Actual source code: ex139.c

petsc-3.13.6 2020-09-29
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  2: const char help[] = "Test MatCreateLocalRef()\n\n";

  4:  #include <petscmat.h>

  6: static PetscErrorCode GetLocalRef(Mat A,IS isrow,IS iscol,Mat *B)
  7: {
  9:   IS             istmp;

 12:   PetscPrintf(PETSC_COMM_WORLD,"Extracting LocalRef with isrow:\n");
 13:   ISOnComm(isrow,PETSC_COMM_WORLD,PETSC_COPY_VALUES,&istmp);
 14:   ISView(istmp,PETSC_VIEWER_STDOUT_WORLD);
 15:   ISDestroy(&istmp);
 16:   PetscPrintf(PETSC_COMM_WORLD,"Extracting LocalRef with iscol (only rank=0 shown):\n");
 17:   ISOnComm(iscol,PETSC_COMM_WORLD,PETSC_COPY_VALUES,&istmp);
 18:   ISView(istmp,PETSC_VIEWER_STDOUT_WORLD);
 19:   ISDestroy(&istmp);

 21:   MatCreateLocalRef(A,isrow,iscol,B);
 22:   return(0);
 23: }

 25: int main(int argc,char *argv[])
 26: {
 27:   PetscErrorCode         ierr;
 28:   MPI_Comm               comm;
 29:   Mat                    J,B;
 30:   PetscInt               i,j,k,l,rstart,rend,m,n,top_bs,row_bs,col_bs,nlocblocks,*idx,nrowblocks,ncolblocks,*ridx,*cidx,*icol,*irow;
 31:   PetscScalar            *vals;
 32:   ISLocalToGlobalMapping brmap;
 33:   IS                     is0,is1;
 34:   PetscBool              diag,blocked;

 36:   PetscInitialize(&argc,&argv,0,help);if (ierr) return ierr;
 37:   comm = PETSC_COMM_WORLD;

 39:   PetscOptionsBegin(comm,NULL,"LocalRef Test Options",NULL);
 40:   {
 41:     top_bs = 2; row_bs = 2; col_bs = 2; diag = PETSC_FALSE; blocked = PETSC_FALSE;
 42:     PetscOptionsInt("-top_bs","Block size of top-level matrix",0,top_bs,&top_bs,NULL);
 43:     PetscOptionsInt("-row_bs","Block size of row map",0,row_bs,&row_bs,NULL);
 44:     PetscOptionsInt("-col_bs","Block size of col map",0,col_bs,&col_bs,NULL);
 45:     PetscOptionsBool("-diag","Extract a diagonal black",0,diag,&diag,NULL);
 46:     PetscOptionsBool("-blocked","Use block insertion",0,blocked,&blocked,NULL);
 47:   }
 48:   PetscOptionsEnd();

 50:   MatCreate(comm,&J);
 51:   MatSetSizes(J,6,6,PETSC_DETERMINE,PETSC_DETERMINE);
 52:   MatSetBlockSize(J,top_bs);
 53:   MatSetFromOptions(J);
 54:   MatSeqBAIJSetPreallocation(J,top_bs,PETSC_DECIDE,0);
 55:   MatMPIBAIJSetPreallocation(J,top_bs,PETSC_DECIDE,0,PETSC_DECIDE,0);
 56:   MatSetUp(J);
 57:   MatGetSize(J,&m,&n);
 58:   MatGetOwnershipRange(J,&rstart,&rend);

 60:   nlocblocks = (rend-rstart)/top_bs + 2;
 61:   PetscMalloc1(nlocblocks,&idx);
 62:   for (i=0; i<nlocblocks; i++) {
 63:     idx[i] = (rstart/top_bs + i - 1 + m/top_bs) % (m/top_bs);
 64:   }
 65:   ISLocalToGlobalMappingCreate(comm,top_bs,nlocblocks,idx,PETSC_OWN_POINTER,&brmap);
 66:   PetscPrintf(comm,"Block ISLocalToGlobalMapping:\n");
 67:   ISLocalToGlobalMappingView(brmap,PETSC_VIEWER_STDOUT_WORLD);

 69:   MatSetLocalToGlobalMapping(J,brmap,brmap);
 70:   ISLocalToGlobalMappingDestroy(&brmap);

 72:   /* Create index sets for local submatrix */
 73:   nrowblocks = (rend-rstart)/row_bs;
 74:   ncolblocks = (rend-rstart)/col_bs;
 75:   PetscMalloc2(nrowblocks,&ridx,ncolblocks,&cidx);
 76:   for (i=0; i<nrowblocks; i++) ridx[i] = i + ((i > nrowblocks/2) ^ !rstart);
 77:   for (i=0; i<ncolblocks; i++) cidx[i] = i + ((i < ncolblocks/2) ^ !!rstart);
 78:   ISCreateBlock(PETSC_COMM_SELF,row_bs,nrowblocks,ridx,PETSC_COPY_VALUES,&is0);
 79:   ISCreateBlock(PETSC_COMM_SELF,col_bs,ncolblocks,cidx,PETSC_COPY_VALUES,&is1);
 80:   PetscFree2(ridx,cidx);

 82:   if (diag) {
 83:     ISDestroy(&is1);
 84:     PetscObjectReference((PetscObject)is0);
 85:     is1        = is0;
 86:     ncolblocks = nrowblocks;
 87:   }

 89:   GetLocalRef(J,is0,is1,&B);

 91:   MatZeroEntries(J);

 93:   PetscMalloc3(row_bs,&irow,col_bs,&icol,row_bs*col_bs,&vals);
 94:   for (i=0; i<nrowblocks; i++) {
 95:     for (j=0; j<ncolblocks; j++) {
 96:       for (k=0; k<row_bs; k++) {
 97:         for (l=0; l<col_bs; l++) {
 98:           vals[k*col_bs+l] = i * 100000 + j * 1000 + k * 10 + l;
 99:         }
100:         irow[k] = i*row_bs+k;
101:       }
102:       for (l=0; l<col_bs; l++) icol[l] = j*col_bs+l;
103:       if (blocked) {
104:         MatSetValuesBlockedLocal(B,1,&i,1,&j,vals,ADD_VALUES);
105:       } else {
106:         MatSetValuesLocal(B,row_bs,irow,col_bs,icol,vals,ADD_VALUES);
107:       }
108:     }
109:   }
110:   PetscFree3(irow,icol,vals);

112:   MatAssemblyBegin(J,MAT_FINAL_ASSEMBLY);
113:   MatAssemblyEnd(J,MAT_FINAL_ASSEMBLY);

115:   MatView(J,PETSC_VIEWER_STDOUT_WORLD);

117:   ISDestroy(&is0);
118:   ISDestroy(&is1);
119:   MatDestroy(&B);
120:   MatDestroy(&J);
121:   PetscFinalize();
122:   return ierr;
123: }

125: /*TEST

127:    test:
128:       nsize: 2
129:       filter: grep -v "type: mpi"
130:       args: -blocked {{0 1}} -mat_type {{aij baij}}

132: TEST*/