xref: /petsc/src/dm/impls/plex/tests/dmplexcomputecellgeometryfem.F90 (revision 2ff79c18c26c94ed8cb599682f680f231dca6444)
1!     Contributed by Noem T
2program test
3#include <petsc/finclude/petscdmplex.h>
4#include <petsc/finclude/petscdm.h>
5use PETScDM
6use PETScDMplex
7implicit none
8DM       :: dm
9PetscInt :: numCells = 1
10PetscInt :: cStart
11PetscInt :: numVertices = 3, numCorners = 3
12PetscErrorCode :: ierr
13PetscInt, parameter :: numDim = 2
14PetscReal,    parameter :: eps = 5.0 * epsilon(1.0)
15PetscCallA(PetscInitialize(ierr))
16triangle: block
17
18!
19! Single triangle element
20! Corner coordinates (1, 1), (5, 5), (3, 6)
21! Using a 3-point quadrature rule
22!
23PetscInt :: i
24PetscInt :: zero = 0
25
26! Number of quadrature points
27PetscInt, parameter :: tria_qpts = 3
28! Quadrature order
29PetscInt, parameter :: tria_qorder = 2
30! Mapped quadrature points
31PetscReal, parameter :: tria_v(tria_qpts*numDim)    = [2.0, 2.5, 3.0, 5.0, 4.0, 4.5]
32! Jacobian (constant, repeated tria_qpts times)
33PetscReal, parameter :: tria_J(tria_qpts*numDim**2) = [([2.0, 1.0, 2.0, 2.5], i = 1, tria_qpts)]
34
35PetscQuadrature :: q
36PetscReal :: J(tria_qpts*numDim**2), invJ(tria_qpts*numDim**2), v(tria_qpts*numDim), detJ(tria_qpts)
37PetscReal :: vertexCoords(6) = 1.0 * [1.0, 1.0, 5.0, 5.0, 3.0, 6.0]
38PetscInt  :: cells(3) = [0, 1, 2]
39
40PetscCallA(DMPlexCreateFromCellListPetsc(PETSC_COMM_WORLD,numDim,numCells,numVertices,numCorners,PETSC_FALSE,cells,numDim,vertexCoords,dm,ierr))
41PetscCallA(PetscDTSimplexQuadrature(numDim, tria_qorder, PETSCDTSIMPLEXQUAD_DEFAULT, q, ierr))
42PetscCallA(DMPlexGetHeightStratum(dm, zero, cStart, PETSC_NULL_INTEGER, ierr))
43PetscCallA(DMPlexComputeCellGeometryFEM(dm, cStart, q, v, J, invJ, detJ, ierr))
44PetscCheckA(all(abs(v - tria_v) < eps), PETSC_COMM_WORLD, PETSC_ERR_PLIB, 'Wrong mapped quadrature points (triangle)')
45PetscCheckA(all(abs(J - tria_J) < eps), PETSC_COMM_WORLD, PETSC_ERR_PLIB, 'Wrong jacobian (triangle)')
46PetscCallA(PetscQuadratureDestroy(q, ierr))
47PetscCallA(DMDestroy(dm,ierr))
48end block triangle
49
50quadrilateral: block
51
52!
53! Single quadrilateral element
54! Corner coordinates (-3, -2), (3, -1), (2, 4), (-2, 3)
55! Using a 4-point (2x2) Gauss quadrature rule
56!
57
58! Number of quadrature points
59PetscInt, parameter :: quad_qpts = 4
60
61PetscQuadrature :: q
62PetscReal :: vertexCoords(8) = [-3.0, -2.0, 3.0, -1.0, 2.0, 4.0, -2.0, 3.0]
63PetscReal :: J(quad_qpts*numDim**2), invJ(quad_qpts*numDim**2), v(quad_qpts*numDim), detJ(quad_qpts)
64PetscReal :: a = -1.0, b = 1.0
65PetscInt  :: cells(4) = [0, 1, 2, 3]
66PetscInt  :: nc = 1, npoints = 2
67PetscInt  :: k
68PetscInt :: zero = 0
69
70numCells = 1
71numCorners = 4
72numVertices = 4
73
74PetscCallA(DMPlexCreateFromCellListPetsc(PETSC_COMM_WORLD,numDim,numCells,numVertices, numCorners,PETSC_FALSE,cells,numDim,vertexCoords,dm,ierr))
75PetscCallA(PetscDTGaussTensorQuadrature(numDim, nc, npoints, a, b, q, ierr))
76PetscCallA(DMPlexGetHeightStratum(dm, zero, cStart, PETSC_NULL_INTEGER, ierr))
77PetscCallA(DMPlexComputeCellGeometryFEM(dm, cStart, q, v, J, invJ, detJ, ierr))
78do k = 1, quad_qpts
79  PetscCheckA(all(abs(v((k-1)*numDim+1:k*numDim) - quad_v(Gauss_rs(k))) < eps), PETSC_COMM_WORLD, PETSC_ERR_PLIB, 'Wrong mapped quadrature points (quadrilateral)')
80  PetscCheckA(all(abs(J((k-1)*numDim**2+1:k*numDim**2) - quad_J(Gauss_rs(k))) < eps), PETSC_COMM_WORLD, PETSC_ERR_PLIB,  'Wrong jacobian (quadrilateral)')
81end do
82PetscCallA(PetscQuadratureDestroy(q, ierr))
83PetscCallA(DMDestroy(dm,ierr))
84end block quadrilateral
85PetscCallA(PetscFinalize(ierr))
86
87contains
88! Quadrature points in a quadrilateral in [-1,+1]
89function Gauss_rs(n)
90PetscInt, intent(in) :: n
91PetscReal :: Gauss_rs(2)
92
93  PetscReal, parameter :: p = 1.0/sqrt(3.0)
94
95  select case(n)
96  case(1)
97    Gauss_rs = [-p, -p]
98  case(2)
99    Gauss_rs = [-p, +p]
100  case(3)
101    Gauss_rs = [+p, -p]
102  case(4)
103    Gauss_rs = [+p, +p]
104end select
105end function Gauss_rs
106! Mapped quadrature points
107function quad_v(rs)
108PetscReal, intent(in) :: rs(2)
109PetscReal :: quad_v(2)
110
111  PetscReal :: r, s
112
113  r = rs(1)
114  s = rs(2)
115  quad_v(1) = -0.5*r*(s-5)       ! sum N_i * x_i
116  quad_v(2) = 0.5*(r+5*s+2)      ! sum N_i * y_i
117
118end function quad_v
119! Jacobian
120function quad_J(rs)
121PetscReal, intent(in) :: rs(2)
122PetscReal :: quad_J(4)
123
124  PetscReal :: r, s
125  PetscReal :: pfive = .5, twopfive = 2.5
126
127  r = rs(1)
128  s = rs(2)
129  quad_J = [-0.5*(s-5), -0.5*r, pfive, twopfive]
130end function quad_J
131end program test
132
133! /*TEST
134!
135! test:
136!   output_file: output/empty.out
137!
138! TEST*/
139