xref: /petsc/src/mat/impls/aij/mpi/fdmpiaij.c (revision e3225e9dc71240658ff8694e906a72dc65d8b579)
1 
2 #include <../src/mat/impls/aij/mpi/mpiaij.h>
3 #include <../src/mat/impls/baij/mpi/mpibaij.h>
4 
5 #undef __FUNCT__
6 #define __FUNCT__ "MatFDColoringApply_BAIJ"
7 PetscErrorCode  MatFDColoringApply_BAIJ(Mat J,MatFDColoring coloring,Vec x1,MatStructure *flag,void *sctx)
8 {
9   PetscErrorCode (*f)(void*,Vec,Vec,void*) = (PetscErrorCode (*)(void*,Vec,Vec,void*))coloring->f;
10   PetscErrorCode ierr;
11   PetscInt       k,cstart,cend,l,row,col,nz,spidx,i,j;
12   PetscScalar    dx=0.0,*y,*xx,*w3_array,*dy_i,*dy=coloring->dy;
13   PetscScalar    *vscale_array;
14   PetscReal      epsilon=coloring->error_rel,umin=coloring->umin,unorm;
15   Vec            w1=coloring->w1,w2=coloring->w2,w3,vscale=coloring->vscale;
16   void           *fctx=coloring->fctx;
17   PetscBool      flg=PETSC_FALSE;
18   PetscInt       ctype=coloring->ctype,nxloc,nrows_k;
19   PetscScalar    *valaddr;
20   MatEntry       *Jentry=coloring->matentry;
21   const PetscInt ncolors=coloring->ncolors,*ncolumns=coloring->ncolumns,*nrows=coloring->nrows;
22   PetscInt       bs=J->rmap->bs;
23 
24   PetscFunctionBegin;
25   ierr = MatSetUnfactored(J);CHKERRQ(ierr);
26   ierr = PetscOptionsGetBool(NULL,"-mat_fd_coloring_dont_rezero",&flg,NULL);CHKERRQ(ierr);
27   if (flg) {
28     ierr = PetscInfo(coloring,"Not calling MatZeroEntries()\n");CHKERRQ(ierr);
29   } else {
30     PetscBool assembled;
31     ierr = MatAssembled(J,&assembled);CHKERRQ(ierr);
32     if (assembled) {
33       ierr = MatZeroEntries(J);CHKERRQ(ierr);
34     }
35   }
36 
37   /* create vscale for storing dx */
38   if (!vscale) {
39     if (ctype == IS_COLORING_GLOBAL && coloring->htype[0] == 'd') {
40       /* contain the "diagonal" on processor scalings followed by the off processor* - garray must be non-bloced! */
41       Mat_MPIBAIJ    *baij=(Mat_MPIBAIJ*)J->data;
42       PetscInt       *garray;
43       ierr = PetscMalloc(baij->B->cmap->n*sizeof(PetscInt),&garray);CHKERRQ(ierr);
44       for (i=0; i<baij->B->cmap->n/bs; i++) {
45         for (j=0; j<bs; j++) {
46           garray[i*bs+j] = bs*baij->garray[i]+j;
47         }
48       }
49       ierr = VecCreateGhost(PetscObjectComm((PetscObject)J),J->cmap->n,PETSC_DETERMINE,baij->B->cmap->n,garray,&vscale);CHKERRQ(ierr);
50       ierr = PetscFree(garray);CHKERRQ(ierr);
51     } else if (ctype == IS_COLORING_GHOSTED) {
52       ierr = VecDuplicate(x1,&vscale);CHKERRQ(ierr);
53     }
54     coloring->vscale = vscale;
55   }
56 
57   /* (1) Set w1 = F(x1) */
58   if (!coloring->fset) {
59     ierr = PetscLogEventBegin(MAT_FDColoringFunction,0,0,0,0);CHKERRQ(ierr);
60     ierr = (*f)(sctx,x1,w1,fctx);CHKERRQ(ierr);
61     ierr = PetscLogEventEnd(MAT_FDColoringFunction,0,0,0,0);CHKERRQ(ierr);
62   } else {
63     coloring->fset = PETSC_FALSE;
64   }
65 
66   /* (2) Compute vscale = 1./dx - the local scale factors, including ghost points */
67   ierr = VecGetLocalSize(x1,&nxloc);CHKERRQ(ierr);
68   if (coloring->htype[0] == 'w') {
69     /* vscale = dx is a constant scalar */
70     ierr = VecNorm(x1,NORM_2,&unorm);CHKERRQ(ierr);
71     dx = 1.0/(PetscSqrtReal(1.0 + unorm)*epsilon);
72   } else {
73     ierr = VecGetArray(x1,&xx);CHKERRQ(ierr);
74     ierr = VecGetArray(vscale,&vscale_array);CHKERRQ(ierr);
75     for (col=0; col<nxloc; col++) {
76       dx = xx[col];
77       if (PetscAbsScalar(dx) < umin) {
78         if (PetscRealPart(dx) >= 0.0)      dx = umin;
79         else if (PetscRealPart(dx) < 0.0 ) dx = -umin;
80       }
81       dx               *= epsilon;
82       vscale_array[col] = 1.0/dx;
83     }
84     ierr = VecRestoreArray(x1,&xx);CHKERRQ(ierr);
85     ierr = VecRestoreArray(vscale,&vscale_array);CHKERRQ(ierr);
86   }
87   if (ctype == IS_COLORING_GLOBAL && coloring->htype[0] != 'w') {
88     ierr = VecGhostUpdateBegin(vscale,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
89     ierr = VecGhostUpdateEnd(vscale,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
90   }
91 
92   /* (3) Loop over each color */
93   if (!coloring->w3) {
94     ierr = VecDuplicate(x1,&coloring->w3);CHKERRQ(ierr);
95     ierr = PetscLogObjectParent((PetscObject)coloring,(PetscObject)coloring->w3);CHKERRQ(ierr);
96   }
97   w3 = coloring->w3;
98 
99   ierr = VecGetOwnershipRange(x1,&cstart,&cend);CHKERRQ(ierr); /* used by ghosted vscale */
100   if (vscale) {
101     ierr = VecGetArray(vscale,&vscale_array);CHKERRQ(ierr);
102   }
103   nz   = 0;
104   for (k=0; k<ncolors; k++) {
105     coloring->currentcolor = k;
106 
107     /*
108       (3-1) Loop over each column associated with color
109       adding the perturbation to the vector w3 = x1 + dx.
110     */
111     ierr = VecCopy(x1,w3);CHKERRQ(ierr);
112     dy_i = dy;
113     for (i=0; i<bs; i++) {     /* Loop over a block of columns */
114       ierr = VecGetArray(w3,&w3_array);CHKERRQ(ierr);
115       if (ctype == IS_COLORING_GLOBAL) w3_array -= cstart; /* shift pointer so global index can be used */
116       if (coloring->htype[0] == 'w') {
117         for (l=0; l<ncolumns[k]; l++) {
118           col            = i + bs*coloring->columns[k][l];  /* local column (in global index!) of the matrix we are probing for */
119           w3_array[col] += 1.0/dx;
120 
121           if (i) {
122             w3_array[col-1] -= 1.0/dx; /* resume original w3[col-1] */
123           }
124 
125         }
126       } else { /* htype == 'ds' */
127         vscale_array -= cstart; /* shift pointer so global index can be used */
128         for (l=0; l<ncolumns[k]; l++) {
129           col = i + bs*coloring->columns[k][l]; /* local column (in global index!) of the matrix we are probing for */
130           w3_array[col] += 1.0/vscale_array[col];
131 
132           if (i) {
133             w3_array[col-1] -=  1.0/vscale_array[col-1]; /* resume original w3[col-1] */
134           }
135 
136         }
137         vscale_array += cstart;
138       }
139       if (ctype == IS_COLORING_GLOBAL) w3_array += cstart;
140       ierr = VecRestoreArray(w3,&w3_array);CHKERRQ(ierr);
141 
142       /*
143        (3-2) Evaluate function at w3 = x1 + dx (here dx is a vector of perturbations)
144                            w2 = F(x1 + dx) - F(x1)
145        */
146       ierr = PetscLogEventBegin(MAT_FDColoringFunction,0,0,0,0);CHKERRQ(ierr);
147       ierr = VecPlaceArray(w2,dy_i);CHKERRQ(ierr); /* place w2 to the array dy_i */
148       ierr = (*f)(sctx,w3,w2,fctx);CHKERRQ(ierr);
149       ierr = PetscLogEventEnd(MAT_FDColoringFunction,0,0,0,0);CHKERRQ(ierr);
150       ierr = VecAXPY(w2,-1.0,w1);CHKERRQ(ierr);
151       ierr = VecResetArray(w2);CHKERRQ(ierr);
152       dy_i += nxloc; /* points to dy+i*nxloc */
153     }
154 
155     /*
156      (3-3) Loop over rows of vector, putting results into Jacobian matrix
157     */
158     nrows_k = nrows[k];
159     ierr = VecGetArray(w2,&y);CHKERRQ(ierr);
160     if (coloring->htype[0] == 'w') {
161       for (l=0; l<nrows_k; l++) {
162         row     = bs*Jentry[nz].row;   /* local row index */
163         valaddr = Jentry[nz].valaddr;
164         nz++;
165         spidx = 0;
166         dy_i  = dy;
167         for (i=0; i<bs; i++) {   /* column of the block */
168           for (j=0; j<bs; j++) { /* row of the block */
169             valaddr[spidx++] = dy_i[row+j]*dx;
170           }
171           dy_i += nxloc; /* points to dy+i*nxloc */
172         }
173       }
174     } else { /* htype == 'ds' */
175       for (l=0; l<nrows_k; l++) {
176         row     = bs*Jentry[nz].row;   /* local row index */
177         col     = bs*Jentry[nz].col;   /* local column index */
178         valaddr = Jentry[nz].valaddr;
179         nz++;
180         spidx = 0;
181         dy_i  = dy;
182         for (i=0; i<bs; i++) {   /* column of the block */
183           for (j=0; j<bs; j++) { /* row of the block */
184             valaddr[spidx++] = dy_i[row+j]*vscale_array[col+i];
185           }
186           dy_i += nxloc; /* points to dy+i*nxloc */
187         }
188       }
189     }
190     ierr = VecRestoreArray(w2,&y);CHKERRQ(ierr);
191   }
192   ierr = MatAssemblyBegin(J,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
193   ierr = MatAssemblyEnd(J,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
194   if (vscale) {
195     ierr = VecRestoreArray(vscale,&vscale_array);CHKERRQ(ierr);
196   }
197 
198   coloring->currentcolor = -1;
199   PetscFunctionReturn(0);
200 }
201 
202 #undef __FUNCT__
203 #define __FUNCT__ "MatFDColoringApply_AIJ"
204 PetscErrorCode  MatFDColoringApply_AIJ(Mat J,MatFDColoring coloring,Vec x1,MatStructure *flag,void *sctx)
205 {
206   PetscErrorCode (*f)(void*,Vec,Vec,void*) = (PetscErrorCode (*)(void*,Vec,Vec,void*))coloring->f;
207   PetscErrorCode ierr;
208   PetscInt       k,cstart,cend,l,row,col,nz;
209   PetscScalar    dx=0.0,*y,*xx,*w3_array;
210   PetscScalar    *vscale_array;
211   PetscReal      epsilon=coloring->error_rel,umin=coloring->umin,unorm;
212   Vec            w1=coloring->w1,w2=coloring->w2,w3,vscale=coloring->vscale;
213   void           *fctx=coloring->fctx;
214   PetscBool      flg=PETSC_FALSE;
215   PetscInt       ctype=coloring->ctype,nxloc,nrows_k;
216   MatEntry       *Jentry=coloring->matentry;
217   const PetscInt ncolors=coloring->ncolors,*ncolumns=coloring->ncolumns,*nrows=coloring->nrows;
218 
219   PetscFunctionBegin;
220   ierr = MatSetUnfactored(J);CHKERRQ(ierr);
221   ierr = PetscOptionsGetBool(NULL,"-mat_fd_coloring_dont_rezero",&flg,NULL);CHKERRQ(ierr);
222   if (flg) {
223     ierr = PetscInfo(coloring,"Not calling MatZeroEntries()\n");CHKERRQ(ierr);
224   } else {
225     PetscBool assembled;
226     ierr = MatAssembled(J,&assembled);CHKERRQ(ierr);
227     if (assembled) {
228       ierr = MatZeroEntries(J);CHKERRQ(ierr);
229     }
230   }
231 
232   /* create vscale for storing dx */
233   if (!vscale) {
234     if (ctype == IS_COLORING_GLOBAL && coloring->htype[0] == 'd') {
235       Mat_MPIAIJ     *aij=(Mat_MPIAIJ*)J->data;
236       ierr = VecCreateGhost(PetscObjectComm((PetscObject)J),J->cmap->n,PETSC_DETERMINE,aij->B->cmap->n,aij->garray,&vscale);CHKERRQ(ierr);
237     } else if (ctype == IS_COLORING_GHOSTED) {
238       ierr = VecDuplicate(x1,&vscale);CHKERRQ(ierr);
239     }
240     coloring->vscale = vscale;
241   }
242 
243   /* (1) Set w1 = F(x1) */
244   if (!coloring->fset) {
245     ierr = PetscLogEventBegin(MAT_FDColoringFunction,0,0,0,0);CHKERRQ(ierr);
246     ierr = (*f)(sctx,x1,w1,fctx);CHKERRQ(ierr);
247     ierr = PetscLogEventEnd(MAT_FDColoringFunction,0,0,0,0);CHKERRQ(ierr);
248   } else {
249     coloring->fset = PETSC_FALSE;
250   }
251 
252   /* (2) Compute vscale = 1./dx - the local scale factors, including ghost points */
253   if (coloring->htype[0] == 'w') {
254     /* vscale = dx is a constant scalar */
255     ierr = VecNorm(x1,NORM_2,&unorm);CHKERRQ(ierr);
256     dx = 1.0/(PetscSqrtReal(1.0 + unorm)*epsilon);
257   } else {
258     ierr = VecGetLocalSize(x1,&nxloc);CHKERRQ(ierr);
259     ierr = VecGetArray(x1,&xx);CHKERRQ(ierr);
260     ierr = VecGetArray(vscale,&vscale_array);CHKERRQ(ierr);
261     for (col=0; col<nxloc; col++) {
262       dx = xx[col];
263       if (PetscAbsScalar(dx) < umin) {
264         if (PetscRealPart(dx) >= 0.0)      dx = umin;
265         else if (PetscRealPart(dx) < 0.0 ) dx = -umin;
266       }
267       dx               *= epsilon;
268       vscale_array[col] = 1.0/dx;
269     }
270     ierr = VecRestoreArray(x1,&xx);CHKERRQ(ierr);
271     ierr = VecRestoreArray(vscale,&vscale_array);CHKERRQ(ierr);
272   }
273   if (ctype == IS_COLORING_GLOBAL && coloring->htype[0] != 'w') {
274     ierr = VecGhostUpdateBegin(vscale,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
275     ierr = VecGhostUpdateEnd(vscale,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
276   }
277 
278   /* (3) Loop over each color */
279   if (!coloring->w3) {
280     ierr = VecDuplicate(x1,&coloring->w3);CHKERRQ(ierr);
281     ierr = PetscLogObjectParent((PetscObject)coloring,(PetscObject)coloring->w3);CHKERRQ(ierr);
282   }
283   w3 = coloring->w3;
284 
285   ierr = VecGetOwnershipRange(x1,&cstart,&cend);CHKERRQ(ierr); /* used by ghosted vscale */
286   if (vscale) {
287     ierr = VecGetArray(vscale,&vscale_array);CHKERRQ(ierr);
288   }
289   nz   = 0;
290   for (k=0; k<ncolors; k++) {
291     coloring->currentcolor = k;
292 
293     /*
294       (3-1) Loop over each column associated with color
295       adding the perturbation to the vector w3 = x1 + dx.
296     */
297     ierr = VecCopy(x1,w3);CHKERRQ(ierr);
298     ierr = VecGetArray(w3,&w3_array);CHKERRQ(ierr);
299     if (ctype == IS_COLORING_GLOBAL) w3_array -= cstart; /* shift pointer so global index can be used */
300     if (coloring->htype[0] == 'w') {
301       for (l=0; l<ncolumns[k]; l++) {
302         col = coloring->columns[k][l]; /* local column (in global index!) of the matrix we are probing for */
303         w3_array[col] += 1.0/dx;
304       }
305     } else { /* htype == 'ds' */
306       vscale_array -= cstart; /* shift pointer so global index can be used */
307       for (l=0; l<ncolumns[k]; l++) {
308         col = coloring->columns[k][l]; /* local column (in global index!) of the matrix we are probing for */
309         w3_array[col] += 1.0/vscale_array[col];
310       }
311       vscale_array += cstart;
312     }
313     if (ctype == IS_COLORING_GLOBAL) w3_array += cstart;
314     ierr = VecRestoreArray(w3,&w3_array);CHKERRQ(ierr);
315 
316     /*
317       (3-2) Evaluate function at w3 = x1 + dx (here dx is a vector of perturbations)
318                            w2 = F(x1 + dx) - F(x1)
319     */
320     ierr = PetscLogEventBegin(MAT_FDColoringFunction,0,0,0,0);CHKERRQ(ierr);
321     ierr = (*f)(sctx,w3,w2,fctx);CHKERRQ(ierr);
322     ierr = PetscLogEventEnd(MAT_FDColoringFunction,0,0,0,0);CHKERRQ(ierr);
323     ierr = VecAXPY(w2,-1.0,w1);CHKERRQ(ierr);
324 
325     /*
326      (3-3) Loop over rows of vector, putting results into Jacobian matrix
327     */
328     nrows_k = nrows[k];
329     ierr = VecGetArray(w2,&y);CHKERRQ(ierr);
330     if (coloring->htype[0] == 'w') {
331       for (l=0; l<nrows_k; l++) {
332         row                     = Jentry[nz].row;   /* local row index */
333         *(Jentry[nz++].valaddr) = y[row]*dx;
334       }
335     } else { /* htype == 'ds' */
336       for (l=0; l<nrows_k; l++) {
337         row                   = Jentry[nz].row;   /* local row index */
338         *(Jentry[nz].valaddr) = y[row]*vscale_array[Jentry[nz].col];
339         nz++;
340       }
341     }
342     ierr = VecRestoreArray(w2,&y);CHKERRQ(ierr);
343   }
344   ierr = MatAssemblyBegin(J,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
345   ierr = MatAssemblyEnd(J,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
346   if (vscale) {
347     ierr = VecRestoreArray(vscale,&vscale_array);CHKERRQ(ierr);
348   }
349 
350   coloring->currentcolor = -1;
351   PetscFunctionReturn(0);
352 }
353 
354 #undef __FUNCT__
355 #define __FUNCT__ "MatFDColoringCreate_MPIXAIJ"
356 PetscErrorCode MatFDColoringCreate_MPIXAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
357 {
358   PetscErrorCode         ierr;
359   PetscMPIInt            size,*ncolsonproc,*disp,nn;
360   PetscInt               i,n,nrows,nrows_i,j,k,m,ncols,col,*rowhit,cstart,cend,colb;
361   const PetscInt         *is,*A_ci,*A_cj,*B_ci,*B_cj,*row=NULL,*ltog=NULL;
362   PetscInt               nis=iscoloring->n,nctot,*cols;
363   IS                     *isa;
364   ISLocalToGlobalMapping map=mat->cmap->mapping;
365   PetscInt               ctype=c->ctype,*spidxA,*spidxB,nz,bs,bs2,spidx;
366   Mat                    A,B;
367   PetscScalar            *A_val,*B_val,**valaddrhit;
368   MatEntry               *Jentry;
369   PetscBool              isBAIJ;
370 #if defined(PETSC_USE_CTABLE)
371   PetscTable             colmap=NULL;
372 #else
373   PetscInt               *colmap=NULL;     /* local col number of off-diag col */
374 #endif
375 
376   PetscFunctionBegin;
377   if (ctype == IS_COLORING_GHOSTED) {
378     if (!map) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_INCOMP,"When using ghosted differencing matrix must have local to global mapping provided with MatSetLocalToGlobalMapping");
379     ierr = ISLocalToGlobalMappingGetIndices(map,&ltog);CHKERRQ(ierr);
380   }
381 
382   ierr = MatGetBlockSize(mat,&bs);CHKERRQ(ierr);
383   ierr = PetscObjectTypeCompare((PetscObject)mat,MATMPIBAIJ,&isBAIJ);CHKERRQ(ierr);
384   if (isBAIJ) {
385     Mat_MPIBAIJ *aij=(Mat_MPIBAIJ*)mat->data;
386     Mat_SeqBAIJ *spA,*spB;
387     A = aij->A;  spA = (Mat_SeqBAIJ*)A->data; A_val = spA->a;
388     B = aij->B;  spB = (Mat_SeqBAIJ*)B->data; B_val = spB->a;
389     nz = spA->nz + spB->nz; /* total nonzero entries of mat */
390     if (!aij->colmap) {
391       ierr = MatCreateColmap_MPIBAIJ_Private(mat);CHKERRQ(ierr);
392       colmap = aij->colmap;
393     }
394     ierr = MatGetColumnIJ_SeqBAIJ_Color(A,0,PETSC_FALSE,PETSC_FALSE,&ncols,&A_ci,&A_cj,&spidxA,NULL);CHKERRQ(ierr);
395     ierr = MatGetColumnIJ_SeqBAIJ_Color(B,0,PETSC_FALSE,PETSC_FALSE,&ncols,&B_ci,&B_cj,&spidxB,NULL);CHKERRQ(ierr);
396   } else {
397     Mat_MPIAIJ *aij=(Mat_MPIAIJ*)mat->data;
398     Mat_SeqAIJ *spA,*spB;
399     A = aij->A;  spA = (Mat_SeqAIJ*)A->data; A_val = spA->a;
400     B = aij->B;  spB = (Mat_SeqAIJ*)B->data; B_val = spB->a;
401     nz = spA->nz + spB->nz; /* total nonzero entries of mat */
402     if (!aij->colmap) {
403       /* Allow access to data structures of local part of matrix
404        - creates aij->colmap which maps global column number to local number in part B */
405       ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
406       colmap = aij->colmap;
407     }
408     ierr = MatGetColumnIJ_SeqAIJ_Color(A,0,PETSC_FALSE,PETSC_FALSE,&ncols,&A_ci,&A_cj,&spidxA,NULL);CHKERRQ(ierr);
409     ierr = MatGetColumnIJ_SeqAIJ_Color(B,0,PETSC_FALSE,PETSC_FALSE,&ncols,&B_ci,&B_cj,&spidxB,NULL);CHKERRQ(ierr);
410 
411     bs = 1; /* only bs=1 is supported for non MPIBAIJ matrix */
412   }
413 
414   m         = mat->rmap->n/bs;
415   cstart    = mat->cmap->rstart/bs;
416   cend      = mat->cmap->rend/bs;
417   c->M      = mat->rmap->N/bs;         /* set the global rows and columns and local rows */
418   c->N      = mat->cmap->N/bs;
419   c->m      = m;
420   c->rstart = mat->rmap->rstart/bs;
421 
422   c->ncolors = nis;
423   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->ncolumns);CHKERRQ(ierr);
424   ierr       = PetscMalloc(nis*sizeof(PetscInt*),&c->columns);CHKERRQ(ierr);
425   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->nrows);CHKERRQ(ierr);
426   ierr       = PetscLogObjectMemory((PetscObject)c,3*nis*sizeof(PetscInt));CHKERRQ(ierr);
427 
428   ierr       = PetscMalloc(nz*sizeof(MatEntry),&Jentry);CHKERRQ(ierr);
429   ierr       = PetscLogObjectMemory((PetscObject)c,nz*sizeof(MatEntry));CHKERRQ(ierr);
430   c->matentry = Jentry;
431 
432   ierr = PetscMalloc2(m+1,PetscInt,&rowhit,m+1,PetscScalar*,&valaddrhit);CHKERRQ(ierr);
433   nz = 0;
434   ierr = ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);CHKERRQ(ierr);
435   for (i=0; i<nis; i++) { /* for each local color */
436     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
437     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
438 
439     c->ncolumns[i] = n; /* local number of columns of this color on this process */
440     if (n) {
441       ierr = PetscMalloc(n*sizeof(PetscInt),&c->columns[i]);CHKERRQ(ierr);
442       ierr = PetscLogObjectMemory((PetscObject)c,n*sizeof(PetscInt));CHKERRQ(ierr);
443       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(PetscInt));CHKERRQ(ierr);
444     } else {
445       c->columns[i] = 0;
446     }
447 
448     if (ctype == IS_COLORING_GLOBAL) {
449       /* Determine nctot, the total (parallel) number of columns of this color */
450       ierr = MPI_Comm_size(PetscObjectComm((PetscObject)mat),&size);CHKERRQ(ierr);
451       ierr = PetscMalloc2(size,PetscMPIInt,&ncolsonproc,size,PetscMPIInt,&disp);CHKERRQ(ierr);
452 
453       /* ncolsonproc[j]: local ncolumns on proc[j] of this color */
454       ierr  = PetscMPIIntCast(n,&nn);CHKERRQ(ierr);
455       ierr  = MPI_Allgather(&nn,1,MPI_INT,ncolsonproc,1,MPI_INT,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
456       nctot = 0; for (j=0; j<size; j++) nctot += ncolsonproc[j];
457       if (!nctot) {
458         ierr = PetscInfo(mat,"Coloring of matrix has some unneeded colors with no corresponding rows\n");CHKERRQ(ierr);
459       }
460 
461       disp[0] = 0;
462       for (j=1; j<size; j++) {
463         disp[j] = disp[j-1] + ncolsonproc[j-1];
464       }
465 
466       /* Get cols, the complete list of columns for this color on each process */
467       ierr = PetscMalloc((nctot+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
468       ierr = MPI_Allgatherv((void*)is,n,MPIU_INT,cols,ncolsonproc,disp,MPIU_INT,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
469       ierr = PetscFree2(ncolsonproc,disp);CHKERRQ(ierr);
470     } else if (ctype == IS_COLORING_GHOSTED) {
471       /* Determine local number of columns of this color on this process, including ghost points */
472       nctot = n;
473       ierr  = PetscMalloc((nctot+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
474       ierr  = PetscMemcpy(cols,is,n*sizeof(PetscInt));CHKERRQ(ierr);
475     } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not provided for this MatFDColoring type");
476 
477     /* Mark all rows affect by these columns */
478     ierr    = PetscMemzero(rowhit,m*sizeof(PetscInt));CHKERRQ(ierr);
479     bs2     = bs*bs;
480     nrows_i = 0;
481     for (j=0; j<nctot; j++) { /* loop over columns*/
482       if (ctype == IS_COLORING_GHOSTED) {
483         col = ltog[cols[j]];
484       } else {
485         col = cols[j];
486       }
487       if (col >= cstart && col < cend) { /* column is in A, diagonal block of mat */
488         row      = A_cj + A_ci[col-cstart];
489         nrows    = A_ci[col-cstart+1] - A_ci[col-cstart];
490         nrows_i += nrows;
491         /* loop over columns of A marking them in rowhit */
492         for (k=0; k<nrows; k++) {
493           /* set valaddrhit for part A */
494           spidx            = bs2*spidxA[A_ci[col-cstart] + k];
495           valaddrhit[*row] = &A_val[spidx];
496           rowhit[*row++]   = col - cstart + 1; /* local column index */
497         }
498       } else { /* column is in B, off-diagonal block of mat */
499 #if defined(PETSC_USE_CTABLE)
500         ierr = PetscTableFind(colmap,col+1,&colb);CHKERRQ(ierr);
501         colb--;
502 #else
503         colb = colmap[col] - 1; /* local column index */
504 #endif
505         if (colb == -1) {
506           nrows = 0;
507         } else {
508           colb  = colb/bs;
509           row   = B_cj + B_ci[colb];
510           nrows = B_ci[colb+1] - B_ci[colb];
511         }
512         nrows_i += nrows;
513         /* loop over columns of B marking them in rowhit */
514         for (k=0; k<nrows; k++) {
515           /* set valaddrhit for part B */
516           spidx            = bs2*spidxB[B_ci[colb] + k];
517           valaddrhit[*row] = &B_val[spidx];
518           rowhit[*row++]   = colb + 1 + cend - cstart; /* local column index */
519         }
520       }
521     }
522     c->nrows[i] = nrows_i;
523 
524     for (j=0; j<m; j++) {
525       if (rowhit[j]) {
526         Jentry[nz].row     = j;              /* local row index */
527         Jentry[nz].col     = rowhit[j] - 1;  /* local column index */
528         Jentry[nz].valaddr = valaddrhit[j];  /* address of mat value for this entry */
529         nz++;
530       }
531     }
532     ierr = PetscFree(cols);CHKERRQ(ierr);
533   }
534   ierr = ISColoringRestoreIS(iscoloring,&isa);CHKERRQ(ierr);
535 
536   ierr = PetscFree2(rowhit,valaddrhit);CHKERRQ(ierr);
537   if (isBAIJ) {
538     ierr = MatRestoreColumnIJ_SeqBAIJ_Color(A,0,PETSC_FALSE,PETSC_FALSE,&ncols,&A_ci,&A_cj,&spidxA,NULL);CHKERRQ(ierr);
539     ierr = MatRestoreColumnIJ_SeqBAIJ_Color(B,0,PETSC_FALSE,PETSC_FALSE,&ncols,&B_ci,&B_cj,&spidxB,NULL);CHKERRQ(ierr);
540     ierr = PetscMalloc(bs*mat->rmap->n*sizeof(PetscScalar),&c->dy);CHKERRQ(ierr);
541   } else {
542     ierr = MatRestoreColumnIJ_SeqAIJ_Color(A,0,PETSC_FALSE,PETSC_FALSE,&ncols,&A_ci,&A_cj,&spidxA,NULL);CHKERRQ(ierr);
543     ierr = MatRestoreColumnIJ_SeqAIJ_Color(B,0,PETSC_FALSE,PETSC_FALSE,&ncols,&B_ci,&B_cj,&spidxB,NULL);CHKERRQ(ierr);
544   }
545 
546   if (ctype == IS_COLORING_GHOSTED) {
547     ierr = ISLocalToGlobalMappingRestoreIndices(map,&ltog);CHKERRQ(ierr);
548   }
549   PetscFunctionReturn(0);
550 }
551