xref: /petsc/src/dm/dt/tests/ex5.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
1 static char help[] = "Tests affine subspaces.\n\n";
2 
3 #include <petscfe.h>
4 #include <petscdmplex.h>
5 #include <petscdmshell.h>
6 
7 int main(int argc, char **argv)
8 {
9   DM             dm;
10   PetscFE        fe;
11   PetscSpace     space;
12   PetscDualSpace dualspace, dualsubspace;
13   PetscInt       dim = 2, Nc = 3, cStart, cEnd;
14   PetscBool      simplex = PETSC_TRUE;
15   MPI_Comm       comm;
16   PetscErrorCode ierr;
17 
18   PetscCall(PetscInitialize(&argc,&argv,NULL,help));
19   comm = PETSC_COMM_WORLD;
20   ierr = PetscOptionsBegin(comm,"","Options for subspace test","none");PetscCall(ierr);
21   PetscCall(PetscOptionsRangeInt("-dim", "The spatial dimension","ex5.c",dim,&dim,NULL,1,3));
22   PetscCall(PetscOptionsBool("-simplex", "Test simplex element","ex5.c",simplex,&simplex,NULL));
23   PetscCall(PetscOptionsBoundedInt("-num_comp", "Number of components in space","ex5.c",Nc,&Nc,NULL,1));
24   ierr = PetscOptionsEnd();PetscCall(ierr);
25   PetscCall(DMShellCreate(comm,&dm));
26   PetscCall(PetscFECreateDefault(comm,dim,Nc,simplex,NULL,PETSC_DEFAULT,&fe));
27   PetscCall(DMDestroy(&dm));
28   PetscCall(PetscFESetName(fe, "solution"));
29   PetscCall(PetscFEGetBasisSpace(fe,&space));
30   PetscCall(PetscSpaceGetNumComponents(space,&Nc));
31   PetscCall(PetscFEGetDualSpace(fe,&dualspace));
32   PetscCall(PetscDualSpaceGetHeightSubspace(dualspace,1,&dualsubspace));
33   PetscCall(PetscDualSpaceGetDM(dualspace,&dm));
34   PetscCall(DMPlexGetHeightStratum(dm,0,&cStart,&cEnd));
35   if (cEnd > cStart) {
36     PetscInt coneSize;
37 
38     PetscCall(DMPlexGetConeSize(dm,cStart,&coneSize));
39     if (coneSize) {
40       PetscFE traceFE;
41       const PetscInt *cone;
42       PetscInt        point, nSub, nFull;
43       PetscReal       xi0[3] = {-1., -1., -1.};
44       PetscScalar     *outSub, *outFull;
45       PetscReal       *testSub, *testFull;
46       PetscTabulation Tsub, Tfull;
47       PetscReal       J[9], detJ;
48       PetscInt        i, j;
49       PetscSection    sectionFull;
50       Vec             vecFull;
51       PetscScalar     *arrayFull, *arraySub;
52       PetscReal       err;
53       PetscRandom     rand;
54 
55       PetscCall(DMPlexGetCone(dm,cStart,&cone));
56       point = cone[0];
57       PetscCall(PetscFECreatePointTrace(fe,point,&traceFE));
58       PetscCall(PetscFESetUp(traceFE));
59       PetscCall(PetscFEViewFromOptions(traceFE,NULL,"-trace_fe_view"));
60       PetscCall(PetscMalloc4(dim - 1,&testSub,dim,&testFull,Nc,&outSub,Nc,&outFull));
61       PetscCall(PetscRandomCreate(PETSC_COMM_SELF,&rand));
62       PetscCall(PetscRandomSetFromOptions(rand));
63       PetscCall(PetscRandomSetInterval(rand,-1.,1.));
64       /* create a random point in the trace domain */
65       for (i = 0; i < dim - 1; i++) {
66         PetscCall(PetscRandomGetValueReal(rand,&testSub[i]));
67       }
68       PetscCall(DMPlexComputeCellGeometryFEM(dm,point,NULL,testFull,J,NULL,&detJ));
69       /* project it into the full domain */
70       for (i = 0; i < dim; i++) {
71         for (j = 0; j < dim - 1; j++) testFull[i] += J[i * dim + j] * (testSub[j] - xi0[j]);
72       }
73       /* create a random vector in the full domain */
74       PetscCall(PetscFEGetDimension(fe,&nFull));
75       PetscCall(VecCreateSeq(PETSC_COMM_SELF,nFull,&vecFull));
76       PetscCall(VecGetArray(vecFull,&arrayFull));
77       for (i = 0; i < nFull; i++) {
78         PetscCall(PetscRandomGetValue(rand,&arrayFull[i]));
79       }
80       PetscCall(VecRestoreArray(vecFull,&arrayFull));
81       /* create a vector on the trace domain */
82       PetscCall(PetscFEGetDimension(traceFE,&nSub));
83       /* get the subset of the original finite element space that is supported on the trace space */
84       PetscCall(PetscDualSpaceGetSection(dualspace,&sectionFull));
85       PetscCall(PetscSectionSetUp(sectionFull));
86       /* get the trace degrees of freedom */
87       PetscCall(PetscMalloc1(nSub,&arraySub));
88       PetscCall(DMPlexVecGetClosure(dm,sectionFull,vecFull,point,&nSub,&arraySub));
89       /* get the tabulations */
90       PetscCall(PetscFECreateTabulation(traceFE,1,1,testSub,0,&Tsub));
91       PetscCall(PetscFECreateTabulation(fe,1,1,testFull,0,&Tfull));
92       for (i = 0; i < Nc; i++) {
93         outSub[i] = 0.0;
94         for (j = 0; j < nSub; j++) {
95           outSub[i] += Tsub->T[0][j * Nc + i] * arraySub[j];
96         }
97       }
98       PetscCall(VecGetArray(vecFull,&arrayFull));
99       err = 0.0;
100       for (i = 0; i < Nc; i++) {
101         PetscScalar diff;
102 
103         outFull[i] = 0.0;
104         for (j = 0; j < nFull; j++) {
105           outFull[i] += Tfull->T[0][j * Nc + i] * arrayFull[j];
106         }
107         diff = outFull[i] - outSub[i];
108         err += PetscRealPart(PetscConj(diff) * diff);
109       }
110       err = PetscSqrtReal(err);
111       if (err > PETSC_SMALL) {
112         SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Trace FE error %g",err);
113       }
114       PetscCall(VecRestoreArray(vecFull,&arrayFull));
115       PetscCall(PetscTabulationDestroy(&Tfull));
116       PetscCall(PetscTabulationDestroy(&Tsub));
117       /* clean up */
118       PetscCall(PetscFree(arraySub));
119       PetscCall(VecDestroy(&vecFull));
120       PetscCall(PetscRandomDestroy(&rand));
121       PetscCall(PetscFree4(testSub,testFull,outSub,outFull));
122       PetscCall(PetscFEDestroy(&traceFE));
123     }
124   }
125   PetscCall(PetscFEDestroy(&fe));
126   PetscCall(PetscFinalize());
127   return 0;
128 }
129 
130 /*TEST
131   test:
132     suffix: 0
133     args: -petscspace_degree 1 -trace_fe_view
134 TEST*/
135