ESMF_GetMesh3DFromUGrid Subroutine

private subroutine ESMF_GetMesh3DFromUGrid(filename, ncid, meshid, nodeCoords, elmtConn, elmtNums, startElmt, faceCoords, rc)

Arguments

Type IntentOptional Attributes Name
character(len=*), intent(in) :: filename
integer, intent(in) :: ncid
integer, intent(in) :: meshid
real(kind=ESMF_KIND_R8), pointer :: nodeCoords(:,:)
integer(kind=ESMF_KIND_I4), pointer :: elmtConn(:)
integer(kind=ESMF_KIND_I4), pointer :: elmtNums(:)
integer, intent(out) :: startElmt
real(kind=ESMF_KIND_R8), optional, pointer :: faceCoords(:,:)
integer, intent(out), optional :: rc

Source Code

subroutine ESMF_GetMesh3DFromUGrid (filename, ncid, meshid, nodeCoords, elmtConn, &
                                elmtNums, startElmt, faceCoords, rc)

    character(len=*), intent(in)   :: filename
    integer,           intent(in)  :: ncid, meshid                              
    real(ESMF_KIND_R8), pointer    :: nodeCoords (:,:)
    integer(ESMF_KIND_I4), pointer :: elmtConn (:)
    integer(ESMF_KIND_I4), pointer :: elmtNums (:)
    integer,           intent(out) :: startElmt
    real(ESMF_KIND_R8), pointer, optional   :: faceCoords(:,:)
    integer, intent(out), optional :: rc

    type(ESMF_VM) :: vm
    integer :: PetNo, PetCnt

    integer(ESMF_KIND_I4), allocatable :: elmtConnT(:,:)
    integer :: DimIds(2), VarId
    integer :: ncStatus

    integer :: coordinateDims(3), coordDim, meshDim
    integer :: i, j, count, nodeCount, MaxNodePerElmt, localFillValue
    integer :: localCount, remain, elmtCount, localPolyBreakValue

    character(len=256) :: errmsg, locations, locNames(3), elmtConnName
    character(len=256) :: nodeCoordString, faceCoordString
    character(len=80), allocatable :: nodeCoordNames(:), faceCoordNames(:)
    integer :: pos0, pos, pos1, pos2, n, yesNode
    integer :: len, indexBase
    character(len=24) :: units
    real(ESMF_KIND_R8) :: deg2rad, earthradius
    real(ESMF_KIND_R8) :: coord(3)
    integer, parameter :: nf90_noerror = 0
    real(ESMF_KIND_R8), allocatable:: nodeCoord1D(:), faceCoord1D(:)
    integer            :: localrc
    integer            :: totalConnections

#ifdef ESMF_NETCDF

    ! Get VM information
    call ESMF_VMGetCurrent(vm, rc=rc)
    if (rc /= ESMF_SUCCESS) return
    ! set up local pet info
    call ESMF_VMGet(vm, localPet=PetNo, petCount=PetCnt, rc=rc)
    if (rc /= ESMF_SUCCESS) return

    ! Get node coordinates
    ncStatus = nf90_inquire_attribute(ncid, meshId, "node_coordinates", len=len)
    errmsg = "Attribute node_coordinates in "//trim(filename)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return
    allocate( nodeCoordNames(3))
    ncStatus = nf90_get_att (ncid, meshId, "node_coordinates", nodeCoordString)
    errmsg = "Attribute node_coordinates in "//trim(filename)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return
    ! Parse the attribute to find the varible names for node_coordinates
    pos1 = index(nodeCoordString(1:)," ")
    nodeCoordNames(1) = nodeCoordString(1:pos1-1)
    pos2 = index(nodeCoordString(pos1+1:)," ")
    nodeCoordNames(2) = nodeCoordString(pos1+1:pos1+pos2-1)
    nodeCoordNames(3)=nodeCoordString(pos1+pos2+1:len)

    ! Get face coordinates if faceCoords argument is given
    if (present(faceCoords)) then
       ncStatus = nf90_inquire_attribute(ncid, meshId, "face_coordinates", len=len)
       errmsg = "Attribute face_coordinates in "//trim(filename)
       if (CDFCheckError (ncStatus, &
          ESMF_METHOD,  &
          ESMF_SRCLINE, errmsg, &
          rc)) return
       allocate( faceCoordNames(3) )
       ncStatus = nf90_get_att (ncid, meshId, "face_coordinates", faceCoordString)
       errmsg = "Attribute face_coordinates in "//trim(filename)
       if (CDFCheckError (ncStatus, &
          ESMF_METHOD,  &
          ESMF_SRCLINE, errmsg, &
          rc)) return
       ! Parse the attribute to find the varible names for face_coordinates
       pos1 = index(faceCoordString(1:)," ")
       faceCoordNames(1) = faceCoordString(1:pos1-1)
       pos2 = index(faceCoordString(pos1+1:)," ")
       faceCoordNames(2)=faceCoordString(pos1+1:pos1+pos2-1)
       faceCoordNames(3)=faceCoordString(pos1+pos2+1:len)
    endif
    ! Get dimension (# nodes) used to define the node coordinates
    errmsg = "Variable "//trim(nodeCoordNames(1))//" in "//trim(filename)
    ncStatus = nf90_inq_varid (ncid, nodeCoordNames(1), VarId)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return
    ncStatus = nf90_inquire_variable (ncid, VarId, dimids=DimIds)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return
    ncStatus = nf90_inquire_dimension (ncid, DimIds(1), len=nodeCount)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return

    allocate( nodeCoords(3,nodeCount), nodeCoord1D(nodeCount) )
    do i=1,3
      errmsg = "Variable "//nodeCoordNames(i)//" in "//trim(filename)
      ncStatus = nf90_inq_varid (ncid, nodeCoordNames(i), VarId)
      if (CDFCheckError (ncStatus, &
        ESMF_METHOD,  &
        ESMF_SRCLINE, errmsg, &
        rc)) return
      ncStatus = nf90_get_var (ncid, VarId, nodeCoord1D)
      if (CDFCheckError (ncStatus, &
        ESMF_METHOD,  &
        ESMF_SRCLINE, errmsg, &
        rc)) return

      do j=1,nodeCount
        nodeCoords(i,j)=nodeCoord1d(j)
      enddo

      ! Convert to Cartisian 3D coordinates
      ! get the attribute 'units'
      ncStatus = nf90_inquire_attribute(ncid, VarId, "units", len=len)
      errmsg = "Attribute units for "//nodeCoordNames(i)//" in "//trim(filename)
      if (CDFCheckError (ncStatus, &
          ESMF_METHOD, &
          ESMF_SRCLINE,&
          errmsg,&
          rc)) return
      ncStatus = nf90_get_att(ncid, VarId, "units", units)
      if (CDFCheckError (ncStatus, &
          ESMF_METHOD, &
          ESMF_SRCLINE,&
          errmsg,&
          rc)) return
      if (i==1 .or. i==2) then
        ! if units is not "degrees" or "radians" return errors
        units = ESMF_UtilStringLowerCase(units(1:len))
        if (units(len:len) .eq. achar(0)) len = len-1
        if (units(1:7) .ne. 'degrees' .and. units(1:7) .ne. 'radians') then
          call ESMF_LogSetError(rcToCheck=ESMF_FAILURE, &
                 msg="- units attribute is not degrees or radians", &
                 ESMF_CONTEXT, rcToReturn=rc)
          return
        endif
        ! if units is "radians", convert it to degrees
        if (units(1:7) .eq. "radians") then
            nodeCoords(i,:) = nodeCoords(i,:)*ESMF_COORDSYS_RAD2DEG
        endif
      else      
        ! normalize the height using the earth radius
        if (units(len:len) .eq. achar(0)) len = len-1
        if (units(1:len) .eq. "meters") then
          earthradius = 6371000.0
        else if (units(1:len) .eq. "km" .or. units(1:len) .eq. "kilometers") then
          earthradius = 6371.0
        else
          call ESMF_LogSetError(rcToCheck=ESMF_FAILURE, &
                 msg="- units attribute for height is not meters, km, or kilometers", &
                 ESMF_CONTEXT, rcToReturn=rc)
          return
        endif
        nodeCoords(i,:)=1+nodeCoords(i,:)/earthradius
      endif
    enddo

! save coordinates as ESMF_COORDSYS_SPH_DEG, no need to convert to CART
#if 0
    ! Convert the coordinates into Cartesian 3D
    do i=1,nodeCount
      call c_esmc_sphdeg_to_cart(nodeCoords(1,i), nodeCoords(2,i), &
                  coord(1), coord(2), coord(3), &
                  localrc)
      if (ESMF_LogFoundError(localrc, ESMF_ERR_PASSTHRU, &
                  ESMF_CONTEXT, rcToReturn=rc)) return
      nodeCoords(1,i)=nodeCoords(3,i)*coord(1)
      nodeCoords(2,i)=nodeCoords(3,i)*coord(2)
      nodeCoords(3,i)=nodeCoords(3,i)*coord(3)
    enddo
#endif

    ! Get element connectivity, if it does not exist, bail out
    errmsg = "Attribute volume_node_connectivity in "//trim(filename)
    ncStatus = nf90_inquire_attribute(ncid, meshId, "volume_node_connectivity", len=len)
    ncStatus = nf90_get_att (ncid, meshId, "volume_node_connectivity", values=elmtConnName)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return
    ! Get element connectivity (UGRID convention is transposed compared to others)
    errmsg = "Variable "//elmtConnName(1:len)//" in "//trim(filename)
    ncStatus = nf90_inq_varid (ncid, elmtConnName(1:len), VarId)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return
    ! Currently, only hexahedron and tetrahedrons are supported, but
    ! eventually, we want to support prisms (or wedge as used in UGRID)
    errmsg = "Attribute "//elmtConnName(1:len)//" _FillValue in "//trim(filename)
    ncStatus = nf90_get_att (ncid, VarId, "_FillValue", values=localFillValue)
    if (ncStatus .ne. nf90_noerror) localFillValue = -1

    ! Get PolyBreak Value if it's not present, then set it to localFillValue, so
    ! it's ignored
    ncStatus = nf90_get_att (ncid, VarId, "polygon_break_value", &
         values=localPolyBreakValue)
    if (ncStatus /= nf90_noerror) then
       localPolyBreakValue = localFillValue
    else
       ! If it's been set, then make sure that this value isn't the same as _FillValue
       if (localPolyBreakValue == localFillValue) then
          call ESMF_LogSetError(rcToCheck=ESMF_FAILURE, &
            msg="- polygon_break_value can't be the same as _localFillValue", &
                 ESMF_CONTEXT, rcToReturn=rc)
          return
       endif
    endif

    ! Get start_index attribute to find out the index base (0 or 1)
    ncStatus = nf90_get_att (ncid, VarId, "start_index", values=indexBase)
    ! if not defined, default to 0-based
    if (ncStatus /= nf90_noerror) indexBase = 0
    ! Get dimensions of element connectivity (transposed) (for allocation)
    errmsg = "Dimensions of "//trim(elmtConnName)//" in "//trim(filename)
    ncStatus = nf90_inquire_variable (ncid, VarId, dimids=DimIds)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return
    ncStatus = nf90_inquire_dimension (ncid, DimIds(2), len=elmtCount)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return
    ncStatus = nf90_inquire_dimension (ncid, DimIds(1), len=MaxNodePerElmt)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return

    ! Decompose the element array evenly across all PETs
    localCount = elmtCount/PetCnt
    remain = mod (elmtCount,PetCnt)
    startElmt = localCount*PetNo +1
    if (PetNo==PetCnt-1) localCount=localCount+remain
    allocate(elmtConnT(MaxNodePerElmt,localCount) )
    allocate( elmtNums(localCount) )
    ! Get element connectivity... transposed
    ncStatus = nf90_get_var (ncid, VarId, elmtConnT, start=(/1,startElmt/), &
                            count=(/MaxNodePerElmt,localCount/))
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, errmsg, &
      rc)) return

    ! Get faceCoordinates if faceCoords is present
    if (present(faceCoords)) then
       allocate(faceCoords(3,localCount), faceCoord1D(localCount))
       do i=1,3
          errmsg = "Variable "//faceCoordNames(i)//" in "//trim(filename)
          ncStatus = nf90_inq_varid (ncid, faceCoordNames(i), VarId)
          if (CDFCheckError (ncStatus, &
              ESMF_METHOD,  &
              ESMF_SRCLINE, errmsg, &
              rc)) return
          ncStatus = nf90_get_var (ncid, VarId, faceCoord1D, start=(/startElmt/), &
                                  count=(/localCount/))
          if (CDFCheckError (ncStatus, &
              ESMF_METHOD,  &
              ESMF_SRCLINE, errmsg, &
              rc)) return

          do j=1,localCount
             faceCoords(i,j)=faceCoord1d(j)
          enddo

       enddo
       deallocate(faceCoordNames, faceCoord1d)
    endif

    ! Get the number of nodes for each element
    ! if indexBase is 0, change it to 1 based index
    totalConnections = 0
    elmtNums(:)=MaxNodePerElmt
    if (indexBase == 0) then
      do i=1,localcount
        do j=1,MaxNodePerElmt
          ! change 0-base to 1-base
          if (elmtConnT(j,i) /= localFillValue) then
             if (elmtConnT(j,i) /= localPolyBreakValue) then
                elmtConnT(j,i)=elmtConnT(j,i)+1
             endif
          else
             ! find the first FillValue
             elmtNums(i) = j-1  
             totalConnections = totalConnections+elmtNums(i)
             exit
          endif
         enddo  
      enddo
    else
      do i=1,localcount
        j = MaxNodePerElmt
        do while (elmtConnT(j,i) == localFillValue)
          j = j - 1
        enddo
        elmtNums(i) = j
        totalConnections = totalConnections+elmtNums(i)
      enddo
    endif

    ! Change File PolyBreak to MeshPolyBreak
    ! (if localPolyBreakValue was set then it'll be different than localFillValue)
    if (localPolyBreakValue /= localFillValue) then
       do i=1,localcount
          do j=1,elmtNums(i)
             if (elmtConnT(j,i)==localPolyBreakValue) then
                elmtConnT(j,i)=ESMF_MESH_POLYBREAK
             endif
          enddo
       enddo
    endif

    allocate(elmtConn(totalConnections))
    j=1
    do i=1,localcount
       elmtConn(j:j+elmtNums(i)-1)=elmtConnT(1:elmtNums(i),i)
       j = j + elmtNums(i)
    enddo

    if (totalConnections /= j-1) then
      print *, PetNo, 'totalconnection does match ', totalConnections, j-1
    endif
    deallocate(elmtConnT)

    ! Deallocations
    deallocate( nodeCoordNames, nodeCoord1D )

    ncStatus = nf90_close (ncid=ncid)
    if (CDFCheckError (ncStatus, &
      ESMF_METHOD,  &
      ESMF_SRCLINE, trim(filename), &
      rc)) return
#else
    call ESMF_LogSetError(ESMF_RC_LIB_NOT_PRESENT, &
                 msg="- ESMF_NETCDF not defined when lib was compiled", &
                 ESMF_CONTEXT, rcToReturn=rc)
    return
#endif

end subroutine ESMF_GetMesh3DFromUGrid