xref: /petsc/src/mat/tests/ex240.c (revision d5b43468fb8780a8feea140ccd6fa3e6a50411cc)
1 static char help[] = "Tests MatFDColoringSetValues()\n\n";
2 
3 #include <petscdm.h>
4 #include <petscdmda.h>
5 
6 int main(int argc, char **argv)
7 {
8   DM                     da;
9   PetscInt               N, mx = 5, my = 4, i, j, nc, nrow, n, ncols, rstart, *colors, *map;
10   const PetscInt        *cols;
11   const PetscScalar     *vals;
12   Mat                    A, B;
13   PetscReal              norm;
14   MatFDColoring          fdcoloring;
15   ISColoring             iscoloring;
16   PetscScalar           *cm;
17   const ISColoringValue *icolors;
18   PetscMPIInt            rank;
19   ISLocalToGlobalMapping ltog;
20   PetscBool              single, two;
21 
22   PetscFunctionBeginUser;
23   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
24   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
25   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_STAR, mx, my, PETSC_DECIDE, PETSC_DECIDE, 1, 1, NULL, NULL, &da));
26   PetscCall(DMSetUp(da));
27   PetscCall(DMCreateMatrix(da, &A));
28 
29   /* as a test copy the matrices from the standard format to the compressed format; this is not scalable but is ok because just for testing */
30   /*    first put the coloring in the global ordering */
31   PetscCall(DMCreateColoring(da, IS_COLORING_LOCAL, &iscoloring));
32   PetscCall(ISColoringGetColors(iscoloring, &n, &nc, &icolors));
33   PetscCall(DMGetLocalToGlobalMapping(da, &ltog));
34   PetscCall(PetscMalloc1(n, &map));
35   for (i = 0; i < n; i++) map[i] = i;
36   PetscCall(ISLocalToGlobalMappingApply(ltog, n, map, map));
37   PetscCall(MatGetSize(A, &N, NULL));
38   PetscCall(PetscMalloc1(N, &colors));
39   for (i = 0; i < N; i++) colors[i] = -1;
40   for (i = 0; i < n; i++) colors[map[i]] = icolors[i];
41   PetscCall(PetscFree(map));
42   PetscCall(PetscSynchronizedPrintf(MPI_COMM_WORLD, "[%d]Global colors \n", rank));
43   for (i = 0; i < N; i++) PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%" PetscInt_FMT " %" PetscInt_FMT "\n", i, colors[i]));
44   PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, stdout));
45 
46   /*   second, compress the A matrix */
47   PetscCall(MatSetRandom(A, NULL));
48   PetscCall(MatView(A, NULL));
49   PetscCall(MatGetLocalSize(A, &nrow, NULL));
50   PetscCall(MatGetOwnershipRange(A, &rstart, NULL));
51   PetscCall(PetscCalloc1(nrow * nc, &cm));
52   for (i = 0; i < nrow; i++) {
53     PetscCall(MatGetRow(A, rstart + i, &ncols, &cols, &vals));
54     for (j = 0; j < ncols; j++) {
55       PetscCheck(colors[cols[j]] >= 0, PETSC_COMM_WORLD, PETSC_ERR_PLIB, "Global column %" PetscInt_FMT " had no color", cols[j]);
56       cm[i + nrow * colors[cols[j]]] = vals[j];
57     }
58     PetscCall(MatRestoreRow(A, rstart + i, &ncols, &cols, &vals));
59   }
60 
61   /* print compressed matrix */
62   PetscCall(PetscSynchronizedPrintf(MPI_COMM_WORLD, "[%d] Compressed matrix \n", rank));
63   for (i = 0; i < nrow; i++) {
64     for (j = 0; j < nc; j++) PetscCall(PetscSynchronizedPrintf(MPI_COMM_WORLD, "%12.4e  ", (double)PetscAbsScalar(cm[i + nrow * j])));
65     PetscCall(PetscSynchronizedPrintf(MPI_COMM_WORLD, "\n"));
66   }
67   PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, stdout));
68 
69   /* put the compressed matrix into the standard matrix */
70   PetscCall(MatDuplicate(A, MAT_COPY_VALUES, &B));
71   PetscCall(MatZeroEntries(A));
72   PetscCall(MatView(B, 0));
73   PetscCall(MatFDColoringCreate(A, iscoloring, &fdcoloring));
74   PetscCall(PetscOptionsHasName(NULL, NULL, "-single_block", &single));
75   if (single) PetscCall(MatFDColoringSetBlockSize(fdcoloring, PETSC_DEFAULT, nc));
76   PetscCall(PetscOptionsHasName(NULL, NULL, "-two_block", &two));
77   if (two) PetscCall(MatFDColoringSetBlockSize(fdcoloring, PETSC_DEFAULT, 2));
78   PetscCall(MatFDColoringSetFromOptions(fdcoloring));
79   PetscCall(MatFDColoringSetUp(A, iscoloring, fdcoloring));
80 
81   PetscCall(MatFDColoringSetValues(A, fdcoloring, cm));
82   PetscCall(MatView(A, NULL));
83 
84   /* check the values were put in the correct locations */
85   PetscCall(MatAXPY(A, -1.0, B, SAME_NONZERO_PATTERN));
86   PetscCall(MatView(A, NULL));
87   PetscCall(MatNorm(A, NORM_FROBENIUS, &norm));
88   if (norm > PETSC_MACHINE_EPSILON) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Matrix is not identical, problem with MatFDColoringSetValues()\n"));
89   PetscCall(PetscFree(colors));
90   PetscCall(PetscFree(cm));
91   PetscCall(ISColoringDestroy(&iscoloring));
92   PetscCall(MatFDColoringDestroy(&fdcoloring));
93   PetscCall(MatDestroy(&A));
94   PetscCall(MatDestroy(&B));
95   PetscCall(DMDestroy(&da));
96   PetscCall(PetscFinalize());
97   return 0;
98 }
99 
100 /*TEST
101 
102    test:
103       nsize: 2
104       requires: !complex
105 
106    test:
107       suffix: single
108       requires: !complex
109       nsize: 2
110       args: -single_block
111       output_file: output/ex240_1.out
112 
113    test:
114       suffix: two
115       requires: !complex
116       nsize: 2
117       args: -two_block
118       output_file: output/ex240_1.out
119 
120    test:
121       suffix: 2
122       requires: !complex
123       nsize: 5
124 
125 TEST*/
126