2: static char help[] = "Tests the use of MatZeroRows() for parallel matrices.\n\
  3: This example also tests the use of MatDuplicate() for both MPIAIJ and MPIBAIJ matrices";

  5: #include <petscmat.h>

  7: extern PetscErrorCode TestMatZeroRows_Basic(Mat,IS,PetscScalar);
  8: extern PetscErrorCode TestMatZeroRows_with_no_allocation(Mat,IS,PetscScalar);

 12: int main(int argc,char **args)
 13: {
 14:   Mat            A;
 15:   PetscInt       i,j,m = 3,n,Ii,J,Imax;
 16:   PetscMPIInt    rank,size;
 18:   PetscScalar    v,diag=-4.0;
 19:   IS             is;

 21:   PetscInitialize(&argc,&args,(char*)0,help);
 22:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
 23:   MPI_Comm_size(PETSC_COMM_WORLD,&size);
 24:   n    = 2*size;

 26:   /* create A Square matrix for the five point stencil,YET AGAIN*/
 27:   MatCreate(PETSC_COMM_WORLD,&A);
 28:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);
 29:   MatSetFromOptions(A);
 30:   MatSetUp(A);
 31:   for (i=0; i<m; i++) {
 32:     for (j=2*rank; j<2*rank+2; j++) {
 33:       v = -1.0;  Ii = j + n*i;
 34:       if (i>0)   {J = Ii - n; MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);}
 35:       if (i<m-1) {J = Ii + n; MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);}
 36:       if (j>0)   {J = Ii - 1; MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);}
 37:       if (j<n-1) {J = Ii + 1; MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);}
 38:       v = 4.0; MatSetValues(A,1,&Ii,1,&Ii,&v,INSERT_VALUES);
 39:     }
 40:   }
 41:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 42:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

 44:   /* Create AN IS required by MatZeroRows() */
 45:   Imax = n*rank; if (Imax>= n*m -m - 1) Imax = m*n - m - 1;
 46:   ISCreateStride(PETSC_COMM_SELF,m,Imax,1,&is);

 48:   TestMatZeroRows_Basic(A,is,0.0);
 49:   TestMatZeroRows_Basic(A,is,diag);

 51:   TestMatZeroRows_with_no_allocation(A,is,0.0);
 52:   TestMatZeroRows_with_no_allocation(A,is,diag);

 54:   MatDestroy(&A);

 56:   /* Now Create a rectangular matrix with five point stencil (app)
 57:    n+size is used so that this dimension is always divisible by size.
 58:    This way, we can always use bs = size for any number of procs */
 59:   MatCreate(PETSC_COMM_WORLD,&A);
 60:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m*n,m*(n+size));
 61:   MatSetFromOptions(A);
 62:   MatSetUp(A);
 63:   for (i=0; i<m; i++) {
 64:     for (j=2*rank; j<2*rank+2; j++) {
 65:       v = -1.0;  Ii = j + n*i;
 66:       if (i>0)   {J = Ii - n; MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);}
 67:       if (i<m-1) {J = Ii + n; MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);}
 68:       if (j>0)   {J = Ii - 1; MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);}
 69:       if (j<n+size-1) {J = Ii + 1; MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);}
 70:       v = 4.0; MatSetValues(A,1,&Ii,1,&Ii,&v,INSERT_VALUES);
 71:     }
 72:   }
 73:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 74:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

 76:   TestMatZeroRows_Basic(A,is,0.0);
 77:   TestMatZeroRows_Basic(A,is,diag);

 79:   MatDestroy(&A);
 80:   ISDestroy(&is);
 81:   PetscFinalize();
 82:   return 0;
 83: }

 87: PetscErrorCode TestMatZeroRows_Basic(Mat A,IS is,PetscScalar diag)
 88: {
 89:   Mat            B;
 91:   PetscBool      keepnonzeropattern;

 93:   /* Now copy A into B, and test it with MatZeroRows() */
 94:   MatDuplicate(A,MAT_COPY_VALUES,&B);

 96:   PetscOptionsHasName(NULL,"-keep_nonzero_pattern",&keepnonzeropattern);
 97:   if (keepnonzeropattern) {
 98:     MatSetOption(B,MAT_KEEP_NONZERO_PATTERN,PETSC_TRUE);
 99:   }

101:   MatZeroRowsIS(B,is,diag,0,0);
102:   MatView(B,PETSC_VIEWER_STDOUT_WORLD);
103:   MatDestroy(&B);
104:   return 0;
105: }

109: PetscErrorCode TestMatZeroRows_with_no_allocation(Mat A,IS is,PetscScalar diag)
110: {
111:   Mat            B;

114:   /* Now copy A into B, and test it with MatZeroRows() */
115:   MatDuplicate(A,MAT_COPY_VALUES,&B);
116:   /* Set this flag after assembly. This way, it affects only MatZeroRows() */
117:   MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE);

119:   MatZeroRowsIS(B,is,diag,0,0);
120:   MatView(B,PETSC_VIEWER_STDOUT_WORLD);
121:   MatDestroy(&B);
122:   return 0;
123: }