Actual source code: ex43.c
petsc-3.4.2 2013-07-02

      2: static char help[] = "Saves a dense matrix in a dense format (binary).\n\n";

      4: #include <petscmat.h>

      8: int main(int argc,char **args)
      9: {
     10:   Mat            C;
     11:   PetscScalar    v;
     12:   PetscInt       i,j,m = 4,n = 4;
     14:   PetscMPIInt    rank,size;
     15:   PetscViewer    viewer;

     17:   PetscInitialize(&argc,&args,(char*)0,help);
     18:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
     19:   MPI_Comm_size(PETSC_COMM_WORLD,&size);
     20:   PetscOptionsGetInt(NULL,"-m",&m,NULL);
     21:   PetscOptionsGetInt(NULL,"-n",&n,NULL);

     23:   /* PART 1:  Generate matrix, then write it in binary format */

     25:   /* Generate matrix */
     26:   MatCreateSeqDense(PETSC_COMM_WORLD,m,n,NULL,&C);
     27:   for (i=0; i<m; i++) {
     28:     for (j=0; j<n; j++) {
     29:       v    = i*m+j;
     30:       MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);
     31:     }
     32:   }
     33:   MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
     34:   MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
     35:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,"matrix.dat",FILE_MODE_WRITE,&viewer);
     36:   MatView(C,viewer);
     37:   PetscViewerDestroy(&viewer);
     38:   MatDestroy(&C);
     39:   PetscFinalize();
     40:   return 0;
     41: }