Actual source code: ex6.c
2: static char help[] = "Tests reordering a matrix.\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;
11: IS perm,iperm;
13: PetscInitialize(&argc,&args,(char*)0,help);
14: MatCreate(PETSC_COMM_SELF,&C);
15: MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);
16: MatSetFromOptions(C);
17: MatSetUp(C);
19: /* create the matrix for the five point stencil, YET AGAIN*/
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: MatGetOrdering(C,MATORDERINGND,&perm,&iperm);
34: ISView(perm,PETSC_VIEWER_STDOUT_SELF);
35: ISView(iperm,PETSC_VIEWER_STDOUT_SELF);
36: MatView(C,PETSC_VIEWER_STDOUT_SELF);
38: ISDestroy(&perm);
39: ISDestroy(&iperm);
40: MatDestroy(&C);
41: PetscFinalize();
42: return 0;
43: }
45: /*TEST
47: test:
49: TEST*/