xref: /petsc/src/dm/dt/tests/ex2.c (revision 63a3b9bc7a1f24f247904ccba9383635fe6abade)
1c4762a1bSJed Brown static char help[] = "Tests 1D cell-based discretization tools.\n\n";
2c4762a1bSJed Brown 
3c4762a1bSJed Brown #include <petscdt.h>
4c4762a1bSJed Brown #include <petscviewer.h>
5c4762a1bSJed Brown 
6c4762a1bSJed Brown int main(int argc,char **argv)
7c4762a1bSJed Brown {
8c4762a1bSJed Brown   PetscInt       i,j,degrees[1000],ndegrees,nsrc_points,ntarget_points;
9c4762a1bSJed Brown   PetscReal      src_points[1000],target_points[1000],*R;
10c4762a1bSJed Brown   PetscBool      flg;
11c4762a1bSJed Brown 
129566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
13d0609cedSBarry Smith   PetscOptionsBegin(PETSC_COMM_WORLD,NULL,"Discretization tools test options",NULL);
14c4762a1bSJed Brown   {
15c4762a1bSJed Brown     ndegrees   = 1000;
16c4762a1bSJed Brown     degrees[0] = 1;
17c4762a1bSJed Brown     degrees[1] = 2;
18c4762a1bSJed Brown     degrees[2] = 3;
199566063dSJacob Faibussowitsch     PetscCall(PetscOptionsIntArray("-degrees","list of max degrees to evaluate","",degrees,&ndegrees,&flg));
20c4762a1bSJed Brown     if (!flg) ndegrees = 3;
21c4762a1bSJed Brown 
22c4762a1bSJed Brown     nsrc_points   = 1000;
23c4762a1bSJed Brown     src_points[0] = -1.;
24c4762a1bSJed Brown     src_points[1] = 0.;
25c4762a1bSJed Brown     src_points[2] = 1.;
269566063dSJacob Faibussowitsch     PetscCall(PetscOptionsRealArray("-src_points","list of points defining intervals on which to integrate","",src_points,&nsrc_points,&flg));
27c4762a1bSJed Brown     if (!flg) nsrc_points = 3;
28c4762a1bSJed Brown 
29c4762a1bSJed Brown     ntarget_points   = 1000;
30c4762a1bSJed Brown     target_points[0] = -1.;
31c4762a1bSJed Brown     target_points[1] = 0.;
32c4762a1bSJed Brown     target_points[2] = 1.;
339566063dSJacob Faibussowitsch     PetscCall(PetscOptionsRealArray("-target_points","list of points defining intervals on which to integrate","",target_points,&ntarget_points,&flg));
34c4762a1bSJed Brown     if (!flg) ntarget_points = 3;
35c4762a1bSJed Brown   }
36d0609cedSBarry Smith   PetscOptionsEnd();
37c4762a1bSJed Brown 
389566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1((nsrc_points-1)*(ntarget_points-1),&R));
39c4762a1bSJed Brown   for (i=0; i<ndegrees; i++) {
409566063dSJacob Faibussowitsch     PetscCall(PetscDTReconstructPoly(degrees[i],nsrc_points-1,src_points,ntarget_points-1,target_points,R));
41c4762a1bSJed Brown     for (j=0; j<(ntarget_points-1)*(nsrc_points-1); j++) { /* Truncate to zero for nicer output */
42c4762a1bSJed Brown       if (PetscAbs(R[j]) < 10*PETSC_MACHINE_EPSILON) R[j] = 0;
43c4762a1bSJed Brown     }
44c4762a1bSJed Brown     for (j=0; j<ntarget_points-1; j++) {
45*63a3b9bcSJacob Faibussowitsch       PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Degree %" PetscInt_FMT " target interval (%g,%g)\n",degrees[i],(double)target_points[j],(double)target_points[j+1]));
469566063dSJacob Faibussowitsch       PetscCall(PetscRealView(nsrc_points-1,R+j*(nsrc_points-1),PETSC_VIEWER_STDOUT_WORLD));
47c4762a1bSJed Brown     }
48c4762a1bSJed Brown   }
499566063dSJacob Faibussowitsch   PetscCall(PetscFree(R));
509566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
51b122ec5aSJacob Faibussowitsch   return 0;
52c4762a1bSJed Brown }
53c4762a1bSJed Brown 
54c4762a1bSJed Brown /*TEST
55c4762a1bSJed Brown   test:
56c4762a1bSJed Brown     suffix: 1
57c4762a1bSJed Brown     args: -degrees 1,2,3 -target_points -0.3,0,.2 -src_points -1,-.3,0,.2,1
58c4762a1bSJed Brown TEST*/
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