xref: /petsc/src/mat/tests/ex240.c (revision 8fb5bd83c3955fefcf33a54e3bb66920a9fa884b)
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   PetscCall(PetscInitialize(&argc,&argv,NULL,help));
23   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
24   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));
25   PetscCall(DMSetUp(da));
26   PetscCall(DMCreateMatrix(da,&A));
27 
28   /* 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 */
29   /*    first put the coloring in the global ordering */
30   PetscCall(DMCreateColoring(da,IS_COLORING_LOCAL,&iscoloring));
31   PetscCall(ISColoringGetColors(iscoloring,&n,&nc,&icolors));
32   PetscCall(DMGetLocalToGlobalMapping(da,&ltog));
33   PetscCall(PetscMalloc1(n,&map));
34   for (i=0; i<n; i++) map[i] = i;
35   PetscCall(ISLocalToGlobalMappingApply(ltog,n,map,map));
36   PetscCall(MatGetSize(A,&N,NULL));
37   PetscCall(PetscMalloc1(N,&colors));
38   for (i=0; i<N; i++) colors[i] = -1;
39   for (i=0; i<n; i++) colors[map[i]]= icolors[i];
40   PetscCall(PetscFree(map));
41   PetscCall(PetscSynchronizedPrintf(MPI_COMM_WORLD,"[%d]Global colors \n",rank));
42   for (i=0; i<N; i++) PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD,"%" PetscInt_FMT " %" PetscInt_FMT "\n",i,colors[i]));
43   PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD,stdout));
44 
45   /*   second, compress the A matrix */
46   PetscCall(MatSetRandom(A,NULL));
47   PetscCall(MatView(A,NULL));
48   PetscCall(MatGetLocalSize(A,&nrow,NULL));
49   PetscCall(MatGetOwnershipRange(A,&rstart,NULL));
50   PetscCall(PetscCalloc1(nrow*nc,&cm));
51   for (i=0; i<nrow; i++) {
52     PetscCall(MatGetRow(A,rstart+i,&ncols,&cols,&vals));
53     for (j=0; j<ncols; j++) {
54       PetscCheck(colors[cols[j]] >= 0,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Global column %" PetscInt_FMT " had no color",cols[j]);
55       cm[i + nrow*colors[cols[j]]] = vals[j];
56     }
57     PetscCall(MatRestoreRow(A,rstart+i,&ncols,&cols,&vals));
58   }
59 
60   /* print compressed matrix */
61   PetscCall(PetscSynchronizedPrintf(MPI_COMM_WORLD,"[%d] Compressed matrix \n",rank));
62   for (i=0; i<nrow; i++) {
63     for (j=0; j<nc; j++) {
64       PetscCall(PetscSynchronizedPrintf(MPI_COMM_WORLD,"%12.4e  ",(double)PetscAbsScalar(cm[i+nrow*j])));
65     }
66     PetscCall(PetscSynchronizedPrintf(MPI_COMM_WORLD,"\n"));
67   }
68   PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD,stdout));
69 
70   /* put the compressed matrix into the standard matrix */
71   PetscCall(MatDuplicate(A,MAT_COPY_VALUES,&B));
72   PetscCall(MatZeroEntries(A));
73   PetscCall(MatView(B,0));
74   PetscCall(MatFDColoringCreate(A,iscoloring,&fdcoloring));
75   PetscCall(PetscOptionsHasName(NULL,NULL,"-single_block",&single));
76   if (single) PetscCall(MatFDColoringSetBlockSize(fdcoloring,PETSC_DEFAULT,nc));
77   PetscCall(PetscOptionsHasName(NULL,NULL,"-two_block",&two));
78   if (two) PetscCall(MatFDColoringSetBlockSize(fdcoloring,PETSC_DEFAULT,2));
79   PetscCall(MatFDColoringSetFromOptions(fdcoloring));
80   PetscCall(MatFDColoringSetUp(A,iscoloring,fdcoloring));
81 
82   PetscCall(MatFDColoringSetValues(A,fdcoloring,cm));
83   PetscCall(MatView(A,NULL));
84 
85   /* check the values were put in the correct locations */
86   PetscCall(MatAXPY(A,-1.0,B,SAME_NONZERO_PATTERN));
87   PetscCall(MatView(A,NULL));
88   PetscCall(MatNorm(A,NORM_FROBENIUS,&norm));
89   if (norm > PETSC_MACHINE_EPSILON) {
90     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Matrix is not identical, problem with MatFDColoringSetValues()\n"));
91   }
92   PetscCall(PetscFree(colors));
93   PetscCall(PetscFree(cm));
94   PetscCall(ISColoringDestroy(&iscoloring));
95   PetscCall(MatFDColoringDestroy(&fdcoloring));
96   PetscCall(MatDestroy(&A));
97   PetscCall(MatDestroy(&B));
98   PetscCall(DMDestroy(&da));
99   PetscCall(PetscFinalize());
100   return 0;
101 }
102 
103 /*TEST
104 
105    test:
106       nsize: 2
107       requires: !complex
108 
109    test:
110       suffix: single
111       requires: !complex
112       nsize: 2
113       args: -single_block
114       output_file: output/ex240_1.out
115 
116    test:
117       suffix: two
118       requires: !complex
119       nsize: 2
120       args: -two_block
121       output_file: output/ex240_1.out
122 
123    test:
124       suffix: 2
125       requires: !complex
126       nsize: 5
127 
128 TEST*/
129