GetTotalFaceDOF

The GetTotalFaceDOF generic method in the FEDOF_Class provides the total number of degrees of freedom (DOF) associated with a face in a finite element mesh.

Interfaces

From the FEDOF_Class.F90 file, the GetTotalFaceDOF generic method has the following interfaces:

PROCEDURE, PASS(obj) :: GetTotalFaceDOF1 => GetTotalFaceDOF1
!! Get total face dof
PROCEDURE, PASS(obj) :: GetTotalFaceDOF2 => GetTotalFaceDOF2
!! Get total face dof from global element and local face number
GENERIC, PUBLIC :: GetTotalFaceDOF => GetTotalFaceDOF1, GetTotalFaceDOF2

The specific interfaces are defined as:

MODULE FUNCTION GetTotalFaceDOF1(obj, globalFace, islocal) RESULT(ans)
  CLASS(FEDOF_), INTENT(IN) :: obj
  INTEGER(I4B), INTENT(IN) :: globalFace
  LOGICAL(LGT), INTENT(IN), OPTIONAL :: islocal
  INTEGER(I4B) :: ans
END FUNCTION GetTotalFaceDOF1

MODULE FUNCTION GetTotalFaceDOF2(obj, globalElement, localFaceNumber, &
                                 islocal) RESULT(ans)
  CLASS(FEDOF_), INTENT(IN) :: obj
  !! DOF object
  INTEGER(I4B), INTENT(IN) :: globalElement
  !! global or local element number
  INTEGER(I4B), INTENT(IN) :: localFaceNumber
  !! local face number in globall element
  LOGICAL(LGT), INTENT(IN), OPTIONAL :: islocal
  !! if true then globalElement is local element
  INTEGER(I4B) :: ans
  !! Total number of degree of freedom on face
END FUNCTION GetTotalFaceDOF2

Description

The GetTotalFaceDOF generic method provides two implementations to retrieve the total face DOF count:

1. GetTotalFaceDOF1 - Gets total DOF count directly using a global face number
2. GetTotalFaceDOF2 - Gets total DOF count using a global element number and local face number within that element

Interface 1: GetTotalFaceDOF1

Parameters

• obj - Input, CLASS(FEDOF_), FEDOF object instance
• globalFace - Input, INTEGER(I4B), global face number
• islocal - Optional Input, LOGICAL(LGT), if true, globalFace is treated as a local face number
• ans - Output, INTEGER(I4B), total number of DOFs on the specified face

Implementation Details

The implementation uses the internal face index array structure to calculate the total DOF count:

ans = obj%faceIA(globalface + 1) - obj%faceIA(globalface)

This efficiently computes the number of DOFs by finding the difference between consecutive indices in the compressed sparse row format.

Interface 2: GetTotalFaceDOF2

Parameters

• obj - Input, CLASS(FEDOF_), DOF object
• globalElement - Input, INTEGER(I4B), global or local element number
• localFaceNumber - Input, INTEGER(I4B), local face number in global element
• islocal - Optional Input, LOGICAL(LGT), if true, globalElement is treated as a local element
• ans - Output, INTEGER(I4B), total number of degrees of freedom on the specified face

Implementation Details

This implementation first converts the element and local face information to a global face number, then calls the first implementation:

INTEGER(I4B) :: globalFace
globalFace = obj%mesh%GetGlobalFaceNumber(globalElement=globalElement, &
                             islocal=islocal, localFaceNumber=localFaceNumber)
ans = obj%GetTotalFaceDOF(globalFace=globalFace, islocal=islocal)

Usage Example

! Example to get total DOFs on a face
INTEGER(I4B) :: totalDOFs
TYPE(FEDOF_) :: myDOF

! Method 1: Using global face number
totalDOFs = myDOF%GetTotalFaceDOF(globalFace=3)

! Method 2: Using element and local face number
totalDOFs = myDOF%GetTotalFaceDOF(globalElement=7, localFaceNumber=2)

Related Methods

• GetFaceDOF - Retrieves the actual DOF indices for a face
• GetTotalEdgeDOF - Similar function but for element edges
• GetTotalDOF - Gets total DOF count for an entire element or the entire mesh
• GetTotalVertexDOF - Gets total DOF count for vertices

These methods are essential for traversing and accessing degrees of freedom in different components of the mesh hierarchy (vertices, edges, faces, cells).

Example 1

!> author: Vikas Sharma, Ph. D.
! date: 2025-06-07
! summary:  Testing GetTotalFaceDOF method of FEDOF class
! H1 Heirarchical Second Order Triangular Mesh

PROGRAM main
USE FEDOF_Class
USE FEDomain_Class
USE AbstractMesh_Class
USE HDF5File_Class
USE Display_Method
USE GlobalData
USE Test_Method
USE ExceptionHandler_Class, ONLY: e, EXCEPTION_INFORMATION
USE AppendUtility
USE ArangeUtility
USE ReallocateUtility

IMPLICIT NONE

CHARACTER(*), PARAMETER :: &
  filename = "../../FEMesh/examples/meshdata/small_tri3_mesh.h5", &
  baseContinuity = "H1", &
  baseInterpolation = "Heirarchical", &
  testname = baseContinuity//" "//baseInterpolation//" GetTotalFaceDOF test"

TYPE(FEDOF_) :: fedof
TYPE(FEDomain_) :: dom
CLASS(AbstractMesh_), POINTER :: meshptr => NULL()
TYPE(HDF5File_) :: meshfile
INTEGER(I4B) :: order, totalVertexNodes, totalFaces
LOGICAL(LGT) :: isok

CALL e%SetQuietMode(EXCEPTION_INFORMATION, .TRUE.)

CALL meshfile%Initiate(filename, mode="READ")
CALL meshfile%OPEN()
CALL dom%Initiate(meshfile, '')
meshptr => dom%GetMeshPointer()
totalVertexNodes = meshptr%GetTotalVertexNodes()
totalFaces = meshptr%GetTotalFaces()

CALL test1
CALL test2
CALL test3

CALL dom%DEALLOCATE()
CALL meshfile%DEALLOCATE()

CONTAINS

!----------------------------------------------------------------------------
!                                                                      test1
!----------------------------------------------------------------------------

SUBROUTINE test1

  INTEGER(I4B) :: tsize, found, want
  INTEGER(I4B), ALLOCATABLE :: con(:)

  order = 1
  CALL fedof%Initiate(baseContinuity=baseContinuity, &
                      baseInterpolation=baseInterpolation, &
                      order=order, mesh=meshptr)

  found = fedof%GetTotalFaceDOF(globalFace=1, islocal=.TRUE.)
  want = 0

  CALL IS(found, want, testname//" (order= "//ToString(order)//"): ")

  found = fedof%GetTotalFaceDOF(globalElement=1, islocal=.TRUE., &
                                localFaceNumber=1)

  CALL IS(found, want, testname//" interface 2 (order= "//ToString(order)//"): ")

END SUBROUTINE test1

!----------------------------------------------------------------------------
!                                                                      test2
!----------------------------------------------------------------------------

SUBROUTINE test2
  INTEGER(I4B) :: tsize, found, want

  order = 2
  CALL fedof%Initiate(baseContinuity=baseContinuity, &
                      baseInterpolation=baseInterpolation, &
                      order=order, mesh=meshptr)

  found = fedof%GetTotalFaceDOF(globalFace=1, islocal=.TRUE.)
  want = 1

  CALL IS(found, want, testname//" (order= "//ToString(order)//"): ")

  found = fedof%GetTotalFaceDOF(globalElement=1, islocal=.TRUE., &
                                localFaceNumber=1)

  CALL IS(found, want, testname//" (order= "//ToString(order)//"): ")

END SUBROUTINE test2

!----------------------------------------------------------------------------
!                                                                     test3
!----------------------------------------------------------------------------

SUBROUTINE test3
  INTEGER(I4B) :: tsize, found, want

  order = 3
  CALL fedof%Initiate(baseContinuity=baseContinuity, &
                      baseInterpolation=baseInterpolation, &
                      order=order, mesh=meshptr)

  found = fedof%GetTotalFaceDOF(globalFace=1, islocal=.TRUE.)
  want = 2

  CALL IS(found, want, testname//" (order= "//ToString(order)//"): ")

  found = fedof%GetTotalFaceDOF(globalElement=1, islocal=.TRUE., &
                                localFaceNumber=1)

  CALL IS(found, want, testname//" (order= "//ToString(order)//"): ")

END SUBROUTINE test3

!----------------------------------------------------------------------------
!
!----------------------------------------------------------------------------

END PROGRAM main