xref: /petsc/src/ksp/pc/impls/fieldsplit/fieldsplit.c (revision 2dcb1b2a648e6798dfef446393ab7396b79ac556)
1dba47a55SKris Buschelman #define PETSCKSP_DLL
2dba47a55SKris Buschelman 
30971522cSBarry Smith /*
40971522cSBarry Smith 
50971522cSBarry Smith */
60971522cSBarry Smith #include "src/ksp/pc/pcimpl.h"     /*I "petscpc.h" I*/
70971522cSBarry Smith 
80971522cSBarry Smith typedef struct _PC_FieldSplitLink *PC_FieldSplitLink;
90971522cSBarry Smith struct _PC_FieldSplitLink {
1069a612a9SBarry Smith   KSP               ksp;
110971522cSBarry Smith   Vec               x,y;
120971522cSBarry Smith   PetscInt          nfields;
130971522cSBarry Smith   PetscInt          *fields;
141b9fc7fcSBarry Smith   VecScatter        sctx;
150971522cSBarry Smith   PC_FieldSplitLink next;
160971522cSBarry Smith };
170971522cSBarry Smith 
180971522cSBarry Smith typedef struct {
1979416396SBarry Smith   PCCompositeType   type;              /* additive or multiplicative */
2097bbdb24SBarry Smith   PetscTruth        defaultsplit;
210971522cSBarry Smith   PetscInt          bs;
220971522cSBarry Smith   PetscInt          nsplits;
2379416396SBarry Smith   Vec               *x,*y,w1,w2;
2497bbdb24SBarry Smith   Mat               *pmat;
2597bbdb24SBarry Smith   IS                *is;
2697bbdb24SBarry Smith   PC_FieldSplitLink head;
270971522cSBarry Smith } PC_FieldSplit;
280971522cSBarry Smith 
290971522cSBarry Smith #undef __FUNCT__
300971522cSBarry Smith #define __FUNCT__ "PCView_FieldSplit"
310971522cSBarry Smith static PetscErrorCode PCView_FieldSplit(PC pc,PetscViewer viewer)
320971522cSBarry Smith {
330971522cSBarry Smith   PC_FieldSplit     *jac = (PC_FieldSplit*)pc->data;
340971522cSBarry Smith   PetscErrorCode    ierr;
350971522cSBarry Smith   PetscTruth        iascii;
360971522cSBarry Smith   PetscInt          i,j;
375a9f2f41SSatish Balay   PC_FieldSplitLink ilink = jac->head;
380971522cSBarry Smith 
390971522cSBarry Smith   PetscFunctionBegin;
400971522cSBarry Smith   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);CHKERRQ(ierr);
410971522cSBarry Smith   if (iascii) {
429dcbbd2bSBarry Smith     ierr = PetscViewerASCIIPrintf(viewer,"  FieldSplit with %s composition: total splits = %D",PCCompositeTypes[jac->type],jac->nsplits);CHKERRQ(ierr);
4369a612a9SBarry Smith     ierr = PetscViewerASCIIPrintf(viewer,"  Solver info for each split is in the following KSP objects:\n");CHKERRQ(ierr);
440971522cSBarry Smith     ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
450971522cSBarry Smith     for (i=0; i<jac->nsplits; i++) {
460971522cSBarry Smith       ierr = PetscViewerASCIIPrintf(viewer,"Split number %D Fields ",i);CHKERRQ(ierr);
4779416396SBarry Smith       ierr = PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);CHKERRQ(ierr);
485a9f2f41SSatish Balay       for (j=0; j<ilink->nfields; j++) {
4979416396SBarry Smith         if (j > 0) {
5079416396SBarry Smith           ierr = PetscViewerASCIIPrintf(viewer,",");CHKERRQ(ierr);
5179416396SBarry Smith         }
525a9f2f41SSatish Balay         ierr = PetscViewerASCIIPrintf(viewer," %D",ilink->fields[j]);CHKERRQ(ierr);
530971522cSBarry Smith       }
540971522cSBarry Smith       ierr = PetscViewerASCIIPrintf(viewer,"\n");CHKERRQ(ierr);
5579416396SBarry Smith       ierr = PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);CHKERRQ(ierr);
565a9f2f41SSatish Balay       ierr = KSPView(ilink->ksp,viewer);CHKERRQ(ierr);
575a9f2f41SSatish Balay       ilink = ilink->next;
580971522cSBarry Smith     }
590971522cSBarry Smith     ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
600971522cSBarry Smith   } else {
610971522cSBarry Smith     SETERRQ1(PETSC_ERR_SUP,"Viewer type %s not supported for PCFieldSplit",((PetscObject)viewer)->type_name);
620971522cSBarry Smith   }
630971522cSBarry Smith   PetscFunctionReturn(0);
640971522cSBarry Smith }
650971522cSBarry Smith 
660971522cSBarry Smith #undef __FUNCT__
6769a612a9SBarry Smith #define __FUNCT__ "PCFieldSplitSetDefaults"
6869a612a9SBarry Smith static PetscErrorCode PCFieldSplitSetDefaults(PC pc)
690971522cSBarry Smith {
700971522cSBarry Smith   PC_FieldSplit     *jac  = (PC_FieldSplit*)pc->data;
710971522cSBarry Smith   PetscErrorCode    ierr;
725a9f2f41SSatish Balay   PC_FieldSplitLink ilink = jac->head;
7369a612a9SBarry Smith   PetscInt          i;
7479416396SBarry Smith   PetscTruth        flg = PETSC_FALSE,*fields;
750971522cSBarry Smith 
760971522cSBarry Smith   PetscFunctionBegin;
7779416396SBarry Smith   ierr = PetscOptionsGetLogical(pc->prefix,"-pc_fieldsplit_default",&flg,PETSC_NULL);CHKERRQ(ierr);
785a9f2f41SSatish Balay   if (!ilink || flg) {
7963ba0a88SBarry Smith     ierr = PetscLogInfo((pc,"PCFieldSplitSetDefaults: Using default splitting of fields\n"));CHKERRQ(ierr);
80521d7252SBarry Smith     if (jac->bs <= 0) {
81521d7252SBarry Smith       ierr   = MatGetBlockSize(pc->pmat,&jac->bs);CHKERRQ(ierr);
82521d7252SBarry Smith     }
8379416396SBarry Smith     ierr = PetscMalloc(jac->bs*sizeof(PetscTruth),&fields);CHKERRQ(ierr);
8479416396SBarry Smith     ierr = PetscMemzero(fields,jac->bs*sizeof(PetscTruth));CHKERRQ(ierr);
855a9f2f41SSatish Balay     while (ilink) {
865a9f2f41SSatish Balay       for (i=0; i<ilink->nfields; i++) {
875a9f2f41SSatish Balay         fields[ilink->fields[i]] = PETSC_TRUE;
88521d7252SBarry Smith       }
895a9f2f41SSatish Balay       ilink = ilink->next;
9079416396SBarry Smith     }
9197bbdb24SBarry Smith     jac->defaultsplit = PETSC_TRUE;
9279416396SBarry Smith     for (i=0; i<jac->bs; i++) {
9379416396SBarry Smith       if (!fields[i]) {
9479416396SBarry Smith 	ierr = PCFieldSplitSetFields(pc,1,&i);CHKERRQ(ierr);
9579416396SBarry Smith       } else {
9679416396SBarry Smith         jac->defaultsplit = PETSC_FALSE;
9779416396SBarry Smith       }
9879416396SBarry Smith     }
99521d7252SBarry Smith   }
10069a612a9SBarry Smith   PetscFunctionReturn(0);
10169a612a9SBarry Smith }
10269a612a9SBarry Smith 
10369a612a9SBarry Smith 
10469a612a9SBarry Smith #undef __FUNCT__
10569a612a9SBarry Smith #define __FUNCT__ "PCSetUp_FieldSplit"
10669a612a9SBarry Smith static PetscErrorCode PCSetUp_FieldSplit(PC pc)
10769a612a9SBarry Smith {
10869a612a9SBarry Smith   PC_FieldSplit     *jac = (PC_FieldSplit*)pc->data;
10969a612a9SBarry Smith   PetscErrorCode    ierr;
1105a9f2f41SSatish Balay   PC_FieldSplitLink ilink;
11169a612a9SBarry Smith   PetscInt          i,nsplit;
11269a612a9SBarry Smith   MatStructure      flag = pc->flag;
11369a612a9SBarry Smith 
11469a612a9SBarry Smith   PetscFunctionBegin;
11569a612a9SBarry Smith   ierr   = PCFieldSplitSetDefaults(pc);CHKERRQ(ierr);
11697bbdb24SBarry Smith   nsplit = jac->nsplits;
1175a9f2f41SSatish Balay   ilink   = jac->head;
11897bbdb24SBarry Smith 
11997bbdb24SBarry Smith   /* get the matrices for each split */
12097bbdb24SBarry Smith   if (!jac->is) {
1211b9fc7fcSBarry Smith     PetscInt rstart,rend,nslots,bs;
12297bbdb24SBarry Smith 
1231b9fc7fcSBarry Smith     ierr   = MatGetBlockSize(pc->pmat,&bs);CHKERRQ(ierr);
12497bbdb24SBarry Smith     ierr   = MatGetOwnershipRange(pc->pmat,&rstart,&rend);CHKERRQ(ierr);
1251b9fc7fcSBarry Smith     nslots = (rend - rstart)/bs;
1261b9fc7fcSBarry Smith     ierr   = PetscMalloc(nsplit*sizeof(IS),&jac->is);CHKERRQ(ierr);
1271b9fc7fcSBarry Smith     for (i=0; i<nsplit; i++) {
1281b9fc7fcSBarry Smith       if (jac->defaultsplit) {
1291b9fc7fcSBarry Smith 	ierr = ISCreateStride(pc->comm,nslots,rstart+i,nsplit,&jac->is[i]);CHKERRQ(ierr);
13097bbdb24SBarry Smith       } else {
1315a9f2f41SSatish Balay         PetscInt   *ii,j,k,nfields = ilink->nfields,*fields = ilink->fields;
1321b9fc7fcSBarry Smith         PetscTruth sorted;
1335a9f2f41SSatish Balay         ierr = PetscMalloc(ilink->nfields*nslots*sizeof(PetscInt),&ii);CHKERRQ(ierr);
1341b9fc7fcSBarry Smith         for (j=0; j<nslots; j++) {
1351b9fc7fcSBarry Smith           for (k=0; k<nfields; k++) {
1361b9fc7fcSBarry Smith             ii[nfields*j + k] = rstart + bs*j + fields[k];
13797bbdb24SBarry Smith           }
13897bbdb24SBarry Smith         }
1391b9fc7fcSBarry Smith 	ierr = ISCreateGeneral(pc->comm,nslots*nfields,ii,&jac->is[i]);CHKERRQ(ierr);
1401b9fc7fcSBarry Smith         ierr = ISSorted(jac->is[i],&sorted);CHKERRQ(ierr);
1411b9fc7fcSBarry Smith         if (!sorted) SETERRQ(PETSC_ERR_USER,"Fields must be sorted when creating split");
1421b9fc7fcSBarry Smith         ierr = PetscFree(ii);CHKERRQ(ierr);
1435a9f2f41SSatish Balay         ilink = ilink->next;
1441b9fc7fcSBarry Smith       }
1451b9fc7fcSBarry Smith     }
1461b9fc7fcSBarry Smith   }
1471b9fc7fcSBarry Smith 
14897bbdb24SBarry Smith   if (!jac->pmat) {
14997bbdb24SBarry Smith     ierr = MatGetSubMatrices(pc->pmat,nsplit,jac->is,jac->is,MAT_INITIAL_MATRIX,&jac->pmat);CHKERRQ(ierr);
15097bbdb24SBarry Smith   } else {
15197bbdb24SBarry Smith     ierr = MatGetSubMatrices(pc->pmat,nsplit,jac->is,jac->is,MAT_REUSE_MATRIX,&jac->pmat);CHKERRQ(ierr);
15297bbdb24SBarry Smith   }
15397bbdb24SBarry Smith 
15497bbdb24SBarry Smith   /* set up the individual PCs */
15597bbdb24SBarry Smith   i    = 0;
1565a9f2f41SSatish Balay   ilink = jac->head;
1575a9f2f41SSatish Balay   while (ilink) {
1585a9f2f41SSatish Balay     ierr = KSPSetOperators(ilink->ksp,jac->pmat[i],jac->pmat[i],flag);CHKERRQ(ierr);
1595a9f2f41SSatish Balay     ierr = KSPSetFromOptions(ilink->ksp);CHKERRQ(ierr);
1605a9f2f41SSatish Balay     ierr = KSPSetUp(ilink->ksp);CHKERRQ(ierr);
16197bbdb24SBarry Smith     i++;
1625a9f2f41SSatish Balay     ilink = ilink->next;
1630971522cSBarry Smith   }
16497bbdb24SBarry Smith 
16597bbdb24SBarry Smith   /* create work vectors for each split */
1661b9fc7fcSBarry Smith   if (!jac->x) {
16779416396SBarry Smith     Vec xtmp;
16897bbdb24SBarry Smith     ierr = PetscMalloc2(nsplit,Vec,&jac->x,nsplit,Vec,&jac->y);CHKERRQ(ierr);
1695a9f2f41SSatish Balay     ilink = jac->head;
17097bbdb24SBarry Smith     for (i=0; i<nsplit; i++) {
17197bbdb24SBarry Smith       Mat A;
1725a9f2f41SSatish Balay       ierr      = KSPGetOperators(ilink->ksp,PETSC_NULL,&A,PETSC_NULL);CHKERRQ(ierr);
1735a9f2f41SSatish Balay       ierr      = MatGetVecs(A,&ilink->x,&ilink->y);CHKERRQ(ierr);
1745a9f2f41SSatish Balay       jac->x[i] = ilink->x;
1755a9f2f41SSatish Balay       jac->y[i] = ilink->y;
1765a9f2f41SSatish Balay       ilink      = ilink->next;
17797bbdb24SBarry Smith     }
17879416396SBarry Smith     /* compute scatter contexts needed by multiplicative versions and non-default splits */
1791b9fc7fcSBarry Smith 
1805a9f2f41SSatish Balay     ilink = jac->head;
1811b9fc7fcSBarry Smith     ierr = MatGetVecs(pc->pmat,&xtmp,PETSC_NULL);CHKERRQ(ierr);
1821b9fc7fcSBarry Smith     for (i=0; i<nsplit; i++) {
1835a9f2f41SSatish Balay       ierr = VecScatterCreate(xtmp,jac->is[i],jac->x[i],PETSC_NULL,&ilink->sctx);CHKERRQ(ierr);
1845a9f2f41SSatish Balay       ilink = ilink->next;
1851b9fc7fcSBarry Smith     }
1861b9fc7fcSBarry Smith     ierr = VecDestroy(xtmp);CHKERRQ(ierr);
1871b9fc7fcSBarry Smith   }
1880971522cSBarry Smith   PetscFunctionReturn(0);
1890971522cSBarry Smith }
1900971522cSBarry Smith 
1915a9f2f41SSatish Balay #define FieldSplitSplitSolveAdd(ilink,xx,yy) \
1925a9f2f41SSatish Balay     (VecScatterBegin(xx,ilink->x,INSERT_VALUES,SCATTER_FORWARD,ilink->sctx) || \
1935a9f2f41SSatish Balay      VecScatterEnd(xx,ilink->x,INSERT_VALUES,SCATTER_FORWARD,ilink->sctx) || \
1945a9f2f41SSatish Balay      KSPSolve(ilink->ksp,ilink->x,ilink->y) || \
1955a9f2f41SSatish Balay      VecScatterBegin(ilink->y,yy,ADD_VALUES,SCATTER_REVERSE,ilink->sctx) || \
1965a9f2f41SSatish Balay      VecScatterEnd(ilink->y,yy,ADD_VALUES,SCATTER_REVERSE,ilink->sctx))
19779416396SBarry Smith 
1980971522cSBarry Smith #undef __FUNCT__
1990971522cSBarry Smith #define __FUNCT__ "PCApply_FieldSplit"
2000971522cSBarry Smith static PetscErrorCode PCApply_FieldSplit(PC pc,Vec x,Vec y)
2010971522cSBarry Smith {
2020971522cSBarry Smith   PC_FieldSplit     *jac = (PC_FieldSplit*)pc->data;
2030971522cSBarry Smith   PetscErrorCode    ierr;
2045a9f2f41SSatish Balay   PC_FieldSplitLink ilink = jac->head;
20579416396SBarry Smith   PetscScalar       zero = 0.0,mone = -1.0;
2060971522cSBarry Smith 
2070971522cSBarry Smith   PetscFunctionBegin;
20879416396SBarry Smith   if (jac->type == PC_COMPOSITE_ADDITIVE) {
2091b9fc7fcSBarry Smith     if (jac->defaultsplit) {
2100971522cSBarry Smith       ierr = VecStrideGatherAll(x,jac->x,INSERT_VALUES);CHKERRQ(ierr);
2115a9f2f41SSatish Balay       while (ilink) {
2125a9f2f41SSatish Balay 	ierr = KSPSolve(ilink->ksp,ilink->x,ilink->y);CHKERRQ(ierr);
2135a9f2f41SSatish Balay 	ilink = ilink->next;
2140971522cSBarry Smith       }
2150971522cSBarry Smith       ierr = VecStrideScatterAll(jac->y,y,INSERT_VALUES);CHKERRQ(ierr);
2161b9fc7fcSBarry Smith     } else {
2171b9fc7fcSBarry Smith       PetscInt    i = 0;
2181b9fc7fcSBarry Smith 
219*2dcb1b2aSMatthew Knepley       ierr = VecSet(y,zero);CHKERRQ(ierr);
2205a9f2f41SSatish Balay       while (ilink) {
2215a9f2f41SSatish Balay         ierr = FieldSplitSplitSolveAdd(ilink,x,y);CHKERRQ(ierr);
2225a9f2f41SSatish Balay 	ilink = ilink->next;
2231b9fc7fcSBarry Smith 	i++;
2241b9fc7fcSBarry Smith       }
2251b9fc7fcSBarry Smith     }
22679416396SBarry Smith   } else {
22779416396SBarry Smith     if (!jac->w1) {
22879416396SBarry Smith       ierr = VecDuplicate(x,&jac->w1);CHKERRQ(ierr);
22979416396SBarry Smith       ierr = VecDuplicate(x,&jac->w2);CHKERRQ(ierr);
23079416396SBarry Smith     }
231*2dcb1b2aSMatthew Knepley     ierr = VecSet(y,zero);CHKERRQ(ierr);
2325a9f2f41SSatish Balay     ierr = FieldSplitSplitSolveAdd(ilink,x,y);CHKERRQ(ierr);
2335a9f2f41SSatish Balay     while (ilink->next) {
2345a9f2f41SSatish Balay       ilink = ilink->next;
23579416396SBarry Smith       ierr = MatMult(pc->pmat,y,jac->w1);CHKERRQ(ierr);
236*2dcb1b2aSMatthew Knepley       ierr = VecWAXPY(jac->w2,mone,jac->w1,x);CHKERRQ(ierr);
2375a9f2f41SSatish Balay       ierr = FieldSplitSplitSolveAdd(ilink,jac->w2,y);CHKERRQ(ierr);
23879416396SBarry Smith     }
23979416396SBarry Smith   }
2400971522cSBarry Smith   PetscFunctionReturn(0);
2410971522cSBarry Smith }
2420971522cSBarry Smith 
2430971522cSBarry Smith #undef __FUNCT__
2440971522cSBarry Smith #define __FUNCT__ "PCDestroy_FieldSplit"
2450971522cSBarry Smith static PetscErrorCode PCDestroy_FieldSplit(PC pc)
2460971522cSBarry Smith {
2470971522cSBarry Smith   PC_FieldSplit     *jac = (PC_FieldSplit*)pc->data;
2480971522cSBarry Smith   PetscErrorCode    ierr;
2495a9f2f41SSatish Balay   PC_FieldSplitLink ilink = jac->head,next;
2500971522cSBarry Smith 
2510971522cSBarry Smith   PetscFunctionBegin;
2525a9f2f41SSatish Balay   while (ilink) {
2535a9f2f41SSatish Balay     ierr = KSPDestroy(ilink->ksp);CHKERRQ(ierr);
2545a9f2f41SSatish Balay     if (ilink->x) {ierr = VecDestroy(ilink->x);CHKERRQ(ierr);}
2555a9f2f41SSatish Balay     if (ilink->y) {ierr = VecDestroy(ilink->y);CHKERRQ(ierr);}
2565a9f2f41SSatish Balay     if (ilink->sctx) {ierr = VecScatterDestroy(ilink->sctx);CHKERRQ(ierr);}
2575a9f2f41SSatish Balay     next = ilink->next;
2585a9f2f41SSatish Balay     ierr = PetscFree2(ilink,ilink->fields);CHKERRQ(ierr);
2595a9f2f41SSatish Balay     ilink = next;
2600971522cSBarry Smith   }
2610971522cSBarry Smith   if (jac->x) {ierr = PetscFree2(jac->x,jac->y);CHKERRQ(ierr);}
26297bbdb24SBarry Smith   if (jac->pmat) {ierr = MatDestroyMatrices(jac->nsplits,&jac->pmat);CHKERRQ(ierr);}
26397bbdb24SBarry Smith   if (jac->is) {
26497bbdb24SBarry Smith     PetscInt i;
26597bbdb24SBarry Smith     for (i=0; i<jac->nsplits; i++) {ierr = ISDestroy(jac->is[i]);CHKERRQ(ierr);}
26697bbdb24SBarry Smith     ierr = PetscFree(jac->is);CHKERRQ(ierr);
26797bbdb24SBarry Smith   }
26879416396SBarry Smith   if (jac->w1) {ierr = VecDestroy(jac->w1);CHKERRQ(ierr);}
26979416396SBarry Smith   if (jac->w2) {ierr = VecDestroy(jac->w2);CHKERRQ(ierr);}
2700971522cSBarry Smith   ierr = PetscFree(jac);CHKERRQ(ierr);
2710971522cSBarry Smith   PetscFunctionReturn(0);
2720971522cSBarry Smith }
2730971522cSBarry Smith 
2740971522cSBarry Smith #undef __FUNCT__
2750971522cSBarry Smith #define __FUNCT__ "PCSetFromOptions_FieldSplit"
2760971522cSBarry Smith static PetscErrorCode PCSetFromOptions_FieldSplit(PC pc)
2771b9fc7fcSBarry Smith /*   This does not call KSPSetFromOptions() on the subksp's, see PCSetFromOptionsBJacobi/ASM() */
2780971522cSBarry Smith {
2791b9fc7fcSBarry Smith   PetscErrorCode ierr;
2809dcbbd2bSBarry Smith   PetscInt       i = 0,nfields,fields[12];
2811b9fc7fcSBarry Smith   PetscTruth     flg;
2821b9fc7fcSBarry Smith   char           optionname[128];
2839dcbbd2bSBarry Smith   PC_FieldSplit  *jac = (PC_FieldSplit*)pc->data;
2841b9fc7fcSBarry Smith 
2850971522cSBarry Smith   PetscFunctionBegin;
2861b9fc7fcSBarry Smith   ierr = PetscOptionsHead("FieldSplit options");CHKERRQ(ierr);
2879dcbbd2bSBarry Smith   ierr = PetscOptionsEnum("-pc_fieldsplit_type","Type of composition","PCFieldSplitSetType",PCCompositeTypes,(PetscEnum)jac->type,(PetscEnum*)&jac->type,&flg);CHKERRQ(ierr);
2881b9fc7fcSBarry Smith   while (PETSC_TRUE) {
28913f74950SBarry Smith     sprintf(optionname,"-pc_fieldsplit_%d_fields",(int)i++);
2901b9fc7fcSBarry Smith     nfields = 12;
2911b9fc7fcSBarry Smith     ierr    = PetscOptionsIntArray(optionname,"Fields in this split","PCFieldSplitSetFields",fields,&nfields,&flg);CHKERRQ(ierr);
2921b9fc7fcSBarry Smith     if (!flg) break;
2931b9fc7fcSBarry Smith     if (!nfields) SETERRQ(PETSC_ERR_USER,"Cannot list zero fields");
2941b9fc7fcSBarry Smith     ierr = PCFieldSplitSetFields(pc,nfields,fields);CHKERRQ(ierr);
2951b9fc7fcSBarry Smith   }
2961b9fc7fcSBarry Smith   ierr = PetscOptionsTail();CHKERRQ(ierr);
2970971522cSBarry Smith   PetscFunctionReturn(0);
2980971522cSBarry Smith }
2990971522cSBarry Smith 
3000971522cSBarry Smith /*------------------------------------------------------------------------------------*/
3010971522cSBarry Smith 
3020971522cSBarry Smith EXTERN_C_BEGIN
3030971522cSBarry Smith #undef __FUNCT__
3040971522cSBarry Smith #define __FUNCT__ "PCFieldSplitSetFields_FieldSplit"
305dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCFieldSplitSetFields_FieldSplit(PC pc,PetscInt n,PetscInt *fields)
3060971522cSBarry Smith {
30797bbdb24SBarry Smith   PC_FieldSplit     *jac = (PC_FieldSplit*)pc->data;
3080971522cSBarry Smith   PetscErrorCode    ierr;
3095a9f2f41SSatish Balay   PC_FieldSplitLink ilink,next = jac->head;
31069a612a9SBarry Smith   char              prefix[128];
3110971522cSBarry Smith 
3120971522cSBarry Smith   PetscFunctionBegin;
3130971522cSBarry Smith   if (n <= 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Negative number of fields requested");
3145a9f2f41SSatish Balay   ierr = PetscMalloc2(1,struct _PC_FieldSplitLink,&ilink,n,PetscInt,&ilink->fields);CHKERRQ(ierr);
3155a9f2f41SSatish Balay   ierr = PetscMemcpy(ilink->fields,fields,n*sizeof(PetscInt));CHKERRQ(ierr);
3165a9f2f41SSatish Balay   ilink->nfields = n;
3175a9f2f41SSatish Balay   ilink->next    = PETSC_NULL;
3185a9f2f41SSatish Balay   ierr          = KSPCreate(pc->comm,&ilink->ksp);CHKERRQ(ierr);
3195a9f2f41SSatish Balay   ierr          = KSPSetType(ilink->ksp,KSPPREONLY);CHKERRQ(ierr);
32069a612a9SBarry Smith 
32169a612a9SBarry Smith   if (pc->prefix) {
32213f74950SBarry Smith     sprintf(prefix,"%sfieldsplit_%d_",pc->prefix,(int)jac->nsplits);
32369a612a9SBarry Smith   } else {
32413f74950SBarry Smith     sprintf(prefix,"fieldsplit_%d_",(int)jac->nsplits);
32569a612a9SBarry Smith   }
3265a9f2f41SSatish Balay   ierr = KSPSetOptionsPrefix(ilink->ksp,prefix);CHKERRQ(ierr);
3270971522cSBarry Smith 
3280971522cSBarry Smith   if (!next) {
3295a9f2f41SSatish Balay     jac->head = ilink;
3300971522cSBarry Smith   } else {
3310971522cSBarry Smith     while (next->next) {
3320971522cSBarry Smith       next = next->next;
3330971522cSBarry Smith     }
3345a9f2f41SSatish Balay     next->next = ilink;
3350971522cSBarry Smith   }
3360971522cSBarry Smith   jac->nsplits++;
3370971522cSBarry Smith   PetscFunctionReturn(0);
3380971522cSBarry Smith }
3390971522cSBarry Smith EXTERN_C_END
3400971522cSBarry Smith 
3410971522cSBarry Smith 
3420971522cSBarry Smith EXTERN_C_BEGIN
3430971522cSBarry Smith #undef __FUNCT__
34469a612a9SBarry Smith #define __FUNCT__ "PCFieldSplitGetSubKSP_FieldSplit"
345dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCFieldSplitGetSubKSP_FieldSplit(PC pc,PetscInt *n,KSP **subksp)
3460971522cSBarry Smith {
3470971522cSBarry Smith   PC_FieldSplit     *jac = (PC_FieldSplit*)pc->data;
3480971522cSBarry Smith   PetscErrorCode    ierr;
3490971522cSBarry Smith   PetscInt          cnt = 0;
3505a9f2f41SSatish Balay   PC_FieldSplitLink ilink = jac->head;
3510971522cSBarry Smith 
3520971522cSBarry Smith   PetscFunctionBegin;
35369a612a9SBarry Smith   ierr = PetscMalloc(jac->nsplits*sizeof(KSP*),subksp);CHKERRQ(ierr);
3545a9f2f41SSatish Balay   while (ilink) {
3555a9f2f41SSatish Balay     (*subksp)[cnt++] = ilink->ksp;
3565a9f2f41SSatish Balay     ilink = ilink->next;
3570971522cSBarry Smith   }
3580971522cSBarry Smith   if (cnt != jac->nsplits) SETERRQ2(PETSC_ERR_PLIB,"Corrupt PCFIELDSPLIT object: number splits in linked list %D in object %D",cnt,jac->nsplits);
3590971522cSBarry Smith   *n = jac->nsplits;
3600971522cSBarry Smith   PetscFunctionReturn(0);
3610971522cSBarry Smith }
3620971522cSBarry Smith EXTERN_C_END
3630971522cSBarry Smith 
3640971522cSBarry Smith #undef __FUNCT__
3650971522cSBarry Smith #define __FUNCT__ "PCFieldSplitSetFields"
3660971522cSBarry Smith /*@
3670971522cSBarry Smith     PCFieldSplitSetFields - Sets the fields for one particular split in the field split preconditioner
3680971522cSBarry Smith 
3690971522cSBarry Smith     Collective on PC
3700971522cSBarry Smith 
3710971522cSBarry Smith     Input Parameters:
3720971522cSBarry Smith +   pc  - the preconditioner context
3730971522cSBarry Smith .   n - the number of fields in this split
3740971522cSBarry Smith .   fields - the fields in this split
3750971522cSBarry Smith 
3760971522cSBarry Smith     Level: intermediate
3770971522cSBarry Smith 
37869a612a9SBarry Smith .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT
3790971522cSBarry Smith 
3800971522cSBarry Smith @*/
381dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCFieldSplitSetFields(PC pc,PetscInt n, PetscInt *fields)
3820971522cSBarry Smith {
3830971522cSBarry Smith   PetscErrorCode ierr,(*f)(PC,PetscInt,PetscInt *);
3840971522cSBarry Smith 
3850971522cSBarry Smith   PetscFunctionBegin;
3860971522cSBarry Smith   PetscValidHeaderSpecific(pc,PC_COOKIE,1);
3870971522cSBarry Smith   ierr = PetscObjectQueryFunction((PetscObject)pc,"PCFieldSplitSetFields_C",(void (**)(void))&f);CHKERRQ(ierr);
3880971522cSBarry Smith   if (f) {
3890971522cSBarry Smith     ierr = (*f)(pc,n,fields);CHKERRQ(ierr);
3900971522cSBarry Smith   }
3910971522cSBarry Smith   PetscFunctionReturn(0);
3920971522cSBarry Smith }
3930971522cSBarry Smith 
3940971522cSBarry Smith #undef __FUNCT__
39569a612a9SBarry Smith #define __FUNCT__ "PCFieldSplitGetSubKSP"
3960971522cSBarry Smith /*@C
39769a612a9SBarry Smith    PCFieldSplitGetSubKSP - Gets the KSP contexts for all splits
3980971522cSBarry Smith 
39969a612a9SBarry Smith    Collective on KSP
4000971522cSBarry Smith 
4010971522cSBarry Smith    Input Parameter:
4020971522cSBarry Smith .  pc - the preconditioner context
4030971522cSBarry Smith 
4040971522cSBarry Smith    Output Parameters:
4050971522cSBarry Smith +  n - the number of split
40669a612a9SBarry Smith -  pc - the array of KSP contexts
4070971522cSBarry Smith 
4080971522cSBarry Smith    Note:
40969a612a9SBarry Smith    After PCFieldSplitGetSubKSP() the array of KSPs IS to be freed
4100971522cSBarry Smith 
41169a612a9SBarry Smith    You must call KSPSetUp() before calling PCFieldSplitGetSubKSP().
4120971522cSBarry Smith 
4130971522cSBarry Smith    Level: advanced
4140971522cSBarry Smith 
4150971522cSBarry Smith .seealso: PCFIELDSPLIT
4160971522cSBarry Smith @*/
417dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCFieldSplitGetSubKSP(PC pc,PetscInt *n,KSP *subksp[])
4180971522cSBarry Smith {
41969a612a9SBarry Smith   PetscErrorCode ierr,(*f)(PC,PetscInt*,KSP **);
4200971522cSBarry Smith 
4210971522cSBarry Smith   PetscFunctionBegin;
4220971522cSBarry Smith   PetscValidHeaderSpecific(pc,PC_COOKIE,1);
4230971522cSBarry Smith   PetscValidIntPointer(n,2);
42469a612a9SBarry Smith   ierr = PetscObjectQueryFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",(void (**)(void))&f);CHKERRQ(ierr);
4250971522cSBarry Smith   if (f) {
42669a612a9SBarry Smith     ierr = (*f)(pc,n,subksp);CHKERRQ(ierr);
4270971522cSBarry Smith   } else {
42869a612a9SBarry Smith     SETERRQ(PETSC_ERR_ARG_WRONG,"Cannot get subksp for this type of PC");
4290971522cSBarry Smith   }
4300971522cSBarry Smith   PetscFunctionReturn(0);
4310971522cSBarry Smith }
4320971522cSBarry Smith 
43379416396SBarry Smith EXTERN_C_BEGIN
43479416396SBarry Smith #undef __FUNCT__
43579416396SBarry Smith #define __FUNCT__ "PCFieldSplitSetType_FieldSplit"
436dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCFieldSplitSetType_FieldSplit(PC pc,PCCompositeType type)
43779416396SBarry Smith {
43879416396SBarry Smith   PC_FieldSplit  *jac = (PC_FieldSplit*)pc->data;
43979416396SBarry Smith 
44079416396SBarry Smith   PetscFunctionBegin;
44179416396SBarry Smith   jac->type = type;
44279416396SBarry Smith   PetscFunctionReturn(0);
44379416396SBarry Smith }
44479416396SBarry Smith EXTERN_C_END
44579416396SBarry Smith 
44679416396SBarry Smith #undef __FUNCT__
44779416396SBarry Smith #define __FUNCT__ "PCFieldSplitSetType"
44879416396SBarry Smith /*@C
44979416396SBarry Smith    PCFieldSplitSetType - Sets the type of fieldsplit preconditioner.
45079416396SBarry Smith 
45179416396SBarry Smith    Collective on PC
45279416396SBarry Smith 
45379416396SBarry Smith    Input Parameter:
45479416396SBarry Smith .  pc - the preconditioner context
45579416396SBarry Smith .  type - PC_COMPOSITE_ADDITIVE (default), PC_COMPOSITE_MULTIPLICATIVE
45679416396SBarry Smith 
45779416396SBarry Smith    Options Database Key:
45879416396SBarry Smith .  -pc_fieldsplit_type <type: one of multiplicative, additive, special> - Sets fieldsplit preconditioner type
45979416396SBarry Smith 
46079416396SBarry Smith    Level: Developer
46179416396SBarry Smith 
46279416396SBarry Smith .keywords: PC, set, type, composite preconditioner, additive, multiplicative
46379416396SBarry Smith 
46479416396SBarry Smith .seealso: PCCompositeSetType()
46579416396SBarry Smith 
46679416396SBarry Smith @*/
467dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCFieldSplitSetType(PC pc,PCCompositeType type)
46879416396SBarry Smith {
46979416396SBarry Smith   PetscErrorCode ierr,(*f)(PC,PCCompositeType);
47079416396SBarry Smith 
47179416396SBarry Smith   PetscFunctionBegin;
47279416396SBarry Smith   PetscValidHeaderSpecific(pc,PC_COOKIE,1);
47379416396SBarry Smith   ierr = PetscObjectQueryFunction((PetscObject)pc,"PCFieldSplitSetType_C",(void (**)(void))&f);CHKERRQ(ierr);
47479416396SBarry Smith   if (f) {
47579416396SBarry Smith     ierr = (*f)(pc,type);CHKERRQ(ierr);
47679416396SBarry Smith   }
47779416396SBarry Smith   PetscFunctionReturn(0);
47879416396SBarry Smith }
47979416396SBarry Smith 
4800971522cSBarry Smith /* -------------------------------------------------------------------------------------*/
4810971522cSBarry Smith /*MC
4827cdd61b2SBarry Smith    PCFIELDSPLIT - Preconditioner created by combining seperate preconditioners for individual
4830971522cSBarry Smith                   fields or groups of fields
4840971522cSBarry Smith 
4850971522cSBarry Smith 
4860971522cSBarry Smith      To set options on the solvers for each block append -sub_ to all the PC
4870971522cSBarry Smith         options database keys. For example, -sub_pc_type ilu -sub_pc_ilu_levels 1
4880971522cSBarry Smith 
48969a612a9SBarry Smith      To set the options on the solvers seperate for each block call PCFieldSplitGetSubKSP()
49069a612a9SBarry Smith          and set the options directly on the resulting KSP object
4910971522cSBarry Smith 
4920971522cSBarry Smith    Level: intermediate
4930971522cSBarry Smith 
49479416396SBarry Smith    Options Database Keys:
4952e70eadcSBarry Smith +   -pc_splitfield_%d_fields <a,b,..> - indicates the fields to be used in the %d'th split
4962e70eadcSBarry Smith .   -pc_splitfield_default - automatically add any fields to additional splits that have not
4972e70eadcSBarry Smith                               been supplied explicitly by -pc_splitfield_%d_fields
4982e70eadcSBarry Smith -   -pc_splitfield_type <additive,multiplicative>
49979416396SBarry Smith 
5000971522cSBarry Smith    Concepts: physics based preconditioners
5010971522cSBarry Smith 
5020971522cSBarry Smith .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC,
503c8d321e0SBarry Smith            PCFieldSplitGetSubKSP(), PCFieldSplitSetFields(),PCFieldSplitSetType()
5040971522cSBarry Smith M*/
5050971522cSBarry Smith 
5060971522cSBarry Smith EXTERN_C_BEGIN
5070971522cSBarry Smith #undef __FUNCT__
5080971522cSBarry Smith #define __FUNCT__ "PCCreate_FieldSplit"
509dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCCreate_FieldSplit(PC pc)
5100971522cSBarry Smith {
5110971522cSBarry Smith   PetscErrorCode ierr;
5120971522cSBarry Smith   PC_FieldSplit  *jac;
5130971522cSBarry Smith 
5140971522cSBarry Smith   PetscFunctionBegin;
5150971522cSBarry Smith   ierr = PetscNew(PC_FieldSplit,&jac);CHKERRQ(ierr);
51652e6d16bSBarry Smith   ierr = PetscLogObjectMemory(pc,sizeof(PC_FieldSplit));CHKERRQ(ierr);
5170971522cSBarry Smith   jac->bs      = -1;
5180971522cSBarry Smith   jac->nsplits = 0;
51979416396SBarry Smith   jac->type    = PC_COMPOSITE_ADDITIVE;
5200971522cSBarry Smith   pc->data     = (void*)jac;
5210971522cSBarry Smith 
5220971522cSBarry Smith   pc->ops->apply             = PCApply_FieldSplit;
5230971522cSBarry Smith   pc->ops->setup             = PCSetUp_FieldSplit;
5240971522cSBarry Smith   pc->ops->destroy           = PCDestroy_FieldSplit;
5250971522cSBarry Smith   pc->ops->setfromoptions    = PCSetFromOptions_FieldSplit;
5260971522cSBarry Smith   pc->ops->view              = PCView_FieldSplit;
5270971522cSBarry Smith   pc->ops->applyrichardson   = 0;
5280971522cSBarry Smith 
52969a612a9SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFieldSplitGetSubKSP_C","PCFieldSplitGetSubKSP_FieldSplit",
53069a612a9SBarry Smith                     PCFieldSplitGetSubKSP_FieldSplit);CHKERRQ(ierr);
5310971522cSBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFieldSplitSetFields_C","PCFieldSplitSetFields_FieldSplit",
5320971522cSBarry Smith                     PCFieldSplitSetFields_FieldSplit);CHKERRQ(ierr);
53379416396SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFieldSplitSetType_C","PCFieldSplitSetType_FieldSplit",
53479416396SBarry Smith                     PCFieldSplitSetType_FieldSplit);CHKERRQ(ierr);
5350971522cSBarry Smith   PetscFunctionReturn(0);
5360971522cSBarry Smith }
5370971522cSBarry Smith EXTERN_C_END
5380971522cSBarry Smith 
5390971522cSBarry Smith 
540