Actual source code: ex11.c
2: static char help[] = "Tests the use of MatZeroRows() for uniprocessor matrices.\n\n";
4: #include <petscmat.h>
6: int main(int argc,char **args)
7: {
8: Mat C;
9: PetscInt i,j,m = 5,n = 5,Ii,J;
10: PetscScalar v,five = 5.0;
11: IS isrow;
12: PetscBool keepnonzeropattern;
14: PetscInitialize(&argc,&args,(char*)0,help);
15: /* create the matrix for the five point stencil, YET AGAIN*/
16: MatCreate(PETSC_COMM_SELF,&C);
17: MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);
18: MatSetFromOptions(C);
19: MatSetUp(C);
20: for (i=0; i<m; i++) {
21: for (j=0; j<n; j++) {
22: v = -1.0; Ii = j + n*i;
23: if (i>0) {J = Ii - n; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
24: if (i<m-1) {J = Ii + n; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
25: if (j>0) {J = Ii - 1; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
26: if (j<n-1) {J = Ii + 1; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
27: v = 4.0; MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);
28: }
29: }
30: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
31: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
33: ISCreateStride(PETSC_COMM_SELF,(m*n)/2,0,2,&isrow);
35: PetscOptionsHasName(NULL,NULL,"-keep_nonzero_pattern",&keepnonzeropattern);
36: if (keepnonzeropattern) {
37: MatSetOption(C,MAT_KEEP_NONZERO_PATTERN,PETSC_TRUE);
38: }
40: MatZeroRowsIS(C,isrow,five,0,0);
42: MatView(C,PETSC_VIEWER_STDOUT_SELF);
44: ISDestroy(&isrow);
45: MatDestroy(&C);
46: PetscFinalize();
47: return 0;
48: }
50: /*TEST
52: test:
54: test:
55: suffix: 2
56: args: -mat_type seqbaij -mat_block_size 5
58: test:
59: suffix: 3
60: args: -keep_nonzero_pattern
62: test:
63: suffix: 4
64: args: -keep_nonzero_pattern -mat_type seqbaij -mat_block_size 5
66: TEST*/