xref: /petsc/src/mat/tests/ex13.c (revision 6a98f8dc3f2c9149905a87dc2e9d0fedaf64e09a)
1 
2 static char help[] = "Tests copying and ordering uniprocessor row-based sparse matrices.\n\n";
3 
4 #include <petscmat.h>
5 
6 int main(int argc,char **args)
7 {
8   Mat            C,A;
9   PetscInt       i,j,m = 5,n = 5,Ii,J;
10   PetscErrorCode ierr;
11   PetscScalar    v;
12   IS             perm,iperm;
13 
14   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
15   ierr = MatCreateSeqAIJ(PETSC_COMM_SELF,m*n,m*n,5,NULL,&C);CHKERRQ(ierr);
16   /* create the matrix for the five point stencil, YET AGAIN*/
17   for (i=0; i<m; i++) {
18     for (j=0; j<n; j++) {
19       v = -1.0;  Ii = j + n*i;
20       if (i>0)   {J = Ii - n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
21       if (i<m-1) {J = Ii + n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
22       if (j>0)   {J = Ii - 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
23       if (j<n-1) {J = Ii + 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
24       v = 4.0; ierr = MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);CHKERRQ(ierr);
25     }
26   }
27   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
28   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
29 
30   ierr = MatConvert(C,MATSAME,MAT_INITIAL_MATRIX,&A);CHKERRQ(ierr);
31 
32   ierr = MatGetOrdering(A,MATORDERINGND,&perm,&iperm);CHKERRQ(ierr);
33   ierr = ISView(perm,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
34   ierr = ISView(iperm,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
35   ierr = MatView(A,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
36 
37   ierr = ISDestroy(&perm);CHKERRQ(ierr);
38   ierr = ISDestroy(&iperm);CHKERRQ(ierr);
39   ierr = MatDestroy(&C);CHKERRQ(ierr);
40   ierr = MatDestroy(&A);CHKERRQ(ierr);
41   ierr = PetscFinalize();
42   return ierr;
43 }
44 
45 
46 /*TEST
47 
48    test:
49       filter: grep -v "MPI processes"
50 
51 TEST*/
52