Date: 2016-07-24T16:55:55+00:00

Actual source code: matis.c
petsc-3.7.3 2016-07-24
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      2: /*
      3:     Creates a matrix class for using the Neumann-Neumann type preconditioners.
      4:    This stores the matrices in globally unassembled form. Each processor
      5:    assembles only its local Neumann problem and the parallel matrix vector
      6:    product is handled "implicitly".

      8:      We provide:
      9:          MatMult()

     11:     Currently this allows for only one subdomain per processor.

     13: */

     15: #include <../src/mat/impls/is/matis.h>      /*I "petscmat.h" I*/

     17: static PetscErrorCode MatISComputeSF_Private(Mat);

     21: static PetscErrorCode MatISComputeSF_Private(Mat B)
     22: {
     23:   Mat_IS         *matis = (Mat_IS*)(B->data);
     24:   const PetscInt *gidxs;

     28:   MatGetSize(matis->A,&matis->sf_nleaves,NULL);
     29:   MatGetLocalSize(B,&matis->sf_nroots,NULL);
     30:   PetscSFCreate(PetscObjectComm((PetscObject)B),&matis->sf);
     31:   ISLocalToGlobalMappingGetIndices(B->rmap->mapping,&gidxs);
     32:   /* PETSC_OWN_POINTER refers to ilocal which is NULL */
     33:   PetscSFSetGraphLayout(matis->sf,B->rmap,matis->sf_nleaves,NULL,PETSC_OWN_POINTER,gidxs);
     34:   ISLocalToGlobalMappingRestoreIndices(B->rmap->mapping,&gidxs);
     35:   PetscMalloc2(matis->sf_nroots,&matis->sf_rootdata,matis->sf_nleaves,&matis->sf_leafdata);
     36:   return(0);
     37: }

     41: /*@
     42:    MatISSetPreallocation - Preallocates memory for a MATIS parallel matrix.

     44:    Collective on MPI_Comm

     46:    Input Parameters:
     47: +  B - the matrix
     48: .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
     49:            (same value is used for all local rows)
     50: .  d_nnz - array containing the number of nonzeros in the various rows of the
     51:            DIAGONAL portion of the local submatrix (possibly different for each row)
     52:            or NULL, if d_nz is used to specify the nonzero structure.
     53:            The size of this array is equal to the number of local rows, i.e 'm'.
     54:            For matrices that will be factored, you must leave room for (and set)
     55:            the diagonal entry even if it is zero.
     56: .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
     57:            submatrix (same value is used for all local rows).
     58: -  o_nnz - array containing the number of nonzeros in the various rows of the
     59:            OFF-DIAGONAL portion of the local submatrix (possibly different for
     60:            each row) or NULL, if o_nz is used to specify the nonzero
     61:            structure. The size of this array is equal to the number
     62:            of local rows, i.e 'm'.

     64:    If the *_nnz parameter is given then the *_nz parameter is ignored

     66:    Level: intermediate

     68:    Notes: This function has the same interface as the MPIAIJ preallocation routine in order to simplify the transition
     69:           from the asssembled format to the unassembled one. It overestimates the preallocation of MATIS local
     70:           matrices; for exact preallocation, the user should set the preallocation directly on local matrix objects.

     72: .keywords: matrix

     74: .seealso: MatCreate(), MatCreateIS(), MatMPIAIJSetPreallocation(), MatISGetLocalMat()
     75: @*/
     76: PetscErrorCode  MatISSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
     77: {

     83:   PetscTryMethod(B,"MatISSetPreallocation_C",(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]),(B,d_nz,d_nnz,o_nz,o_nnz));
     84:   return(0);
     85: }

     89: PetscErrorCode  MatISSetPreallocation_IS(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
     90: {
     91:   Mat_IS         *matis = (Mat_IS*)(B->data);
     92:   PetscInt       bs,i,nlocalcols;

     96:   if (!matis->A) SETERRQ(PetscObjectComm((PetscObject)B),PETSC_ERR_SUP,"You should first call MatSetLocalToGlobalMapping");
     97:   if (!matis->sf) { /* setup SF if not yet created and allocate rootdata and leafdata */
     98:     MatISComputeSF_Private(B);
     99:   }
    100:   if (!d_nnz) {
    101:     for (i=0;i<matis->sf_nroots;i++) matis->sf_rootdata[i] = d_nz;
    102:   } else {
    103:     for (i=0;i<matis->sf_nroots;i++) matis->sf_rootdata[i] = d_nnz[i];
    104:   }
    105:   if (!o_nnz) {
    106:     for (i=0;i<matis->sf_nroots;i++) matis->sf_rootdata[i] += o_nz;
    107:   } else {
    108:     for (i=0;i<matis->sf_nroots;i++) matis->sf_rootdata[i] += o_nnz[i];
    109:   }
    110:   PetscSFBcastBegin(matis->sf,MPIU_INT,matis->sf_rootdata,matis->sf_leafdata);
    111:   MatGetSize(matis->A,NULL,&nlocalcols);
    112:   MatGetBlockSize(matis->A,&bs);
    113:   PetscSFBcastEnd(matis->sf,MPIU_INT,matis->sf_rootdata,matis->sf_leafdata);
    114:   for (i=0;i<matis->sf_nleaves;i++) {
    115:     matis->sf_leafdata[i] = PetscMin(matis->sf_leafdata[i],nlocalcols);
    116:   }
    117:   MatSeqAIJSetPreallocation(matis->A,0,matis->sf_leafdata);
    118:   for (i=0;i<matis->sf_nleaves/bs;i++) {
    119:     matis->sf_leafdata[i] = matis->sf_leafdata[i*bs]/bs;
    120:   }
    121:   MatSeqBAIJSetPreallocation(matis->A,bs,0,matis->sf_leafdata);
    122:   for (i=0;i<matis->sf_nleaves/bs;i++) {
    123:     matis->sf_leafdata[i] = matis->sf_leafdata[i]-i;
    124:   }
    125:   MatSeqSBAIJSetPreallocation(matis->A,bs,0,matis->sf_leafdata);
    126:   return(0);
    127: }

    131: PETSC_EXTERN PetscErrorCode MatISSetMPIXAIJPreallocation_Private(Mat A, Mat B, PetscBool maxreduce)
    132: {
    133:   Mat_IS          *matis = (Mat_IS*)(A->data);
    134:   PetscInt        *my_dnz,*my_onz,*dnz,*onz,*mat_ranges,*row_ownership;
    135:   const PetscInt  *global_indices_r,*global_indices_c;
    136:   PetscInt        i,j,bs,rows,cols;
    137:   PetscInt        lrows,lcols;
    138:   PetscInt        local_rows,local_cols;
    139:   PetscMPIInt     nsubdomains;
    140:   PetscBool       isdense,issbaij;
    141:   PetscErrorCode  ierr;

    144:   MPI_Comm_size(PetscObjectComm((PetscObject)A),&nsubdomains);
    145:   MatGetSize(A,&rows,&cols);
    146:   MatGetBlockSize(A,&bs);
    147:   MatGetSize(matis->A,&local_rows,&local_cols);
    148:   PetscObjectTypeCompare((PetscObject)matis->A,MATSEQDENSE,&isdense);
    149:   PetscObjectTypeCompare((PetscObject)matis->A,MATSEQSBAIJ,&issbaij);
    150:   ISLocalToGlobalMappingGetIndices(A->rmap->mapping,&global_indices_r);
    151:   if (A->rmap->mapping != A->cmap->mapping) {
    152:     ISLocalToGlobalMappingGetIndices(A->rmap->mapping,&global_indices_c);
    153:   } else {
    154:     global_indices_c = global_indices_r;
    155:   }

    157:   if (issbaij) {
    158:     MatGetRowUpperTriangular(matis->A);
    159:   }
    160:   /*
    161:      An SF reduce is needed to sum up properly on shared rows.
    162:      Note that generally preallocation is not exact, since it overestimates nonzeros
    163:   */
    164:   if (!matis->sf) { /* setup SF if not yet created and allocate rootdata and leafdata */
    165:     MatISComputeSF_Private(A);
    166:   }
    167:   MatGetLocalSize(A,&lrows,&lcols);
    168:   MatPreallocateInitialize(PetscObjectComm((PetscObject)A),lrows,lcols,dnz,onz);
    169:   /* All processes need to compute entire row ownership */
    170:   PetscMalloc1(rows,&row_ownership);
    171:   MatGetOwnershipRanges(A,(const PetscInt**)&mat_ranges);
    172:   for (i=0;i<nsubdomains;i++) {
    173:     for (j=mat_ranges[i];j<mat_ranges[i+1];j++) {
    174:       row_ownership[j] = i;
    175:     }
    176:   }

    178:   /*
    179:      my_dnz and my_onz contains exact contribution to preallocation from each local mat
    180:      then, they will be summed up properly. This way, preallocation is always sufficient
    181:   */
    182:   PetscCalloc2(local_rows,&my_dnz,local_rows,&my_onz);
    183:   /* preallocation as a MATAIJ */
    184:   if (isdense) { /* special case for dense local matrices */
    185:     for (i=0;i<local_rows;i++) {
    186:       PetscInt index_row = global_indices_r[i];
    187:       for (j=i;j<local_rows;j++) {
    188:         PetscInt owner = row_ownership[index_row];
    189:         PetscInt index_col = global_indices_c[j];
    190:         if (index_col > mat_ranges[owner]-1 && index_col < mat_ranges[owner+1] ) { /* diag block */
    191:           my_dnz[i] += 1;
    192:         } else { /* offdiag block */
    193:           my_onz[i] += 1;
    194:         }
    195:         /* same as before, interchanging rows and cols */
    196:         if (i != j) {
    197:           owner = row_ownership[index_col];
    198:           if (index_row > mat_ranges[owner]-1 && index_row < mat_ranges[owner+1] ) {
    199:             my_dnz[j] += 1;
    200:           } else {
    201:             my_onz[j] += 1;
    202:           }
    203:         }
    204:       }
    205:     }
    206:   } else { /* TODO: this could be optimized using MatGetRowIJ */
    207:     for (i=0;i<local_rows;i++) {
    208:       const PetscInt *cols;
    209:       PetscInt       ncols,index_row = global_indices_r[i];
    210:       MatGetRow(matis->A,i,&ncols,&cols,NULL);
    211:       for (j=0;j<ncols;j++) {
    212:         PetscInt owner = row_ownership[index_row];
    213:         PetscInt index_col = global_indices_c[cols[j]];
    214:         if (index_col > mat_ranges[owner]-1 && index_col < mat_ranges[owner+1] ) { /* diag block */
    215:           my_dnz[i] += 1;
    216:         } else { /* offdiag block */
    217:           my_onz[i] += 1;
    218:         }
    219:         /* same as before, interchanging rows and cols */
    220:         if (issbaij && index_col != index_row) {
    221:           owner = row_ownership[index_col];
    222:           if (index_row > mat_ranges[owner]-1 && index_row < mat_ranges[owner+1] ) {
    223:             my_dnz[cols[j]] += 1;
    224:           } else {
    225:             my_onz[cols[j]] += 1;
    226:           }
    227:         }
    228:       }
    229:       MatRestoreRow(matis->A,i,&ncols,&cols,NULL);
    230:     }
    231:   }
    232:   ISLocalToGlobalMappingRestoreIndices(A->rmap->mapping,&global_indices_r);
    233:   if (global_indices_c != global_indices_r) {
    234:     ISLocalToGlobalMappingRestoreIndices(A->rmap->mapping,&global_indices_c);
    235:   }
    236:   PetscFree(row_ownership);

    238:   /* Reduce my_dnz and my_onz */
    239:   if (maxreduce) {
    240:     PetscSFReduceBegin(matis->sf,MPIU_INT,my_dnz,dnz,MPI_MAX);
    241:     PetscSFReduceEnd(matis->sf,MPIU_INT,my_dnz,dnz,MPI_MAX);
    242:     PetscSFReduceBegin(matis->sf,MPIU_INT,my_onz,onz,MPI_MAX);
    243:     PetscSFReduceEnd(matis->sf,MPIU_INT,my_onz,onz,MPI_MAX);
    244:   } else {
    245:     PetscSFReduceBegin(matis->sf,MPIU_INT,my_dnz,dnz,MPI_SUM);
    246:     PetscSFReduceEnd(matis->sf,MPIU_INT,my_dnz,dnz,MPI_SUM);
    247:     PetscSFReduceBegin(matis->sf,MPIU_INT,my_onz,onz,MPI_SUM);
    248:     PetscSFReduceEnd(matis->sf,MPIU_INT,my_onz,onz,MPI_SUM);
    249:   }
    250:   PetscFree2(my_dnz,my_onz);

    252:   /* Resize preallocation if overestimated */
    253:   for (i=0;i<lrows;i++) {
    254:     dnz[i] = PetscMin(dnz[i],lcols);
    255:     onz[i] = PetscMin(onz[i],cols-lcols);
    256:   }
    257:   /* set preallocation */
    258:   MatMPIAIJSetPreallocation(B,0,dnz,0,onz);
    259:   for (i=0;i<lrows/bs;i++) {
    260:     dnz[i] = dnz[i*bs]/bs;
    261:     onz[i] = onz[i*bs]/bs;
    262:   }
    263:   MatMPIBAIJSetPreallocation(B,bs,0,dnz,0,onz);
    264:   MatMPISBAIJSetPreallocation(B,bs,0,dnz,0,onz);
    265:   MatPreallocateFinalize(dnz,onz);
    266:   if (issbaij) {
    267:     MatRestoreRowUpperTriangular(matis->A);
    268:   }
    269:   return(0);
    270: }

    274: PetscErrorCode MatISGetMPIXAIJ_IS(Mat mat, MatReuse reuse, Mat *M)
    275: {
    276:   Mat_IS         *matis = (Mat_IS*)(mat->data);
    277:   Mat            local_mat;
    278:   /* info on mat */
    279:   PetscInt       bs,rows,cols,lrows,lcols;
    280:   PetscInt       local_rows,local_cols;
    281:   PetscBool      isdense,issbaij,isseqaij;
    282:   PetscMPIInt    nsubdomains;
    283:   /* values insertion */
    284:   PetscScalar    *array;
    285:   /* work */

    289:   /* get info from mat */
    290:   MPI_Comm_size(PetscObjectComm((PetscObject)mat),&nsubdomains);
    291:   if (nsubdomains == 1) {
    292:     if (reuse == MAT_INITIAL_MATRIX) {
    293:       MatDuplicate(matis->A,MAT_COPY_VALUES,&(*M));
    294:     } else {
    295:       MatCopy(matis->A,*M,SAME_NONZERO_PATTERN);
    296:     }
    297:     return(0);
    298:   }
    299:   MatGetSize(mat,&rows,&cols);
    300:   MatGetBlockSize(mat,&bs);
    301:   MatGetLocalSize(mat,&lrows,&lcols);
    302:   MatGetSize(matis->A,&local_rows,&local_cols);
    303:   PetscObjectTypeCompare((PetscObject)matis->A,MATSEQDENSE,&isdense);
    304:   PetscObjectTypeCompare((PetscObject)matis->A,MATSEQAIJ,&isseqaij);
    305:   PetscObjectTypeCompare((PetscObject)matis->A,MATSEQSBAIJ,&issbaij);

    307:   if (reuse == MAT_INITIAL_MATRIX) {
    308:     MatType     new_mat_type;
    309:     PetscBool   issbaij_red;

    311:     /* determining new matrix type */
    312:     MPIU_Allreduce(&issbaij,&issbaij_red,1,MPIU_BOOL,MPI_LAND,PetscObjectComm((PetscObject)mat));
    313:     if (issbaij_red) {
    314:       new_mat_type = MATSBAIJ;
    315:     } else {
    316:       if (bs>1) {
    317:         new_mat_type = MATBAIJ;
    318:       } else {
    319:         new_mat_type = MATAIJ;
    320:       }
    321:     }

    323:     MatCreate(PetscObjectComm((PetscObject)mat),M);
    324:     MatSetSizes(*M,lrows,lcols,rows,cols);
    325:     MatSetBlockSize(*M,bs);
    326:     MatSetType(*M,new_mat_type);
    327:     MatISSetMPIXAIJPreallocation_Private(mat,*M,PETSC_FALSE);
    328:   } else {
    329:     PetscInt mbs,mrows,mcols,mlrows,mlcols;
    330:     /* some checks */
    331:     MatGetBlockSize(*M,&mbs);
    332:     MatGetSize(*M,&mrows,&mcols);
    333:     MatGetLocalSize(*M,&mlrows,&mlcols);
    334:     if (mrows != rows) SETERRQ2(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot reuse matrix. Wrong number of rows (%d != %d)",rows,mrows);
    335:     if (mcols != cols) SETERRQ2(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot reuse matrix. Wrong number of cols (%d != %d)",cols,mcols);
    336:     if (mlrows != lrows) SETERRQ2(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot reuse matrix. Wrong number of local rows (%d != %d)",lrows,mlrows);
    337:     if (mlcols != lcols) SETERRQ2(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot reuse matrix. Wrong number of local cols (%d != %d)",lcols,mlcols);
    338:     if (mbs != bs) SETERRQ2(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot reuse matrix. Wrong block size (%d != %d)",bs,mbs);
    339:     MatZeroEntries(*M);
    340:   }

    342:   if (issbaij) {
    343:     MatConvert(matis->A,MATSEQBAIJ,MAT_INITIAL_MATRIX,&local_mat);
    344:   } else {
    345:     PetscObjectReference((PetscObject)matis->A);
    346:     local_mat = matis->A;
    347:   }

    349:   /* Set values */
    350:   MatSetLocalToGlobalMapping(*M,mat->rmap->mapping,mat->cmap->mapping);
    351:   if (isdense) { /* special case for dense local matrices */
    352:     PetscInt i,*dummy_rows,*dummy_cols;

    354:     if (local_rows != local_cols) {
    355:       PetscMalloc2(local_rows,&dummy_rows,local_cols,&dummy_cols);
    356:       for (i=0;i<local_rows;i++) dummy_rows[i] = i;
    357:       for (i=0;i<local_cols;i++) dummy_cols[i] = i;
    358:     } else {
    359:       PetscMalloc1(local_rows,&dummy_rows);
    360:       for (i=0;i<local_rows;i++) dummy_rows[i] = i;
    361:       dummy_cols = dummy_rows;
    362:     }
    363:     MatSetOption(*M,MAT_ROW_ORIENTED,PETSC_FALSE);
    364:     MatDenseGetArray(local_mat,&array);
    365:     MatSetValuesLocal(*M,local_rows,dummy_rows,local_cols,dummy_cols,array,ADD_VALUES);
    366:     MatDenseRestoreArray(local_mat,&array);
    367:     if (dummy_rows != dummy_cols) {
    368:       PetscFree2(dummy_rows,dummy_cols);
    369:     } else {
    370:       PetscFree(dummy_rows);
    371:     }
    372:   } else if (isseqaij) {
    373:     PetscInt  i,nvtxs,*xadj,*adjncy;
    374:     PetscBool done;

    376:     MatGetRowIJ(local_mat,0,PETSC_FALSE,PETSC_FALSE,&nvtxs,(const PetscInt**)&xadj,(const PetscInt**)&adjncy,&done);
    377:     if (!done) SETERRQ1(PetscObjectComm((PetscObject)local_mat),PETSC_ERR_PLIB,"Error in MatRestoreRowIJ called in %s\n",__FUNCT__);
    378:     MatSeqAIJGetArray(local_mat,&array);
    379:     for (i=0;i<nvtxs;i++) {
    380:       MatSetValuesLocal(*M,1,&i,xadj[i+1]-xadj[i],adjncy+xadj[i],array+xadj[i],ADD_VALUES);
    381:     }
    382:     MatRestoreRowIJ(local_mat,0,PETSC_FALSE,PETSC_FALSE,&nvtxs,(const PetscInt**)&xadj,(const PetscInt**)&adjncy,&done);
    383:     if (!done) SETERRQ1(PetscObjectComm((PetscObject)local_mat),PETSC_ERR_PLIB,"Error in MatRestoreRowIJ called in %s\n",__FUNCT__);
    384:     MatSeqAIJRestoreArray(local_mat,&array);
    385:   } else { /* very basic values insertion for all other matrix types */
    386:     PetscInt i;

    388:     for (i=0;i<local_rows;i++) {
    389:       PetscInt       j;
    390:       const PetscInt *local_indices_cols;

    392:       MatGetRow(local_mat,i,&j,&local_indices_cols,(const PetscScalar**)&array);
    393:       MatSetValuesLocal(*M,1,&i,j,local_indices_cols,array,ADD_VALUES);
    394:       MatRestoreRow(local_mat,i,&j,&local_indices_cols,(const PetscScalar**)&array);
    395:     }
    396:   }
    397:   MatAssemblyBegin(*M,MAT_FINAL_ASSEMBLY);
    398:   MatDestroy(&local_mat);
    399:   MatAssemblyEnd(*M,MAT_FINAL_ASSEMBLY);
    400:   if (isdense) {
    401:     MatSetOption(*M,MAT_ROW_ORIENTED,PETSC_TRUE);
    402:   }
    403:   return(0);
    404: }

    408: /*@
    409:     MatISGetMPIXAIJ - Converts MATIS matrix into a parallel AIJ format

    411:   Input Parameter:
    412: .  mat - the matrix (should be of type MATIS)
    413: .  reuse - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX

    415:   Output Parameter:
    416: .  newmat - the matrix in AIJ format

    418:   Level: developer

    420:   Notes: mat and *newmat cannot be the same object when MAT_REUSE_MATRIX is requested.

    422: .seealso: MATIS
    423: @*/
    424: PetscErrorCode MatISGetMPIXAIJ(Mat mat, MatReuse reuse, Mat *newmat)
    425: {

    432:   if (reuse != MAT_INITIAL_MATRIX) {
    435:     if (mat == *newmat) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot reuse the same matrix");
    436:   }
    437:   PetscUseMethod(mat,"MatISGetMPIXAIJ_C",(Mat,MatReuse,Mat*),(mat,reuse,newmat));
    438:   return(0);
    439: }

    443: PetscErrorCode MatDuplicate_IS(Mat mat,MatDuplicateOption op,Mat *newmat)
    444: {
    446:   Mat_IS         *matis = (Mat_IS*)(mat->data);
    447:   PetscInt       bs,m,n,M,N;
    448:   Mat            B,localmat;

    451:   MatGetBlockSize(mat,&bs);
    452:   MatGetSize(mat,&M,&N);
    453:   MatGetLocalSize(mat,&m,&n);
    454:   MatCreateIS(PetscObjectComm((PetscObject)mat),bs,m,n,M,N,mat->rmap->mapping,mat->cmap->mapping,&B);
    455:   MatDuplicate(matis->A,op,&localmat);
    456:   MatISSetLocalMat(B,localmat);
    457:   MatDestroy(&localmat);
    458:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
    459:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
    460:   *newmat = B;
    461:   return(0);
    462: }

    466: PetscErrorCode MatIsHermitian_IS(Mat A,PetscReal tol,PetscBool  *flg)
    467: {
    469:   Mat_IS         *matis = (Mat_IS*)A->data;
    470:   PetscBool      local_sym;

    473:   MatIsHermitian(matis->A,tol,&local_sym);
    474:   MPIU_Allreduce(&local_sym,flg,1,MPIU_BOOL,MPI_LAND,PetscObjectComm((PetscObject)A));
    475:   return(0);
    476: }

    480: PetscErrorCode MatIsSymmetric_IS(Mat A,PetscReal tol,PetscBool  *flg)
    481: {
    483:   Mat_IS         *matis = (Mat_IS*)A->data;
    484:   PetscBool      local_sym;

    487:   MatIsSymmetric(matis->A,tol,&local_sym);
    488:   MPIU_Allreduce(&local_sym,flg,1,MPIU_BOOL,MPI_LAND,PetscObjectComm((PetscObject)A));
    489:   return(0);
    490: }

    494: PetscErrorCode MatDestroy_IS(Mat A)
    495: {
    497:   Mat_IS         *b = (Mat_IS*)A->data;

    500:   MatDestroy(&b->A);
    501:   VecScatterDestroy(&b->cctx);
    502:   VecScatterDestroy(&b->rctx);
    503:   VecDestroy(&b->x);
    504:   VecDestroy(&b->y);
    505:   PetscSFDestroy(&b->sf);
    506:   PetscFree2(b->sf_rootdata,b->sf_leafdata);
    507:   PetscFree(A->data);
    508:   PetscObjectChangeTypeName((PetscObject)A,0);
    509:   PetscObjectComposeFunction((PetscObject)A,"MatISGetLocalMat_C",NULL);
    510:   PetscObjectComposeFunction((PetscObject)A,"MatISSetLocalMat_C",NULL);
    511:   PetscObjectComposeFunction((PetscObject)A,"MatISGetMPIXAIJ_C",NULL);
    512:   PetscObjectComposeFunction((PetscObject)A,"MatISSetPreallocation_C",NULL);
    513:   return(0);
    514: }

    518: PetscErrorCode MatMult_IS(Mat A,Vec x,Vec y)
    519: {
    521:   Mat_IS         *is  = (Mat_IS*)A->data;
    522:   PetscScalar    zero = 0.0;

    525:   /*  scatter the global vector x into the local work vector */
    526:   VecScatterBegin(is->cctx,x,is->x,INSERT_VALUES,SCATTER_FORWARD);
    527:   VecScatterEnd(is->cctx,x,is->x,INSERT_VALUES,SCATTER_FORWARD);

    529:   /* multiply the local matrix */
    530:   MatMult(is->A,is->x,is->y);

    532:   /* scatter product back into global memory */
    533:   VecSet(y,zero);
    534:   VecScatterBegin(is->rctx,is->y,y,ADD_VALUES,SCATTER_REVERSE);
    535:   VecScatterEnd(is->rctx,is->y,y,ADD_VALUES,SCATTER_REVERSE);
    536:   return(0);
    537: }

    541: PetscErrorCode MatMultAdd_IS(Mat A,Vec v1,Vec v2,Vec v3)
    542: {
    543:   Vec            temp_vec;

    547:   if (v3 != v2) {
    548:     MatMult(A,v1,v3);
    549:     VecAXPY(v3,1.0,v2);
    550:   } else {
    551:     VecDuplicate(v2,&temp_vec);
    552:     MatMult(A,v1,temp_vec);
    553:     VecAXPY(temp_vec,1.0,v2);
    554:     VecCopy(temp_vec,v3);
    555:     VecDestroy(&temp_vec);
    556:   }
    557:   return(0);
    558: }

    562: PetscErrorCode MatMultTranspose_IS(Mat A,Vec y,Vec x)
    563: {
    564:   Mat_IS         *is = (Mat_IS*)A->data;

    568:   /*  scatter the global vector x into the local work vector */
    569:   VecScatterBegin(is->rctx,y,is->y,INSERT_VALUES,SCATTER_FORWARD);
    570:   VecScatterEnd(is->rctx,y,is->y,INSERT_VALUES,SCATTER_FORWARD);

    572:   /* multiply the local matrix */
    573:   MatMultTranspose(is->A,is->y,is->x);

    575:   /* scatter product back into global vector */
    576:   VecSet(x,0);
    577:   VecScatterBegin(is->cctx,is->x,x,ADD_VALUES,SCATTER_REVERSE);
    578:   VecScatterEnd(is->cctx,is->x,x,ADD_VALUES,SCATTER_REVERSE);
    579:   return(0);
    580: }

    584: PetscErrorCode MatMultTransposeAdd_IS(Mat A,Vec v1,Vec v2,Vec v3)
    585: {
    586:   Vec            temp_vec;

    590:   if (v3 != v2) {
    591:     MatMultTranspose(A,v1,v3);
    592:     VecAXPY(v3,1.0,v2);
    593:   } else {
    594:     VecDuplicate(v2,&temp_vec);
    595:     MatMultTranspose(A,v1,temp_vec);
    596:     VecAXPY(temp_vec,1.0,v2);
    597:     VecCopy(temp_vec,v3);
    598:     VecDestroy(&temp_vec);
    599:   }
    600:   return(0);
    601: }

    605: PetscErrorCode MatView_IS(Mat A,PetscViewer viewer)
    606: {
    607:   Mat_IS         *a = (Mat_IS*)A->data;
    609:   PetscViewer    sviewer;

    612:   PetscViewerGetSubViewer(viewer,PETSC_COMM_SELF,&sviewer);
    613:   MatView(a->A,sviewer);
    614:   PetscViewerRestoreSubViewer(viewer,PETSC_COMM_SELF,&sviewer);
    615:   return(0);
    616: }

    620: PetscErrorCode MatSetLocalToGlobalMapping_IS(Mat A,ISLocalToGlobalMapping rmapping,ISLocalToGlobalMapping cmapping)
    621: {
    623:   PetscInt       nr,rbs,nc,cbs;
    624:   Mat_IS         *is = (Mat_IS*)A->data;
    625:   IS             from,to;
    626:   Vec            cglobal,rglobal;

    631:   /* Destroy any previous data */
    632:   VecDestroy(&is->x);
    633:   VecDestroy(&is->y);
    634:   VecScatterDestroy(&is->rctx);
    635:   VecScatterDestroy(&is->cctx);
    636:   MatDestroy(&is->A);
    637:   PetscSFDestroy(&is->sf);
    638:   PetscFree2(is->sf_rootdata,is->sf_leafdata);

    640:   /* Setup Layout and set local to global maps */
    641:   PetscLayoutSetUp(A->rmap);
    642:   PetscLayoutSetUp(A->cmap);
    643:   PetscLayoutSetISLocalToGlobalMapping(A->rmap,rmapping);
    644:   PetscLayoutSetISLocalToGlobalMapping(A->cmap,cmapping);

    646:   /* Create the local matrix A */
    647:   ISLocalToGlobalMappingGetSize(rmapping,&nr);
    648:   ISLocalToGlobalMappingGetBlockSize(rmapping,&rbs);
    649:   ISLocalToGlobalMappingGetSize(cmapping,&nc);
    650:   ISLocalToGlobalMappingGetBlockSize(cmapping,&cbs);
    651:   MatCreate(PETSC_COMM_SELF,&is->A);
    652:   MatSetType(is->A,MATAIJ);
    653:   MatSetSizes(is->A,nr,nc,nr,nc);
    654:   MatSetBlockSizes(is->A,rbs,cbs);
    655:   MatSetOptionsPrefix(is->A,((PetscObject)A)->prefix);
    656:   MatAppendOptionsPrefix(is->A,"is_");
    657:   MatSetFromOptions(is->A);

    659:   /* Create the local work vectors */
    660:   MatCreateVecs(is->A,&is->x,&is->y);

    662:   /* setup the global to local scatters */
    663:   MatCreateVecs(A,&cglobal,&rglobal);
    664:   ISCreateStride(PETSC_COMM_SELF,nr,0,1,&to);
    665:   ISLocalToGlobalMappingApplyIS(rmapping,to,&from);
    666:   VecScatterCreate(rglobal,from,is->y,to,&is->rctx);
    667:   if (rmapping != cmapping) {
    668:     ISDestroy(&to);
    669:     ISDestroy(&from);
    670:     ISCreateStride(PETSC_COMM_SELF,nc,0,1,&to);
    671:     ISLocalToGlobalMappingApplyIS(cmapping,to,&from);
    672:     VecScatterCreate(cglobal,from,is->x,to,&is->cctx);
    673:   } else {
    674:     PetscObjectReference((PetscObject)is->rctx);
    675:     is->cctx = is->rctx;
    676:   }
    677:   VecDestroy(&rglobal);
    678:   VecDestroy(&cglobal);
    679:   ISDestroy(&to);
    680:   ISDestroy(&from);
    681:   return(0);
    682: }

    686: PetscErrorCode MatSetValues_IS(Mat mat, PetscInt m,const PetscInt *rows, PetscInt n,const PetscInt *cols, const PetscScalar *values, InsertMode addv)
    687: {
    688:   Mat_IS         *is = (Mat_IS*)mat->data;
    689:   PetscInt       rows_l[2048],cols_l[2048];

    693: #if defined(PETSC_USE_DEBUG)
    694:   if (m > 2048 || n > 2048) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_SUP,"Number of row/column indices must be <= 2048: they are %D %D",m,n);
    695: #endif
    696:   ISG2LMapApply(mat->rmap->mapping,m,rows,rows_l);
    697:   ISG2LMapApply(mat->cmap->mapping,n,cols,cols_l);
    698:   MatSetValues(is->A,m,rows_l,n,cols_l,values,addv);
    699:   return(0);
    700: }

    704: PetscErrorCode MatSetValuesLocal_IS(Mat A,PetscInt m,const PetscInt *rows, PetscInt n,const PetscInt *cols,const PetscScalar *values,InsertMode addv)
    705: {
    707:   Mat_IS         *is = (Mat_IS*)A->data;

    710:   MatSetValues(is->A,m,rows,n,cols,values,addv);
    711:   return(0);
    712: }

    716: PetscErrorCode MatSetValuesBlockedLocal_IS(Mat A,PetscInt m,const PetscInt *rows, PetscInt n,const PetscInt *cols,const PetscScalar *values,InsertMode addv)
    717: {
    719:   Mat_IS         *is = (Mat_IS*)A->data;

    722:   MatSetValuesBlocked(is->A,m,rows,n,cols,values,addv);
    723:   return(0);
    724: }

    728: PetscErrorCode MatZeroRows_IS(Mat A,PetscInt n,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
    729: {
    730:   PetscInt       n_l = 0, *rows_l = NULL;

    734:   if (x && b) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"No support");
    735:   if (n) {
    736:     PetscMalloc1(n,&rows_l);
    737:     ISGlobalToLocalMappingApply(A->rmap->mapping,IS_GTOLM_DROP,n,rows,&n_l,rows_l);
    738:   }
    739:   MatZeroRowsLocal(A,n_l,rows_l,diag,x,b);
    740:   PetscFree(rows_l);
    741:   return(0);
    742: }

    746: PetscErrorCode MatZeroRowsLocal_IS(Mat A,PetscInt n,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
    747: {
    748:   Mat_IS         *is = (Mat_IS*)A->data;
    750:   PetscInt       i;
    751:   PetscScalar    *array;

    754:   if (x && b) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"No support");
    755:   {
    756:     /*
    757:        Set up is->x as a "counting vector". This is in order to MatMult_IS
    758:        work properly in the interface nodes.
    759:     */
    760:     Vec counter;
    761:     MatCreateVecs(A,NULL,&counter);
    762:     VecSet(counter,0.);
    763:     VecSet(is->y,1.);
    764:     VecScatterBegin(is->rctx,is->y,counter,ADD_VALUES,SCATTER_REVERSE);
    765:     VecScatterEnd(is->rctx,is->y,counter,ADD_VALUES,SCATTER_REVERSE);
    766:     VecScatterBegin(is->rctx,counter,is->y,INSERT_VALUES,SCATTER_FORWARD);
    767:     VecScatterEnd(is->rctx,counter,is->y,INSERT_VALUES,SCATTER_FORWARD);
    768:     VecDestroy(&counter);
    769:   }
    770:   if (!n) {
    771:     is->pure_neumann = PETSC_TRUE;
    772:   } else {
    773:     is->pure_neumann = PETSC_FALSE;

    775:     VecGetArray(is->y,&array);
    776:     MatZeroRows(is->A,n,rows,diag,0,0);
    777:     for (i=0; i<n; i++) {
    778:       MatSetValue(is->A,rows[i],rows[i],diag/(array[rows[i]]),INSERT_VALUES);
    779:     }
    780:     MatAssemblyBegin(is->A,MAT_FINAL_ASSEMBLY);
    781:     MatAssemblyEnd(is->A,MAT_FINAL_ASSEMBLY);
    782:     VecRestoreArray(is->y,&array);
    783:   }
    784:   return(0);
    785: }

    789: PetscErrorCode MatAssemblyBegin_IS(Mat A,MatAssemblyType type)
    790: {
    791:   Mat_IS         *is = (Mat_IS*)A->data;

    795:   MatAssemblyBegin(is->A,type);
    796:   return(0);
    797: }

    801: PetscErrorCode MatAssemblyEnd_IS(Mat A,MatAssemblyType type)
    802: {
    803:   Mat_IS         *is = (Mat_IS*)A->data;

    807:   MatAssemblyEnd(is->A,type);
    808:   return(0);
    809: }

    813: PetscErrorCode MatISGetLocalMat_IS(Mat mat,Mat *local)
    814: {
    815:   Mat_IS *is = (Mat_IS*)mat->data;

    818:   *local = is->A;
    819:   return(0);
    820: }

    824: /*@
    825:     MatISGetLocalMat - Gets the local matrix stored inside a MATIS matrix.

    827:   Input Parameter:
    828: .  mat - the matrix

    830:   Output Parameter:
    831: .  local - the local matrix

    833:   Level: advanced

    835:   Notes:
    836:     This can be called if you have precomputed the nonzero structure of the
    837:   matrix and want to provide it to the inner matrix object to improve the performance
    838:   of the MatSetValues() operation.

    840: .seealso: MATIS
    841: @*/
    842: PetscErrorCode MatISGetLocalMat(Mat mat,Mat *local)
    843: {

    849:   PetscUseMethod(mat,"MatISGetLocalMat_C",(Mat,Mat*),(mat,local));
    850:   return(0);
    851: }

    855: PetscErrorCode MatISSetLocalMat_IS(Mat mat,Mat local)
    856: {
    857:   Mat_IS         *is = (Mat_IS*)mat->data;
    858:   PetscInt       nrows,ncols,orows,ocols;

    862:   if (is->A) {
    863:     MatGetSize(is->A,&orows,&ocols);
    864:     MatGetSize(local,&nrows,&ncols);
    865:     if (orows != nrows || ocols != ncols) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Local MATIS matrix should be of size %dx%d (you passed a %dx%d matrix)\n",orows,ocols,nrows,ncols);
    866:   }
    867:   PetscObjectReference((PetscObject)local);
    868:   MatDestroy(&is->A);
    869:   is->A = local;
    870:   return(0);
    871: }

    875: /*@
    876:     MatISSetLocalMat - Replace the local matrix stored inside a MATIS object.

    878:   Input Parameter:
    879: .  mat - the matrix
    880: .  local - the local matrix

    882:   Output Parameter:

    884:   Level: advanced

    886:   Notes:
    887:     This can be called if you have precomputed the local matrix and
    888:   want to provide it to the matrix object MATIS.

    890: .seealso: MATIS
    891: @*/
    892: PetscErrorCode MatISSetLocalMat(Mat mat,Mat local)
    893: {

    899:   PetscUseMethod(mat,"MatISSetLocalMat_C",(Mat,Mat),(mat,local));
    900:   return(0);
    901: }

    905: PetscErrorCode MatZeroEntries_IS(Mat A)
    906: {
    907:   Mat_IS         *a = (Mat_IS*)A->data;

    911:   MatZeroEntries(a->A);
    912:   return(0);
    913: }

    917: PetscErrorCode MatScale_IS(Mat A,PetscScalar a)
    918: {
    919:   Mat_IS         *is = (Mat_IS*)A->data;

    923:   MatScale(is->A,a);
    924:   return(0);
    925: }

    929: PetscErrorCode MatGetDiagonal_IS(Mat A, Vec v)
    930: {
    931:   Mat_IS         *is = (Mat_IS*)A->data;

    935:   /* get diagonal of the local matrix */
    936:   MatGetDiagonal(is->A,is->y);

    938:   /* scatter diagonal back into global vector */
    939:   VecSet(v,0);
    940:   VecScatterBegin(is->rctx,is->y,v,ADD_VALUES,SCATTER_REVERSE);
    941:   VecScatterEnd(is->rctx,is->y,v,ADD_VALUES,SCATTER_REVERSE);
    942:   return(0);
    943: }

    947: PetscErrorCode MatSetOption_IS(Mat A,MatOption op,PetscBool flg)
    948: {
    949:   Mat_IS         *a = (Mat_IS*)A->data;

    953:   MatSetOption(a->A,op,flg);
    954:   return(0);
    955: }

    959: /*@
    960:     MatCreateIS - Creates a "process" unassmembled matrix, it is assembled on each
    961:        process but not across processes.

    963:    Input Parameters:
    964: +     comm    - MPI communicator that will share the matrix
    965: .     bs      - block size of the matrix
    966: .     m,n,M,N - local and/or global sizes of the left and right vector used in matrix vector products
    967: .     rmap    - local to global map for rows
    968: -     cmap    - local to global map for cols

    970:    Output Parameter:
    971: .    A - the resulting matrix

    973:    Level: advanced

    975:    Notes: See MATIS for more details
    976:           m and n are NOT related to the size of the map, they are the size of the part of the vector owned
    977:           by that process. The sizes of rmap and cmap define the size of the local matrices.
    978:           If either rmap or cmap are NULL, than the matrix is assumed to be square

    980: .seealso: MATIS, MatSetLocalToGlobalMapping()
    981: @*/
    982: PetscErrorCode  MatCreateIS(MPI_Comm comm,PetscInt bs,PetscInt m,PetscInt n,PetscInt M,PetscInt N,ISLocalToGlobalMapping rmap,ISLocalToGlobalMapping cmap,Mat *A)
    983: {

    987:   if (!rmap && !cmap) SETERRQ(comm,PETSC_ERR_USER,"You need to provide at least one of the mapping");
    988:   MatCreate(comm,A);
    989:   MatSetBlockSize(*A,bs);
    990:   MatSetSizes(*A,m,n,M,N);
    991:   MatSetType(*A,MATIS);
    992:   MatSetUp(*A);
    993:   if (rmap && cmap) {
    994:     MatSetLocalToGlobalMapping(*A,rmap,cmap);
    995:   } else if (!rmap) {
    996:     MatSetLocalToGlobalMapping(*A,cmap,cmap);
    997:   } else {
    998:     MatSetLocalToGlobalMapping(*A,rmap,rmap);
    999:   }
    1000:   return(0);
    1001: }

    1003: /*MC
    1004:    MATIS - MATIS = "is" - A matrix type to be used for using the non-overlapping domain decomposition type preconditioners (e.g. PCBDDC).
    1005:    This stores the matrices in globally unassembled form. Each processor
    1006:    assembles only its local Neumann problem and the parallel matrix vector
    1007:    product is handled "implicitly".

    1009:    Operations Provided:
    1010: +  MatMult()
    1011: .  MatMultAdd()
    1012: .  MatMultTranspose()
    1013: .  MatMultTransposeAdd()
    1014: .  MatZeroEntries()
    1015: .  MatSetOption()
    1016: .  MatZeroRows()
    1017: .  MatZeroRowsLocal()
    1018: .  MatSetValues()
    1019: .  MatSetValuesLocal()
    1020: .  MatScale()
    1021: .  MatGetDiagonal()
    1022: -  MatSetLocalToGlobalMapping()

    1024:    Options Database Keys:
    1025: . -mat_type is - sets the matrix type to "is" during a call to MatSetFromOptions()

    1027:    Notes: Options prefix for the inner matrix are given by -is_mat_xxx

    1029:           You must call MatSetLocalToGlobalMapping() before using this matrix type.

    1031:           You can do matrix preallocation on the local matrix after you obtain it with
    1032:           MatISGetLocalMat(); otherwise, you could use MatISSetPreallocation()

    1034:   Level: advanced

    1036: .seealso: Mat, MatISGetLocalMat(), MatSetLocalToGlobalMapping(), MatISSetPreallocation(), PCBDDC

    1038: M*/

    1042: PETSC_EXTERN PetscErrorCode MatCreate_IS(Mat A)
    1043: {
    1045:   Mat_IS         *b;

    1048:   PetscNewLog(A,&b);
    1049:   A->data = (void*)b;

    1051:   /* matrix ops */
    1052:   PetscMemzero(A->ops,sizeof(struct _MatOps));
    1053:   A->ops->mult                    = MatMult_IS;
    1054:   A->ops->multadd                 = MatMultAdd_IS;
    1055:   A->ops->multtranspose           = MatMultTranspose_IS;
    1056:   A->ops->multtransposeadd        = MatMultTransposeAdd_IS;
    1057:   A->ops->destroy                 = MatDestroy_IS;
    1058:   A->ops->setlocaltoglobalmapping = MatSetLocalToGlobalMapping_IS;
    1059:   A->ops->setvalues               = MatSetValues_IS;
    1060:   A->ops->setvalueslocal          = MatSetValuesLocal_IS;
    1061:   A->ops->setvaluesblockedlocal   = MatSetValuesBlockedLocal_IS;
    1062:   A->ops->zerorows                = MatZeroRows_IS;
    1063:   A->ops->zerorowslocal           = MatZeroRowsLocal_IS;
    1064:   A->ops->assemblybegin           = MatAssemblyBegin_IS;
    1065:   A->ops->assemblyend             = MatAssemblyEnd_IS;
    1066:   A->ops->view                    = MatView_IS;
    1067:   A->ops->zeroentries             = MatZeroEntries_IS;
    1068:   A->ops->scale                   = MatScale_IS;
    1069:   A->ops->getdiagonal             = MatGetDiagonal_IS;
    1070:   A->ops->setoption               = MatSetOption_IS;
    1071:   A->ops->ishermitian             = MatIsHermitian_IS;
    1072:   A->ops->issymmetric             = MatIsSymmetric_IS;
    1073:   A->ops->duplicate               = MatDuplicate_IS;

    1075:   /* special MATIS functions */
    1076:   PetscObjectComposeFunction((PetscObject)A,"MatISGetLocalMat_C",MatISGetLocalMat_IS);
    1077:   PetscObjectComposeFunction((PetscObject)A,"MatISSetLocalMat_C",MatISSetLocalMat_IS);
    1078:   PetscObjectComposeFunction((PetscObject)A,"MatISGetMPIXAIJ_C",MatISGetMPIXAIJ_IS);
    1079:   PetscObjectComposeFunction((PetscObject)A,"MatISSetPreallocation_C",MatISSetPreallocation_IS);
    1080:   PetscObjectChangeTypeName((PetscObject)A,MATIS);
    1081:   return(0);
    1082: }