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
9: int main(int argc,char **args)
10: {
11: Mat C;
12: int i,j,m = 5,n = 5,I,J,ierr,*idx,nz;
13: PetscScalar v,*values;
15: PetscInitialize(&argc,&args,(char *)0,help);
17: /* Create the matrix for the five point stencil, YET AGAIN */
18: MatCreate(PETSC_COMM_SELF,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n,&C);
19: MatSetFromOptions(C);
20: for (i=0; i<m; i++) {
21: for (j=0; j<n; j++) {
22: v = -1.0; I = j + n*i;
23: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
24: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
25: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
26: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
27: v = 4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
28: }
29: }
30: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
31: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
32: MatView(C,PETSC_VIEWER_STDOUT_SELF);
34: for (i=0; i<m*n; i++) {
35: MatGetRow(C,i,&nz,&idx,&values);
36: #if defined(PETSC_USE_COMPLEX)
37: for (j=0; j<nz; j++) {PetscPrintf(PETSC_COMM_SELF,"%d %g ",idx[j],PetscRealPart(values[j]));}
38: #else
39: for (j=0; j<nz; j++) {PetscPrintf(PETSC_COMM_SELF,"%d %g ",idx[j],values[j]);}
40: #endif
41: PetscPrintf(PETSC_COMM_SELF,"\n");
42: MatRestoreRow(C,i,&nz,&idx,&values);
43: }
45: MatDestroy(C);
46: PetscFinalize();
47: return 0;
48: }