xref: /petsc/src/dm/dt/tests/ex6.c (revision 327415f76d85372a4417cf1aaa14db707d4d6c04)
1c4762a1bSJed Brown static char help[] = "Tests 1D Gauss-Lobatto-Legendre discretization on [-1, 1].\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 
9c4762a1bSJed Brown   PetscInt       n = 3,i;
10c4762a1bSJed Brown   PetscReal      *la_nodes,*la_weights,*n_nodes,*n_weights;
11c4762a1bSJed Brown 
12*327415f7SBarry Smith   PetscFunctionBeginUser;
139566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
149566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
15c4762a1bSJed Brown 
169566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(n,&la_nodes));
179566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(n,&la_weights));
189566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(n,&n_nodes));
199566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(n,&n_weights));
209566063dSJacob Faibussowitsch   PetscCall(PetscDTGaussLobattoLegendreQuadrature(n,PETSCGAUSSLOBATTOLEGENDRE_VIA_LINEAR_ALGEBRA,la_nodes,la_weights));
21c4762a1bSJed Brown 
229566063dSJacob Faibussowitsch   PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_SELF,"Gauss-Lobatto-Legendre nodes and weights computed via linear algebra: \n"));
239566063dSJacob Faibussowitsch   PetscCall(PetscRealView(n,la_nodes,PETSC_VIEWER_STDOUT_SELF));
249566063dSJacob Faibussowitsch   PetscCall(PetscRealView(n,la_weights,PETSC_VIEWER_STDOUT_SELF));
259566063dSJacob Faibussowitsch   PetscCall(PetscDTGaussLobattoLegendreQuadrature(n,PETSCGAUSSLOBATTOLEGENDRE_VIA_NEWTON,n_nodes,n_weights));
269566063dSJacob Faibussowitsch   PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_SELF,"Gauss-Lobatto-Legendre nodes and weights computed via Newton: \n"));
279566063dSJacob Faibussowitsch   PetscCall(PetscRealView(n,n_nodes,PETSC_VIEWER_STDOUT_SELF));
289566063dSJacob Faibussowitsch   PetscCall(PetscRealView(n,n_weights,PETSC_VIEWER_STDOUT_SELF));
29c4762a1bSJed Brown 
30c4762a1bSJed Brown   for (i=0; i<n; i++) {
31c4762a1bSJed Brown     la_nodes[i]   -= n_nodes[i];
32c4762a1bSJed Brown     la_weights[i] -= n_weights[i];
33c4762a1bSJed Brown   }
349566063dSJacob Faibussowitsch   PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_SELF,"Difference: \n"));
359566063dSJacob Faibussowitsch   PetscCall(PetscRealView(n,la_nodes,PETSC_VIEWER_STDOUT_SELF));
369566063dSJacob Faibussowitsch   PetscCall(PetscRealView(n,la_weights,PETSC_VIEWER_STDOUT_SELF));
37c4762a1bSJed Brown 
389566063dSJacob Faibussowitsch   PetscCall(PetscFree(la_nodes));
399566063dSJacob Faibussowitsch   PetscCall(PetscFree(la_weights));
409566063dSJacob Faibussowitsch   PetscCall(PetscFree(n_nodes));
419566063dSJacob Faibussowitsch   PetscCall(PetscFree(n_weights));
42c4762a1bSJed Brown 
439566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
44b122ec5aSJacob Faibussowitsch   return 0;
45c4762a1bSJed Brown }
46c4762a1bSJed Brown 
47c4762a1bSJed Brown /*TEST
48c4762a1bSJed Brown 
49c4762a1bSJed Brown    test:
50c4762a1bSJed Brown 
51c4762a1bSJed Brown TEST*/
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