaderSpecific(snes,SNES_CLASSID,2);
2000   ierr = PetscObjectReference((PetscObject)snes);CHKERRQ(ierr);
2001   ierr = SNESDestroy(&ts->snes);CHKERRQ(ierr);
2002 
2003   ts->snes = snes;
2004 
2005   ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
2006   ierr = SNESGetJacobian(ts->snes,NULL,NULL,&func,NULL);CHKERRQ(ierr);
2007   if (func == SNESTSFormJacobian) {
2008     ierr = SNESSetJacobian(ts->snes,NULL,NULL,SNESTSFormJacobian,ts);CHKERRQ(ierr);
2009   }
2010   PetscFunctionReturn(0);
2011 }
2012 
2013 #undef __FUNCT__
2014 #define __FUNCT__ "TSGetKSP"
2015 /*@
2016    TSGetKSP - Returns the KSP (linear solver) associated with
2017    a TS (timestepper) context.
2018 
2019    Not Collective, but KSP is parallel if TS is parallel
2020 
2021    Input Parameter:
2022 .  ts - the TS context obtained from TSCreate()
2023 
2024    Output Parameter:
2025 .  ksp - the nonlinear solver context
2026 
2027    Notes:
2028    The user can then directly manipulate the KSP context to set various
2029    options, etc.  Likewise, the user can then extract and manipulate the
2030    KSP and PC contexts as well.
2031 
2032    TSGetKSP() does not work for integrators that do not use KSP;
2033    in this case TSGetKSP() returns NULL in ksp.
2034 
2035    Level: beginner
2036 
2037 .keywords: timestep, get, KSP
2038 @*/
2039 PetscErrorCode  TSGetKSP(TS ts,KSP *ksp)
2040 {
2041   PetscErrorCode ierr;
2042   SNES           snes;
2043 
2044   PetscFunctionBegin;
2045   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2046   PetscValidPointer(ksp,2);
2047   if (!((PetscObject)ts)->type_name) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"KSP is not created yet. Call TSSetType() first");
2048   if (ts->problem_type != TS_LINEAR) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Linear only; use TSGetSNES()");
2049   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2050   ierr = SNESGetKSP(snes,ksp);CHKERRQ(ierr);
2051   PetscFunctionReturn(0);
2052 }
2053 
2054 /* ----------- Routines to set solver parameters ---------- */
2055 
2056 #undef __FUNCT__
2057 #define __FUNCT__ "TSGetDuration"
2058 /*@
2059    TSGetDuration - Gets the maximum number of timesteps to use and
2060    maximum time for iteration.
2061 
2062    Not Collective
2063 
2064    Input Parameters:
2065 +  ts       - the TS context obtained from TSCreate()
2066 .  maxsteps - maximum number of iterations to use, or NULL
2067 -  maxtime  - final time to iterate to, or NULL
2068 
2069    Level: intermediate
2070 
2071 .keywords: TS, timestep, get, maximum, iterations, time
2072 @*/
2073 PetscErrorCode  TSGetDuration(TS ts, PetscInt *maxsteps, PetscReal *maxtime)
2074 {
2075   PetscFunctionBegin;
2076   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2077   if (maxsteps) {
2078     PetscValidIntPointer(maxsteps,2);
2079     *maxsteps = ts->max_steps;
2080   }
2081   if (maxtime) {
2082     PetscValidScalarPointer(maxtime,3);
2083     *maxtime = ts->max_time;
2084   }
2085   PetscFunctionReturn(0);
2086 }
2087 
2088 #undef __FUNCT__
2089 #define __FUNCT__ "TSSetDuration"
2090 /*@
2091    TSSetDuration - Sets the maximum number of timesteps to use and
2092    maximum time for iteration.
2093 
2094    Logically Collective on TS
2095 
2096    Input Parameters:
2097 +  ts - the TS context obtained from TSCreate()
2098 .  maxsteps - maximum number of iterations to use
2099 -  maxtime - final time to iterate to
2100 
2101    Options Database Keys:
2102 .  -ts_max_steps <maxsteps> - Sets maxsteps
2103 .  -ts_final_time <maxtime> - Sets maxtime
2104 
2105    Notes:
2106    The default maximum number of iterations is 5000. Default time is 5.0
2107 
2108    Level: intermediate
2109 
2110 .keywords: TS, timestep, set, maximum, iterations
2111 
2112 .seealso: TSSetExactFinalTime()
2113 @*/
2114 PetscErrorCode  TSSetDuration(TS ts,PetscInt maxsteps,PetscReal maxtime)
2115 {
2116   PetscFunctionBegin;
2117   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2118   PetscValidLogicalCollectiveInt(ts,maxsteps,2);
2119   PetscValidLogicalCollectiveReal(ts,maxtime,2);
2120   if (maxsteps >= 0) ts->max_steps = maxsteps;
2121   if (maxtime != PETSC_DEFAULT) ts->max_time = maxtime;
2122   PetscFunctionReturn(0);
2123 }
2124 
2125 #undef __FUNCT__
2126 #define __FUNCT__ "TSSetSolution"
2127 /*@
2128    TSSetSolution - Sets the initial solution vector
2129    for use by the TS routines.
2130 
2131    Logically Collective on TS and Vec
2132 
2133    Input Parameters:
2134 +  ts - the TS context obtained from TSCreate()
2135 -  u - the solution vector
2136 
2137    Level: beginner
2138 
2139 .keywords: TS, timestep, set, solution, initial conditions
2140 @*/
2141 PetscErrorCode  TSSetSolution(TS ts,Vec u)
2142 {
2143   PetscErrorCode ierr;
2144   DM             dm;
2145 
2146   PetscFunctionBegin;
2147   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2148   PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2149   ierr = PetscObjectReference((PetscObject)u);CHKERRQ(ierr);
2150   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
2151 
2152   ts->vec_sol = u;
2153 
2154   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
2155   ierr = DMShellSetGlobalVector(dm,u);CHKERRQ(ierr);
2156   PetscFunctionReturn(0);
2157 }
2158 
2159 #undef __FUNCT__
2160 #define __FUNCT__ "TSSetPreStep"
2161 /*@C
2162   TSSetPreStep - Sets the general-purpose function
2163   called once at the beginning of each time step.
2164 
2165   Logically Collective on TS
2166 
2167   Input Parameters:
2168 + ts   - The TS context obtained from TSCreate()
2169 - func - The function
2170 
2171   Calling sequence of func:
2172 . func (TS ts);
2173 
2174   Level: intermediate
2175 
2176   Note:
2177   If a step is rejected, TSStep() will call this routine again before each attempt.
2178   The last completed time step number can be queried using TSGetTimeStepNumber(), the
2179   size of the step being attempted can be obtained using TSGetTimeStep().
2180 
2181 .keywords: TS, timestep
2182 .seealso: TSSetPreStage(), TSSetPostStage(), TSSetPostStep(), TSStep()
2183 @*/
2184 PetscErrorCode  TSSetPreStep(TS ts, PetscErrorCode (*func)(TS))
2185 {
2186   PetscFunctionBegin;
2187   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2188   ts->prestep = func;
2189   PetscFunctionReturn(0);
2190 }
2191 
2192 #undef __FUNCT__
2193 #define __FUNCT__ "TSPreStep"
2194 /*@
2195   TSPreStep - Runs the user-defined pre-step function.
2196 
2197   Collective on TS
2198 
2199   Input Parameters:
2200 . ts   - The TS context obtained from TSCreate()
2201 
2202   Notes:
2203   TSPreStep() is typically used within time stepping implementations,
2204   so most users would not generally call this routine themselves.
2205 
2206   Level: developer
2207 
2208 .keywords: TS, timestep
2209 .seealso: TSSetPreStep(), TSPreStage(), TSPostStage(), TSPostStep()
2210 @*/
2211 PetscErrorCode  TSPreStep(TS ts)
2212 {
2213   PetscErrorCode ierr;
2214 
2215   PetscFunctionBegin;
2216   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2217   if (ts->prestep) {
2218     PetscStackCallStandard((*ts->prestep),(ts));
2219   }
2220   PetscFunctionReturn(0);
2221 }
2222 
2223 #undef __FUNCT__
2224 #define __FUNCT__ "TSSetPreStage"
2225 /*@C
2226   TSSetPreStage - Sets the general-purpose function
2227   called once at the beginning of each stage.
2228 
2229   Logically Collective on TS
2230 
2231   Input Parameters:
2232 + ts   - The TS context obtained from TSCreate()
2233 - func - The function
2234 
2235   Calling sequence of func:
2236 . PetscErrorCode func(TS ts, PetscReal stagetime);
2237 
2238   Level: intermediate
2239 
2240   Note:
2241   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2242   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2243   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2244 
2245 .keywords: TS, timestep
2246 .seealso: TSSetPostStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2247 @*/
2248 PetscErrorCode  TSSetPreStage(TS ts, PetscErrorCode (*func)(TS,PetscReal))
2249 {
2250   PetscFunctionBegin;
2251   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2252   ts->prestage = func;
2253   PetscFunctionReturn(0);
2254 }
2255 
2256 #undef __FUNCT__
2257 #define __FUNCT__ "TSSetPostStage"
2258 /*@C
2259   TSSetPostStage - Sets the general-purpose function
2260   called once at the end of each stage.
2261 
2262   Logically Collective on TS
2263 
2264   Input Parameters:
2265 + ts   - The TS context obtained from TSCreate()
2266 - func - The function
2267 
2268   Calling sequence of func:
2269 . PetscErrorCode func(TS ts, PetscReal stagetime, PetscInt stageindex, Vec* Y);
2270 
2271   Level: intermediate
2272 
2273   Note:
2274   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2275   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2276   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2277 
2278 .keywords: TS, timestep
2279 .seealso: TSSetPreStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2280 @*/
2281 PetscErrorCode  TSSetPostStage(TS ts, PetscErrorCode (*func)(TS,PetscReal,PetscInt,Vec*))
2282 {
2283   PetscFunctionBegin;
2284   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2285   ts->poststage = func;
2286   PetscFunctionReturn(0);
2287 }
2288 
2289 #undef __FUNCT__
2290 #define __FUNCT__ "TSPreStage"
2291 /*@
2292   TSPreStage - Runs the user-defined pre-stage function set using TSSetPreStage()
2293 
2294   Collective on TS
2295 
2296   Input Parameters:
2297 . ts          - The TS context obtained from TSCreate()
2298   stagetime   - The absolute time of the current stage
2299 
2300   Notes:
2301   TSPreStage() is typically used within time stepping implementations,
2302   most users would not generally call this routine themselves.
2303 
2304   Level: developer
2305 
2306 .keywords: TS, timestep
2307 .seealso: TSPostStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2308 @*/
2309 PetscErrorCode  TSPreStage(TS ts, PetscReal stagetime)
2310 {
2311   PetscErrorCode ierr;
2312 
2313   PetscFunctionBegin;
2314   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2315   if (ts->prestage) {
2316     PetscStackCallStandard((*ts->prestage),(ts,stagetime));
2317   }
2318   PetscFunctionReturn(0);
2319 }
2320 
2321 #undef __FUNCT__
2322 #define __FUNCT__ "TSPostStage"
2323 /*@
2324   TSPostStage - Runs the user-defined post-stage function set using TSSetPostStage()
2325 
2326   Collective on TS
2327 
2328   Input Parameters:
2329 . ts          - The TS context obtained from TSCreate()
2330   stagetime   - The absolute time of the current stage
2331   stageindex  - Stage number
2332   Y           - Array of vectors (of size = total number
2333                 of stages) with the stage solutions
2334 
2335   Notes:
2336   TSPostStage() is typically used within time stepping implementations,
2337   most users would not generally call this routine themselves.
2338 
2339   Level: developer
2340 
2341 .keywords: TS, timestep
2342 .seealso: TSPreStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2343 @*/
2344 PetscErrorCode  TSPostStage(TS ts, PetscReal stagetime, PetscInt stageindex, Vec *Y)
2345 {
2346   PetscErrorCode ierr;
2347 
2348   PetscFunctionBegin;
2349   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2350   if (ts->prestage) {
2351     PetscStackCallStandard((*ts->poststage),(ts,stagetime,stageindex,Y));
2352   }
2353   PetscFunctionReturn(0);
2354 }
2355 
2356 #undef __FUNCT__
2357 #define __FUNCT__ "TSSetPostStep"
2358 /*@C
2359   TSSetPostStep - Sets the general-purpose function
2360   called once at the end of each time step.
2361 
2362   Logically Collective on TS
2363 
2364   Input Parameters:
2365 + ts   - The TS context obtained from TSCreate()
2366 - func - The function
2367 
2368   Calling sequence of func:
2369 $ func (TS ts);
2370 
2371   Level: intermediate
2372 
2373 .keywords: TS, timestep
2374 .seealso: TSSetPreStep(), TSSetPreStage(), TSGetTimeStep(), TSGetTimeStepNumber(), TSGetTime()
2375 @*/
2376 PetscErrorCode  TSSetPostStep(TS ts, PetscErrorCode (*func)(TS))
2377 {
2378   PetscFunctionBegin;
2379   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2380   ts->poststep = func;
2381   PetscFunctionReturn(0);
2382 }
2383 
2384 #undef __FUNCT__
2385 #define __FUNCT__ "TSPostStep"
2386 /*@
2387   TSPostStep - Runs the user-defined post-step function.
2388 
2389   Collective on TS
2390 
2391   Input Parameters:
2392 . ts   - The TS context obtained from TSCreate()
2393 
2394   Notes:
2395   TSPostStep() is typically used within time stepping implementations,
2396   so most users would not generally call this routine themselves.
2397 
2398   Level: developer
2399 
2400 .keywords: TS, timestep
2401 @*/
2402 PetscErrorCode  TSPostStep(TS ts)
2403 {
2404   PetscErrorCode ierr;
2405 
2406   PetscFunctionBegin;
2407   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2408   if (ts->poststep) {
2409     PetscStackCallStandard((*ts->poststep),(ts));
2410   }
2411   PetscFunctionReturn(0);
2412 }
2413 
2414 /* ------------ Routines to set performance monitoring options ----------- */
2415 
2416 #undef __FUNCT__
2417 #define __FUNCT__ "TSMonitorSet"
2418 /*@C
2419    TSMonitorSet - Sets an ADDITIONAL function that is to be used at every
2420    timestep to display the iteration's  progress.
2421 
2422    Logically Collective on TS
2423 
2424    Input Parameters:
2425 +  ts - the TS context obtained from TSCreate()
2426 .  monitor - monitoring routine
2427 .  mctx - [optional] user-defined context for private data for the
2428              monitor routine (use NULL if no context is desired)
2429 -  monitordestroy - [optional] routine that frees monitor context
2430           (may be NULL)
2431 
2432    Calling sequence of monitor:
2433 $    int monitor(TS ts,PetscInt steps,PetscReal time,Vec u,void *mctx)
2434 
2435 +    ts - the TS context
2436 .    steps - iteration number (after the final time step the monitor routine is called with a step of -1, this is at the final time which may have
2437                                been interpolated to)
2438 .    time - current time
2439 .    u - current iterate
2440 -    mctx - [optional] monitoring context
2441 
2442    Notes:
2443    This routine adds an additional monitor to the list of monitors that
2444    already has been loaded.
2445 
2446    Fortran notes: Only a single monitor function can be set for each TS object
2447 
2448    Level: intermediate
2449 
2450 .keywords: TS, timestep, set, monitor
2451 
2452 .seealso: TSMonitorDefault(), TSMonitorCancel()
2453 @*/
2454 PetscErrorCode  TSMonitorSet(TS ts,PetscErrorCode (*monitor)(TS,PetscInt,PetscReal,Vec,void*),void *mctx,PetscErrorCode (*mdestroy)(void**))
2455 {
2456   PetscFunctionBegin;
2457   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2458   if (ts->numbermonitors >= MAXTSMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
2459   ts->monitor[ts->numbermonitors]          = monitor;
2460   ts->monitordestroy[ts->numbermonitors]   = mdestroy;
2461   ts->monitorcontext[ts->numbermonitors++] = (void*)mctx;
2462   PetscFunctionReturn(0);
2463 }
2464 
2465 #undef __FUNCT__
2466 #define __FUNCT__ "TSMonitorCancel"
2467 /*@C
2468    TSMonitorCancel - Clears all the monitors that have been set on a time-step object.
2469 
2470    Logically Collective on TS
2471 
2472    Input Parameters:
2473 .  ts - the TS context obtained from TSCreate()
2474 
2475    Notes:
2476    There is no way to remove a single, specific monitor.
2477 
2478    Level: intermediate
2479 
2480 .keywords: TS, timestep, set, monitor
2481 
2482 .seealso: TSMonitorDefault(), TSMonitorSet()
2483 @*/
2484 PetscErrorCode  TSMonitorCancel(TS ts)
2485 {
2486   PetscErrorCode ierr;
2487   PetscInt       i;
2488 
2489   PetscFunctionBegin;
2490   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2491   for (i=0; i<ts->numbermonitors; i++) {
2492     if (ts->monitordestroy[i]) {
2493       ierr = (*ts->monitordestroy[i])(&ts->monitorcontext[i]);CHKERRQ(ierr);
2494     }
2495   }
2496   ts->numbermonitors = 0;
2497   PetscFunctionReturn(0);
2498 }
2499 
2500 #undef __FUNCT__
2501 #define __FUNCT__ "TSMonitorDefault"
2502 /*@
2503    TSMonitorDefault - Sets the Default monitor
2504 
2505    Level: intermediate
2506 
2507 .keywords: TS, set, monitor
2508 
2509 .seealso: TSMonitorDefault(), TSMonitorSet()
2510 @*/
2511 PetscErrorCode TSMonitorDefault(TS ts,PetscInt step,PetscReal ptime,Vec v,void *dummy)
2512 {
2513   PetscErrorCode ierr;
2514   PetscViewer    viewer = dummy ? (PetscViewer) dummy : PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)ts));
2515 
2516   PetscFunctionBegin;
2517   ierr = PetscViewerASCIIAddTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2518   ierr = PetscViewerASCIIPrintf(viewer,"%D TS dt %g time %g\n",step,(double)ts->time_step,(double)ptime);CHKERRQ(ierr);
2519   ierr = PetscViewerASCIISubtractTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2520   PetscFunctionReturn(0);
2521 }
2522 
2523 #undef __FUNCT__
2524 #define __FUNCT__ "TSSetRetainStages"
2525 /*@
2526    TSSetRetainStages - Request that all stages in the upcoming step be stored so that interpolation will be available.
2527 
2528    Logically Collective on TS
2529 
2530    Input Argument:
2531 .  ts - time stepping context
2532 
2533    Output Argument:
2534 .  flg - PETSC_TRUE or PETSC_FALSE
2535 
2536    Level: intermediate
2537 
2538 .keywords: TS, set
2539 
2540 .seealso: TSInterpolate(), TSSetPostStep()
2541 @*/
2542 PetscErrorCode TSSetRetainStages(TS ts,PetscBool flg)
2543 {
2544   PetscFunctionBegin;
2545   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2546   ts->retain_stages = flg;
2547   PetscFunctionReturn(0);
2548 }
2549 
2550 #undef __FUNCT__
2551 #define __FUNCT__ "TSInterpolate"
2552 /*@
2553    TSInterpolate - Interpolate the solution computed during the previous step to an arbitrary location in the interval
2554 
2555    Collective on TS
2556 
2557    Input Argument:
2558 +  ts - time stepping context
2559 -  t - time to interpolate to
2560 
2561    Output Argument:
2562 .  U - state at given time
2563 
2564    Notes:
2565    The user should call TSSetRetainStages() before taking a step in which interpolation will be requested.
2566 
2567    Level: intermediate
2568 
2569    Developer Notes:
2570    TSInterpolate() and the storing of previous steps/stages should be generalized to support delay differential equations and continuous adjoints.
2571 
2572 .keywords: TS, set
2573 
2574 .seealso: TSSetRetainStages(), TSSetPostStep()
2575 @*/
2576 PetscErrorCode TSInterpolate(TS ts,PetscReal t,Vec U)
2577 {
2578   PetscErrorCode ierr;
2579 
2580   PetscFunctionBegin;
2581   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2582   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2583   if (t < ts->ptime - ts->time_step_prev || t > ts->ptime) SETERRQ3(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_OUTOFRANGE,"Requested time %G not in last time steps [%G,%G]",t,ts->ptime-ts->time_step_prev,ts->ptime);
2584   if (!ts->ops->interpolate) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"%s does not provide interpolation",((PetscObject)ts)->type_name);
2585   ierr = (*ts->ops->interpolate)(ts,t,U);CHKERRQ(ierr);
2586   PetscFunctionReturn(0);
2587 }
2588 
2589 #undef __FUNCT__
2590 #define __FUNCT__ "TSStep"
2591 /*@
2592    TSStep - Steps one time step
2593 
2594    Collective on TS
2595 
2596    Input Parameter:
2597 .  ts - the TS context obtained from TSCreate()
2598 
2599    Level: intermediate
2600 
2601    Notes:
2602    The hook set using TSSetPreStep() is called before each attempt to take the step. In general, the time step size may
2603    be changed due to adaptive error controller or solve failures. Note that steps may contain multiple stages.
2604 
2605    This may over-step the final time provided in TSSetDuration() depending on the time-step used. TSSolve() interpolates to exactly the
2606    time provided in TSSetDuration(). One can use TSInterpolate() to determine an interpolated solution within the final timestep.
2607 
2608 .keywords: TS, timestep, solve
2609 
2610 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSInterpolate()
2611 @*/
2612 PetscErrorCode  TSStep(TS ts)
2613 {
2614   PetscReal      ptime_prev;
2615   PetscErrorCode ierr;
2616 
2617   PetscFunctionBegin;
2618   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2619   ierr = TSSetUp(ts);CHKERRQ(ierr);
2620 
2621   ts->reason = TS_CONVERGED_ITERATING;
2622   ptime_prev = ts->ptime;
2623 
2624   ierr = PetscLogEventBegin(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2625   ierr = (*ts->ops->step)(ts);CHKERRQ(ierr);
2626   ierr = PetscLogEventEnd(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2627 
2628   ts->time_step_prev = ts->ptime - ptime_prev;
2629 
2630   if (ts->reason < 0) {
2631     if (ts->errorifstepfailed) {
2632       if (ts->reason == TS_DIVERGED_NONLINEAR_SOLVE) {
2633         SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s, increase -ts_max_snes_failures or make negative to attempt recovery",TSConvergedReasons[ts->reason]);
2634       } else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s",TSConvergedReasons[ts->reason]);
2635     }
2636   } else if (!ts->reason) {
2637     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2638     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2639   }
2640   PetscFunctionReturn(0);
2641 }
2642 
2643 #undef __FUNCT__
2644 #define __FUNCT__ "TSEvaluateStep"
2645 /*@
2646    TSEvaluateStep - Evaluate the solution at the end of a time step with a given order of accuracy.
2647 
2648    Collective on TS
2649 
2650    Input Arguments:
2651 +  ts - time stepping context
2652 .  order - desired order of accuracy
2653 -  done - whether the step was evaluated at this order (pass NULL to generate an error if not available)
2654 
2655    Output Arguments:
2656 .  U - state at the end of the current step
2657 
2658    Level: advanced
2659 
2660    Notes:
2661    This function cannot be called until all stages have been evaluated.
2662    It is normally called by adaptive controllers before a step has been accepted and may also be called by the user after TSStep() has returned.
2663 
2664 .seealso: TSStep(), TSAdapt
2665 @*/
2666 PetscErrorCode TSEvaluateStep(TS ts,PetscInt order,Vec U,PetscBool *done)
2667 {
2668   PetscErrorCode ierr;
2669 
2670   PetscFunctionBegin;
2671   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2672   PetscValidType(ts,1);
2673   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2674   if (!ts->ops->evaluatestep) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSEvaluateStep not implemented for type '%s'",((PetscObject)ts)->type_name);
2675   ierr = (*ts->ops->evaluatestep)(ts,order,U,done);CHKERRQ(ierr);
2676   PetscFunctionReturn(0);
2677 }
2678 
2679 #undef __FUNCT__
2680 #define __FUNCT__ "TSSolve"
2681 /*@
2682    TSSolve - Steps the requested number of timesteps.
2683 
2684    Collective on TS
2685 
2686    Input Parameter:
2687 +  ts - the TS context obtained from TSCreate()
2688 -  u - the solution vector  (can be null if TSSetSolution() was used, otherwise must contain the initial conditions)
2689 
2690    Level: beginner
2691 
2692    Notes:
2693    The final time returned by this function may be different from the time of the internally
2694    held state accessible by TSGetSolution() and TSGetTime() because the method may have
2695    stepped over the final time.
2696 
2697 .keywords: TS, timestep, solve
2698 
2699 .seealso: TSCreate(), TSSetSolution(), TSStep()
2700 @*/
2701 PetscErrorCode TSSolve(TS ts,Vec u)
2702 {
2703   PetscBool         flg;
2704   PetscViewer       viewer;
2705   Vec               solution;
2706   PetscErrorCode    ierr;
2707   PetscViewerFormat format;
2708 
2709   PetscFunctionBegin;
2710   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2711   if (u) PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2712   if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE) {   /* Need ts->vec_sol to be distinct so it is not overwritten when we interpolate at the end */
2713     PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2714     if (!ts->vec_sol || u == ts->vec_sol) {
2715       ierr = VecDuplicate(u,&solution);CHKERRQ(ierr);
2716       ierr = TSSetSolution(ts,solution);CHKERRQ(ierr);
2717       ierr = VecDestroy(&solution);CHKERRQ(ierr); /* grant ownership */
2718     }
2719     ierr = VecCopy(u,ts->vec_sol);CHKERRQ(ierr);
2720   } else if (u) {
2721     ierr = TSSetSolution(ts,u);CHKERRQ(ierr);
2722   }
2723   ierr = TSSetUp(ts);CHKERRQ(ierr);
2724   /* reset time step and iteration counters */
2725   ts->steps             = 0;
2726   ts->ksp_its           = 0;
2727   ts->snes_its          = 0;
2728   ts->num_snes_failures = 0;
2729   ts->reject            = 0;
2730   ts->reason            = TS_CONVERGED_ITERATING;
2731 
2732   ierr = PetscOptionsGetViewer(PetscObjectComm((PetscObject)ts),((PetscObject)ts)->prefix,"-ts_view_pre",&viewer,&format,&flg);CHKERRQ(ierr);
2733   if (flg && !PetscPreLoadingOn) {
2734     ierr = PetscViewerPushFormat(viewer,format);CHKERRQ(ierr);
2735     ierr = TSView(ts,viewer);CHKERRQ(ierr);
2736     ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr);
2737     ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
2738   }
2739 
2740   if (ts->ops->solve) {         /* This private interface is transitional and should be removed when all implementations are updated. */
2741     ierr = (*ts->ops->solve)(ts);CHKERRQ(ierr);
2742     ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);
2743     ts->solvetime = ts->ptime;
2744   } else {
2745     /* steps the requested number of timesteps. */
2746     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2747     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2748     while (!ts->reason) {
2749       ierr = TSMonitor(ts,ts->steps,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
2750       ierr = TSStep(ts);CHKERRQ(ierr);
2751       ierr = TSPostStep(ts);CHKERRQ(ierr);
2752     }
2753     if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE && ts->ptime > ts->max_time) {
2754       ierr = TSInterpolate(ts,ts->max_time,u);CHKERRQ(ierr);
2755       ts->solvetime = ts->max_time;
2756       solution = u;
2757     } else {
2758       if (u) {ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);}
2759       ts->solvetime = ts->ptime;
2760       solution = ts->vec_sol;
2761     }
2762     ierr = TSMonitor(ts,ts->steps,ts->solvetime,solution);CHKERRQ(ierr);
2763   }
2764   ierr = PetscOptionsGetViewer(PetscObjectComm((PetscObject)ts),((PetscObject)ts)->prefix,"-ts_view",&viewer,&format,&flg);CHKERRQ(ierr);
2765   if (flg && !PetscPreLoadingOn) {
2766     ierr = PetscViewerPushFormat(viewer,format);CHKERRQ(ierr);
2767     ierr = TSView(ts,viewer);CHKERRQ(ierr);
2768     ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr);
2769     ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
2770   }
2771   ierr = PetscObjectSAWsBlock((PetscObject)ts);CHKERRQ(ierr);
2772   PetscFunctionReturn(0);
2773 }
2774 
2775 #undef __FUNCT__
2776 #define __FUNCT__ "TSMonitor"
2777 /*@
2778    TSMonitor - Runs all user-provided monitor routines set using TSMonitorSet()
2779 
2780    Collective on TS
2781 
2782    Input Parameters:
2783 +  ts - time stepping context obtained from TSCreate()
2784 .  step - step number that has just completed
2785 .  ptime - model time of the state
2786 -  u - state at the current model time
2787 
2788    Notes:
2789    TSMonitor() is typically used within the time stepping implementations.
2790    Users might call this function when using the TSStep() interface instead of TSSolve().
2791 
2792    Level: advanced
2793 
2794 .keywords: TS, timestep
2795 @*/
2796 PetscErrorCode TSMonitor(TS ts,PetscInt step,PetscReal ptime,Vec u)
2797 {
2798   PetscErrorCode ierr;
2799   PetscInt       i,n = ts->numbermonitors;
2800 
2801   PetscFunctionBegin;
2802   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2803   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
2804   for (i=0; i<n; i++) {
2805     ierr = (*ts->monitor[i])(ts,step,ptime,u,ts->monitorcontext[i]);CHKERRQ(ierr);
2806   }
2807   PetscFunctionReturn(0);
2808 }
2809 
2810 /* ------------------------------------------------------------------------*/
2811 #undef __FUNCT__
2812 #define __FUNCT__ "TSMonitorLGCtxCreate"
2813 /*@C
2814    TSMonitorLGCtxCreate - Creates a line graph context for use with
2815    TS to monitor the solution process graphically in various ways
2816 
2817    Collective on TS
2818 
2819    Input Parameters:
2820 +  host - the X display to open, or null for the local machine
2821 .  label - the title to put in the title bar
2822 .  x, y - the screen coordinates of the upper left coordinate of the window
2823 .  m, n - the screen width and height in pixels
2824 -  howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time
2825 
2826    Output Parameter:
2827 .  ctx - the context
2828 
2829    Options Database Key:
2830 +  -ts_monitor_lg_timestep - automatically sets line graph monitor
2831 .  -ts_monitor_lg_solution -
2832 .  -ts_monitor_lg_error -
2833 .  -ts_monitor_lg_ksp_iterations -
2834 .  -ts_monitor_lg_snes_iterations -
2835 -  -lg_indicate_data_points <true,false> - indicate the data points (at each time step) on the plot; default is true
2836 
2837    Notes:
2838    Use TSMonitorLGCtxDestroy() to destroy.
2839 
2840    Level: intermediate
2841 
2842 .keywords: TS, monitor, line graph, residual, seealso
2843 
2844 .seealso: TSMonitorLGTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError()
2845 
2846 @*/
2847 PetscErrorCode  TSMonitorLGCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorLGCtx *ctx)
2848 {
2849   PetscDraw      win;
2850   PetscErrorCode ierr;
2851 
2852   PetscFunctionBegin;
2853   ierr = PetscNew(struct _n_TSMonitorLGCtx,ctx);CHKERRQ(ierr);
2854   ierr = PetscDrawCreate(comm,host,label,x,y,m,n,&win);CHKERRQ(ierr);
2855   ierr = PetscDrawSetFromOptions(win);CHKERRQ(ierr);
2856   ierr = PetscDrawLGCreate(win,1,&(*ctx)->lg);CHKERRQ(ierr);
2857   ierr = PetscLogObjectParent((PetscObject)(*ctx)->lg,(PetscObject)win);CHKERRQ(ierr);
2858   ierr = PetscDrawLGIndicateDataPoints((*ctx)->lg,PETSC_TRUE);CHKERRQ(ierr);
2859   ierr = PetscDrawLGSetFromOptions((*ctx)->lg);CHKERRQ(ierr);
2860   (*ctx)->howoften = howoften;
2861   PetscFunctionReturn(0);
2862 }
2863 
2864 #undef __FUNCT__
2865 #define __FUNCT__ "TSMonitorLGTimeStep"
2866 PetscErrorCode TSMonitorLGTimeStep(TS ts,PetscInt step,PetscReal ptime,Vec v,void *monctx)
2867 {
2868   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
2869   PetscReal      x   = ptime,y;
2870   PetscErrorCode ierr;
2871 
2872   PetscFunctionBegin;
2873   if (!step) {
2874     PetscDrawAxis axis;
2875     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
2876     ierr = PetscDrawAxisSetLabels(axis,"Timestep as function of time","Time","Time step");CHKERRQ(ierr);
2877     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
2878     ierr = PetscDrawLGIndicateDataPoints(ctx->lg,PETSC_TRUE);CHKERRQ(ierr);
2879   }
2880   ierr = TSGetTimeStep(ts,&y);CHKERRQ(ierr);
2881   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
2882   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
2883     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
2884   }
2885   PetscFunctionReturn(0);
2886 }
2887 
2888 #undef __FUNCT__
2889 #define __FUNCT__ "TSMonitorLGCtxDestroy"
2890 /*@C
2891    TSMonitorLGCtxDestroy - Destroys a line graph context that was created
2892    with TSMonitorLGCtxCreate().
2893 
2894    Collective on TSMonitorLGCtx
2895 
2896    Input Parameter:
2897 .  ctx - the monitor context
2898 
2899    Level: intermediate
2900 
2901 .keywords: TS, monitor, line graph, destroy
2902 
2903 .seealso: TSMonitorLGCtxCreate(),  TSMonitorSet(), TSMonitorLGTimeStep();
2904 @*/
2905 PetscErrorCode  TSMonitorLGCtxDestroy(TSMonitorLGCtx *ctx)
2906 {
2907   PetscDraw      draw;
2908   PetscErrorCode ierr;
2909 
2910   PetscFunctionBegin;
2911   ierr = PetscDrawLGGetDraw((*ctx)->lg,&draw);CHKERRQ(ierr);
2912   ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
2913   ierr = PetscDrawLGDestroy(&(*ctx)->lg);CHKERRQ(ierr);
2914   ierr = PetscStrArrayDestroy(&(*ctx)->names);CHKERRQ(ierr);
2915   ierr = PetscFree(*ctx);CHKERRQ(ierr);
2916   PetscFunctionReturn(0);
2917 }
2918 
2919 #undef __FUNCT__
2920 #define __FUNCT__ "TSGetTime"
2921 /*@
2922    TSGetTime - Gets the time of the most recently completed step.
2923 
2924    Not Collective
2925 
2926    Input Parameter:
2927 .  ts - the TS context obtained from TSCreate()
2928 
2929    Output Parameter:
2930 .  t  - the current time
2931 
2932    Level: beginner
2933 
2934    Note:
2935    When called during time step evaluation (e.g. during residual evaluation or via hooks set using TSSetPreStep(),
2936    TSSetPreStage(), TSSetPostStage(), or TSSetPostStep()), the time is the time at the start of the step being evaluated.
2937 
2938 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
2939 
2940 .keywords: TS, get, time
2941 @*/
2942 PetscErrorCode  TSGetTime(TS ts,PetscReal *t)
2943 {
2944   PetscFunctionBegin;
2945   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2946   PetscValidRealPointer(t,2);
2947   *t = ts->ptime;
2948   PetscFunctionReturn(0);
2949 }
2950 
2951 #undef __FUNCT__
2952 #define __FUNCT__ "TSSetTime"
2953 /*@
2954    TSSetTime - Allows one to reset the time.
2955 
2956    Logically Collective on TS
2957 
2958    Input Parameters:
2959 +  ts - the TS context obtained from TSCreate()
2960 -  time - the time
2961 
2962    Level: intermediate
2963 
2964 .seealso: TSGetTime(), TSSetDuration()
2965 
2966 .keywords: TS, set, time
2967 @*/
2968 PetscErrorCode  TSSetTime(TS ts, PetscReal t)
2969 {
2970   PetscFunctionBegin;
2971   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2972   PetscValidLogicalCollectiveReal(ts,t,2);
2973   ts->ptime = t;
2974   PetscFunctionReturn(0);
2975 }
2976 
2977 #undef __FUNCT__
2978 #define __FUNCT__ "TSSetOptionsPrefix"
2979 /*@C
2980    TSSetOptionsPrefix - Sets the prefix used for searching for all
2981    TS options in the database.
2982 
2983    Logically Collective on TS
2984 
2985    Input Parameter:
2986 +  ts     - The TS context
2987 -  prefix - The prefix to prepend to all option names
2988 
2989    Notes:
2990    A hyphen (-) must NOT be given at the beginning of the prefix name.
2991    The first character of all runtime options is AUTOMATICALLY the
2992    hyphen.
2993 
2994    Level: advanced
2995 
2996 .keywords: TS, set, options, prefix, database
2997 
2998 .seealso: TSSetFromOptions()
2999 
3000 @*/
3001 PetscErrorCode  TSSetOptionsPrefix(TS ts,const char prefix[])
3002 {
3003   PetscErrorCode ierr;
3004   SNES           snes;
3005 
3006   PetscFunctionBegin;
3007   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3008   ierr = PetscObjectSetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3009   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3010   ierr = SNESSetOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3011   PetscFunctionReturn(0);
3012 }
3013 
3014 
3015 #undef __FUNCT__
3016 #define __FUNCT__ "TSAppendOptionsPrefix"
3017 /*@C
3018    TSAppendOptionsPrefix - Appends to the prefix used for searching for all
3019    TS options in the database.
3020 
3021    Logically Collective on TS
3022 
3023    Input Parameter:
3024 +  ts     - The TS context
3025 -  prefix - The prefix to prepend to all option names
3026 
3027    Notes:
3028    A hyphen (-) must NOT be given at the beginning of the prefix name.
3029    The first character of all runtime options is AUTOMATICALLY the
3030    hyphen.
3031 
3032    Level: advanced
3033 
3034 .keywords: TS, append, options, prefix, database
3035 
3036 .seealso: TSGetOptionsPrefix()
3037 
3038 @*/
3039 PetscErrorCode  TSAppendOptionsPrefix(TS ts,const char prefix[])
3040 {
3041   PetscErrorCode ierr;
3042   SNES           snes;
3043 
3044   PetscFunctionBegin;
3045   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3046   ierr = PetscObjectAppendOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3047   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3048   ierr = SNESAppendOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3049   PetscFunctionReturn(0);
3050 }
3051 
3052 #undef __FUNCT__
3053 #define __FUNCT__ "TSGetOptionsPrefix"
3054 /*@C
3055    TSGetOptionsPrefix - Sets the prefix used for searching for all
3056    TS options in the database.
3057 
3058    Not Collective
3059 
3060    Input Parameter:
3061 .  ts - The TS context
3062 
3063    Output Parameter:
3064 .  prefix - A pointer to the prefix string used
3065 
3066    Notes: On the fortran side, the user should pass in a string 'prifix' of
3067    sufficient length to hold the prefix.
3068 
3069    Level: intermediate
3070 
3071 .keywords: TS, get, options, prefix, database
3072 
3073 .seealso: TSAppendOptionsPrefix()
3074 @*/
3075 PetscErrorCode  TSGetOptionsPrefix(TS ts,const char *prefix[])
3076 {
3077   PetscErrorCode ierr;
3078 
3079   PetscFunctionBegin;
3080   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3081   PetscValidPointer(prefix,2);
3082   ierr = PetscObjectGetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3083   PetscFunctionReturn(0);
3084 }
3085 
3086 #undef __FUNCT__
3087 #define __FUNCT__ "TSGetRHSJacobian"
3088 /*@C
3089    TSGetRHSJacobian - Returns the Jacobian J at the present timestep.
3090 
3091    Not Collective, but parallel objects are returned if TS is parallel
3092 
3093    Input Parameter:
3094 .  ts  - The TS context obtained from TSCreate()
3095 
3096    Output Parameters:
3097 +  Amat - The (approximate) Jacobian J of G, where U_t = G(U,t)  (or NULL)
3098 .  Pmat - The matrix from which the preconditioner is constructed, usually the same as Amat  (or NULL)
3099 .  func - Function to compute the Jacobian of the RHS  (or NULL)
3100 -  ctx - User-defined context for Jacobian evaluation routine  (or NULL)
3101 
3102    Notes: You can pass in NULL for any return argument you do not need.
3103 
3104    Level: intermediate
3105 
3106 .seealso: TSGetTimeStep(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3107 
3108 .keywords: TS, timestep, get, matrix, Jacobian
3109 @*/
3110 PetscErrorCode  TSGetRHSJacobian(TS ts,Mat *Amat,Mat *Pmat,TSRHSJacobian *func,void **ctx)
3111 {
3112   PetscErrorCode ierr;
3113   SNES           snes;
3114   DM             dm;
3115 
3116   PetscFunctionBegin;
3117   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3118   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3119   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3120   ierr = DMTSGetRHSJacobian(dm,func,ctx);CHKERRQ(ierr);
3121   PetscFunctionReturn(0);
3122 }
3123 
3124 #undef __FUNCT__
3125 #define __FUNCT__ "TSGetIJacobian"
3126 /*@C
3127    TSGetIJacobian - Returns the implicit Jacobian at the present timestep.
3128 
3129    Not Collective, but parallel objects are returned if TS is parallel
3130 
3131    Input Parameter:
3132 .  ts  - The TS context obtained from TSCreate()
3133 
3134    Output Parameters:
3135 +  Amat  - The (approximate) Jacobian of F(t,U,U_t)
3136 .  Pmat - The matrix from which the preconditioner is constructed, often the same as Amat
3137 .  f   - The function to compute the matrices
3138 - ctx - User-defined context for Jacobian evaluation routine
3139 
3140    Notes: You can pass in NULL for any return argument you do not need.
3141 
3142    Level: advanced
3143 
3144 .seealso: TSGetTimeStep(), TSGetRHSJacobian(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3145 
3146 .keywords: TS, timestep, get, matrix, Jacobian
3147 @*/
3148 PetscErrorCode  TSGetIJacobian(TS ts,Mat *Amat,Mat *Pmat,TSIJacobian *f,void **ctx)
3149 {
3150   PetscErrorCode ierr;
3151   SNES           snes;
3152   DM             dm;
3153 
3154   PetscFunctionBegin;
3155   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3156   ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);
3157   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3158   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3159   ierr = DMTSGetIJacobian(dm,f,ctx);CHKERRQ(ierr);
3160   PetscFunctionReturn(0);
3161 }
3162 
3163 
3164 #undef __FUNCT__
3165 #define __FUNCT__ "TSMonitorDrawSolution"
3166 /*@C
3167    TSMonitorDrawSolution - Monitors progress of the TS solvers by calling
3168    VecView() for the solution at each timestep
3169 
3170    Collective on TS
3171 
3172    Input Parameters:
3173 +  ts - the TS context
3174 .  step - current time-step
3175 .  ptime - current time
3176 -  dummy - either a viewer or NULL
3177 
3178    Options Database:
3179 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3180 
3181    Notes: the initial solution and current solution are not displayed with a common axis scaling so generally the option -ts_monitor_draw_solution_initial
3182        will look bad
3183 
3184    Level: intermediate
3185 
3186 .keywords: TS,  vector, monitor, view
3187 
3188 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3189 @*/
3190 PetscErrorCode  TSMonitorDrawSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3191 {
3192   PetscErrorCode   ierr;
3193   TSMonitorDrawCtx ictx = (TSMonitorDrawCtx)dummy;
3194   PetscDraw        draw;
3195 
3196   PetscFunctionBegin;
3197   if (!step && ictx->showinitial) {
3198     if (!ictx->initialsolution) {
3199       ierr = VecDuplicate(u,&ictx->initialsolution);CHKERRQ(ierr);
3200     }
3201     ierr = VecCopy(u,ictx->initialsolution);CHKERRQ(ierr);
3202   }
3203   if (!(((ictx->howoften > 0) && (!(step % ictx->howoften))) || ((ictx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3204 
3205   if (ictx->showinitial) {
3206     PetscReal pause;
3207     ierr = PetscViewerDrawGetPause(ictx->viewer,&pause);CHKERRQ(ierr);
3208     ierr = PetscViewerDrawSetPause(ictx->viewer,0.0);CHKERRQ(ierr);
3209     ierr = VecView(ictx->initialsolution,ictx->viewer);CHKERRQ(ierr);
3210     ierr = PetscViewerDrawSetPause(ictx->viewer,pause);CHKERRQ(ierr);
3211     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_TRUE);CHKERRQ(ierr);
3212   }
3213   ierr = VecView(u,ictx->viewer);CHKERRQ(ierr);
3214   if (ictx->showtimestepandtime) {
3215     PetscReal xl,yl,xr,yr,tw,w,h;
3216     char      time[32];
3217     size_t    len;
3218 
3219     ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3220     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3221     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3222     ierr =  PetscStrlen(time,&len);CHKERRQ(ierr);
3223     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3224     w    = xl + .5*(xr - xl) - .5*len*tw;
3225     h    = yl + .95*(yr - yl);
3226     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3227     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3228   }
3229 
3230   if (ictx->showinitial) {
3231     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_FALSE);CHKERRQ(ierr);
3232   }
3233   PetscFunctionReturn(0);
3234 }
3235 
3236 #undef __FUNCT__
3237 #define __FUNCT__ "TSMonitorDrawSolutionPhase"
3238 /*@C
3239    TSMonitorDrawSolutionPhase - Monitors progress of the TS solvers by plotting the solution as a phase diagram
3240 
3241    Collective on TS
3242 
3243    Input Parameters:
3244 +  ts - the TS context
3245 .  step - current time-step
3246 .  ptime - current time
3247 -  dummy - either a viewer or NULL
3248 
3249    Level: intermediate
3250 
3251 .keywords: TS,  vector, monitor, view
3252 
3253 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3254 @*/
3255 PetscErrorCode  TSMonitorDrawSolutionPhase(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3256 {
3257   PetscErrorCode    ierr;
3258   TSMonitorDrawCtx  ictx = (TSMonitorDrawCtx)dummy;
3259   PetscDraw         draw;
3260   MPI_Comm          comm;
3261   PetscInt          n;
3262   PetscMPIInt       size;
3263   PetscReal         xl,yl,xr,yr,tw,w,h;
3264   char              time[32];
3265   size_t            len;
3266   const PetscScalar *U;
3267 
3268   PetscFunctionBegin;
3269   ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
3270   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3271   if (size != 1) SETERRQ(comm,PETSC_ERR_SUP,"Only allowed for sequential runs");
3272   ierr = VecGetSize(u,&n);CHKERRQ(ierr);
3273   if (n != 2) SETERRQ(comm,PETSC_ERR_SUP,"Only for ODEs with two unknowns");
3274 
3275   ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3276 
3277   ierr = VecGetArrayRead(u,&U);CHKERRQ(ierr);
3278   ierr = PetscDrawAxisGetLimits(ictx->axis,&xl,&xr,&yl,&yr);CHKERRQ(ierr);
3279   if ((PetscRealPart(U[0]) < xl) || (PetscRealPart(U[1]) < yl) || (PetscRealPart(U[0]) > xr) || (PetscRealPart(U[1]) > yr)) {
3280       ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3281       PetscFunctionReturn(0);
3282   }
3283   if (!step) ictx->color++;
3284   ierr = PetscDrawPoint(draw,PetscRealPart(U[0]),PetscRealPart(U[1]),ictx->color);CHKERRQ(ierr);
3285   ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3286 
3287   if (ictx->showtimestepandtime) {
3288     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3289     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3290     ierr = PetscStrlen(time,&len);CHKERRQ(ierr);
3291     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3292     w    = xl + .5*(xr - xl) - .5*len*tw;
3293     h    = yl + .95*(yr - yl);
3294     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3295   }
3296   ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3297   PetscFunctionReturn(0);
3298 }
3299 
3300 
3301 #undef __FUNCT__
3302 #define __FUNCT__ "TSMonitorDrawCtxDestroy"
3303 /*@C
3304    TSMonitorDrawCtxDestroy - Destroys the monitor context for TSMonitorDrawSolution()
3305 
3306    Collective on TS
3307 
3308    Input Parameters:
3309 .    ctx - the monitor context
3310 
3311    Level: intermediate
3312 
3313 .keywords: TS,  vector, monitor, view
3314 
3315 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawSolution(), TSMonitorDrawError()
3316 @*/
3317 PetscErrorCode  TSMonitorDrawCtxDestroy(TSMonitorDrawCtx *ictx)
3318 {
3319   PetscErrorCode ierr;
3320 
3321   PetscFunctionBegin;
3322   ierr = PetscDrawAxisDestroy(&(*ictx)->axis);CHKERRQ(ierr);
3323   ierr = PetscViewerDestroy(&(*ictx)->viewer);CHKERRQ(ierr);
3324   ierr = VecDestroy(&(*ictx)->initialsolution);CHKERRQ(ierr);
3325   ierr = PetscFree(*ictx);CHKERRQ(ierr);
3326   PetscFunctionReturn(0);
3327 }
3328 
3329 #undef __FUNCT__
3330 #define __FUNCT__ "TSMonitorDrawCtxCreate"
3331 /*@C
3332    TSMonitorDrawCtxCreate - Creates the monitor context for TSMonitorDrawCtx
3333 
3334    Collective on TS
3335 
3336    Input Parameter:
3337 .    ts - time-step context
3338 
3339    Output Patameter:
3340 .    ctx - the monitor context
3341 
3342    Options Database:
3343 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3344 
3345    Level: intermediate
3346 
3347 .keywords: TS,  vector, monitor, view
3348 
3349 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawCtx()
3350 @*/
3351 PetscErrorCode  TSMonitorDrawCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorDrawCtx *ctx)
3352 {
3353   PetscErrorCode   ierr;
3354 
3355   PetscFunctionBegin;
3356   ierr = PetscNew(struct _n_TSMonitorDrawCtx,ctx);CHKERRQ(ierr);
3357   ierr = PetscViewerDrawOpen(comm,host,label,x,y,m,n,&(*ctx)->viewer);CHKERRQ(ierr);
3358   ierr = PetscViewerSetFromOptions((*ctx)->viewer);CHKERRQ(ierr);
3359 
3360   (*ctx)->howoften    = howoften;
3361   (*ctx)->showinitial = PETSC_FALSE;
3362   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_initial",&(*ctx)->showinitial,NULL);CHKERRQ(ierr);
3363 
3364   (*ctx)->showtimestepandtime = PETSC_FALSE;
3365   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_show_time",&(*ctx)->showtimestepandtime,NULL);CHKERRQ(ierr);
3366   (*ctx)->color = PETSC_DRAW_WHITE;
3367   PetscFunctionReturn(0);
3368 }
3369 
3370 #undef __FUNCT__
3371 #define __FUNCT__ "TSMonitorDrawError"
3372 /*@C
3373    TSMonitorDrawError - Monitors progress of the TS solvers by calling
3374    VecView() for the error at each timestep
3375 
3376    Collective on TS
3377 
3378    Input Parameters:
3379 +  ts - the TS context
3380 .  step - current time-step
3381 .  ptime - current time
3382 -  dummy - either a viewer or NULL
3383 
3384    Level: intermediate
3385 
3386 .keywords: TS,  vector, monitor, view
3387 
3388 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3389 @*/
3390 PetscErrorCode  TSMonitorDrawError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3391 {
3392   PetscErrorCode   ierr;
3393   TSMonitorDrawCtx ctx    = (TSMonitorDrawCtx)dummy;
3394   PetscViewer      viewer = ctx->viewer;
3395   Vec              work;
3396 
3397   PetscFunctionBegin;
3398   if (!(((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3399   ierr = VecDuplicate(u,&work);CHKERRQ(ierr);
3400   ierr = TSComputeSolutionFunction(ts,ptime,work);CHKERRQ(ierr);
3401   ierr = VecAXPY(work,-1.0,u);CHKERRQ(ierr);
3402   ierr = VecView(work,viewer);CHKERRQ(ierr);
3403   ierr = VecDestroy(&work);CHKERRQ(ierr);
3404   PetscFunctionReturn(0);
3405 }
3406 
3407 #include <petsc-private/dmimpl.h>
3408 #undef __FUNCT__
3409 #define __FUNCT__ "TSSetDM"
3410 /*@
3411    TSSetDM - Sets the DM that may be used by some preconditioners
3412 
3413    Logically Collective on TS and DM
3414 
3415    Input Parameters:
3416 +  ts - the preconditioner context
3417 -  dm - the dm
3418 
3419    Level: intermediate
3420 
3421 
3422 .seealso: TSGetDM(), SNESSetDM(), SNESGetDM()
3423 @*/
3424 PetscErrorCode  TSSetDM(TS ts,DM dm)
3425 {
3426   PetscErrorCode ierr;
3427   SNES           snes;
3428   DMTS           tsdm;
3429 
3430   PetscFunctionBegin;
3431   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3432   ierr = PetscObjectReference((PetscObject)dm);CHKERRQ(ierr);
3433   if (ts->dm) {               /* Move the DMTS context over to the new DM unless the new DM already has one */
3434     if (ts->dm->dmts && !dm->dmts) {
3435       ierr = DMCopyDMTS(ts->dm,dm);CHKERRQ(ierr);
3436       ierr = DMGetDMTS(ts->dm,&tsdm);CHKERRQ(ierr);
3437       if (tsdm->originaldm == ts->dm) { /* Grant write privileges to the replacement DM */
3438         tsdm->originaldm = dm;
3439       }
3440     }
3441     ierr = DMDestroy(&ts->dm);CHKERRQ(ierr);
3442   }
3443   ts->dm = dm;
3444 
3445   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3446   ierr = SNESSetDM(snes,dm);CHKERRQ(ierr);
3447   PetscFunctionReturn(0);
3448 }
3449 
3450 #undef __FUNCT__
3451 #define __FUNCT__ "TSGetDM"
3452 /*@
3453    TSGetDM - Gets the DM that may be used by some preconditioners
3454 
3455    Not Collective
3456 
3457    Input Parameter:
3458 . ts - the preconditioner context
3459 
3460    Output Parameter:
3461 .  dm - the dm
3462 
3463    Level: intermediate
3464 
3465 
3466 .seealso: TSSetDM(), SNESSetDM(), SNESGetDM()
3467 @*/
3468 PetscErrorCode  TSGetDM(TS ts,DM *dm)
3469 {
3470   PetscErrorCode ierr;
3471 
3472   PetscFunctionBegin;
3473   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3474   if (!ts->dm) {
3475     ierr = DMShellCreate(PetscObjectComm((PetscObject)ts),&ts->dm);CHKERRQ(ierr);
3476     if (ts->snes) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
3477   }
3478   *dm = ts->dm;
3479   PetscFunctionReturn(0);
3480 }
3481 
3482 #undef __FUNCT__
3483 #define __FUNCT__ "SNESTSFormFunction"
3484 /*@
3485    SNESTSFormFunction - Function to evaluate nonlinear residual
3486 
3487    Logically Collective on SNES
3488 
3489    Input Parameter:
3490 + snes - nonlinear solver
3491 . U - the current state at which to evaluate the residual
3492 - ctx - user context, must be a TS
3493 
3494    Output Parameter:
3495 . F - the nonlinear residual
3496 
3497    Notes:
3498    This function is not normally called by users and is automatically registered with the SNES used by TS.
3499    It is most frequently passed to MatFDColoringSetFunction().
3500 
3501    Level: advanced
3502 
3503 .seealso: SNESSetFunction(), MatFDColoringSetFunction()
3504 @*/
3505 PetscErrorCode  SNESTSFormFunction(SNES snes,Vec U,Vec F,void *ctx)
3506 {
3507   TS             ts = (TS)ctx;
3508   PetscErrorCode ierr;
3509 
3510   PetscFunctionBegin;
3511   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3512   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3513   PetscValidHeaderSpecific(F,VEC_CLASSID,3);
3514   PetscValidHeaderSpecific(ts,TS_CLASSID,4);
3515   ierr = (ts->ops->snesfunction)(snes,U,F,ts);CHKERRQ(ierr);
3516   PetscFunctionReturn(0);
3517 }
3518 
3519 #undef __FUNCT__
3520 #define __FUNCT__ "SNESTSFormJacobian"
3521 /*@
3522    SNESTSFormJacobian - Function to evaluate the Jacobian
3523 
3524    Collective on SNES
3525 
3526    Input Parameter:
3527 + snes - nonlinear solver
3528 . U - the current state at which to evaluate the residual
3529 - ctx - user context, must be a TS
3530 
3531    Output Parameter:
3532 + A - the Jacobian
3533 . B - the preconditioning matrix (may be the same as A)
3534 - flag - indicates any structure change in the matrix
3535 
3536    Notes:
3537    This function is not normally called by users and is automatically registered with the SNES used by TS.
3538 
3539    Level: developer
3540 
3541 .seealso: SNESSetJacobian()
3542 @*/
3543 PetscErrorCode  SNESTSFormJacobian(SNES snes,Vec U,Mat *A,Mat *B,MatStructure *flag,void *ctx)
3544 {
3545   TS             ts = (TS)ctx;
3546   PetscErrorCode ierr;
3547 
3548   PetscFunctionBegin;
3549   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3550   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3551   PetscValidPointer(A,3);
3552   PetscValidHeaderSpecific(*A,MAT_CLASSID,3);
3553   PetscValidPointer(B,4);
3554   PetscValidHeaderSpecific(*B,MAT_CLASSID,4);
3555   PetscValidPointer(flag,5);
3556   PetscValidHeaderSpecific(ts,TS_CLASSID,6);
3557   ierr = (ts->ops->snesjacobian)(snes,U,A,B,flag,ts);CHKERRQ(ierr);
3558   PetscFunctionReturn(0);
3559 }
3560 
3561 #undef __FUNCT__
3562 #define __FUNCT__ "TSComputeRHSFunctionLinear"
3563 /*@C
3564    TSComputeRHSFunctionLinear - Evaluate the right hand side via the user-provided Jacobian, for linear problems only
3565 
3566    Collective on TS
3567 
3568    Input Arguments:
3569 +  ts - time stepping context
3570 .  t - time at which to evaluate
3571 .  U - state at which to evaluate
3572 -  ctx - context
3573 
3574    Output Arguments:
3575 .  F - right hand side
3576 
3577    Level: intermediate
3578 
3579    Notes:
3580    This function is intended to be passed to TSSetRHSFunction() to evaluate the right hand side for linear problems.
3581    The matrix (and optionally the evaluation context) should be passed to TSSetRHSJacobian().
3582 
3583 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
3584 @*/
3585 PetscErrorCode TSComputeRHSFunctionLinear(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
3586 {
3587   PetscErrorCode ierr;
3588   Mat            Arhs,Brhs;
3589   MatStructure   flg2;
3590 
3591   PetscFunctionBegin;
3592   ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
3593   ierr = TSComputeRHSJacobian(ts,t,U,&Arhs,&Brhs,&flg2);CHKERRQ(ierr);
3594   ierr = MatMult(Arhs,U,F);CHKERRQ(ierr);
3595   PetscFunctionReturn(0);
3596 }
3597 
3598 #undef __FUNCT__
3599 #define __FUNCT__ "TSComputeRHSJacobianConstant"
3600 /*@C
3601    TSComputeRHSJacobianConstant - Reuses a Jacobian that is time-independent.
3602 
3603    Collective on TS
3604 
3605    Input Arguments:
3606 +  ts - time stepping context
3607 .  t - time at which to evaluate
3608 .  U - state at which to evaluate
3609 -  ctx - context
3610 
3611    Output Arguments:
3612 +  A - pointer to operator
3613 .  B - pointer to preconditioning matrix
3614 -  flg - matrix structure flag
3615 
3616    Level: intermediate
3617 
3618    Notes:
3619    This function is intended to be passed to TSSetRHSJacobian() to evaluate the Jacobian for linear time-independent problems.
3620 
3621 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSFunctionLinear()
3622 @*/
3623 PetscErrorCode TSComputeRHSJacobianConstant(TS ts,PetscReal t,Vec U,Mat *A,Mat *B,MatStructure *flg,void *ctx)
3624 {
3625   PetscFunctionBegin;
3626   *flg = SAME_PRECONDITIONER;
3627   PetscFunctionReturn(0);
3628 }
3629 
3630 #undef __FUNCT__
3631 #define __FUNCT__ "TSComputeIFunctionLinear"
3632 /*@C
3633    TSComputeIFunctionLinear - Evaluate the left hand side via the user-provided Jacobian, for linear problems only
3634 
3635    Collective on TS
3636 
3637    Input Arguments:
3638 +  ts - time stepping context
3639 .  t - time at which to evaluate
3640 .  U - state at which to evaluate
3641 .  Udot - time derivative of state vector
3642 -  ctx - context
3643 
3644    Output Arguments:
3645 .  F - left hand side
3646 
3647    Level: intermediate
3648 
3649    Notes:
3650    The assumption here is that the left hand side is of the form A*Udot (and not A*Udot + B*U). For other cases, the
3651    user is required to write their own TSComputeIFunction.
3652    This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems.
3653    The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().
3654 
3655 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant()
3656 @*/
3657 PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
3658 {
3659   PetscErrorCode ierr;
3660   Mat            A,B;
3661   MatStructure   flg2;
3662 
3663   PetscFunctionBegin;
3664   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
3665   ierr = TSComputeIJacobian(ts,t,U,Udot,1.0,&A,&B,&flg2,PETSC_TRUE);CHKERRQ(ierr);
3666   ierr = MatMult(A,Udot,F);CHKERRQ(ierr);
3667   PetscFunctionReturn(0);
3668 }
3669 
3670 #undef __FUNCT__
3671 #define __FUNCT__ "TSComputeIJacobianConstant"
3672 /*@C
3673    TSComputeIJacobianConstant - Reuses a time-independent for a semi-implicit DAE or ODE
3674 
3675    Collective on TS
3676 
3677    Input Arguments:
3678 +  ts - time stepping context
3679 .  t - time at which to evaluate
3680 .  U - state at which to evaluate
3681 .  Udot - time derivative of state vector
3682 .  shift - shift to apply
3683 -  ctx - context
3684 
3685    Output Arguments:
3686 +  A - pointer to operator
3687 .  B - pointer to preconditioning matrix
3688 -  flg - matrix structure flag
3689 
3690    Level: advanced
3691 
3692    Notes:
3693    This function is intended to be passed to TSSetIJacobian() to evaluate the Jacobian for linear time-independent problems.
3694 
3695    It is only appropriate for problems of the form
3696 
3697 $     M Udot = F(U,t)
3698 
3699   where M is constant and F is non-stiff.  The user must pass M to TSSetIJacobian().  The current implementation only
3700   works with IMEX time integration methods such as TSROSW and TSARKIMEX, since there is no support for de-constructing
3701   an implicit operator of the form
3702 
3703 $    shift*M + J
3704 
3705   where J is the Jacobian of -F(U).  Support may be added in a future version of PETSc, but for now, the user must store
3706   a copy of M or reassemble it when requested.
3707 
3708 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIFunctionLinear()
3709 @*/
3710 PetscErrorCode TSComputeIJacobianConstant(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat *A,Mat *B,MatStructure *flg,void *ctx)
3711 {
3712   PetscErrorCode ierr;
3713 
3714   PetscFunctionBegin;
3715   ierr = MatScale(*A, shift / ts->ijacobian.shift);CHKERRQ(ierr);
3716   ts->ijacobian.shift = shift;
3717   *flg = SAME_PRECONDITIONER;
3718   PetscFunctionReturn(0);
3719 }
3720 
3721 #undef __FUNCT__
3722 #define __FUNCT__ "TSGetEquationType"
3723 /*@
3724    TSGetEquationType - Gets the type of the equation that TS is solving.
3725 
3726    Not Collective
3727 
3728    Input Parameter:
3729 .  ts - the TS context
3730 
3731    Output Parameter:
3732 .  equation_type - see TSEquationType
3733 
3734    Level: beginner
3735 
3736 .keywords: TS, equation type
3737 
3738 .seealso: TSSetEquationType(), TSEquationType
3739 @*/
3740 PetscErrorCode  TSGetEquationType(TS ts,TSEquationType *equation_type)
3741 {
3742   PetscFunctionBegin;
3743   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3744   PetscValidPointer(equation_type,2);
3745   *equation_type = ts->equation_type;
3746   PetscFunctionReturn(0);
3747 }
3748 
3749 #undef __FUNCT__
3750 #define __FUNCT__ "TSSetEquationType"
3751 /*@
3752    TSSetEquationType - Sets the type of the equation that TS is solving.
3753 
3754    Not Collective
3755 
3756    Input Parameter:
3757 +  ts - the TS context
3758 .  equation_type - see TSEquationType
3759 
3760    Level: advanced
3761 
3762 .keywords: TS, equation type
3763 
3764 .seealso: TSGetEquationType(), TSEquationType
3765 @*/
3766 PetscErrorCode  TSSetEquationType(TS ts,TSEquationType equation_type)
3767 {
3768   PetscFunctionBegin;
3769   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3770   ts->equation_type = equation_type;
3771   PetscFunctionReturn(0);
3772 }
3773 
3774 #undef __FUNCT__
3775 #define __FUNCT__ "TSGetConvergedReason"
3776 /*@
3777    TSGetConvergedReason - Gets the reason the TS iteration was stopped.
3778 
3779    Not Collective
3780 
3781    Input Parameter:
3782 .  ts - the TS context
3783 
3784    Output Parameter:
3785 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3786             manual pages for the individual convergence tests for complete lists
3787 
3788    Level: beginner
3789 
3790    Notes:
3791    Can only be called after the call to TSSolve() is complete.
3792 
3793 .keywords: TS, nonlinear, set, convergence, test
3794 
3795 .seealso: TSSetConvergenceTest(), TSConvergedReason
3796 @*/
3797 PetscErrorCode  TSGetConvergedReason(TS ts,TSConvergedReason *reason)
3798 {
3799   PetscFunctionBegin;
3800   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3801   PetscValidPointer(reason,2);
3802   *reason = ts->reason;
3803   PetscFunctionReturn(0);
3804 }
3805 
3806 #undef __FUNCT__
3807 #define __FUNCT__ "TSSetConvergedReason"
3808 /*@
3809    TSSetConvergedReason - Sets the reason for handling the convergence of TSSolve.
3810 
3811    Not Collective
3812 
3813    Input Parameter:
3814 +  ts - the TS context
3815 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3816             manual pages for the individual convergence tests for complete lists
3817 
3818    Level: advanced
3819 
3820    Notes:
3821    Can only be called during TSSolve() is active.
3822 
3823 .keywords: TS, nonlinear, set, convergence, test
3824 
3825 .seealso: TSConvergedReason
3826 @*/
3827 PetscErrorCode  TSSetConvergedReason(TS ts,TSConvergedReason reason)
3828 {
3829   PetscFunctionBegin;
3830   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3831   ts->reason = reason;
3832   PetscFunctionReturn(0);
3833 }
3834 
3835 #undef __FUNCT__
3836 #define __FUNCT__ "TSGetSolveTime"
3837 /*@
3838    TSGetSolveTime - Gets the time after a call to TSSolve()
3839 
3840    Not Collective
3841 
3842    Input Parameter:
3843 .  ts - the TS context
3844 
3845    Output Parameter:
3846 .  ftime - the final time. This time should correspond to the final time set with TSSetDuration()
3847 
3848    Level: beginner
3849 
3850    Notes:
3851    Can only be called after the call to TSSolve() is complete.
3852 
3853 .keywords: TS, nonlinear, set, convergence, test
3854 
3855 .seealso: TSSetConvergenceTest(), TSConvergedReason
3856 @*/
3857 PetscErrorCode  TSGetSolveTime(TS ts,PetscReal *ftime)
3858 {
3859   PetscFunctionBegin;
3860   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3861   PetscValidPointer(ftime,2);
3862   *ftime = ts->solvetime;
3863   PetscFunctionReturn(0);
3864 }
3865 
3866 #undef __FUNCT__
3867 #define __FUNCT__ "TSGetSNESIterations"
3868 /*@
3869    TSGetSNESIterations - Gets the total number of nonlinear iterations
3870    used by the time integrator.
3871 
3872    Not Collective
3873 
3874    Input Parameter:
3875 .  ts - TS context
3876 
3877    Output Parameter:
3878 .  nits - number of nonlinear iterations
3879 
3880    Notes:
3881    This counter is reset to zero for each successive call to TSSolve().
3882 
3883    Level: intermediate
3884 
3885 .keywords: TS, get, number, nonlinear, iterations
3886 
3887 .seealso:  TSGetKSPIterations()
3888 @*/
3889 PetscErrorCode TSGetSNESIterations(TS ts,PetscInt *nits)
3890 {
3891   PetscFunctionBegin;
3892   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3893   PetscValidIntPointer(nits,2);
3894   *nits = ts->snes_its;
3895   PetscFunctionReturn(0);
3896 }
3897 
3898 #undef __FUNCT__
3899 #define __FUNCT__ "TSGetKSPIterations"
3900 /*@
3901    TSGetKSPIterations - Gets the total number of linear iterations
3902    used by the time integrator.
3903 
3904    Not Collective
3905 
3906    Input Parameter:
3907 .  ts - TS context
3908 
3909    Output Parameter:
3910 .  lits - number of linear iterations
3911 
3912    Notes:
3913    This counter is reset to zero for each successive call to TSSolve().
3914 
3915    Level: intermediate
3916 
3917 .keywords: TS, get, number, linear, iterations
3918 
3919 .seealso:  TSGetSNESIterations(), SNESGetKSPIterations()
3920 @*/
3921 PetscErrorCode TSGetKSPIterations(TS ts,PetscInt *lits)
3922 {
3923   PetscFunctionBegin;
3924   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3925   PetscValidIntPointer(lits,2);
3926   *lits = ts->ksp_its;
3927   PetscFunctionReturn(0);
3928 }
3929 
3930 #undef __FUNCT__
3931 #define __FUNCT__ "TSGetStepRejections"
3932 /*@
3933    TSGetStepRejections - Gets the total number of rejected steps.
3934 
3935    Not Collective
3936 
3937    Input Parameter:
3938 .  ts - TS context
3939 
3940    Output Parameter:
3941 .  rejects - number of steps rejected
3942 
3943    Notes:
3944    This counter is reset to zero for each successive call to TSSolve().
3945 
3946    Level: intermediate
3947 
3948 .keywords: TS, get, number
3949 
3950 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetSNESFailures(), TSSetMaxSNESFailures(), TSSetErrorIfStepFails()
3951 @*/
3952 PetscErrorCode TSGetStepRejections(TS ts,PetscInt *rejects)
3953 {
3954   PetscFunctionBegin;
3955   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3956   PetscValidIntPointer(rejects,2);
3957   *rejects = ts->reject;
3958   PetscFunctionReturn(0);
3959 }
3960 
3961 #undef __FUNCT__
3962 #define __FUNCT__ "TSGetSNESFailures"
3963 /*@
3964    TSGetSNESFailures - Gets the total number of failed SNES solves
3965 
3966    Not Collective
3967 
3968    Input Parameter:
3969 .  ts - TS context
3970 
3971    Output Parameter:
3972 .  fails - number of failed nonlinear solves
3973 
3974    Notes:
3975    This counter is reset to zero for each successive call to TSSolve().
3976 
3977    Level: intermediate
3978 
3979 .keywords: TS, get, number
3980 
3981 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSSetMaxSNESFailures()
3982 @*/
3983 PetscErrorCode TSGetSNESFailures(TS ts,PetscInt *fails)
3984 {
3985   PetscFunctionBegin;
3986   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3987   PetscValidIntPointer(fails,2);
3988   *fails = ts->num_snes_failures;
3989   PetscFunctionReturn(0);
3990 }
3991 
3992 #undef __FUNCT__
3993 #define __FUNCT__ "TSSetMaxStepRejections"
3994 /*@
3995    TSSetMaxStepRejections - Sets the maximum number of step rejections before a step fails
3996 
3997    Not Collective
3998 
3999    Input Parameter:
4000 +  ts - TS context
4001 -  rejects - maximum number of rejected steps, pass -1 for unlimited
4002 
4003    Notes:
4004    The counter is reset to zero for each step
4005 
4006    Options Database Key:
4007  .  -ts_max_reject - Maximum number of step rejections before a step fails
4008 
4009    Level: intermediate
4010 
4011 .keywords: TS, set, maximum, number
4012 
4013 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxSNESFailures(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4014 @*/
4015 PetscErrorCode TSSetMaxStepRejections(TS ts,PetscInt rejects)
4016 {
4017   PetscFunctionBegin;
4018   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4019   ts->max_reject = rejects;
4020   PetscFunctionReturn(0);
4021 }
4022 
4023 #undef __FUNCT__
4024 #define __FUNCT__ "TSSetMaxSNESFailures"
4025 /*@
4026    TSSetMaxSNESFailures - Sets the maximum number of failed SNES solves
4027 
4028    Not Collective
4029 
4030    Input Parameter:
4031 +  ts - TS context
4032 -  fails - maximum number of failed nonlinear solves, pass -1 for unlimited
4033 
4034    Notes:
4035    The counter is reset to zero for each successive call to TSSolve().
4036 
4037    Options Database Key:
4038  .  -ts_max_snes_failures - Maximum number of nonlinear solve failures
4039 
4040    Level: intermediate
4041 
4042 .keywords: TS, set, maximum, number
4043 
4044 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), SNESGetConvergedReason(), TSGetConvergedReason()
4045 @*/
4046 PetscErrorCode TSSetMaxSNESFailures(TS ts,PetscInt fails)
4047 {
4048   PetscFunctionBegin;
4049   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4050   ts->max_snes_failures = fails;
4051   PetscFunctionReturn(0);
4052 }
4053 
4054 #undef __FUNCT__
4055 #define __FUNCT__ "TSSetErrorIfStepFails"
4056 /*@
4057    TSSetErrorIfStepFails - Error if no step succeeds
4058 
4059    Not Collective
4060 
4061    Input Parameter:
4062 +  ts - TS context
4063 -  err - PETSC_TRUE to error if no step succeeds, PETSC_FALSE to return without failure
4064 
4065    Options Database Key:
4066  .  -ts_error_if_step_fails - Error if no step succeeds
4067 
4068    Level: intermediate
4069 
4070 .keywords: TS, set, error
4071 
4072 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4073 @*/
4074 PetscErrorCode TSSetErrorIfStepFails(TS ts,PetscBool err)
4075 {
4076   PetscFunctionBegin;
4077   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4078   ts->errorifstepfailed = err;
4079   PetscFunctionReturn(0);
4080 }
4081 
4082 #undef __FUNCT__
4083 #define __FUNCT__ "TSMonitorSolutionBinary"
4084 /*@C
4085    TSMonitorSolutionBinary - Monitors progress of the TS solvers by VecView() for the solution at each timestep. Normally the viewer is a binary file
4086 
4087    Collective on TS
4088 
4089    Input Parameters:
4090 +  ts - the TS context
4091 .  step - current time-step
4092 .  ptime - current time
4093 .  u - current state
4094 -  viewer - binary viewer
4095 
4096    Level: intermediate
4097 
4098 .keywords: TS,  vector, monitor, view
4099 
4100 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4101 @*/
4102 PetscErrorCode  TSMonitorSolutionBinary(TS ts,PetscInt step,PetscReal ptime,Vec u,void *viewer)
4103 {
4104   PetscErrorCode ierr;
4105   PetscViewer    v = (PetscViewer)viewer;
4106 
4107   PetscFunctionBegin;
4108   ierr = VecView(u,v);CHKERRQ(ierr);
4109   PetscFunctionReturn(0);
4110 }
4111 
4112 #undef __FUNCT__
4113 #define __FUNCT__ "TSMonitorSolutionVTK"
4114 /*@C
4115    TSMonitorSolutionVTK - Monitors progress of the TS solvers by VecView() for the solution at each timestep.
4116 
4117    Collective on TS
4118 
4119    Input Parameters:
4120 +  ts - the TS context
4121 .  step - current time-step
4122 .  ptime - current time
4123 .  u - current state
4124 -  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4125 
4126    Level: intermediate
4127 
4128    Notes:
4129    The VTK format does not allow writing multiple time steps in the same file, therefore a different file will be written for each time step.
4130    These are named according to the file name template.
4131 
4132    This function is normally passed as an argument to TSMonitorSet() along with TSMonitorSolutionVTKDestroy().
4133 
4134 .keywords: TS,  vector, monitor, view
4135 
4136 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4137 @*/
4138 PetscErrorCode TSMonitorSolutionVTK(TS ts,PetscInt step,PetscReal ptime,Vec u,void *filenametemplate)
4139 {
4140   PetscErrorCode ierr;
4141   char           filename[PETSC_MAX_PATH_LEN];
4142   PetscViewer    viewer;
4143 
4144   PetscFunctionBegin;
4145   ierr = PetscSNPrintf(filename,sizeof(filename),(const char*)filenametemplate,step);CHKERRQ(ierr);
4146   ierr = PetscViewerVTKOpen(PetscObjectComm((PetscObject)ts),filename,FILE_MODE_WRITE,&viewer);CHKERRQ(ierr);
4147   ierr = VecView(u,viewer);CHKERRQ(ierr);
4148   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
4149   PetscFunctionReturn(0);
4150 }
4151 
4152 #undef __FUNCT__
4153 #define __FUNCT__ "TSMonitorSolutionVTKDestroy"
4154 /*@C
4155    TSMonitorSolutionVTKDestroy - Destroy context for monitoring
4156 
4157    Collective on TS
4158 
4159    Input Parameters:
4160 .  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4161 
4162    Level: intermediate
4163 
4164    Note:
4165    This function is normally passed to TSMonitorSet() along with TSMonitorSolutionVTK().
4166 
4167 .keywords: TS,  vector, monitor, view
4168 
4169 .seealso: TSMonitorSet(), TSMonitorSolutionVTK()
4170 @*/
4171 PetscErrorCode TSMonitorSolutionVTKDestroy(void *filenametemplate)
4172 {
4173   PetscErrorCode ierr;
4174 
4175   PetscFunctionBegin;
4176   ierr = PetscFree(*(char**)filenametemplate);CHKERRQ(ierr);
4177   PetscFunctionReturn(0);
4178 }
4179 
4180 #undef __FUNCT__
4181 #define __FUNCT__ "TSGetAdapt"
4182 /*@
4183    TSGetAdapt - Get the adaptive controller context for the current method
4184 
4185    Collective on TS if controller has not been created yet
4186 
4187    Input Arguments:
4188 .  ts - time stepping context
4189 
4190    Output Arguments:
4191 .  adapt - adaptive controller
4192 
4193    Level: intermediate
4194 
4195 .seealso: TSAdapt, TSAdaptSetType(), TSAdaptChoose()
4196 @*/
4197 PetscErrorCode TSGetAdapt(TS ts,TSAdapt *adapt)
4198 {
4199   PetscErrorCode ierr;
4200 
4201   PetscFunctionBegin;
4202   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4203   PetscValidPointer(adapt,2);
4204   if (!ts->adapt) {
4205     ierr = TSAdaptCreate(PetscObjectComm((PetscObject)ts),&ts->adapt);CHKERRQ(ierr);
4206     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->adapt);CHKERRQ(ierr);
4207     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->adapt,(PetscObject)ts,1);CHKERRQ(ierr);
4208   }
4209   *adapt = ts->adapt;
4210   PetscFunctionReturn(0);
4211 }
4212 
4213 #undef __FUNCT__
4214 #define __FUNCT__ "TSSetTolerances"
4215 /*@
4216    TSSetTolerances - Set tolerances for local truncation error when using adaptive controller
4217 
4218    Logically Collective
4219 
4220    Input Arguments:
4221 +  ts - time integration context
4222 .  atol - scalar absolute tolerances, PETSC_DECIDE to leave current value
4223 .  vatol - vector of absolute tolerances or NULL, used in preference to atol if present
4224 .  rtol - scalar relative tolerances, PETSC_DECIDE to leave current value
4225 -  vrtol - vector of relative tolerances or NULL, used in preference to atol if present
4226 
4227    Level: beginner
4228 
4229 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSGetTolerances()
4230 @*/
4231 PetscErrorCode TSSetTolerances(TS ts,PetscReal atol,Vec vatol,PetscReal rtol,Vec vrtol)
4232 {
4233   PetscErrorCode ierr;
4234 
4235   PetscFunctionBegin;
4236   if (atol != PETSC_DECIDE && atol != PETSC_DEFAULT) ts->atol = atol;
4237   if (vatol) {
4238     ierr = PetscObjectReference((PetscObject)vatol);CHKERRQ(ierr);
4239     ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
4240 
4241     ts->vatol = vatol;
4242   }
4243   if (rtol != PETSC_DECIDE && rtol != PETSC_DEFAULT) ts->rtol = rtol;
4244   if (vrtol) {
4245     ierr = PetscObjectReference((PetscObject)vrtol);CHKERRQ(ierr);
4246     ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
4247 
4248     ts->vrtol = vrtol;
4249   }
4250   PetscFunctionReturn(0);
4251 }
4252 
4253 #undef __FUNCT__
4254 #define __FUNCT__ "TSGetTolerances"
4255 /*@
4256    TSGetTolerances - Get tolerances for local truncation error when using adaptive controller
4257 
4258    Logically Collective
4259 
4260    Input Arguments:
4261 .  ts - time integration context
4262 
4263    Output Arguments:
4264 +  atol - scalar absolute tolerances, NULL to ignore
4265 .  vatol - vector of absolute tolerances, NULL to ignore
4266 .  rtol - scalar relative tolerances, NULL to ignore
4267 -  vrtol - vector of relative tolerances, NULL to ignore
4268 
4269    Level: beginner
4270 
4271 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSSetTolerances()
4272 @*/
4273 PetscErrorCode TSGetTolerances(TS ts,PetscReal *atol,Vec *vatol,PetscReal *rtol,Vec *vrtol)
4274 {
4275   PetscFunctionBegin;
4276   if (atol)  *atol  = ts->atol;
4277   if (vatol) *vatol = ts->vatol;
4278   if (rtol)  *rtol  = ts->rtol;
4279   if (vrtol) *vrtol = ts->vrtol;
4280   PetscFunctionReturn(0);
4281 }
4282 
4283 #undef __FUNCT__
4284 #define __FUNCT__ "TSErrorNormWRMS"
4285 /*@
4286    TSErrorNormWRMS - compute a weighted norm of the difference between a vector and the current state
4287 
4288    Collective on TS
4289 
4290    Input Arguments:
4291 +  ts - time stepping context
4292 -  Y - state vector to be compared to ts->vec_sol
4293 
4294    Output Arguments:
4295 .  norm - weighted norm, a value of 1.0 is considered small
4296 
4297    Level: developer
4298 
4299 .seealso: TSSetTolerances()
4300 @*/
4301 PetscErrorCode TSErrorNormWRMS(TS ts,Vec Y,PetscReal *norm)
4302 {
4303   PetscErrorCode    ierr;
4304   PetscInt          i,n,N;
4305   const PetscScalar *u,*y;
4306   Vec               U;
4307   PetscReal         sum,gsum;
4308 
4309   PetscFunctionBegin;
4310   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4311   PetscValidHeaderSpecific(Y,VEC_CLASSID,2);
4312   PetscValidPointer(norm,3);
4313   U = ts->vec_sol;
4314   PetscCheckSameTypeAndComm(U,1,Y,2);
4315   if (U == Y) SETERRQ(PetscObjectComm((PetscObject)U),PETSC_ERR_ARG_IDN,"Y cannot be the TS solution vector");
4316 
4317   ierr = VecGetSize(U,&N);CHKERRQ(ierr);
4318   ierr = VecGetLocalSize(U,&n);CHKERRQ(ierr);
4319   ierr = VecGetArrayRead(U,&u);CHKERRQ(ierr);
4320   ierr = VecGetArrayRead(Y,&y);CHKERRQ(ierr);
4321   sum  = 0.;
4322   if (ts->vatol && ts->vrtol) {
4323     const PetscScalar *atol,*rtol;
4324     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4325     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4326     for (i=0; i<n; i++) {
4327       PetscReal tol = PetscRealPart(atol[i]) + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4328       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4329     }
4330     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4331     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4332   } else if (ts->vatol) {       /* vector atol, scalar rtol */
4333     const PetscScalar *atol;
4334     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4335     for (i=0; i<n; i++) {
4336       PetscReal tol = PetscRealPart(atol[i]) + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4337       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4338     }
4339     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4340   } else if (ts->vrtol) {       /* scalar atol, vector rtol */
4341     const PetscScalar *rtol;
4342     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4343     for (i=0; i<n; i++) {
4344       PetscReal tol = ts->atol + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4345       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4346     }
4347     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4348   } else {                      /* scalar atol, scalar rtol */
4349     for (i=0; i<n; i++) {
4350       PetscReal tol = ts->atol + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4351       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4352     }
4353   }
4354   ierr = VecRestoreArrayRead(U,&u);CHKERRQ(ierr);
4355   ierr = VecRestoreArrayRead(Y,&y);CHKERRQ(ierr);
4356 
4357   ierr  = MPI_Allreduce(&sum,&gsum,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4358   *norm = PetscSqrtReal(gsum / N);
4359   if (PetscIsInfOrNanScalar(*norm)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
4360   PetscFunctionReturn(0);
4361 }
4362 
4363 #undef __FUNCT__
4364 #define __FUNCT__ "TSSetCFLTimeLocal"
4365 /*@
4366    TSSetCFLTimeLocal - Set the local CFL constraint relative to forward Euler
4367 
4368    Logically Collective on TS
4369 
4370    Input Arguments:
4371 +  ts - time stepping context
4372 -  cfltime - maximum stable time step if using forward Euler (value can be different on each process)
4373 
4374    Note:
4375    After calling this function, the global CFL time can be obtained by calling TSGetCFLTime()
4376 
4377    Level: intermediate
4378 
4379 .seealso: TSGetCFLTime(), TSADAPTCFL
4380 @*/
4381 PetscErrorCode TSSetCFLTimeLocal(TS ts,PetscReal cfltime)
4382 {
4383   PetscFunctionBegin;
4384   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4385   ts->cfltime_local = cfltime;
4386   ts->cfltime       = -1.;
4387   PetscFunctionReturn(0);
4388 }
4389 
4390 #undef __FUNCT__
4391 #define __FUNCT__ "TSGetCFLTime"
4392 /*@
4393    TSGetCFLTime - Get the maximum stable time step according to CFL criteria applied to forward Euler
4394 
4395    Collective on TS
4396 
4397    Input Arguments:
4398 .  ts - time stepping context
4399 
4400    Output Arguments:
4401 .  cfltime - maximum stable time step for forward Euler
4402 
4403    Level: advanced
4404 
4405 .seealso: TSSetCFLTimeLocal()
4406 @*/
4407 PetscErrorCode TSGetCFLTime(TS ts,PetscReal *cfltime)
4408 {
4409   PetscErrorCode ierr;
4410 
4411   PetscFunctionBegin;
4412   if (ts->cfltime < 0) {
4413     ierr = MPI_Allreduce(&ts->cfltime_local,&ts->cfltime,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4414   }
4415   *cfltime = ts->cfltime;
4416   PetscFunctionReturn(0);
4417 }
4418 
4419 #undef __FUNCT__
4420 #define __FUNCT__ "TSVISetVariableBounds"
4421 /*@
4422    TSVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu
4423 
4424    Input Parameters:
4425 .  ts   - the TS context.
4426 .  xl   - lower bound.
4427 .  xu   - upper bound.
4428 
4429    Notes:
4430    If this routine is not called then the lower and upper bounds are set to
4431    SNES_VI_NINF and SNES_VI_INF respectively during SNESSetUp().
4432 
4433    Level: advanced
4434 
4435 @*/
4436 PetscErrorCode TSVISetVariableBounds(TS ts, Vec xl, Vec xu)
4437 {
4438   PetscErrorCode ierr;
4439   SNES           snes;
4440 
4441   PetscFunctionBegin;
4442   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
4443   ierr = SNESVISetVariableBounds(snes,xl,xu);CHKERRQ(ierr);
4444   PetscFunctionReturn(0);
4445 }
4446 
4447 #if defined(PETSC_HAVE_MATLAB_ENGINE)
4448 #include <mex.h>
4449 
4450 typedef struct {char *funcname; mxArray *ctx;} TSMatlabContext;
4451 
4452 #undef __FUNCT__
4453 #define __FUNCT__ "TSComputeFunction_Matlab"
4454 /*
4455    TSComputeFunction_Matlab - Calls the function that has been set with
4456                          TSSetFunctionMatlab().
4457 
4458    Collective on TS
4459 
4460    Input Parameters:
4461 +  snes - the TS context
4462 -  u - input vector
4463 
4464    Output Parameter:
4465 .  y - function vector, as set by TSSetFunction()
4466 
4467    Notes:
4468    TSComputeFunction() is typically used within nonlinear solvers
4469    implementations, so most users would not generally call this routine
4470    themselves.
4471 
4472    Level: developer
4473 
4474 .keywords: TS, nonlinear, compute, function
4475 
4476 .seealso: TSSetFunction(), TSGetFunction()
4477 */
4478 PetscErrorCode  TSComputeFunction_Matlab(TS snes,PetscReal time,Vec u,Vec udot,Vec y, void *ctx)
4479 {
4480   PetscErrorCode  ierr;
4481   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4482   int             nlhs  = 1,nrhs = 7;
4483   mxArray         *plhs[1],*prhs[7];
4484   long long int   lx = 0,lxdot = 0,ly = 0,ls = 0;
4485 
4486   PetscFunctionBegin;
4487   PetscValidHeaderSpecific(snes,TS_CLASSID,1);
4488   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4489   PetscValidHeaderSpecific(udot,VEC_CLASSID,4);
4490   PetscValidHeaderSpecific(y,VEC_CLASSID,5);
4491   PetscCheckSameComm(snes,1,u,3);
4492   PetscCheckSameComm(snes,1,y,5);
4493 
4494   ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr);
4495   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4496   ierr = PetscMemcpy(&lxdot,&udot,sizeof(udot));CHKERRQ(ierr);
4497   ierr = PetscMemcpy(&ly,&y,sizeof(u));CHKERRQ(ierr);
4498 
4499   prhs[0] =  mxCreateDoubleScalar((double)ls);
4500   prhs[1] =  mxCreateDoubleScalar(time);
4501   prhs[2] =  mxCreateDoubleScalar((double)lx);
4502   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4503   prhs[4] =  mxCreateDoubleScalar((double)ly);
4504   prhs[5] =  mxCreateString(sctx->funcname);
4505   prhs[6] =  sctx->ctx;
4506   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeFunctionInternal");CHKERRQ(ierr);
4507   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4508   mxDestroyArray(prhs[0]);
4509   mxDestroyArray(prhs[1]);
4510   mxDestroyArray(prhs[2]);
4511   mxDestroyArray(prhs[3]);
4512   mxDestroyArray(prhs[4]);
4513   mxDestroyArray(prhs[5]);
4514   mxDestroyArray(plhs[0]);
4515   PetscFunctionReturn(0);
4516 }
4517 
4518 
4519 #undef __FUNCT__
4520 #define __FUNCT__ "TSSetFunctionMatlab"
4521 /*
4522    TSSetFunctionMatlab - Sets the function evaluation routine and function
4523    vector for use by the TS routines in solving ODEs
4524    equations from MATLAB. Here the function is a string containing the name of a MATLAB function
4525 
4526    Logically Collective on TS
4527 
4528    Input Parameters:
4529 +  ts - the TS context
4530 -  func - function evaluation routine
4531 
4532    Calling sequence of func:
4533 $    func (TS ts,PetscReal time,Vec u,Vec udot,Vec f,void *ctx);
4534 
4535    Level: beginner
4536 
4537 .keywords: TS, nonlinear, set, function
4538 
4539 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4540 */
4541 PetscErrorCode  TSSetFunctionMatlab(TS ts,const char *func,mxArray *ctx)
4542 {
4543   PetscErrorCode  ierr;
4544   TSMatlabContext *sctx;
4545 
4546   PetscFunctionBegin;
4547   /* currently sctx is memory bleed */
4548   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4549   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4550   /*
4551      This should work, but it doesn't
4552   sctx->ctx = ctx;
4553   mexMakeArrayPersistent(sctx->ctx);
4554   */
4555   sctx->ctx = mxDuplicateArray(ctx);
4556 
4557   ierr = TSSetIFunction(ts,NULL,TSComputeFunction_Matlab,sctx);CHKERRQ(ierr);
4558   PetscFunctionReturn(0);
4559 }
4560 
4561 #undef __FUNCT__
4562 #define __FUNCT__ "TSComputeJacobian_Matlab"
4563 /*
4564    TSComputeJacobian_Matlab - Calls the function that has been set with
4565                          TSSetJacobianMatlab().
4566 
4567    Collective on TS
4568 
4569    Input Parameters:
4570 +  ts - the TS context
4571 .  u - input vector
4572 .  A, B - the matrices
4573 -  ctx - user context
4574 
4575    Output Parameter:
4576 .  flag - structure of the matrix
4577 
4578    Level: developer
4579 
4580 .keywords: TS, nonlinear, compute, function
4581 
4582 .seealso: TSSetFunction(), TSGetFunction()
4583 @*/
4584 PetscErrorCode  TSComputeJacobian_Matlab(TS ts,PetscReal time,Vec u,Vec udot,PetscReal shift,Mat *A,Mat *B,MatStructure *flag, void *ctx)
4585 {
4586   PetscErrorCode  ierr;
4587   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4588   int             nlhs  = 2,nrhs = 9;
4589   mxArray         *plhs[2],*prhs[9];
4590   long long int   lx = 0,lxdot = 0,lA = 0,ls = 0, lB = 0;
4591 
4592   PetscFunctionBegin;
4593   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4594   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4595 
4596   /* call Matlab function in ctx with arguments u and y */
4597 
4598   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4599   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4600   ierr = PetscMemcpy(&lxdot,&udot,sizeof(u));CHKERRQ(ierr);
4601   ierr = PetscMemcpy(&lA,A,sizeof(u));CHKERRQ(ierr);
4602   ierr = PetscMemcpy(&lB,B,sizeof(u));CHKERRQ(ierr);
4603 
4604   prhs[0] =  mxCreateDoubleScalar((double)ls);
4605   prhs[1] =  mxCreateDoubleScalar((double)time);
4606   prhs[2] =  mxCreateDoubleScalar((double)lx);
4607   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4608   prhs[4] =  mxCreateDoubleScalar((double)shift);
4609   prhs[5] =  mxCreateDoubleScalar((double)lA);
4610   prhs[6] =  mxCreateDoubleScalar((double)lB);
4611   prhs[7] =  mxCreateString(sctx->funcname);
4612   prhs[8] =  sctx->ctx;
4613   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeJacobianInternal");CHKERRQ(ierr);
4614   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4615   *flag   =  (MatStructure) mxGetScalar(plhs[1]);CHKERRQ(ierr);
4616   mxDestroyArray(prhs[0]);
4617   mxDestroyArray(prhs[1]);
4618   mxDestroyArray(prhs[2]);
4619   mxDestroyArray(prhs[3]);
4620   mxDestroyArray(prhs[4]);
4621   mxDestroyArray(prhs[5]);
4622   mxDestroyArray(prhs[6]);
4623   mxDestroyArray(prhs[7]);
4624   mxDestroyArray(plhs[0]);
4625   mxDestroyArray(plhs[1]);
4626   PetscFunctionReturn(0);
4627 }
4628 
4629 
4630 #undef __FUNCT__
4631 #define __FUNCT__ "TSSetJacobianMatlab"
4632 /*
4633    TSSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
4634    vector for use by the TS routines in solving ODEs from MATLAB. Here the function is a string containing the name of a MATLAB function
4635 
4636    Logically Collective on TS
4637 
4638    Input Parameters:
4639 +  ts - the TS context
4640 .  A,B - Jacobian matrices
4641 .  func - function evaluation routine
4642 -  ctx - user context
4643 
4644    Calling sequence of func:
4645 $    flag = func (TS ts,PetscReal time,Vec u,Vec udot,Mat A,Mat B,void *ctx);
4646 
4647 
4648    Level: developer
4649 
4650 .keywords: TS, nonlinear, set, function
4651 
4652 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4653 */
4654 PetscErrorCode  TSSetJacobianMatlab(TS ts,Mat A,Mat B,const char *func,mxArray *ctx)
4655 {
4656   PetscErrorCode  ierr;
4657   TSMatlabContext *sctx;
4658 
4659   PetscFunctionBegin;
4660   /* currently sctx is memory bleed */
4661   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4662   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4663   /*
4664      This should work, but it doesn't
4665   sctx->ctx = ctx;
4666   mexMakeArrayPersistent(sctx->ctx);
4667   */
4668   sctx->ctx = mxDuplicateArray(ctx);
4669 
4670   ierr = TSSetIJacobian(ts,A,B,TSComputeJacobian_Matlab,sctx);CHKERRQ(ierr);
4671   PetscFunctionReturn(0);
4672 }
4673 
4674 #undef __FUNCT__
4675 #define __FUNCT__ "TSMonitor_Matlab"
4676 /*
4677    TSMonitor_Matlab - Calls the function that has been set with TSMonitorSetMatlab().
4678 
4679    Collective on TS
4680 
4681 .seealso: TSSetFunction(), TSGetFunction()
4682 @*/
4683 PetscErrorCode  TSMonitor_Matlab(TS ts,PetscInt it, PetscReal time,Vec u, void *ctx)
4684 {
4685   PetscErrorCode  ierr;
4686   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4687   int             nlhs  = 1,nrhs = 6;
4688   mxArray         *plhs[1],*prhs[6];
4689   long long int   lx = 0,ls = 0;
4690 
4691   PetscFunctionBegin;
4692   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4693   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
4694 
4695   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4696   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4697 
4698   prhs[0] =  mxCreateDoubleScalar((double)ls);
4699   prhs[1] =  mxCreateDoubleScalar((double)it);
4700   prhs[2] =  mxCreateDoubleScalar((double)time);
4701   prhs[3] =  mxCreateDoubleScalar((double)lx);
4702   prhs[4] =  mxCreateString(sctx->funcname);
4703   prhs[5] =  sctx->ctx;
4704   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSMonitorInternal");CHKERRQ(ierr);
4705   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4706   mxDestroyArray(prhs[0]);
4707   mxDestroyArray(prhs[1]);
4708   mxDestroyArray(prhs[2]);
4709   mxDestroyArray(prhs[3]);
4710   mxDestroyArray(prhs[4]);
4711   mxDestroyArray(plhs[0]);
4712   PetscFunctionReturn(0);
4713 }
4714 
4715 
4716 #undef __FUNCT__
4717 #define __FUNCT__ "TSMonitorSetMatlab"
4718 /*
4719    TSMonitorSetMatlab - Sets the monitor function from Matlab
4720 
4721    Level: developer
4722 
4723 .keywords: TS, nonlinear, set, function
4724 
4725 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4726 */
4727 PetscErrorCode  TSMonitorSetMatlab(TS ts,const char *func,mxArray *ctx)
4728 {
4729   PetscErrorCode  ierr;
4730   TSMatlabContext *sctx;
4731 
4732   PetscFunctionBegin;
4733   /* currently sctx is memory bleed */
4734   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4735   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4736   /*
4737      This should work, but it doesn't
4738   sctx->ctx = ctx;
4739   mexMakeArrayPersistent(sctx->ctx);
4740   */
4741   sctx->ctx = mxDuplicateArray(ctx);
4742 
4743   ierr = TSMonitorSet(ts,TSMonitor_Matlab,sctx,NULL);CHKERRQ(ierr);
4744   PetscFunctionReturn(0);
4745 }
4746 #endif
4747 
4748 
4749 
4750 #undef __FUNCT__
4751 #define __FUNCT__ "TSMonitorLGSolution"
4752 /*@C
4753    TSMonitorLGSolution - Monitors progress of the TS solvers by plotting each component of the solution vector
4754        in a time based line graph
4755 
4756    Collective on TS
4757 
4758    Input Parameters:
4759 +  ts - the TS context
4760 .  step - current time-step
4761 .  ptime - current time
4762 -  lg - a line graph object
4763 
4764    Level: intermediate
4765 
4766     Notes: each process in a parallel run displays its component solutions in a separate window
4767 
4768 .keywords: TS,  vector, monitor, view
4769 
4770 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4771 @*/
4772 PetscErrorCode  TSMonitorLGSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4773 {
4774   PetscErrorCode    ierr;
4775   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4776   const PetscScalar *yy;
4777   PetscInt          dim;
4778 
4779   PetscFunctionBegin;
4780   if (!step) {
4781     PetscDrawAxis axis;
4782     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4783     ierr = PetscDrawAxisSetLabels(axis,"Solution as function of time","Time","Solution");CHKERRQ(ierr);
4784     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4785     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4786     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4787   }
4788   ierr = VecGetArrayRead(u,&yy);CHKERRQ(ierr);
4789 #if defined(PETSC_USE_COMPLEX)
4790   {
4791     PetscReal *yreal;
4792     PetscInt  i,n;
4793     ierr = VecGetLocalSize(u,&n);CHKERRQ(ierr);
4794     ierr = PetscMalloc(n*sizeof(PetscReal),&yreal);CHKERRQ(ierr);
4795     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4796     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4797     ierr = PetscFree(yreal);CHKERRQ(ierr);
4798   }
4799 #else
4800   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4801 #endif
4802   ierr = VecRestoreArrayRead(u,&yy);CHKERRQ(ierr);
4803   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4804     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4805   }
4806   PetscFunctionReturn(0);
4807 }
4808 
4809 #undef __FUNCT__
4810 #define __FUNCT__ "TSMonitorLGSetVariableNames"
4811 /*@C
4812    TSMonitorLGSetVariableNames - Sets the name of each component in the solution vector so that it may be displayed in the plot
4813 
4814    Collective on TS
4815 
4816    Input Parameters:
4817 +  ts - the TS context
4818 .  names - the names of the components, final string must be NULL
4819 
4820    Level: intermediate
4821 
4822 .keywords: TS,  vector, monitor, view
4823 
4824 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4825 @*/
4826 PetscErrorCode  TSMonitorLGSetVariableNames(TS ts,const char * const *names)
4827 {
4828   PetscErrorCode    ierr;
4829   PetscInt          i;
4830 
4831   PetscFunctionBegin;
4832   for (i=0; i<ts->numbermonitors; i++) {
4833     if (ts->monitor[i] == TSMonitorLGSolution) {
4834       TSMonitorLGCtx  ctx = ts->monitorcontext[i];
4835       Vec             u;
4836       ierr = PetscStrArrayallocpy(names,&ctx->names);CHKERRQ(ierr);
4837       ierr = TSGetSolution(ts,&u);CHKERRQ(ierr);
4838       if (u) {
4839         PetscInt dim;
4840         ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4841         ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4842         ierr = PetscDrawLGSetLegend(ctx->lg,names);CHKERRQ(ierr);
4843       }
4844     }
4845   }
4846   PetscFunctionReturn(0);
4847 }
4848 
4849 #undef __FUNCT__
4850 #define __FUNCT__ "TSMonitorLGError"
4851 /*@C
4852    TSMonitorLGError - Monitors progress of the TS solvers by plotting each component of the solution vector
4853        in a time based line graph
4854 
4855    Collective on TS
4856 
4857    Input Parameters:
4858 +  ts - the TS context
4859 .  step - current time-step
4860 .  ptime - current time
4861 -  lg - a line graph object
4862 
4863    Level: intermediate
4864 
4865    Notes:
4866    Only for sequential solves.
4867 
4868    The user must provide the solution using TSSetSolutionFunction() to use this monitor.
4869 
4870    Options Database Keys:
4871 .  -ts_monitor_lg_error - create a graphical monitor of error history
4872 
4873 .keywords: TS,  vector, monitor, view
4874 
4875 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSSetSolutionFunction()
4876 @*/
4877 PetscErrorCode  TSMonitorLGError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4878 {
4879   PetscErrorCode    ierr;
4880   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4881   const PetscScalar *yy;
4882   Vec               y;
4883   PetscInt          dim;
4884 
4885   PetscFunctionBegin;
4886   if (!step) {
4887     PetscDrawAxis axis;
4888     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4889     ierr = PetscDrawAxisSetLabels(axis,"Error in solution as function of time","Time","Solution");CHKERRQ(ierr);
4890     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4891     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4892     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4893   }
4894   ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
4895   ierr = TSComputeSolutionFunction(ts,ptime,y);CHKERRQ(ierr);
4896   ierr = VecAXPY(y,-1.0,u);CHKERRQ(ierr);
4897   ierr = VecGetArrayRead(y,&yy);CHKERRQ(ierr);
4898 #if defined(PETSC_USE_COMPLEX)
4899   {
4900     PetscReal *yreal;
4901     PetscInt  i,n;
4902     ierr = VecGetLocalSize(y,&n);CHKERRQ(ierr);
4903     ierr = PetscMalloc(n*sizeof(PetscReal),&yreal);CHKERRQ(ierr);
4904     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4905     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4906     ierr = PetscFree(yreal);CHKERRQ(ierr);
4907   }
4908 #else
4909   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4910 #endif
4911   ierr = VecRestoreArrayRead(y,&yy);CHKERRQ(ierr);
4912   ierr = VecDestroy(&y);CHKERRQ(ierr);
4913   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4914     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4915   }
4916   PetscFunctionReturn(0);
4917 }
4918 
4919 #undef __FUNCT__
4920 #define __FUNCT__ "TSMonitorLGSNESIterations"
4921 PetscErrorCode TSMonitorLGSNESIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4922 {
4923   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4924   PetscReal      x   = ptime,y;
4925   PetscErrorCode ierr;
4926   PetscInt       its;
4927 
4928   PetscFunctionBegin;
4929   if (!n) {
4930     PetscDrawAxis axis;
4931 
4932     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4933     ierr = PetscDrawAxisSetLabels(axis,"Nonlinear iterations as function of time","Time","SNES Iterations");CHKERRQ(ierr);
4934     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4935 
4936     ctx->snes_its = 0;
4937   }
4938   ierr = TSGetSNESIterations(ts,&its);CHKERRQ(ierr);
4939   y    = its - ctx->snes_its;
4940   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4941   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4942     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4943   }
4944   ctx->snes_its = its;
4945   PetscFunctionReturn(0);
4946 }
4947 
4948 #undef __FUNCT__
4949 #define __FUNCT__ "TSMonitorLGKSPIterations"
4950 PetscErrorCode TSMonitorLGKSPIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4951 {
4952   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4953   PetscReal      x   = ptime,y;
4954   PetscErrorCode ierr;
4955   PetscInt       its;
4956 
4957   PetscFunctionBegin;
4958   if (!n) {
4959     PetscDrawAxis axis;
4960 
4961     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4962     ierr = PetscDrawAxisSetLabels(axis,"Linear iterations as function of time","Time","KSP Iterations");CHKERRQ(ierr);
4963     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4964 
4965     ctx->ksp_its = 0;
4966   }
4967   ierr = TSGetKSPIterations(ts,&its);CHKERRQ(ierr);
4968   y    = its - ctx->ksp_its;
4969   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4970   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4971     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4972   }
4973   ctx->ksp_its = its;
4974   PetscFunctionReturn(0);
4975 }
4976 
4977 #undef __FUNCT__
4978 #define __FUNCT__ "TSComputeLinearStability"
4979 /*@
4980    TSComputeLinearStability - computes the linear stability function at a point
4981 
4982    Collective on TS and Vec
4983 
4984    Input Parameters:
4985 +  ts - the TS context
4986 -  xr,xi - real and imaginary part of input arguments
4987 
4988    Output Parameters:
4989 .  yr,yi - real and imaginary part of function value
4990 
4991    Level: developer
4992 
4993 .keywords: TS, compute
4994 
4995 .seealso: TSSetRHSFunction(), TSComputeIFunction()
4996 @*/
4997 PetscErrorCode TSComputeLinearStability(TS ts,PetscReal xr,PetscReal xi,PetscReal *yr,PetscReal *yi)
4998 {
4999   PetscErrorCode ierr;
5000 
5001   PetscFunctionBegin;
5002   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
5003   if (!ts->ops->linearstability) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"Linearized stability function not provided for this method");
5004   ierr = (*ts->ops->linearstability)(ts,xr,xi,yr,yi);CHKERRQ(ierr);
5005   PetscFunctionReturn(0);
5006 }
5007