2: static char help[] = "Tests MatIncreaseOverlap() and MatGetSubmatrices() for the parallel case.\n\
  3: This example is similar to ex40.c; here the index sets used are random.\n\
  4: Input arguments are:\n\
  5:   -f <input_file> : file to load.  For example see $PETSC_DIR/share/petsc/datafiles/matrices\n\
  6:   -nd <size>      : > 0  no of domains per processor \n\
  7:   -ov <overlap>   : >=0  amount of overlap between domains\n\n";

  9: #include <petscmat.h>

 13: int main(int argc,char **args)
 14: {
 16:   PetscInt       nd = 2,ov=1,i,j,lsize,m,n,*idx,bs;
 17:   PetscMPIInt    rank, size;
 18:   PetscBool      flg;
 19:   Mat            A,B,*submatA,*submatB;
 20:   char           file[PETSC_MAX_PATH_LEN];
 21:   PetscViewer    fd;
 22:   IS             *is1,*is2;
 23:   PetscRandom    r;
 24:   PetscBool      test_unsorted = PETSC_FALSE;
 25:   PetscScalar    rand;

 27:   PetscInitialize(&argc,&args,(char*)0,help);
 28: #if defined(PETSC_USE_COMPLEX)
 29:   SETERRQ(PETSC_COMM_WORLD,1,"This example does not work with complex numbers");
 30: #else

 32:   MPI_Comm_size(PETSC_COMM_WORLD,&size);
 33:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
 34:   PetscOptionsGetString(NULL,NULL,"-f",file,PETSC_MAX_PATH_LEN,NULL);
 35:   PetscOptionsGetInt(NULL,NULL,"-nd",&nd,NULL);
 36:   PetscOptionsGetInt(NULL,NULL,"-ov",&ov,NULL);
 37:   PetscOptionsGetBool(NULL,NULL,"-test_unsorted",&test_unsorted,NULL);

 39:   /* Read matrix and RHS */
 40:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd);
 41:   MatCreate(PETSC_COMM_WORLD,&A);
 42:   MatSetType(A,MATMPIAIJ);
 43:   MatSetFromOptions(A);
 44:   MatLoad(A,fd);
 45:   PetscViewerDestroy(&fd);

 47:   /* Read the matrix again as a seq matrix */
 48:   PetscViewerBinaryOpen(PETSC_COMM_SELF,file,FILE_MODE_READ,&fd);
 49:   MatCreate(PETSC_COMM_SELF,&B);
 50:   MatSetType(B,MATSEQAIJ);
 51:   MatSetFromOptions(B);
 52:   MatLoad(B,fd);
 53:   PetscViewerDestroy(&fd);

 55:   MatGetBlockSize(A,&bs);

 57:   /* Create the Random no generator */
 58:   MatGetSize(A,&m,&n);
 59:   PetscRandomCreate(PETSC_COMM_SELF,&r);
 60:   PetscRandomSetFromOptions(r);

 62:   /* Create the IS corresponding to subdomains */
 63:   PetscMalloc1(nd,&is1);
 64:   PetscMalloc1(nd,&is2);
 65:   PetscMalloc1(m ,&idx);
 66:   for (i = 0; i < m; i++) {idx[i] = i;}

 68:   /* Create the random Index Sets */
 69:   for (i=0; i<nd; i++) {
 70:     /* Skip a few,so that the IS on different procs are diffeent*/
 71:     for (j=0; j<rank; j++) {
 72:       PetscRandomGetValue(r,&rand);
 73:     }
 74:     PetscRandomGetValue(r,&rand);
 75:     lsize = (PetscInt)(rand*(m/bs));
 76:     /* shuffle */
 77:     for (j=0; j<lsize; j++) {
 78:       PetscInt k, swap, l;

 80:       PetscRandomGetValue(r,&rand);
 81:       k      = j + (PetscInt)(rand*((m/bs)-j));
 82:       for (l = 0; l < bs; l++) {
 83:         swap        = idx[bs*j+l];
 84:         idx[bs*j+l] = idx[bs*k+l];
 85:         idx[bs*k+l] = swap;
 86:       }
 87:     }
 88:     if (!test_unsorted) {PetscSortInt(lsize*bs,idx);}
 89:     ISCreateGeneral(PETSC_COMM_SELF,lsize*bs,idx,PETSC_COPY_VALUES,is1+i);
 90:     ISCreateGeneral(PETSC_COMM_SELF,lsize*bs,idx,PETSC_COPY_VALUES,is2+i);
 91:     ISSetBlockSize(is1[i],bs);
 92:     ISSetBlockSize(is2[i],bs);
 93:   }

 95:   if (!test_unsorted) {
 96:     MatIncreaseOverlap(A,nd,is1,ov);
 97:     MatIncreaseOverlap(B,nd,is2,ov);

 99:     for (i=0; i<nd; ++i) {
100:       ISSort(is1[i]);
101:       ISSort(is2[i]);
102:     }
103:   }

105:   MatGetSubMatrices(A,nd,is1,is1,MAT_INITIAL_MATRIX,&submatA);
106:   MatGetSubMatrices(B,nd,is2,is2,MAT_INITIAL_MATRIX,&submatB);

108:   /* Now see if the serial and parallel case have the same answers */
109:   for (i=0; i<nd; ++i) {
110:     MatEqual(submatA[i],submatB[i],&flg);
111:     PetscSynchronizedPrintf(PETSC_COMM_WORLD,"proc:[%d], i=%D, flg =%d\n",rank,i,(int)flg);
112:     PetscSynchronizedFlush(PETSC_COMM_WORLD,stdout);
113:   }

115:   /* Free Allocated Memory */
116:   for (i=0; i<nd; ++i) {
117:     ISDestroy(&is1[i]);
118:     ISDestroy(&is2[i]);
119:     MatDestroy(&submatA[i]);
120:     MatDestroy(&submatB[i]);
121:   }
122:   PetscFree(submatA);
123:   PetscFree(submatB);
124:   PetscRandomDestroy(&r);
125:   PetscFree(is1);
126:   PetscFree(is2);
127:   MatDestroy(&A);
128:   MatDestroy(&B);
129:   PetscFree(idx);

131:   PetscFinalize();
132: #endif
133:   return 0;
134: }