1:       program DMPlexTestField
  2: #include <petsc/finclude/petscdmplex.h>
  3: #include <petsc/finclude/petscdmlabel.h>
  4:       use petscdm
  5:       implicit none

  7:       DM :: dm
  8:       DMLabel :: label
  9:       Vec :: u
 10:       PetscViewer :: viewer
 11:       PetscSection :: section
 12:       PetscInt :: dim,numFields,numBC
 13:       PetscInt :: i,val
 14:       PetscInt, target, dimension(3) ::  numComp
 15:       PetscInt, pointer :: pNumComp(:)
 16:       PetscInt, target, dimension(12) ::  numDof
 17:       PetscInt, pointer :: pNumDof(:)
 18:       PetscInt, target, dimension(1) ::  bcField
 19:       PetscInt, pointer :: pBcField(:)
 20:       PetscInt, parameter :: zero = 0, one = 1, two = 2, eight = 8
 21:       PetscMPIInt :: size
 22:       IS, target, dimension(1) ::   bcCompIS
 23:       IS, target, dimension(1) ::   bcPointIS
 24:       IS, pointer :: pBcCompIS(:)
 25:       IS, pointer :: pBcPointIS(:)
 26:       PetscErrorCode :: ierr

 28:       PetscCallA(PetscInitialize(ierr))
 29:       PetscCallMPIA(MPI_Comm_size(PETSC_COMM_WORLD, size, ierr))
 30: !     Create a mesh
 31:       PetscCallA(DMCreate(PETSC_COMM_WORLD, dm, ierr))
 32:       PetscCallA(DMSetType(dm, DMPLEX, ierr))
 33:       PetscCallA(DMSetFromOptions(dm, ierr))
 34:       PetscCallA(DMViewFromOptions(dm, PETSC_NULL_OBJECT, '-dm_view', ierr))
 35:       PetscCallA(DMGetDimension(dm, dim, ierr))
 36: !     Create a scalar field u, a vector field v, and a surface vector field w
 37:       numFields  = 3
 38:       numComp(1) = 1
 39:       numComp(2) = dim
 40:       numComp(3) = dim-1
 41:       pNumComp => numComp
 42:       do i = 1, numFields*(dim+1)
 43:          numDof(i) = 0
 44:       end do
 45: !     Let u be defined on vertices
 46:       numDof(0*(dim+1)+1)     = 1
 47: !     Let v be defined on cells
 48:       numDof(1*(dim+1)+dim+1) = dim
 49: !     Let v be defined on faces
 50:       numDof(2*(dim+1)+dim)   = dim-1
 51:       pNumDof => numDof
 52: !     Setup boundary conditions
 53:       numBC = 1
 54: !     Test label retrieval
 55:       PetscCallA(DMGetLabel(dm, 'marker', label, ierr))
 56:       PetscCallA(DMLabelGetValue(label, zero, val, ierr))
 57:       PetscCheckA(size .ne. 1 .or. val .eq. -1,PETSC_COMM_SELF,PETSC_ERR_PLIB,'Error in library')
 58:       PetscCallA(DMLabelGetValue(label, eight, val, ierr))
 59:       PetscCheckA(size .ne. 1 .or. val .eq. 1,PETSC_COMM_SELF,PETSC_ERR_PLIB,'Error in library')
 60: !     Prescribe a Dirichlet condition on u on the boundary
 61: !       Label "marker" is made by the mesh creation routine
 62:       bcField(1) = 0
 63:       pBcField => bcField
 64:       PetscCallA(ISCreateStride(PETSC_COMM_WORLD, one, zero, one, bcCompIS(1), ierr))
 65:       pBcCompIS => bcCompIS
 66:       PetscCallA(DMGetStratumIS(dm, 'marker', one, bcPointIS(1),ierr))
 67:       pBcPointIS => bcPointIS
 68: !     Create a PetscSection with this data layout
 69:       PetscCallA(DMSetNumFields(dm, numFields,ierr))
 70:       PetscCallA(DMPlexCreateSection(dm,PETSC_NULL_DMLABEL_ARRAY,pNumComp,pNumDof,numBC,pBcField,pBcCompIS,pBcPointIS,PETSC_NULL_IS,section,ierr))
 71:       PetscCallA(ISDestroy(bcCompIS(1), ierr))
 72:       PetscCallA(ISDestroy(bcPointIS(1), ierr))
 73: !     Name the Field variables
 74:       PetscCallA(PetscSectionSetFieldName(section, zero, 'u', ierr))
 75:       PetscCallA(PetscSectionSetFieldName(section, one,  'v', ierr))
 76:       PetscCallA(PetscSectionSetFieldName(section, two,  'w', ierr))
 77:       if (size .eq. 1) then
 78:         PetscCallA(PetscSectionView(section, PETSC_VIEWER_STDOUT_WORLD, ierr))
 79:       endif
 80: !     Tell the DM to use this data layout
 81:       PetscCallA(DMSetLocalSection(dm, section, ierr))
 82: !     Create a Vec with this layout and view it
 83:       PetscCallA(DMGetGlobalVector(dm, u, ierr))
 84:       PetscCallA(PetscViewerCreate(PETSC_COMM_WORLD, viewer, ierr))
 85:       PetscCallA(PetscViewerSetType(viewer, PETSCVIEWERVTK, ierr))
 86:       PetscCallA(PetscViewerFileSetName(viewer, 'sol.vtu', ierr))
 87:       PetscCallA(VecView(u, viewer, ierr))
 88:       PetscCallA(PetscViewerDestroy(viewer, ierr))
 89:       PetscCallA(DMRestoreGlobalVector(dm, u, ierr))
 90: !     Cleanup
 91:       PetscCallA(PetscSectionDestroy(section, ierr))
 92:       PetscCallA(DMDestroy(dm, ierr))

 94:       PetscCallA(PetscFinalize(ierr))
 95:       end program DMPlexTestField

 97: !/*TEST
 98: !  build:
 99: !    requires: defined(PETSC_USING_F90FREEFORM)
100: !
101: !  test:
102: !    suffix: 0
103: !    requires: triangle
104: !    args: -info :~sys,mat:
105: !
106: !  test:
107: !    suffix: 0_2
108: !    requires: triangle
109: !    nsize: 2
110: !    args: -info :~sys,mat,partitioner:
111: !
112: !  test:
113: !    suffix: 1
114: !    requires: ctetgen
115: !    args: -dm_plex_dim 3 -info :~sys,mat:
116: !
117: !TEST*/