xref: /petsc/src/dm/tests/ex35.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 
2 static char help[] = "MatLoad test for loading matrices that are created by DMCreateMatrix() and\n\
3                       stored in binary via MatView_MPI_DA.MatView_MPI_DA stores the matrix\n\
4                       in natural ordering. Hence MatLoad() has to read the matrix first in\n\
5                       natural ordering and then permute it back to the application ordering.This\n\
6                       example is used for testing the subroutine MatLoad_MPI_DA\n\n";
7 
8 #include <petscdm.h>
9 #include <petscdmda.h>
10 
11 int main(int argc,char **argv)
12 {
13   PetscInt       X = 10,Y = 8,Z=8;
14   DM             da;
15   PetscViewer    viewer;
16   Mat            A;
17 
18   PetscFunctionBeginUser;
19   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
20   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"temp.dat",FILE_MODE_WRITE,&viewer));
21 
22   /* Read options */
23   PetscCall(PetscOptionsGetInt(NULL,NULL,"-X",&X,NULL));
24   PetscCall(PetscOptionsGetInt(NULL,NULL,"-Y",&Y,NULL));
25   PetscCall(PetscOptionsGetInt(NULL,NULL,"-Z",&Z,NULL));
26 
27   /* Create distributed array and get vectors */
28   PetscCall(DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,X,Y,Z,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,1,1,NULL,NULL,NULL,&da));
29   PetscCall(DMSetFromOptions(da));
30   PetscCall(DMSetUp(da));
31   PetscCall(DMSetMatType(da,MATMPIAIJ));
32   PetscCall(DMCreateMatrix(da,&A));
33   PetscCall(MatShift(A,X));
34   PetscCall(MatView(A,viewer));
35   PetscCall(MatDestroy(&A));
36   PetscCall(PetscViewerDestroy(&viewer));
37 
38   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"temp.dat",FILE_MODE_READ,&viewer));
39   PetscCall(DMCreateMatrix(da,&A));
40   PetscCall(MatLoad(A,viewer));
41 
42   /* Free memory */
43   PetscCall(MatDestroy(&A));
44   PetscCall(PetscViewerDestroy(&viewer));
45   PetscCall(DMDestroy(&da));
46   PetscCall(PetscFinalize());
47   return 0;
48 }
49