xref: /petsc/src/dm/tests/ex7.c (revision 732aec7a18f2199fb53bb9a2f3aef439a834ce31)
1 static char help[] = "Tests DMLocalToLocalxxx() for DMDA.\n\n";
2 
3 #include <petscdmda.h>
4 
main(int argc,char ** argv)5 int main(int argc, char **argv)
6 {
7   PetscMPIInt     rank;
8   PetscInt        M = 8, dof = 1, stencil_width = 1, i, start, end, P = 5, N = 6, m = PETSC_DECIDE, n = PETSC_DECIDE, p = PETSC_DECIDE, pt = 0, st = 0;
9   PetscBool       flg = PETSC_FALSE, flg2, flg3;
10   DMBoundaryType  periodic;
11   DMDAStencilType stencil_type;
12   DM              da;
13   Vec             local, global, local_copy;
14   PetscScalar     value;
15   PetscReal       norm, work;
16   PetscViewer     viewer;
17   char            filename[64];
18   FILE           *file;
19 
20   PetscFunctionBeginUser;
21   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
22   PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
23   PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
24   PetscCall(PetscOptionsGetInt(NULL, NULL, "-dof", &dof, NULL));
25   PetscCall(PetscOptionsGetInt(NULL, NULL, "-stencil_width", &stencil_width, NULL));
26   PetscCall(PetscOptionsGetInt(NULL, NULL, "-periodic", &pt, NULL));
27 
28   periodic = (DMBoundaryType)pt;
29 
30   PetscCall(PetscOptionsGetInt(NULL, NULL, "-stencil_type", &st, NULL));
31 
32   stencil_type = (DMDAStencilType)st;
33 
34   PetscCall(PetscOptionsHasName(NULL, NULL, "-grid2d", &flg2));
35   PetscCall(PetscOptionsHasName(NULL, NULL, "-grid3d", &flg3));
36   if (flg2) {
37     PetscCall(DMDACreate2d(PETSC_COMM_WORLD, periodic, periodic, stencil_type, M, N, m, n, dof, stencil_width, NULL, NULL, &da));
38   } else if (flg3) {
39     PetscCall(DMDACreate3d(PETSC_COMM_WORLD, periodic, periodic, periodic, stencil_type, M, N, P, m, n, p, dof, stencil_width, NULL, NULL, NULL, &da));
40   } else {
41     PetscCall(DMDACreate1d(PETSC_COMM_WORLD, periodic, M, dof, stencil_width, NULL, &da));
42   }
43   PetscCall(DMSetFromOptions(da));
44   PetscCall(DMSetUp(da));
45 
46   PetscCall(DMCreateGlobalVector(da, &global));
47   PetscCall(DMCreateLocalVector(da, &local));
48   PetscCall(VecDuplicate(local, &local_copy));
49 
50   /* zero out vectors so that ghostpoints are zero */
51   value = 0;
52   PetscCall(VecSet(local, value));
53   PetscCall(VecSet(local_copy, value));
54 
55   PetscCall(VecGetOwnershipRange(global, &start, &end));
56   for (i = start; i < end; i++) {
57     value = i + 1;
58     PetscCall(VecSetValues(global, 1, &i, &value, INSERT_VALUES));
59   }
60   PetscCall(VecAssemblyBegin(global));
61   PetscCall(VecAssemblyEnd(global));
62 
63   PetscCall(DMGlobalToLocalBegin(da, global, INSERT_VALUES, local));
64   PetscCall(DMGlobalToLocalEnd(da, global, INSERT_VALUES, local));
65 
66   PetscCall(DMLocalToLocalBegin(da, local, INSERT_VALUES, local_copy));
67   PetscCall(DMLocalToLocalEnd(da, local, INSERT_VALUES, local_copy));
68 
69   PetscCall(PetscOptionsGetBool(NULL, NULL, "-save", &flg, NULL));
70   if (flg) {
71     PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
72     PetscCall(PetscSNPrintf(filename, PETSC_STATIC_ARRAY_LENGTH(filename), "local.%d", rank));
73     PetscCall(PetscViewerASCIIOpen(PETSC_COMM_SELF, filename, &viewer));
74     PetscCall(PetscViewerASCIIGetPointer(viewer, &file));
75     PetscCall(VecView(local, viewer));
76     fprintf(file, "Vector with correct ghost points\n");
77     PetscCall(VecView(local_copy, viewer));
78     PetscCall(PetscViewerDestroy(&viewer));
79   }
80 
81   PetscCall(VecAXPY(local_copy, -1.0, local));
82   PetscCall(VecNorm(local_copy, NORM_MAX, &work));
83   PetscCallMPI(MPIU_Allreduce(&work, &norm, 1, MPIU_REAL, MPIU_MAX, PETSC_COMM_WORLD));
84   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Norm of difference %g should be zero\n", (double)norm));
85 
86   PetscCall(VecDestroy(&local_copy));
87   PetscCall(VecDestroy(&local));
88   PetscCall(VecDestroy(&global));
89   PetscCall(DMDestroy(&da));
90   PetscCall(PetscFinalize());
91   return 0;
92 }
93 
94 /*TEST
95 
96    test:
97       nsize: 8
98       args: -dof 3 -stencil_width 2 -M 50 -N 50 -periodic
99 
100    test:
101       suffix: 2
102       nsize: 8
103       args: -dof 3 -stencil_width 2 -M 50 -N 50 -periodic -grid2d
104       output_file: output/ex7_1.out
105 
106    test:
107       suffix: 3
108       nsize: 8
109       args: -dof 3 -stencil_width 2 -M 50 -N 50 -periodic -grid3d
110       output_file: output/ex7_1.out
111 
112 TEST*/
113