read_M_files_4_swath Subroutine

  subroutine read_M_files_4_swath ( filenames, Xdim, Ydim, &
       index_name_lon, index_name_lat,&
       var_name_lon, var_name_lat, var_name_time, &
       lon, lat, time, Tfilter, rc )
    use pFlogger, only: logging, Logger
    character(len=ESMF_MAXSTR), intent(in) :: filenames(:)
    integer,  intent(out) :: Xdim
    integer,  intent(out) :: Ydim
    character(len=ESMF_MAXSTR), intent(in) :: index_name_lon
    character(len=ESMF_MAXSTR), intent(in) :: index_name_lat
    character(len=ESMF_MAXSTR), optional, intent(in) :: var_name_lon
    character(len=ESMF_MAXSTR), optional, intent(in) :: var_name_lat
    character(len=ESMF_MAXSTR), optional, intent(in) :: var_name_time
    real(ESMF_KIND_R8), allocatable, optional, intent(inout) :: lon(:,:)
    real(ESMF_KIND_R8), allocatable, optional, intent(inout) :: lat(:,:)
    real(ESMF_KIND_R8), allocatable, optional, intent(inout) :: time(:,:)
    logical, optional, intent(in)  ::  Tfilter
    integer, optional, intent(out) :: rc

    integer :: M
    integer :: i, j, jx, j2, status
    integer :: nlon, nlat
    integer :: ncid, ncid2
    character(len=ESMF_MAXSTR) :: grp1, grp2
    integer :: varid
    logical :: found_group

    character(len=ESMF_MAXSTR) :: filename
    integer, allocatable :: nlons(:), nlats(:)
    real(ESMF_KIND_R8), allocatable :: time_loc_R8(:,:)
    real(ESMF_KIND_R8), allocatable :: lon_loc(:,:)
    real(ESMF_KIND_R8), allocatable :: lat_loc(:,:)
    class(Logger), pointer :: lgr

    !__ s1. get Xdim Ydim
    M = size(filenames)
    _ASSERT(M/=0, 'M is zero, no files found')
    lgr => logging%get_logger('MAPL.Sampler')

    allocate(nlons(M), nlats(M))
    jx=0
    do i = 1, M
       filename = filenames(i)
       CALL get_ncfile_dimension(filename, nlon=nlon, nlat=nlat, &
            key_lon=index_name_lon, key_lat=index_name_lat, _RC)
       nlons(i)=nlon
       nlats(i)=nlat
       jx=jx+nlat

       call lgr%debug('Input filename: %a', trim(filename))
       call lgr%debug('Input file    : nlon, nlat= %i6  %i6', nlon, nlat)
    end do
    !
    ! __ output results wo filter
    !
    Xdim=nlon
    Ydim=jx
    j2=jx

    !__ s2. get fields

    if ( present(Tfilter) .AND. Tfilter ) then
       if ( .not. (present(time) .AND. present(lon) .AND. present(lat)) ) then
          _FAIL('when Tfilter present, time/lon/lat must also present')
       end if

       !
       ! -- determine jx
       !
       jx=0
       do i = 1, M
          filename = filenames(i)
          nlon = nlons(i)
          nlat = nlats(i)
          allocate (time_loc_R8(nlon, nlat))
          call get_var_from_name_w_group (var_name_time, time_loc_R8, filename, _RC)
!!          write(6,*) 'af ith, filename', i, trim(filename)

          do j=1, nlat
             !
             ! -- filter, e.g., eliminate -9999
             !
             if ( time_loc_R8(1, j) > 0.0 ) then
                jx = jx + 1
             end if
          end do
          deallocate(time_loc_R8)
       end do
       Xdim=nlon
       Ydim=jx
       if (allocated (time)) then
          deallocate(time)
          allocate (time(Xdim, Ydim))
       end if
       if (allocated (lon)) then
          deallocate(lon)
          allocate (lon(Xdim, Ydim))
       end if
       if (allocated (lat)) then
          deallocate(lat)
          allocate (lat(Xdim, Ydim))
       end if
       !
       !!write(6,'(2x,a,10i10)') 'true  Xdim, Ydim:', Xdim, Ydim
       !!write(6,'(2x,a,10i10)') 'false Xdim, Ydim:', nlon, j2
       !


       !
       ! -- determine true time/lon/lat by filtering T < 0
       !
       jx=0
       do i = 1, M
          filename = filenames(i)
          nlon = nlons(i)
          nlat = nlats(i)
          !!write(6,'(2x,a,10i6)')  'M, i, nlon, nlat:', M, i, nlon, nlat
          !!write(6,'(2x,a)') 'time_loc_r8'
          !
          allocate (time_loc_R8(nlon, nlat))
          call get_var_from_name_w_group (var_name_time, time_loc_R8, filename, _RC)
          allocate (lon_loc(nlon, nlat))
          call get_var_from_name_w_group (var_name_lon, lon_loc, filename, _RC)
          allocate (lat_loc(nlon, nlat))
          call get_var_from_name_w_group (var_name_lat, lat_loc, filename, _RC)
          !
          do j=1, nlat
             !
             ! -- filter, e.g., eliminate -9999
             !
             if ( time_loc_R8(1, j) > 0.0 ) then
                jx = jx + 1
                time(1:nlon,jx) = time_loc_R8(1:nlon,j)
                lon (1:nlon,jx) = lon_loc (1:nlon,j)
                lat (1:nlon,jx) = lat_loc (1:nlon,j)
             end if
             !!write(6,'(5f20.2)') time_loc_R8(1,j)
          end do

          deallocate(time_loc_R8)
          deallocate(lon_loc)
          deallocate(lat_loc)
       end do

    else

       if (allocated (time)) then
          deallocate(time)
          allocate (time(Xdim, Ydim))
       end if
       if (allocated (lon)) then
          deallocate(lon)
          allocate (lon(Xdim, Ydim))
       end if
       if (allocated (lat)) then
          deallocate(lat)
          allocate (lat(Xdim, Ydim))
       end if

       jx=0
       do i = 1, M
          filename = filenames(i)
          nlon = nlons(i)
          nlat = nlats(i)

          if (present(var_name_time).AND.present(time)) then
             call get_var_from_name_w_group (var_name_time, time(1:nlon,jx+1:jx+nlat), filename, _RC)
          end if
          if (present(var_name_lon).AND.present(lon)) then
             call get_var_from_name_w_group (var_name_lon, lon(1:nlon,jx+1:jx+nlat), filename, _RC)
          end if
          if (present(var_name_lat).AND.present(lat)) then
             call get_var_from_name_w_group (var_name_lat, lat(1:nlon,jx+1:jx+nlat), filename, _RC)
          end if

          jx = jx + nlat
       end do

    end if

    _RETURN(_SUCCESS)
  end subroutine read_M_files_4_swath