Date: 2013-07-02T14:44:06+00:00

Actual source code: ex65.c
petsc-3.4.2 2013-07-02

      2: static char help[] = "Saves a rectangular sparse matrix to disk.\n\n";

      4: #include <petscmat.h>

      8: int main(int argc,char **args)
      9: {
     10:   Mat            A;
     12:   PetscInt       m = 100,n = 11,js[11],i,j,cnt;
     13:   PetscScalar    values[11];
     14:   PetscViewer    view;

     16:   PetscInitialize(&argc,&args,(char*)0,help);

     18:   MatCreateSeqAIJ(PETSC_COMM_WORLD,m,n,20,0,&A);

     20:   for (i=0; i<n; i++) values[i] = (PetscReal)i;

     22:   for (i=0; i<m; i++) {
     23:     cnt = 0;
     24:     if (i % 2) {
     25:       for (j=0; j<n; j += 2) {
     26:         js[cnt++] = j;
     27:       }
     28:     } else {
     29:       ;
     30:     }
     31:     MatSetValues(A,1,&i,cnt,js,values,INSERT_VALUES);
     32:   }
     33:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
     34:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

     36:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,"rect",FILE_MODE_WRITE,&view);
     37:   MatView(A,view);
     38:   PetscViewerDestroy(&view);

     40:   MatDestroy(&A);

     42:   PetscFinalize();
     43:   return 0;
     44: }