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

  8:  #include <petscmat.h>

 10: int main(int argc,char **args)
 11: {
 12:   PetscInt       nd = 2,ov=1,i,j,m,n,*idx,lsize;
 14:   PetscMPIInt    rank;
 15:   PetscBool      flg;
 16:   Mat            A,B;
 17:   char           file[PETSC_MAX_PATH_LEN];
 18:   PetscViewer    fd;
 19:   IS             *is1,*is2;
 20:   PetscRandom    r;
 21:   PetscScalar    rand;

 23:   PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
 24: #if defined(PETSC_USE_COMPLEX)
 25:   SETERRQ(PETSC_COMM_WORLD,1,"This example does not work with complex numbers");
 26: #else
 27:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
 28:   PetscOptionsGetString(NULL,NULL,"-f",file,PETSC_MAX_PATH_LEN,NULL);
 29:   PetscOptionsGetInt(NULL,NULL,"-nd",&nd,NULL);
 30:   PetscOptionsGetInt(NULL,NULL,"-ov",&ov,NULL);

 32:   /* Read matrix and RHS */
 33:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd);
 34:   MatCreate(PETSC_COMM_WORLD,&A);
 35:   MatSetType(A,MATMPIAIJ);
 36:   MatLoad(A,fd);
 37:   PetscViewerDestroy(&fd);

 39:   /* Read the matrix again as a seq matrix */
 40:   PetscViewerBinaryOpen(PETSC_COMM_SELF,file,FILE_MODE_READ,&fd);
 41:   MatCreate(PETSC_COMM_SELF,&B);
 42:   MatSetType(B,MATSEQAIJ);
 43:   MatLoad(B,fd);
 44:   PetscViewerDestroy(&fd);

 46:   /* Create the Random no generator */
 47:   MatGetSize(A,&m,&n);
 48:   PetscRandomCreate(PETSC_COMM_SELF,&r);
 49:   PetscRandomSetFromOptions(r);

 51:   /* Create the IS corresponding to subdomains */
 52:   PetscMalloc1(nd,&is1);
 53:   PetscMalloc1(nd,&is2);
 54:   PetscMalloc1(m ,&idx);

 56:   /* Create the random Index Sets */
 57:   for (i=0; i<nd; i++) {
 58:     for (j=0; j<rank; j++) {
 59:       PetscRandomGetValue(r,&rand);
 60:     }
 61:     PetscRandomGetValue(r,&rand);
 62:     lsize = (PetscInt)(rand*m);
 63:     for (j=0; j<lsize; j++) {
 64:       PetscRandomGetValue(r,&rand);
 65:       idx[j] = (PetscInt)(rand*m);
 66:     }
 67:     ISCreateGeneral(PETSC_COMM_SELF,lsize,idx,PETSC_COPY_VALUES,is1+i);
 68:     ISCreateGeneral(PETSC_COMM_SELF,lsize,idx,PETSC_COPY_VALUES,is2+i);
 69:   }

 71:   MatIncreaseOverlap(A,nd,is1,ov);
 72:   MatIncreaseOverlap(B,nd,is2,ov);

 74:   /* Now see if the serial and parallel case have the same answers */
 75:   for (i=0; i<nd; ++i) {
 76:     PetscInt sz1,sz2;
 77:     ISEqual(is1[i],is2[i],&flg);
 78:     ISGetSize(is1[i],&sz1);
 79:     ISGetSize(is2[i],&sz2);
 80:     PetscPrintf(PETSC_COMM_SELF,"[%d], i=%D, flg =%d sz1 = %D sz2 = %D\n",rank,i,(int)flg,sz1,sz2);
 81:   }

 83:   /* Free Allocated Memory */
 84:   for (i=0; i<nd; ++i) {
 85:     ISDestroy(&is1[i]);
 86:     ISDestroy(&is2[i]);
 87:   }
 88:   PetscRandomDestroy(&r);
 89:   PetscFree(is1);
 90:   PetscFree(is2);
 91:   MatDestroy(&A);
 92:   MatDestroy(&B);
 93:   PetscFree(idx);
 94: #endif
 95:   PetscFinalize();
 96:   return ierr;
 97: }