Actual source code: ex14.c
1: /*$Id: ex14.c,v 1.19 2001/08/07 03:03:07 balay Exp $*/
3: static char help[] = "Tests MatGetRow() and MatRestoreRow().n";
5: #include petscmat.h
7: int main(int argc,char **args)
8: {
9: Mat C;
10: int i,j,m = 5,n = 5,I,J,ierr,*idx,nz;
11: PetscScalar v,*values;
13: PetscInitialize(&argc,&args,(char *)0,help);
15: /* Create the matrix for the five point stencil, YET AGAIN */
16: MatCreate(PETSC_COMM_SELF,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n,&C);
17: MatSetFromOptions(C);
18: for (i=0; i<m; i++) {
19: for (j=0; j<n; j++) {
20: v = -1.0; I = j + n*i;
21: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
22: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
23: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
24: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
25: v = 4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
26: }
27: }
28: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
29: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
30: MatView(C,PETSC_VIEWER_STDOUT_SELF);
32: for (i=0; i<m*n; i++) {
33: MatGetRow(C,i,&nz,&idx,&values);
34: #if defined(PETSC_USE_COMPLEX)
35: for (j=0; j<nz; j++) {PetscPrintf(PETSC_COMM_SELF,"%d %g ",idx[j],PetscRealPart(values[j]));}
36: #else
37: for (j=0; j<nz; j++) {PetscPrintf(PETSC_COMM_SELF,"%d %g ",idx[j],values[j]);}
38: #endif
39: PetscPrintf(PETSC_COMM_SELF,"n");
40: MatRestoreRow(C,i,&nz,&idx,&values);
41: }
43: MatDestroy(C);
44: PetscFinalize();
45: return 0;
46: }