xref: /petsc/src/dm/dt/dualspace/impls/lagrange/tutorials/ex1.c (revision 061e922f3926be00487707c73b78dd3d40309129)
1 const char help[] = "Construct and set a Lagrange dual space from options, then view it to\n"
2                     "understand the effects of different parameters.";
3 
4 #include <petscfe.h>
5 #include <petscdmplex.h>
6 
main(int argc,char ** argv)7 int main(int argc, char **argv)
8 {
9   PetscInt       dim;
10   PetscBool      tensorCell;
11   DM             K;
12   PetscDualSpace dsp;
13 
14   PetscFunctionBeginUser;
15   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
16   dim        = 2;
17   tensorCell = PETSC_FALSE;
18   PetscOptionsBegin(PETSC_COMM_WORLD, "", "Options for PETSCDUALSPACELAGRANGE test", "none");
19   PetscCall(PetscOptionsRangeInt("-dim", "The spatial dimension", "ex1.c", dim, &dim, NULL, 0, 3));
20   PetscCall(PetscOptionsBool("-tensor", "Whether the cell is a tensor product cell or a simplex", "ex1.c", tensorCell, &tensorCell, NULL));
21   PetscOptionsEnd();
22 
23   PetscCall(PetscDualSpaceCreate(PETSC_COMM_WORLD, &dsp));
24   PetscCall(PetscObjectSetName((PetscObject)dsp, "Lagrange dual space"));
25   PetscCall(PetscDualSpaceSetType(dsp, PETSCDUALSPACELAGRANGE));
26   /* While Lagrange nodes don't require the existence of a reference cell to
27    * be refined, when we construct finite element dual spaces we have to be
28    * careful about what kind of continuity is maintained when cells are glued
29    * together to make a mesh.  The PetscDualSpace object is responsible for
30    * conveying continuity requirements to a finite element assembly routines,
31    * so a PetscDualSpace needs a reference element: a single element mesh,
32    * whose boundary points are the interstitial points in a mesh */
33   PetscCall(DMPlexCreateReferenceCell(PETSC_COMM_WORLD, DMPolytopeTypeSimpleShape(dim, (PetscBool)!tensorCell), &K));
34   PetscCall(PetscDualSpaceSetDM(dsp, K));
35   /* This gives us the opportunity to change the parameters of the dual space
36    * from the command line, as we do in the tests below.  When
37    * PetscDualSpaceSetFromOptions() is called, it also enables other optional
38    * behavior (see the next step) */
39   PetscCall(PetscDualSpaceSetFromOptions(dsp));
40   /* This step parses the parameters of the dual space into
41    * sets of functionals that are assigned to each of the mesh points in K.
42    *
43    * The functionals can be accessed individually by
44    * PetscDualSpaceGetFunctional(), or more efficiently all at once by
45    * PetscDualSpaceGetAllData(), which returns a set of quadrature points
46    * at which to evaluate a function, and a matrix that takes those
47    * evaluations and turns them into the evaluation of the dual space's
48    * functionals on the function.
49    *
50    * (TODO: tutorial for PetscDualSpaceGetAllData() and
51    * PetscDualSpaceGetInteriorData().)
52    *
53    * Because we called PetscDualSpaceSetFromOptions(), we have the opportunity
54    * to inspect the results of PetscDualSpaceSetUp() from the command line
55    * with "-petscdualspace_view", followed by an optional description of how
56    * we would like to see the dual space (see examples in the tests below).
57    * */
58   PetscCall(PetscDualSpaceSetUp(dsp));
59   PetscCall(DMDestroy(&K));
60   PetscCall(PetscDualSpaceDestroy(&dsp));
61   PetscCall(PetscFinalize());
62   return 0;
63 }
64 
65 /*TEST
66 
67   # quadratic nodes on the triangle
68   test:
69     suffix: 0
70     filter: sed -E "s/\(\+0, \+0\)/(+0., +0.)/g"
71     args: -dim 2 -tensor 0 -petscdualspace_order 2 -petscdualspace_view ascii::ascii_info_detail
72 
73   # linear nodes on the quadrilateral
74   test:
75     suffix: 1
76     args: -dim 2 -tensor 1 -petscdualspace_order 1 -petscdualspace_lagrange_tensor 1 -petscdualspace_view ascii::ascii_info_detail
77 
78   # lowest order Raviart-Thomas / Nedelec edge nodes on the hexahedron
79   test:
80     suffix: 2
81     args: -dim 3 -tensor 1 -petscdualspace_order 1 -petscdualspace_components 3 -petscdualspace_form_degree 1 -petscdualspace_lagrange_trimmed 1 -petscdualspace_lagrange_tensor 1 -petscdualspace_view ascii::ascii_info_detail
82 
83   # first order Nedelec second type face nodes on the tetrahedron
84   test:
85     suffix: 3
86     args: -dim 3 -tensor 0 -petscdualspace_order 1 -petscdualspace_components 3 -petscdualspace_form_degree -2 -petscdualspace_view ascii::ascii_info_detail
87 
88   ## Comparing different node types
89 
90   test:
91     suffix: 4
92     args: -dim 2 -tensor 0 -petscdualspace_order 3 -petscdualspace_lagrange_continuity 0 -petscdualspace_lagrange_node_type equispaced -petscdualspace_lagrange_node_endpoints 0 -petscdualspace_view ascii::ascii_info_detail
93 
94   test:
95     suffix: 5
96     args: -dim 2 -tensor 0 -petscdualspace_order 3 -petscdualspace_lagrange_continuity 0 -petscdualspace_lagrange_node_type equispaced -petscdualspace_lagrange_node_endpoints 1 -petscdualspace_view ascii::ascii_info_detail
97 
98   test:
99     suffix: 6
100     args: -dim 2 -tensor 0 -petscdualspace_order 3 -petscdualspace_lagrange_continuity 0 -petscdualspace_lagrange_node_type gaussjacobi -petscdualspace_lagrange_node_endpoints 0 -petscdualspace_view ascii::ascii_info_detail
101 
102   test:
103     suffix: 7
104     args: -dim 2 -tensor 0 -petscdualspace_order 3 -petscdualspace_lagrange_continuity 0 -petscdualspace_lagrange_node_type gaussjacobi -petscdualspace_lagrange_node_endpoints 1 -petscdualspace_view ascii::ascii_info_detail
105 
106 TEST*/
107