2: static char help[] = "Tests MatDenseGetArray() and MatView_SeqDense_Binary(), MatView_MPIDense_Binary().\n\n";

  4: #include <petscmat.h>
  5: #include <petscviewer.h>

  9: int main(int argc,char **args)
 10: {
 11:   Mat            A;
 12:   PetscInt       i,j,m = 3,n = 2,rstart,rend;
 14:   PetscScalar    v,*array;
 15:   PetscViewer    view;

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

 19:   /*
 20:       Create a parallel dense matrix shared by all processors
 21:   */
 22:   MatCreateDense(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m,n,NULL,&A);

 24:   /*
 25:      Set values into the matrix
 26:   */
 27:   for (i=0; i<m; i++) {
 28:     for (j=0; j<n; j++) {
 29:       v = 9.0/(i+j+1); MatSetValues(A,1,&i,1,&j,&v,INSERT_VALUES);
 30:     }
 31:   }
 32:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 33:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

 35:   /*
 36:        Print the matrix to the screen
 37:   */
 38:   MatView(A,PETSC_VIEWER_STDOUT_WORLD);


 41:   /*
 42:       Print the local portion of the matrix to the screen
 43:   */
 44:   MatDenseGetArray(A,&array);
 45:   MatGetOwnershipRange(A,&rstart,&rend);
 46:   for (i=rstart; i<rend; i++) {
 47:     for (j=0; j<n; j++) {
 48:       PetscSynchronizedPrintf(PETSC_COMM_WORLD,"%6.4e ",(double)PetscRealPart(array[j*(rend-rstart)+i-rstart]));
 49:     }
 50:     PetscSynchronizedPrintf(PETSC_COMM_WORLD,"\n");
 51:   }
 52:   PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT);
 53:   MatDenseRestoreArray(A,&array);

 55:   /*
 56:       Store the binary matrix to a file
 57:   */
 58:   PetscViewerBinaryOpen(PETSC_COMM_WORLD, "matrix.dat", FILE_MODE_WRITE, &view);
 59:   PetscViewerPushFormat(view,PETSC_VIEWER_NATIVE);
 60:   MatView(A,view);
 61:   PetscViewerPopFormat(view);
 62:   PetscViewerDestroy(&view);
 63:   MatDestroy(&A);

 65:   /*
 66:      Now reload the matrix and view it
 67:   */
 68:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,"matrix.dat",FILE_MODE_READ,&view);
 69:   MatCreate(PETSC_COMM_WORLD,&A);
 70:   MatSetType(A,MATMPIDENSE);
 71:   MatLoad(A,view);
 72:   PetscViewerDestroy(&view);
 73:   MatView(A,PETSC_VIEWER_STDOUT_WORLD);
 74:   MatDestroy(&A);

 76:   PetscFinalize();
 77:   return 0;
 78: }