Actual source code: ex10.c
2: static char help[] = "Tests repeated use of assembly for matrices.\n\n";
4: #include petscmat.h
8: int main(int argc,char **args)
9: {
10: Mat C;
11: PetscInt i,j,m = 5,n = 2,I,J;
13: PetscMPIInt rank,size;
14: PetscScalar v;
17: PetscInitialize(&argc,&args,(char *)0,help);
18: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
19: MPI_Comm_size(PETSC_COMM_WORLD,&size);
20: n = 2*size;
22: /* create the matrix for the five point stencil, YET AGAIN*/
23: MatCreate(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n,&C);
24: MatSetFromOptions(C);
25: for (i=0; i<m; i++) {
26: for (j=2*rank; j<2*rank+2; j++) {
27: v = -1.0; I = j + n*i;
28: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
29: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
30: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
31: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
32: v = 4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
33: }
34: }
35: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
36: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
37: for (i=0; i<m; i++) {
38: for (j=2*rank; j<2*rank+2; j++) {
39: v = 1.0; I = j + n*i;
40: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
41: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
42: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
43: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
44: v = -4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
45: }
46: }
47: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
48: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
50: MatView(C,PETSC_VIEWER_STDOUT_WORLD);
52: MatDestroy(C);
53: PetscFinalize();
54: return 0;
55: }