!***********************************************************************
!*                   GNU Lesser General Public License
!*
!* This file is part of the GFDL Flexible Modeling System (FMS).
!*
!* FMS is free software: you can redistribute it and/or modify it under
!* the terms of the GNU Lesser General Public License as published by
!* the Free Software Foundation, either version 3 of the License, or (at
!* your option) any later version.
!*
!* FMS is distributed in the hope that it will be useful, but WITHOUT
!* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
!* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
!* for more details.
!*
!* You should have received a copy of the GNU Lesser General Public
!* License along with FMS.  If not, see <http://www.gnu.org/licenses/>.
!***********************************************************************

MODULE diag_util_mod
#include <fms_platform.h>
  ! <CONTACT EMAIL="seth.underwood@noaa.gov">
  !   Seth Underwood
  ! </CONTACT>
  ! <HISTORY SRC="http://cobweb.gfdl.noaa.gov/fms-cgi-bin/viewcvs/FMS/shared/diag_manager/"/>

  ! <OVERVIEW>
  !   Functions and subroutines necessary for the <TT>diag_manager_mod</TT>.
  ! </OVERVIEW>

  ! <DESCRIPTION>
  !   <TT>diag_util_mod</TT> is a set of Fortran functions and subroutines used by the <TT>diag_manager_mod</TT>.
  ! </DESCRIPTION>

  ! <INFO>
  !   <FUTURE>
  !     Make an interface <TT>check_bounds_are_exact</TT> for the subroutines <TT>check_bounds_are_exact_static</TT> and
  !     <TT>check_bounds_are_exact_dynamic</TT>.
  !     <PRE>
  !       INTERFACE check_bounds_are_exact
  !         MODULE PROCEDURE check_bounds_are_exact_static
  !         MODULE PROCEDURE check_bounds_are_exact_dynamic
  !       END INTERFACE check_bounds_are_exact
  !     </PRE>
  !   </FUTURE>
  ! </INFO>
  USE diag_data_mod, ONLY: output_fields, input_fields, files, do_diag_field_log, diag_log_unit,&
       & VERY_LARGE_AXIS_LENGTH, time_zero, VERY_LARGE_FILE_FREQ, END_OF_RUN, EVERY_TIME,&
       & DIAG_SECONDS, DIAG_MINUTES, DIAG_HOURS, DIAG_DAYS, DIAG_MONTHS, DIAG_YEARS, base_time,&
       & time_unit_list, max_files, base_year, base_month, base_day, base_hour, base_minute,&
       & base_second, num_files, max_files, max_fields_per_file, max_out_per_in_field,&
       & max_input_fields,num_input_fields, max_output_fields, num_output_fields, coord_type,&
       & mix_snapshot_average_fields, global_descriptor, CMOR_MISSING_VALUE, use_cmor, pack_size,&
       & debug_diag_manager, flush_nc_files, output_field_type, max_field_attributes, max_file_attributes,&
       & file_type, prepend_date, region_out_use_alt_value, GLO_REG_VAL, GLO_REG_VAL_ALT,&
       & DIAG_FIELD_NOT_FOUND, diag_init_time
  USE diag_axis_mod, ONLY: get_diag_axis_data, get_axis_global_length, get_diag_axis_cart,&
       & get_domain1d, get_domain2d, diag_subaxes_init, diag_axis_init, get_diag_axis, get_axis_aux,&
       & get_axes_shift, get_diag_axis_name, get_diag_axis_domain_name, get_domainUG, &
       & get_axis_reqfld, axis_is_compressed, get_compressed_axes_ids
  USE diag_output_mod, ONLY: diag_flush, diag_field_out, diag_output_init, write_axis_meta_data,&
       & write_field_meta_data, done_meta_data
  USE diag_grid_mod, ONLY: get_local_indexes
  USE fms_mod, ONLY: error_mesg, FATAL, WARNING, NOTE, mpp_pe, mpp_root_pe, lowercase, fms_error_handler,&
       & write_version_number, do_cf_compliance
  USE fms_io_mod, ONLY: get_tile_string, return_domain, string, get_instance_filename
  USE mpp_domains_mod,ONLY: domain1d, domain2d, mpp_get_compute_domain, null_domain1d, null_domain2d,&
       & OPERATOR(.NE.), OPERATOR(.EQ.), mpp_modify_domain, mpp_get_domain_components,&
       & mpp_get_ntile_count, mpp_get_current_ntile, mpp_get_tile_id, mpp_mosaic_defined, mpp_get_tile_npes,&
       & domainUG, null_domainUG
  USE time_manager_mod,ONLY: time_type, OPERATOR(==), OPERATOR(>), NO_CALENDAR, increment_date,&
       & increment_time, get_calendar_type, get_date, get_time, leap_year, OPERATOR(-),&
       & OPERATOR(<), OPERATOR(>=), OPERATOR(<=), OPERATOR(==)
  USE mpp_io_mod, ONLY: mpp_close
  USE mpp_mod, ONLY: mpp_npes
  USE fms_io_mod, ONLY: get_instance_filename, get_mosaic_tile_file_ug
  USE constants_mod, ONLY: SECONDS_PER_DAY, SECONDS_PER_HOUR, SECONDS_PER_MINUTE

#ifdef use_netCDF
  USE netcdf, ONLY: NF90_CHAR
#endif

  IMPLICIT NONE
  PRIVATE
  PUBLIC get_subfield_size, log_diag_field_info, update_bounds, check_out_of_bounds,&
       & check_bounds_are_exact_dynamic, check_bounds_are_exact_static, init_file, diag_time_inc,&
       & find_input_field, init_input_field, init_output_field, diag_data_out, write_static,&
       & check_duplicate_output_fields, get_date_dif, get_subfield_vert_size, sync_file_times,&
       & prepend_attribute, attribute_init, diag_util_init

  ! <INTERFACE NAME="prepend_attribute">
  !   <OVERVIEW>
  !     prepend a value to a string attribute in the output field or output file
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE prepend_attribute(output_field, att_name, att_value)
  !     SUBROUTINE prepend_attribute(output_file, att_name, att_value)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Prepend a character string to a character attribute for a give field, or to a global attribute
  !     in a give file.
  !   </DESCRIPTION>
  !   <IN NAME="output_field" TYPE="TYPE(output_field_type)" />
  !   <IN NAME="output_file" TYPE="TYPE(file_type)" />
  !   <IN NAME="att_name" TYPE="CHARACTER(len=*)" />
  !   <IN NAME="att_value" TYPE="REAL|INTEGER|CHARACTER(len=*)" />
  INTERFACE prepend_attribute
     MODULE PROCEDURE prepend_attribute_field
     MODULE PROCEDURE prepend_attribute_file
  END INTERFACE prepend_attribute
  ! </INTERFACE>

  ! <INTERFACE NAME="attribute_init">
  !   <OVERVIEW>
  !     Allocates the atttype in out_file
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE attribute_init(out_file, err_msg)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Allocates memory in out_file for the attributes.  Will <TT>FATAL</TT> if err_msg is not included
  !     in the subroutine call.
  !   </DESCRIPTION>
  !   <INOUT NAME="out_field" TYPE="TYPE(output_field_type)">output field to allocate memory for attribute</INOUT>
  !   <INOUT NAME="out_file" TYPE="TYPE(file_type)">output file to allocate memory for attribute</INOUT>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*), OPTIONAL">Error message, passed back to calling function</OUT>
  INTERFACE attribute_init
     MODULE PROCEDURE attribute_init_field
     MODULE PROCEDURE attribute_init_file
  END INTERFACE attribute_init
  ! </INTERFACE>

  ! Include variable "version" to be written to log file.
#include <file_version.h>

  LOGICAL :: module_initialized = .FALSE.


CONTAINS

  ! <SUBROUTINE NAME="diag_util_init">
  !   <OVERVIEW>
  !     Write the version number of this file
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE diag_util_init
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Write the version number of this file to the log file.
  !   </DESCRIPTION>
  SUBROUTINE diag_util_init()
    IF (module_initialized) THEN
       RETURN
    END IF

    ! Write version number out to log file
    call write_version_number("DIAG_UTIL_MOD", version)
  END SUBROUTINE diag_util_init
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="get_subfield_size">
  !   <OVERVIEW>
  !     Get the size, start, and end indices for output fields.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE get_subfield_size(axes, outnum)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Get the size, start and end indices for <TT>output_fields(outnum)</TT>, then
  !     fill in <TT>output_fields(outnum)%output_grid%(start_indx, end_indx)</TT>
  !   </DESCRIPTION>
  !   <IN NAME="axes" TYPE="INTEGER, DIMENSION(:)">Axes of the <TT>input_field</TT>.</IN>
  !   <IN NAME="outnum" TYPE="INTEGER">Position in array <TT>output_fields</TT>.</IN>
  SUBROUTINE get_subfield_size(axes, outnum)
    INTEGER, INTENT(in) :: axes(:) ! axes of the input_field
    INTEGER, INTENT(in) :: outnum  ! position in array output_fields

    REAL, ALLOCATABLE   :: global_lat(:), global_lon(:), global_depth(:)
    INTEGER :: global_axis_size, global_axis_sizey
    INTEGER :: i,xbegin,xend,ybegin,yend,xbegin_l,xend_l,ybegin_l,yend_l
    CHARACTER(len=1) :: cart
    TYPE(domain2d) :: Domain2, Domain2_new
    TYPE(domain1d) :: Domain1, Domain1x, Domain1y
    REAL :: start(3), end(3) ! start and end coordinates in 3 axes
    INTEGER :: gstart_indx(3), gend_indx(3) ! global start and end indices of output domain in 3 axes
    REAL, ALLOCATABLE :: subaxis_x(:), subaxis_y(:), subaxis_z(:) !containing local coordinates in x,y,z axes
    CHARACTER(len=128) :: msg
    INTEGER :: ishift, jshift
    INTEGER :: grv !< Value used to determine if the region defined in the diag_table is for the whole axis, or a sub-axis
    CHARACTER(len=128), DIMENSION(2) :: axis_domain_name

    !initilization for local output
    ! initially out of (lat/lon/depth) range
    start = -1.e10
    end = -1.e10
    gstart_indx = -1
    gend_indx = -1

    ! get the value to compare to determine if writing full axis data
    IF ( region_out_use_alt_value ) THEN
       grv = GLO_REG_VAL_ALT
    ELSE
       grv = GLO_REG_VAL
    END IF

    ! get axis data (lat, lon, depth) and indices
    start = output_fields(outnum)%output_grid%start
    end = output_fields(outnum)%output_grid%end

    CALL get_diag_axis_domain_name(axes(1), axis_domain_name(1))
    CALL get_diag_axis_domain_name(axes(2), axis_domain_name(2))

    IF (   INDEX(lowercase(axis_domain_name(1)), 'cubed') == 0 .AND. &
         & INDEX(lowercase(axis_domain_name(2)), 'cubed') == 0 ) THEN
       DO i = 1, SIZE(axes(:))
          global_axis_size = get_axis_global_length(axes(i))
          output_fields(outnum)%output_grid%subaxes(i) = -1
          CALL get_diag_axis_cart(axes(i), cart)
          SELECT CASE(cart)
          CASE ('X')
             ! <ERROR STATUS="FATAL">wrong order of axes.  X should come first.</ERROR>
             IF( i.NE.1 ) CALL error_mesg('diag_util_mod::get_subfield_size',&
                  & 'wrong order of axes, X should come first',FATAL)
             ALLOCATE(global_lon(global_axis_size))
             CALL get_diag_axis_data(axes(i),global_lon)
             IF( INT(start(i)) == grv .AND. INT(end(i)) == grv ) THEN
                gstart_indx(i) = 1
                gend_indx(i) = global_axis_size
                output_fields(outnum)%output_grid%subaxes(i) = axes(i)
             ELSE
                gstart_indx(i) = get_index(start(i),global_lon)
                gend_indx(i) = get_index(END(i),global_lon)
             END IF
             ALLOCATE(subaxis_x(gstart_indx(i):gend_indx(i)))
             subaxis_x=global_lon(gstart_indx(i):gend_indx(i))
          CASE ('Y')
             ! <ERROR STATUS="FATAL">wrong order of axes, Y should come second.</ERROR>
             IF( i.NE.2 ) CALL error_mesg('diag_util_mod::get_subfield_size',&
                  & 'wrong order of axes, Y should come second',FATAL)
             ALLOCATE(global_lat(global_axis_size))
             CALL get_diag_axis_data(axes(i),global_lat)
             IF( INT(start(i)) == grv .AND. INT(END(i)) == grv ) THEN
                gstart_indx(i) = 1
                gend_indx(i) = global_axis_size
                output_fields(outnum)%output_grid%subaxes(i) = axes(i)
             ELSE
                gstart_indx(i) = get_index(start(i),global_lat)
                gend_indx(i) = get_index(END(i),global_lat)
             END IF
             ALLOCATE(subaxis_y(gstart_indx(i):gend_indx(i)))
             subaxis_y=global_lat(gstart_indx(i):gend_indx(i))
          CASE ('Z')
             ! <ERROR STATUS="FATAL">wrong values in vertical axis of region</ERROR>
             IF ( start(i)*END(i)<0. ) CALL error_mesg('diag_util_mod::get_subfield_size',&
                  & 'wrong values in vertical axis of region',FATAL)
             IF ( start(i)>=0. .AND. END(i)>0. ) THEN
                ALLOCATE(global_depth(global_axis_size))
                CALL get_diag_axis_data(axes(i),global_depth)
                gstart_indx(i) = get_index(start(i),global_depth)
                gend_indx(i) = get_index(END(i),global_depth)
                ALLOCATE(subaxis_z(gstart_indx(i):gend_indx(i)))
                subaxis_z=global_depth(gstart_indx(i):gend_indx(i))
                output_fields(outnum)%output_grid%subaxes(i) =&
                     & diag_subaxes_init(axes(i),subaxis_z, gstart_indx(i),gend_indx(i))
                DEALLOCATE(subaxis_z,global_depth)
             ELSE ! regional vertical axis is the same as global vertical axis
                gstart_indx(i) = 1
                gend_indx(i) = global_axis_size
                output_fields(outnum)%output_grid%subaxes(i) = axes(i)
                ! <ERROR STATUS="FATAL">i should equal 3 for z axis</ERROR>
                IF( i /= 3 ) CALL error_mesg('diag_util_mod::get_subfield_size',&
                     & 'i should equal 3 for z axis', FATAL)
             END IF
          CASE default
             ! <ERROR STATUS="FATAL">Wrong axis_cart</ERROR>
             CALL error_mesg('diag_util_mod::get_subfield_size', 'Wrong axis_cart', FATAL)
          END SELECT
       END DO

       DO i = 1, SIZE(axes(:))
          IF ( gstart_indx(i) == -1 .OR. gend_indx(i) == -1 ) THEN
             ! <ERROR STATUS="FATAL">
             !   can not find gstart_indx/gend_indx for <output_fields(outnum)%output_name>,
             !   check region bounds for axis <i>.
             ! </ERROR>
             WRITE(msg,'(A,I2)') ' check region bounds for axis ', i
             CALL error_mesg('diag_util_mod::get_subfield_size', 'can not find gstart_indx/gend_indx for '&
                  & //TRIM(output_fields(outnum)%output_name)//','//TRIM(msg), FATAL)
          END IF
       END DO
    ELSE ! cubed sphere
       ! get the i and j start and end indexes
       CALL get_local_indexes(LONSTART=start(1), LONEND=END(1), &
            &                 LATSTART=start(2), LATEND=END(2), &
            &                 ISTART=gstart_indx(1), IEND=gend_indx(1), &
            &                 JSTART=gstart_indx(2), JEND=gend_indx(2))
       global_axis_size =  get_axis_global_length(axes(1))
       ALLOCATE(global_lon(global_axis_size))
       global_axis_sizey = get_axis_global_length(axes(2))
       ALLOCATE(global_lat(global_axis_sizey))
       CALL get_diag_axis_data(axes(1),global_lon)
       CALL get_diag_axis_data(axes(2),global_lat)

       !Potential fix for out-of-bounds error for global_lon and global_lat.
       IF ((gstart_indx(1) .GT. 0 .AND. gstart_indx(2) .GT. 0) .AND. &
           (gstart_indx(1) .LE. global_axis_size .AND. gstart_indx(2) .LE. global_axis_sizey) .AND. &
           (gend_indx(1) .GT. 0 .AND. gend_indx(2) .GT. 0) .AND. &
           (gend_indx(1) .LE. global_axis_size .AND. gend_indx(2) .LE. global_axis_sizey)) THEN
          ALLOCATE(subaxis_x(gstart_indx(1):gend_indx(1)))
          ALLOCATE(subaxis_y(gstart_indx(2):gend_indx(2)))
          subaxis_x=global_lon(gstart_indx(1):gend_indx(1))
          subaxis_y=global_lat(gstart_indx(2):gend_indx(2))
       END IF

       ! Now deal with the Z component
       IF ( SIZE(axes(:)) > 2 ) THEN
          global_axis_size = get_axis_global_length(axes(3))
          output_fields(outnum)%output_grid%subaxes(3) = -1
          CALL get_diag_axis_cart(axes(3), cart)
          ! <ERROR STATUS="FATAL">
          !   axis(3) should be Z-axis
          ! </ERROR>
          IF ( lowercase(cart) /= 'z' ) CALL error_mesg('diag_util_mod::get_subfield_size', &
               &'axis(3) should be Z-axis', FATAL)
          ! <ERROR STATUS="FATAL">
          !   wrong values in vertical axis of region
          ! </ERROR>
          IF ( start(3)*END(3)<0. ) CALL error_mesg('diag_util_mod::get_subfield_size',&
               & 'wrong values in vertical axis of region',FATAL)
          IF ( start(3)>=0. .AND. END(3)>0. ) THEN
             ALLOCATE(global_depth(global_axis_size))
             CALL get_diag_axis_data(axes(3),global_depth)
             gstart_indx(3) = get_index(start(3),global_depth)
             IF( start(3) == 0.0 )  gstart_indx(3) = 1
             gend_indx(3) = get_index(END(3),global_depth)
             IF( start(3) >= MAXVAL(global_depth) ) gstart_indx(3)= global_axis_size
             IF( END(3)   >= MAXVAL(global_depth) ) gend_indx(3)  = global_axis_size

             ALLOCATE(subaxis_z(gstart_indx(3):gend_indx(3)))
             subaxis_z=global_depth(gstart_indx(3):gend_indx(3))
             output_fields(outnum)%output_grid%subaxes(3) =&
                  & diag_subaxes_init(axes(3),subaxis_z, gstart_indx(3),gend_indx(3))
             DEALLOCATE(subaxis_z,global_depth)
          ELSE ! regional vertical axis is the same as global vertical axis
             gstart_indx(3) = 1
             gend_indx(3) = global_axis_size
             output_fields(outnum)%output_grid%subaxes(3) = axes(3)
          END IF
       END IF
    END IF

    ! get domain and compute_domain(xbegin,xend,ybegin,yend)
    xbegin = -1
    xend = -1
    ybegin = -1
    yend = -1

    Domain2 = get_domain2d(axes)
    IF ( Domain2 .NE. NULL_DOMAIN2D ) THEN
       CALL mpp_get_compute_domain(Domain2, xbegin, xend, ybegin, yend)
       CALL mpp_get_domain_components(Domain2, Domain1x, Domain1y)
    ELSE
       DO i = 1, MIN(SIZE(axes(:)),2)
          Domain1 = get_domain1d(axes(i))
          IF ( Domain1 .NE. NULL_DOMAIN1D ) THEN
             CALL get_diag_axis_cart(axes(i),cart)
             SELECT CASE(cart)
             CASE ('X')
                Domain1x = get_domain1d(axes(i))
                CALL mpp_get_compute_domain(Domain1x, xbegin, xend)
             CASE ('Y')
                Domain1y = get_domain1d(axes(i))
                CALL mpp_get_compute_domain(Domain1y, ybegin, yend)
             CASE default ! do nothing here
             END SELECT
          ELSE
             ! <ERROR STATUS="FATAL">No domain available</ERROR>
             CALL error_mesg('diag_util_mod::get_subfield_size', 'NO domain available', FATAL)
          END IF
       END DO
    END IF

    CALL get_axes_shift(axes, ishift, jshift)
    xend = xend+ishift
    yend = yend+jshift

    IF ( xbegin == -1 .OR. xend == -1 .OR. ybegin == -1 .OR. yend == -1 ) THEN
       ! <ERROR STATUS="FATAL">wrong compute domain indices</ERROR>
       CALL error_mesg('diag_util_mod::get_subfield_size', 'wrong compute domain indices',FATAL)
    END IF

    ! get the area containing BOTH compute domain AND local output area
    IF( gstart_indx(1) > xend .OR. xbegin > gend_indx(1) ) THEN
       output_fields(outnum)%output_grid%l_start_indx(1) = -1
       output_fields(outnum)%output_grid%l_end_indx(1) = -1
       output_fields(outnum)%need_compute = .FALSE. ! not involved
    ELSEIF ( gstart_indx(2) > yend .OR. ybegin > gend_indx(2) ) THEN
       output_fields(outnum)%output_grid%l_start_indx(2) = -1
       output_fields(outnum)%output_grid%l_end_indx(2) = -1
       output_fields(outnum)%need_compute = .FALSE. ! not involved
    ELSE
       output_fields(outnum)%output_grid%l_start_indx(1) = MAX(xbegin, gstart_indx(1))
       output_fields(outnum)%output_grid%l_start_indx(2) = MAX(ybegin, gstart_indx(2))
       output_fields(outnum)%output_grid%l_end_indx(1) = MIN(xend, gend_indx(1))
       output_fields(outnum)%output_grid%l_end_indx(2) = MIN(yend, gend_indx(2))
       output_fields(outnum)%need_compute = .TRUE.  ! involved in local output
    END IF

    IF ( output_fields(outnum)%need_compute ) THEN
       ! need to modify domain1d and domain2d for subaxes
       xbegin_l = output_fields(outnum)%output_grid%l_start_indx(1)
       xend_l = output_fields(outnum)%output_grid%l_end_indx(1)
       ybegin_l = output_fields(outnum)%output_grid%l_start_indx(2)
       yend_l = output_fields(outnum)%output_grid%l_end_indx(2)
       CALL mpp_modify_domain(Domain2, Domain2_new, xbegin_l,xend_l, ybegin_l,yend_l,&
            & gstart_indx(1),gend_indx(1), gstart_indx(2),gend_indx(2))

       output_fields(outnum)%output_grid%subaxes(1) =&
            & diag_subaxes_init(axes(1),subaxis_x, gstart_indx(1),gend_indx(1),Domain2_new)
       output_fields(outnum)%output_grid%subaxes(2) =&
            & diag_subaxes_init(axes(2),subaxis_y, gstart_indx(2),gend_indx(2),Domain2_new)
       DO i = 1, SIZE(axes(:))
          IF ( output_fields(outnum)%output_grid%subaxes(i) == -1 ) THEN
             ! <ERROR STATUS="FATAL">
             !   <output_fields(outnum)%output_name> error at i = <i>
             ! </ERROR>
             WRITE(msg,'(a,"/",I4)') 'at i = ',i
             CALL error_mesg('diag_util_mod::get_subfield_size '//TRIM(output_fields(outnum)%output_name),&
                  'error '//TRIM(msg), FATAL)
          END IF
       END DO

       ! local start index should start from 1
       output_fields(outnum)%output_grid%l_start_indx(1) = MAX(xbegin, gstart_indx(1)) - xbegin + 1
       output_fields(outnum)%output_grid%l_start_indx(2) = MAX(ybegin, gstart_indx(2)) - ybegin + 1
       output_fields(outnum)%output_grid%l_end_indx(1) = MIN(xend, gend_indx(1)) - xbegin + 1
       output_fields(outnum)%output_grid%l_end_indx(2) = MIN(yend, gend_indx(2)) - ybegin + 1
       IF ( SIZE(axes(:))>2 ) THEN
          output_fields(outnum)%output_grid%l_start_indx(3) = gstart_indx(3)
          output_fields(outnum)%output_grid%l_end_indx(3) = gend_indx(3)
       ELSE
          output_fields(outnum)%output_grid%l_start_indx(3) = 1
          output_fields(outnum)%output_grid%l_end_indx(3) = 1
       END IF
    END IF
    IF ( ALLOCATED(subaxis_x) ) DEALLOCATE(subaxis_x, global_lon)
    IF ( ALLOCATED(subaxis_y) ) DEALLOCATE(subaxis_y, global_lat)
  END SUBROUTINE get_subfield_size
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="get_subfield_vert_size">
  !   <OVERVIEW>
  !     Get size, start and end indices for output fields.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE get_subfield_vert_size(axes, outnum)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Get size, start and end indices for <TT>output_fields(outnum)</TT>, fill in
  !     <TT>output_fields(outnum)%output_grid%(start_indx, end_indx)</TT>.
  !   </DESCRIPTION>
  !   <IN NAME="axes" TYPE="INTEGER, DIMENSION(:)">Axes of the <TT>input_field</TT></IN>
  !   <IN NAME="outnum" TYPE="INTEGER">Position in array <TT>output_fields</TT>.</IN>
  SUBROUTINE get_subfield_vert_size(axes, outnum)
    INTEGER, DIMENSION(:), INTENT(in) :: axes ! axes of the input_field
    INTEGER, INTENT(in) :: outnum  ! position in array output_fields

    REAL, DIMENSION(3) :: start, end ! start and end coordinates in 3 axes
    REAL, ALLOCATABLE, DIMENSION(:) :: global_depth
    REAL, ALLOCATABLE, DIMENSION(:) :: subaxis_z !containing local coordinates in x,y,z axes
    INTEGER :: i, global_axis_size
    INTEGER, DIMENSION(3) :: gstart_indx, gend_indx ! global start and end indices of output domain in 3 axes
    CHARACTER(len=1) :: cart
    CHARACTER(len=128) :: msg
!----------
!ug support
    integer :: vert_dim_num
!----------

    !initilization for local output
    start = -1.e10
    end = -1.e10 ! initially out of (lat/lon/depth) range
    gstart_indx = -1
    gend_indx=-1

    ! get axis data (lat, lon, depth) and indices
    start= output_fields(outnum)%output_grid%start
    end = output_fields(outnum)%output_grid%end

!----------
!ug support
    vert_dim_num = 3
!----------
    DO i = 1, SIZE(axes(:))
       global_axis_size = get_axis_global_length(axes(i))
       output_fields(outnum)%output_grid%subaxes(i) = -1
       CALL get_diag_axis_cart(axes(i), cart)
       SELECT CASE(cart)
       CASE ('X')
          ! <ERROR STATUS="FATAL">wrong order of axes, X should come first</ERROR>
          IF ( i.NE.1 ) CALL error_mesg('diag_util_mod::get_subfield_vert_size',&
               & 'wrong order of axes, X should come first',FATAL)
          gstart_indx(i) = 1
          gend_indx(i) = global_axis_size
          output_fields(outnum)%output_grid%subaxes(i) = axes(i)
       CASE ('Y')
          ! <ERROR STATUS="FATAL">wrong order of axes, Y should come second</ERROR>
          IF( i.NE.2 ) CALL error_mesg('diag_util_mod::get_subfield_vert_size',&
               & 'wrong order of axes, Y should come second',FATAL)
          gstart_indx(i) = 1
          gend_indx(i) = global_axis_size
          output_fields(outnum)%output_grid%subaxes(i) = axes(i)
!----------
!ug support
       case ("U")
           if (i .ne. 1) then
               call error_mesg("diag_util_mod::get_subfield_vert_size", &
                               "the unstructured axis must be the first dimension.", &
                               FATAL)
           endif
           gstart_indx(i) = 1
           gend_indx(i) = global_axis_size
           output_fields(outnum)%output_grid%subaxes(i) = axes(i)
           vert_dim_num = 2
           start(vert_dim_num) = start(3)
           end(vert_dim_num) = end(3)
!----------
       CASE ('Z')
!----------
!ug support
          if (i .ne. vert_dim_num) then
              call error_mesg("diag_util_mod::get_subfield_vert_size",&
                              "i should equal vert_dim_num for z axis", &
                              FATAL)
          endif
!----------
          ! <ERROR STATUS="FATAL">wrong values in vertical axis of region</ERROR>
          IF( start(i)*END(i) < 0. ) CALL error_mesg('diag_util_mod::get_subfield_vert_size',&
               & 'wrong values in vertical axis of region',FATAL)
          IF( start(i) >= 0. .AND. END(i) > 0. ) THEN
             ALLOCATE(global_depth(global_axis_size))
             CALL get_diag_axis_data(axes(i),global_depth)
             gstart_indx(i) = get_index(start(i),global_depth)
             IF( start(i) == 0.0 )  gstart_indx(i) = 1

             gend_indx(i) = get_index(END(i),global_depth)
             IF( start(i) >= MAXVAL(global_depth) ) gstart_indx(i)= global_axis_size
             IF( END(i)   >= MAXVAL(global_depth) ) gend_indx(i)  = global_axis_size

             ALLOCATE(subaxis_z(gstart_indx(i):gend_indx(i)))
             subaxis_z=global_depth(gstart_indx(i):gend_indx(i))
             output_fields(outnum)%output_grid%subaxes(i) = &
                    diag_subaxes_init(axes(i),subaxis_z, gstart_indx(i),gend_indx(i))
             DEALLOCATE(subaxis_z,global_depth)
          ELSE !   vertical axis is the same as global vertical axis
             gstart_indx(i) = 1
             gend_indx(i) = global_axis_size
             output_fields(outnum)%output_grid%subaxes(i) = axes(i)
          END IF
       CASE default
          ! <ERROR STATUS="FATAL">Wrong axis_cart</ERROR>
          CALL error_mesg('diag_util_mod::get_subfield_vert_size', 'Wrong axis_cart', FATAL)
       END SELECT
    END DO

    DO i = 1,SIZE(axes(:))
       IF ( gstart_indx(i) == -1 .OR. gend_indx(i) == -1 ) THEN
          ! <ERROR STATUS="FATAL">
          !   can not find gstart_indx/gend_indx for <output_fields(outnum)%output_name>
          !   check region bounds for axis
          ! </ERROR>
          WRITE(msg,'(A,I2)') ' check region bounds for axis ', i
          CALL error_mesg('diag_util_mod::get_subfield_vert_size', 'can not find gstart_indx/gend_indx for '&
               & //TRIM(output_fields(outnum)%output_name)//','//TRIM(msg), FATAL)
       END IF
    END DO

    DO i= 1, 2
       output_fields(outnum)%output_grid%l_start_indx(i) = gstart_indx(i)
       output_fields(outnum)%output_grid%l_end_indx(i)   = gend_indx(i)
    END DO

    IF( SIZE(axes(:)) > 2 ) THEN
       output_fields(outnum)%output_grid%l_start_indx(3) = gstart_indx(3)
       output_fields(outnum)%output_grid%l_end_indx(3)   = gend_indx(3)
    ELSE
       output_fields(outnum)%output_grid%l_start_indx(3) = 1
       output_fields(outnum)%output_grid%l_end_indx(3)   = 1
    END IF
  END SUBROUTINE get_subfield_vert_size
  ! </SUBROUTINE>

  ! <PRIVATE>
  ! <FUNCTION NAME="get_index">
  !   <OVERVIEW>
  !     Find index <TT>i</TT> of array such that <TT>array(i)</TT> is closest to number.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     INTEGER FUNCTION get_index(number, array)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Find index <TT>i</TT> of array such that <TT>array(i)</TT> is closest to number.
  !     Array must be  monotonouslly ordered.
  !   </DESCRIPTION>
  !   <IN NAME="number" TYPE="REAL"></IN>
  !   <IN NAME="array" TYPE="REAL, DIMENSION(:)"></IN>
  INTEGER FUNCTION get_index(number, array)
    REAL, INTENT(in) :: number
    REAL, INTENT(in), DIMENSION(:) :: array

    INTEGER :: i, n
    LOGICAL :: found

    n = SIZE(array(:))
    ! check if array is monotonous
    DO i = 2, n-1
       IF( (array(i-1)<array(i).AND.array(i)>array(i+1)) .OR. (array(i-1)>array(i).AND.array(i)<array(i+1))) THEN
          ! <ERROR STATUS="FATAL">array NOT monotonously ordered</ERROR>
          CALL error_mesg('diag_util_mod::get_index', 'array NOT monotonously ordered',FATAL)
       END IF
    END DO
    get_index = -1
    found = .FALSE.
    ! search in increasing array
    DO i = 1, n-1
       IF ( (array(i)<=number).AND.(array(i+1)>= number) ) THEN
          IF( number - array(i) <= array(i+1) - number ) THEN
             get_index = i
             found=.TRUE.
          ELSE
             get_index = i+1
             found=.TRUE.
          ENDIF
          EXIT
       END IF
    END DO
    ! if not found, search in decreasing array
    IF( .NOT.found ) THEN
       DO i = 1, n-1
          IF ( (array(i)>=number).AND.(array(i+1)<= number) ) THEN
             IF ( array(i)-number <= number-array(i+1) ) THEN
                get_index = i
                found = .TRUE.
             ELSE
                get_index = i+1
                found = .TRUE.
             END IF
             EXIT
          END IF
       END DO
    END IF
    ! if still not found, is it less than the first element
    ! or greater than last element? (Increasing Array)
    ! But it must be within 2x the axis spacing
    ! i.e. array(1)-(array(3)-array(1)).LT.number .AND. or 2*array(1)-array(3).LT.number
    IF ( .NOT. found ) THEN
       IF ( 2*array(1)-array(3).LT.number .AND. number.LT.array(1) ) THEN
          get_index = 1
          found = .TRUE.
       ELSE IF ( array(n).LT.number .AND. number.LT.2*array(n)-array(n-2) ) THEN
          get_index = n
          found = .TRUE.
       ELSE
          found = .FALSE.
       END IF
    END IF

    ! if still not found, is it greater than the first element
    ! or less than the last element? (Decreasing Array)
    ! But it must be within 2x the axis spacing (see above)
    IF ( .NOT. found ) THEN
       IF ( 2*array(1)-array(3).GT.number .AND. number.GT.array(1) ) THEN
          get_index = 1
          found = .TRUE.
       ELSE IF ( array(n).GT.number .AND. number.GT.2*array(n)-array(n-2) ) THEN
          get_index = n
          found = .TRUE.
       ELSE
          found = .FALSE.
       END IF
    END IF
  END FUNCTION get_index
  ! </FUNCTION>
  ! </PRIVATE>

  ! <SUBROUTINE NAME="log_diag_field_info">
  !   <OVERVIEW>
  !     Writes brief diagnostic field info to the log file.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE log_diag_field_info(module_name, field_name, axes, long_name, units,
  !     missing_value, range, dynamic)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     If the <TT>do_diag_field_log</TT> namelist parameter is .TRUE.,
  !     then a line briefly describing diagnostic field is added to
  !     the log file.  Normally users should not call this subroutine
  !     directly, since it is called by register_static_field and
  !     register_diag_field if do_not_log is not set to .TRUE..  It is
  !     used, however, in LM3 to avoid excessive logs due to the
  !     number of fields registered for each of the tile types.  LM3
  !     code uses a do_not_log parameter in the registration calls,
  !     and subsequently calls this subroutine to log field information
  !     under a generic name.
  !   </DESCRIPTION>
  !   <IN NAME="module_name" TYPE="CHARACTER(len=*)">Module name.</IN>
  !   <IN NAME="field_name" TYPE="CHARACTER(len=*)">Field name.</IN>
  !   <IN NAME="axes" TYPE="INTEGER, DIMENSION(:)">Axis IDs.</IN>
  !   <IN NAME="long_name" TYPE="CHARACTER(len=*), OPTIONAL">Long name for field.</IN>
  !   <IN NAME="units" TYPE="CHARACTER(len=*), OPTIONAL">Unit of field.</IN>
  !   <IN NAME="missing_value" TYPE="REAL, OPTIONAL">Missing value value.</IN>
  !   <IN NAME="range" TYPE="REAL, DIMENSION(2), OPTIONAL">Valid range of values for field.</IN>
  !   <IN NAME="dynamic" TYPE="LOGICAL, OPTIONAL"><TT>.TRUE.</TT> if field is not static.</IN>
  SUBROUTINE log_diag_field_info(module_name, field_name, axes, long_name, units,&
       & missing_value, range, dynamic)
    CHARACTER(len=*), INTENT(in) :: module_name, field_name
    INTEGER, DIMENSION(:), INTENT(in) :: axes
    CHARACTER(len=*), OPTIONAL, INTENT(in) :: long_name, units
    REAL, OPTIONAL, INTENT(in) :: missing_value
    REAL, DIMENSION(2), OPTIONAL, INTENT(IN) :: range
    LOGICAL, OPTIONAL, INTENT(in) :: dynamic

    ! ---- local vars
    CHARACTER(len=256) :: lmodule, lfield, lname, lunits
    CHARACTER(len=64)  :: lmissval, lmin, lmax
    CHARACTER(len=8)   :: numaxis, timeaxis
    CHARACTER(len=1)   :: sep = '|'
    CHARACTER(len=256) :: axis_name, axes_list
    INTEGER :: i

    IF ( .NOT.do_diag_field_log ) RETURN
    IF ( mpp_pe().NE.mpp_root_pe() ) RETURN

    lmodule = TRIM(module_name)
    lfield = TRIM(field_name)

    IF ( PRESENT(long_name) ) THEN
       lname  = TRIM(long_name)
    ELSE
       lname  = ''
    END IF

    IF ( PRESENT(units) ) THEN
       lunits = TRIM(units)
    ELSE
       lunits = ''
    END IF

    WRITE (numaxis,'(i1)') SIZE(axes)

    IF (PRESENT(missing_value)) THEN
       IF ( use_cmor ) THEN
          WRITE (lmissval,*) CMOR_MISSING_VALUE
       ELSE
          WRITE (lmissval,*) missing_value
       END IF
    ELSE
       lmissval = ''
    ENDIF

    IF ( PRESENT(range) ) THEN
       WRITE (lmin,*) range(1)
       WRITE (lmax,*) range(2)
    ELSE
       lmin = ''
       lmax = ''
    END IF

    IF ( PRESENT(dynamic) ) THEN
       IF (dynamic) THEN
          timeaxis = 'T'
       ELSE
          timeaxis = 'F'
       END IF
    ELSE
       timeaxis = ''
    END IF

    axes_list=''
    DO i = 1, SIZE(axes)
       CALL get_diag_axis_name(axes(i),axis_name)
       IF ( TRIM(axes_list) /= '' ) axes_list = TRIM(axes_list)//','
       axes_list = TRIM(axes_list)//TRIM(axis_name)
    END DO

    !write (diag_log_unit,'(8(a,a),a)') &
    WRITE (diag_log_unit,'(777a)') &
         & TRIM(lmodule),  sep, TRIM(lfield),  sep, TRIM(lname),    sep,&
         & TRIM(lunits),   sep, TRIM(numaxis), sep, TRIM(timeaxis), sep,&
         & TRIM(lmissval), sep, TRIM(lmin),    sep, TRIM(lmax),     sep,&
         & TRIM(axes_list)
  END SUBROUTINE log_diag_field_info
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="update_bounds">
  !   <OVERVIEW>
  !     Update the <TT>output_fields</TT> min and max boundaries.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE update_bounds(out_num, lower_i, upper_i, lower_j, upper_j, lower_k, upper_k)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Update the <TT>output_fields</TT> x, y, and z min and max boundaries (array indices).
  !   </DESCRIPTION>
  !   <IN NAME="out_num" TYPE="INTEGER"><TT>output_field</TT> ID.</IN>
  !   <IN NAME="lower_i" TYPE="INTEGER">Lower <TT>i</TT> bound.</IN>
  !   <IN NAME="upper_i" TYPE="INTEGER">Upper <TT>i</TT> bound.</IN>
  !   <IN NAME="lower_j" TYPE="INTEGER">Lower <TT>j</TT> bound.</IN>
  !   <IN NAME="upper_j" TYPE="INTEGER">Upper <TT>j</TT> bound.</IN>
  !   <IN NAME="lower_k" TYPE="INTEGER">Lower <TT>k</TT> bound.</IN>
  !   <IN NAME="upper_k" TYPE="INTEGER">Upper <TT>k</TT> bound.</IN>
  SUBROUTINE update_bounds(out_num, lower_i, upper_i, lower_j, upper_j, lower_k, upper_k)
    INTEGER, INTENT(in) :: out_num, lower_i, upper_i, lower_j, upper_j, lower_k, upper_k

    output_fields(out_num)%imin = MIN(output_fields(out_num)%imin, lower_i)
    output_fields(out_num)%imax = MAX(output_fields(out_num)%imax, upper_i)
    output_fields(out_num)%jmin = MIN(output_fields(out_num)%jmin, lower_j)
    output_fields(out_num)%jmax = MAX(output_fields(out_num)%jmax, upper_j)
    output_fields(out_num)%kmin = MIN(output_fields(out_num)%kmin, lower_k)
    output_fields(out_num)%kmax = MAX(output_fields(out_num)%kmax, upper_k)
  END SUBROUTINE update_bounds
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="check_out_of_bounds">
  !   <OVERVIEW>
  !     Checks if the array indices for <TT>output_fields(out_num)</TT> are outside the <TT>output_fields(out_num)%buffer</TT> upper
  !     and lower bounds.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE check_out_of_bounds(out_num, diag_field_id, err_msg)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     <TT>check_out_of_bounds</TT> verifies the array min and max indices in the x, y, and z directions of <TT>
  !     output_fields(out_num)</TT> are not outside the upper and lower array boundaries of
  !     <TT>output_fields(out_num)%buffer</TT>.  If the min and max indices are outside the upper and lower bounds of the buffer
  !     array, then <TT>check_out_of_bounds</TT> returns an error string.
  !   </DESCRIPTION>
  !   <IN NAME="out_num" TYPE="INTEGER">
  !     Output field ID number.
  !   </IN>
  !   <IN NAME="diag_field_id" TYPE="INTEGER">
  !     Input field ID number.
  !   </IN>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*)">
  !     Return status of <TT>check_out_of_bounds</TT>.  An empty error string indicates the x, y, and z indices are not outside the
  !     buffer array boundaries.
  !   </OUT>
  SUBROUTINE check_out_of_bounds(out_num, diag_field_id, err_msg)
    INTEGER, INTENT(in) :: out_num, diag_field_id
    CHARACTER(len=*), INTENT(out) :: err_msg

    CHARACTER(len=128) :: error_string1, error_string2

    IF (   output_fields(out_num)%imin < LBOUND(output_fields(out_num)%buffer,1) .OR.&
         & output_fields(out_num)%imax > UBOUND(output_fields(out_num)%buffer,1) .OR.&
         & output_fields(out_num)%jmin < LBOUND(output_fields(out_num)%buffer,2) .OR.&
         & output_fields(out_num)%jmax > UBOUND(output_fields(out_num)%buffer,2) .OR.&
         & output_fields(out_num)%kmin < LBOUND(output_fields(out_num)%buffer,3) .OR.&
         & output_fields(out_num)%kmax > UBOUND(output_fields(out_num)%buffer,3) ) THEN
       WRITE(error_string1,'(a,"/",a)') TRIM(input_fields(diag_field_id)%module_name),&
            & TRIM(output_fields(out_num)%output_name)
       error_string2 ='Buffer bounds=   :   ,   :   ,   :     Actual bounds=   :   ,   :   ,   :   '
       WRITE(error_string2(15:17),'(i3)') LBOUND(output_fields(out_num)%buffer,1)
       WRITE(error_string2(19:21),'(i3)') UBOUND(output_fields(out_num)%buffer,1)
       WRITE(error_string2(23:25),'(i3)') LBOUND(output_fields(out_num)%buffer,2)
       WRITE(error_string2(27:29),'(i3)') UBOUND(output_fields(out_num)%buffer,2)
       WRITE(error_string2(31:33),'(i3)') LBOUND(output_fields(out_num)%buffer,3)
       WRITE(error_string2(35:37),'(i3)') UBOUND(output_fields(out_num)%buffer,3)
       WRITE(error_string2(54:56),'(i3)') output_fields(out_num)%imin
       WRITE(error_string2(58:60),'(i3)') output_fields(out_num)%imax
       WRITE(error_string2(62:64),'(i3)') output_fields(out_num)%jmin
       WRITE(error_string2(66:68),'(i3)') output_fields(out_num)%jmax
       WRITE(error_string2(70:72),'(i3)') output_fields(out_num)%kmin
       WRITE(error_string2(74:76),'(i3)') output_fields(out_num)%kmax
       err_msg = 'module/output_field='//TRIM(error_string1)//&
            & '  Bounds of buffer exceeded.  '//TRIM(error_string2)
       !   imax, imin, etc need to be reset in case the program is not terminated.
       output_fields(out_num)%imax = 0
       output_fields(out_num)%imin = VERY_LARGE_AXIS_LENGTH
       output_fields(out_num)%jmax = 0
       output_fields(out_num)%jmin = VERY_LARGE_AXIS_LENGTH
       output_fields(out_num)%kmax = 0
       output_fields(out_num)%kmin = VERY_LARGE_AXIS_LENGTH
    ELSE
       err_msg = ''
    END IF

  END SUBROUTINE check_out_of_bounds
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="check_bounds_are_exact_dynamic">
  !   <OVERVIEW>
  !     Check if the array indices for <TT>output_fields(out_num)</TT> are equal to the <TT>output_fields(out_num)%buffer</TT>
  !     upper and lower bounds.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE check_bounds_are_exact_dynamic(out_num, diag_field_id, Time, err_msg)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     <TT>check_bounds_are_exact_dynamic</TT> checks if the min and max array indices for <TT>output_fields(out_num)</TT> are
  !     equal to the upper and lower bounds of <TT>output_fields(out_num)%buffer</TT>.  This check is only performed if
  !     <TT>output_fields(out_num)%Time_of_prev_field_data</TT> doesn't equal <TT>Time</TT> or <TT>Time_zero</TT>.
  !     <TT>check_bounds_are_exact_dynamic</TT> returns an error string if the array indices do not match the buffer bounds.
  !   </DESCRIPTION>
  !   <IN NAME="out_num" TYPE="INTEGER">
  !     Output field ID number.
  !   </IN>
  !   <IN NAME="diag_field_id" TYPE="INTEGER">
  !     Input field ID number.
  !   </IN>
  !   <IN NAME="Time" TYPE="TYPE(time_type)">
  !     Time to use in check.  The check is only performed if <TT>output_fields(out_num)%Time_of_prev_field_data</TT> is not
  !     equal to <TT>Time</TT> or <TT>Time_zero</TT>.
  !   </IN>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*)">
  !     Return status of <TT>check_bounds_are_exact_dynamic</TT>.  An empty error string indicates the x, y, and z indices are
  !     equal to the buffer array boundaries.
  !   </OUT>
  SUBROUTINE check_bounds_are_exact_dynamic(out_num, diag_field_id, Time, err_msg)
    INTEGER, INTENT(in) :: out_num, diag_field_id
    TYPE(time_type), INTENT(in) :: Time
    CHARACTER(len=*), INTENT(out) :: err_msg

    CHARACTER(len=128) :: error_string1, error_string2
    LOGICAL :: do_check

    err_msg = ''

    ! Check bounds only when the value of Time changes. When windows are used,
    ! a change in Time indicates that a new loop through the windows has begun,
    !  so a check of the previous loop can be done.
    IF ( Time == output_fields(out_num)%Time_of_prev_field_data ) THEN
       do_check = .FALSE.
    ELSE
       IF ( output_fields(out_num)%Time_of_prev_field_data == Time_zero ) THEN
          ! It may or may not be OK to check, I don't know how to tell.
          ! Check will be done on subsequent calls anyway.
          do_check = .FALSE.
       ELSE
          do_check = .TRUE.
       END IF
       output_fields(out_num)%Time_of_prev_field_data = Time
    END IF

    IF ( do_check ) THEN
       IF (   output_fields(out_num)%imin /= LBOUND(output_fields(out_num)%buffer,1) .OR.&
            & output_fields(out_num)%imax /= UBOUND(output_fields(out_num)%buffer,1) .OR.&
            & output_fields(out_num)%jmin /= LBOUND(output_fields(out_num)%buffer,2) .OR.&
            & output_fields(out_num)%jmax /= UBOUND(output_fields(out_num)%buffer,2) .OR.&
            & output_fields(out_num)%kmin /= LBOUND(output_fields(out_num)%buffer,3) .OR.&
            & output_fields(out_num)%kmax /= UBOUND(output_fields(out_num)%buffer,3) ) THEN
          WRITE(error_string1,'(a,"/",a)') TRIM(input_fields(diag_field_id)%module_name),&
               & TRIM(output_fields(out_num)%output_name)
          error_string2 ='Buffer bounds=   :   ,   :   ,   :     Actual bounds=   :   ,   :   ,   :   '
          WRITE(error_string2(15:17),'(i3)') LBOUND(output_fields(out_num)%buffer,1)
          WRITE(error_string2(19:21),'(i3)') UBOUND(output_fields(out_num)%buffer,1)
          WRITE(error_string2(23:25),'(i3)') LBOUND(output_fields(out_num)%buffer,2)
          WRITE(error_string2(27:29),'(i3)') UBOUND(output_fields(out_num)%buffer,2)
          WRITE(error_string2(31:33),'(i3)') LBOUND(output_fields(out_num)%buffer,3)
          WRITE(error_string2(35:37),'(i3)') UBOUND(output_fields(out_num)%buffer,3)
          WRITE(error_string2(54:56),'(i3)') output_fields(out_num)%imin
          WRITE(error_string2(58:60),'(i3)') output_fields(out_num)%imax
          WRITE(error_string2(62:64),'(i3)') output_fields(out_num)%jmin
          WRITE(error_string2(66:68),'(i3)') output_fields(out_num)%jmax
          WRITE(error_string2(70:72),'(i3)') output_fields(out_num)%kmin
          WRITE(error_string2(74:76),'(i3)') output_fields(out_num)%kmax
          err_msg = TRIM(error_string1)//' Bounds of data do not match those of buffer. '//TRIM(error_string2)
       END IF
       output_fields(out_num)%imax = 0
       output_fields(out_num)%imin = VERY_LARGE_AXIS_LENGTH
       output_fields(out_num)%jmax = 0
       output_fields(out_num)%jmin = VERY_LARGE_AXIS_LENGTH
       output_fields(out_num)%kmax = 0
       output_fields(out_num)%kmin = VERY_LARGE_AXIS_LENGTH
    END IF
  END SUBROUTINE check_bounds_are_exact_dynamic
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="check_bounds_are_exact_static">
  !   <OVERVIEW>
  !     Check if the array indices for <TT>output_fields(out_num)</TT> are equal to the <TT>output_fields(out_num)%buffer</TT>
  !     upper and lower bounds.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE check_bounds_are_exact_static(out_num, diag_field_id, err_msg)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !   </DESCRIPTION>
  !   <IN NAME="out_num" TYPE="INTEGER">Output field ID</IN>
  !   <IN NAME="diag_field_id" TYPE="INTEGER">Input field ID.</IN>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*)"></OUT>
  SUBROUTINE check_bounds_are_exact_static(out_num, diag_field_id, err_msg)
    INTEGER, INTENT(in) :: out_num, diag_field_id
    CHARACTER(len=*), INTENT(out) :: err_msg

    CHARACTER(len=128)  :: error_string1, error_string2

    err_msg = ''

    IF (   output_fields(out_num)%imin /= LBOUND(output_fields(out_num)%buffer,1) .OR.&
         & output_fields(out_num)%imax /= UBOUND(output_fields(out_num)%buffer,1) .OR.&
         & output_fields(out_num)%jmin /= LBOUND(output_fields(out_num)%buffer,2) .OR.&
         & output_fields(out_num)%jmax /= UBOUND(output_fields(out_num)%buffer,2) .OR.&
         & output_fields(out_num)%kmin /= LBOUND(output_fields(out_num)%buffer,3) .OR.&
         & output_fields(out_num)%kmax /= UBOUND(output_fields(out_num)%buffer,3) ) THEN
       WRITE(error_string1,'(a,"/",a)') TRIM(input_fields(diag_field_id)%module_name),&
            & TRIM(output_fields(out_num)%output_name)
       error_string2 ='Buffer bounds=   :   ,   :   ,   :     Actual bounds=   :   ,   :   ,   :   '
       WRITE(error_string2(15:17),'(i3)') LBOUND(output_fields(out_num)%buffer,1)
       WRITE(error_string2(19:21),'(i3)') UBOUND(output_fields(out_num)%buffer,1)
       WRITE(error_string2(23:25),'(i3)') LBOUND(output_fields(out_num)%buffer,2)
       WRITE(error_string2(27:29),'(i3)') UBOUND(output_fields(out_num)%buffer,2)
       WRITE(error_string2(31:33),'(i3)') LBOUND(output_fields(out_num)%buffer,3)
       WRITE(error_string2(35:37),'(i3)') UBOUND(output_fields(out_num)%buffer,3)
       WRITE(error_string2(54:56),'(i3)') output_fields(out_num)%imin
       WRITE(error_string2(58:60),'(i3)') output_fields(out_num)%imax
       WRITE(error_string2(62:64),'(i3)') output_fields(out_num)%jmin
       WRITE(error_string2(66:68),'(i3)') output_fields(out_num)%jmax
       WRITE(error_string2(70:72),'(i3)') output_fields(out_num)%kmin
       WRITE(error_string2(74:76),'(i3)') output_fields(out_num)%kmax
       err_msg = TRIM(error_string1)//' Bounds of data do not match those of buffer. '//TRIM(error_string2)
    END IF
    output_fields(out_num)%imax = 0
    output_fields(out_num)%imin = VERY_LARGE_AXIS_LENGTH
    output_fields(out_num)%jmax = 0
    output_fields(out_num)%jmin = VERY_LARGE_AXIS_LENGTH
    output_fields(out_num)%kmax = 0
    output_fields(out_num)%kmin = VERY_LARGE_AXIS_LENGTH

  END SUBROUTINE check_bounds_are_exact_static
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="init_file">
  !   <OVERVIEW>
  !     Initialize the output file.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE init_file(name, output_freq, output_units, format, time_units
  !     long_name, tile_count, new_file_freq, new_file_freq_units, start_time,
  !     file_duration, file_duration_units)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Initialize the output file.
  !   </DESCRIPTION>
  !   <IN NAME="name" TYPE="CHARACTER(len=*)">File name.</IN>
  !   <IN NAME="output_freq" TYPE="INTEGER">How often data is to be written to the file.</IN>
  !   <IN NAME="output_units" TYPE="INTEGER">The output frequency unit.  (MIN, HOURS, DAYS, etc.)</IN>
  !   <IN NAME="format" TYPE="INTEGER">Number type/kind the data is to be written out to the file.</IN>
  !   <IN NAME="time_units" TYPE="INTEGER">Time axis units.</IN>
  !   <IN NAME="log_name" TYPE="CHARACTER(len=*)">Long name for time axis.</IN>
  !   <IN NAME="tile_count" TYPE="INTEGER">Tile number.</IN>
  !   <IN NAME="new_file_freq" TYPE="INTEGER, OPTIONAL">How often a new file is to be created.</IN>
  !   <IN NAME="new_file_freq_units" TYPE="INTEGER, OPTIONAL">The new file frequency unit.  (MIN, HOURS, DAYS, etc.)</IN>
  !   <IN NAME="start_time" TYPE="TYPE(time_type), OPTIONAL">Time when the file is to start </IN>
  !   <IN NAME="file_duration" TYPE="INTEGER, OPTIONAL">How long file is to be used.</IN>
  !   <IN NAME="file_duration_units" TYPE="INTEGER, OPTIONAL">File duration unit.  (MIN, HOURS, DAYS, etc.)</IN>
  SUBROUTINE init_file(name, output_freq, output_units, format, time_units, long_name, tile_count,&
       & new_file_freq, new_file_freq_units, start_time, file_duration, file_duration_units)
    CHARACTER(len=*), INTENT(in) :: name, long_name
    INTEGER, INTENT(in) :: output_freq, output_units, format, time_units
    INTEGER, INTENT(in) :: tile_count
    INTEGER, INTENT(in), OPTIONAL :: new_file_freq, new_file_freq_units
    INTEGER, INTENT(in), OPTIONAL :: file_duration, file_duration_units
    TYPE(time_type), INTENT(in), OPTIONAL :: start_time

    INTEGER :: new_file_freq1, new_file_freq_units1
    INTEGER :: file_duration1, file_duration_units1
    INTEGER :: n
    LOGICAL :: same_file_err !< .FALSE. indicates that if the file name had
                             !! previously been registered, this new file
                             !! contained differences from the previous.
    REAL, DIMENSION(1) :: tdata
    CHARACTER(len=128) :: time_units_str

    ! Check if this file has already been defined
    same_file_err=.FALSE. ! To indicate that if this file was previously defined
                          ! no differences in this registration was detected.
    DO n=1,num_files
      IF ( TRIM(files(n)%name) == TRIM(name) ) THEN
        ! File is defined, check if all inputs are the same
        ! Start with the required parameters
        IF ( files(n)%output_freq.NE.output_freq .OR.&
           & files(n)%output_units.NE.output_units .OR.&
           & files(n)%format.NE.format .OR.&
           & files(n)%time_units.NE.time_units .OR.&
           & TRIM(files(n)%long_name).NE.TRIM(long_name) .OR.&
           & files(n)%tile_count.NE.tile_count ) THEN
           same_file_err=.TRUE.
        END IF

        ! Now check the OPTIONAL parameters
        IF ( PRESENT(new_file_freq) ) THEN
           IF ( files(n)%new_file_freq.NE.new_file_freq ) THEN
             same_file_err=.TRUE.
           END IF
        END IF

        IF ( PRESENT(new_file_freq_units) ) THEN
          IF ( files(n)%new_file_freq_units.NE.new_file_freq_units ) THEN
            same_file_err=.TRUE.
          END IF
        END IF

        IF ( PRESENT(start_time) ) THEN
          IF ( files(n)%start_time==start_time ) THEN
            same_file_err=.TRUE.
          END IF
        END IF

        IF ( PRESENT(file_duration) ) THEN
          IF ( files(n)%duration.NE.file_duration) THEN
            same_file_err=.TRUE.
          END IF
        END IF

        IF ( PRESENT(file_duration_units) ) THEN
          IF ( files(n)%duration_units.NE.file_duration_units ) THEN
            same_file_err=.TRUE.
          END IF
        END IF

        ! If the same file was defined twice, simply return, else FATAL
        IF ( same_file_err ) THEN
          ! Something in this file is not identical to the previously defined
          ! file of the same name.  FATAL
          CALL error_mesg('diag_util_mod::init_file',&
                  & 'The file "'//TRIM(name)//'" is defined multiple times in&
                  & the diag_table.', FATAL)
        ELSE
          ! Issue a note that the same file is defined multiple times
          CALL error_mesg('diag_util_mod::init_file',&
                  & 'The file "'//TRIM(name)//'" is defined multiple times in&
                  & the diag_table.', NOTE)
          ! Return to the calling function
          RETURN
        END IF
      END IF
    END DO

    ! Get a number for this file
    num_files = num_files + 1
    IF ( num_files >= max_files ) THEN
       ! <ERROR STATUS="FATAL">
       !   max_files exceeded, increase max_files via the max_files variable
       !   in the namelist diag_manager_nml.
       ! </ERROR>
       CALL error_mesg('diag_util_mod::init_file',&
            & ' max_files exceeded, increase max_files via the max_files variable&
            & in the namelist diag_manager_nml.', FATAL)
    END IF

    IF ( PRESENT(new_file_freq) ) THEN
       new_file_freq1 = new_file_freq
    ELSE
       new_file_freq1 = VERY_LARGE_FILE_FREQ
    END IF

    IF ( PRESENT(new_file_freq_units) ) THEN
       new_file_freq_units1 = new_file_freq_units
    ELSE IF ( get_calendar_type() == NO_CALENDAR ) THEN
       new_file_freq_units1 = DIAG_DAYS
    ELSE
       new_file_freq_units1 = DIAG_YEARS
    END IF

    IF ( PRESENT(file_duration) ) THEN
       file_duration1 = file_duration
    ELSE
       file_duration1 = new_file_freq1
    END IF

    IF ( PRESENT(file_duration_units) ) THEN
       file_duration_units1 = file_duration_units
    ELSE
       file_duration_units1 = new_file_freq_units1
    END IF

    files(num_files)%tile_count = tile_count
    files(num_files)%name = TRIM(name)
    files(num_files)%output_freq = output_freq
    files(num_files)%output_units = output_units
    files(num_files)%format = FORMAT
    files(num_files)%time_units = time_units
    files(num_files)%long_name = TRIM(long_name)
    files(num_files)%num_fields = 0
    files(num_files)%local = .FALSE.
    files(num_files)%last_flush = base_time
    files(num_files)%file_unit = -1
    files(num_files)%new_file_freq = new_file_freq1
    files(num_files)%new_file_freq_units = new_file_freq_units1
    files(num_files)%duration = file_duration1
    files(num_files)%duration_units = file_duration_units1
    IF ( PRESENT(start_time) ) THEN
       files(num_files)%start_time = start_time
    ELSE
       files(num_files)%start_time = base_time
    END IF
    files(num_files)%next_open=diag_time_inc(files(num_files)%start_time,new_file_freq1,new_file_freq_units1)
    files(num_files)%close_time = diag_time_inc(files(num_files)%start_time,file_duration1, file_duration_units1)
    IF ( files(num_files)%close_time>files(num_files)%next_open ) THEN
       ! <ERROR STATUS="FATAL">
       !   close time GREATER than next_open time, check file duration,
       !   file frequency in <files(num_files)%name>
       ! </ERROR>
       CALL error_mesg('diag_util_mod::init_file', 'close time GREATER than next_open time, check file duration,&
            & file frequency in '//files(num_files)%name, FATAL)
    END IF

    ! add time_axis_id and time_bounds_id here
    WRITE(time_units_str, 11) TRIM(time_unit_list(files(num_files)%time_units)), base_year,&
         & base_month, base_day, base_hour, base_minute, base_second
11  FORMAT(a, ' since ', i4.4, '-', i2.2, '-', i2.2, ' ', i2.2, ':', i2.2, ':', i2.2)
    files(num_files)%time_axis_id = diag_axis_init (TRIM(long_name), tdata, time_units_str, 'T',&
         & TRIM(long_name) , set_name=TRIM(name) )
    !---- register axis for storing time boundaries
    files(num_files)%time_bounds_id = diag_axis_init( 'nv',(/1.,2./),'none','N','vertex number',&
         & set_name='nv')
  END SUBROUTINE init_file
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="sync_file_times">
  !   <OVERVIEW>
  !     Synchronize the file's start and close times with the model start and end times.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE sync_file_times(init_time)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     <TT>sync_file_times</TT> checks to see if the file start time is less than the
  !     model's init time (passed in as the only argument).  If it is less, then the
  !     both the file start time and end time are synchronized using the passed in initial time
  !     and the duration as calculated by the <TT>diag_time_inc</TT> function.  <TT>sync_file_times</TT>
  !     will also increase the <TT>next_open</TT> until it is greater than the init_time.
  !   </DESCRIPTION>
  !   <IN NAME="file_id" TYPE="INTEGER">The file ID</IN>
  !   <IN NAME="init_time" TYPE="TYPE(time_type)">Initial time use for the synchronization.</IN>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*), OPTIONAL">Return error message</OUT>
  SUBROUTINE sync_file_times(file_id, init_time, err_msg)
    INTEGER, INTENT(in) :: file_id
    TYPE(time_type), INTENT(in) :: init_time
    CHARACTER(len=*), OPTIONAL, INTENT(out) :: err_msg

    CHARACTER(len=128) :: msg

    IF ( PRESENT(err_msg) ) err_msg = ''

    IF ( files(file_id)%start_time < init_time ) THEN
       ! Sync the start_time of the file with the initial time of the model
       files(file_id)%start_time = init_time
       ! Sync the file's close time also
       files(file_id)%close_time = diag_time_inc(files(file_id)%start_time,&
            & files(file_id)%duration, files(file_id)%duration_units)
    END IF

    ! Need to increase next_open until it is greate than init_time
    DO WHILE ( files(file_id)%next_open <= init_time )
       files(file_id)%next_open = diag_time_inc(files(file_id)%next_open,&
            & files(file_id)%new_file_freq, files(file_id)%new_file_freq_units, err_msg=msg)
       IF ( msg /= '' ) THEN
          IF ( fms_error_handler('diag_util_mod::sync_file_times',&
               & ' file='//TRIM(files(file_id)%name)//': '//TRIM(msg), err_msg) ) RETURN
       END IF
    END DO
  END SUBROUTINE sync_file_times
  ! </SUBROUTINE>

  ! <FUNCTION NAME="diag_time_inc">
  !   <OVERVIEW>
  !     Return the next time data/file is to be written based on the frequency and units.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     TYPE(time_type) FUNCTION diag_time_inc(time, output_freq, output_units, err_msg)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Return the next time data/file is to be written.  This value is based on the current time and the frequency and units.
  !     Function completed successful if the optional <TT>err_msg</TT> is empty.
  !   </DESCRIPTION>
  !   <IN NAME="time" TYPE="TYPE(time_type)">Current model time.</IN>
  !   <IN NAME="output_freq" TYPE="INTEGER">Output frequency number value.</IN>
  !   <IN NAME="output_units" TYPE="INTEGER">Output frequency unit.</IN>
  !   <OUT NAME="err_msg" TYPE="CHARACTER, OPTIONAL">
  !     Function error message.  An empty string indicates the next output time was found successfully.
  !   </OUT>
  TYPE(time_type) FUNCTION diag_time_inc(time, output_freq, output_units, err_msg)
    TYPE(time_type), INTENT(in) :: time
    INTEGER, INTENT(in):: output_freq, output_units
    CHARACTER(len=*), INTENT(out), OPTIONAL :: err_msg

    CHARACTER(len=128) :: error_message_local

    IF ( PRESENT(err_msg) ) err_msg = ''
    error_message_local = ''

    ! special values for output frequency are -1 for output at end of run
    ! and 0 for every timestep.  Need to check for these here?
    ! Return zero time increment, hopefully this value is never used
    IF ( output_freq == END_OF_RUN .OR. output_freq == EVERY_TIME ) THEN
       diag_time_inc = time
       RETURN
    END IF

    ! Make sure calendar was not set after initialization
    IF ( output_units == DIAG_SECONDS ) THEN
       IF ( get_calendar_type() == NO_CALENDAR ) THEN
          diag_time_inc = increment_time(time, output_freq, 0, err_msg=error_message_local)
       ELSE
          diag_time_inc = increment_date(time, 0, 0, 0, 0, 0, output_freq, err_msg=error_message_local)
       END IF
    ELSE IF ( output_units == DIAG_MINUTES ) THEN
       IF ( get_calendar_type() == NO_CALENDAR ) THEN
          diag_time_inc = increment_time(time, NINT(output_freq*SECONDS_PER_MINUTE), 0, &
               &err_msg=error_message_local)
       ELSE
          diag_time_inc = increment_date(time, 0, 0, 0, 0, output_freq, 0, err_msg=error_message_local)
       END IF
    ELSE IF ( output_units == DIAG_HOURS ) THEN
       IF ( get_calendar_type() == NO_CALENDAR ) THEN
          diag_time_inc = increment_time(time, NINT(output_freq*SECONDS_PER_HOUR), 0, err_msg=error_message_local)
       ELSE
          diag_time_inc = increment_date(time, 0, 0, 0, output_freq, 0, 0, err_msg=error_message_local)
       END IF
    ELSE IF ( output_units == DIAG_DAYS ) THEN
       IF (get_calendar_type() == NO_CALENDAR) THEN
          diag_time_inc = increment_time(time, 0, output_freq, err_msg=error_message_local)
       ELSE
          diag_time_inc = increment_date(time, 0, 0, output_freq, 0, 0, 0, err_msg=error_message_local)
       END IF
    ELSE IF ( output_units == DIAG_MONTHS ) THEN
       IF (get_calendar_type() == NO_CALENDAR) THEN
          error_message_local = 'output units of months NOT allowed with no calendar'
       ELSE
          diag_time_inc = increment_date(time, 0, output_freq, 0, 0, 0, 0, err_msg=error_message_local)
       END IF
    ELSE IF ( output_units == DIAG_YEARS ) THEN
       IF ( get_calendar_type() == NO_CALENDAR ) THEN
          error_message_local = 'output units of years NOT allowed with no calendar'
       ELSE
          diag_time_inc = increment_date(time, output_freq, 0, 0, 0, 0, 0, err_msg=error_message_local)
       END IF
    ELSE
       error_message_local = 'illegal output units'
    END IF

    IF ( error_message_local /= '' ) THEN
       IF ( fms_error_handler('diag_time_inc',error_message_local,err_msg) ) RETURN
    END IF
  END FUNCTION diag_time_inc
  ! </FUNCTION>

  ! <PRIVATE>
  ! <FUNCTION NAME="find_file">
  !   <OVERVIEW>
  !     Return the file number for file name and tile.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     INTEGER FUNCTION fild_file(name, time_count)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Find the file number for the file name and tile number given.  A return value of <TT>-1</TT> indicates the file was not found.
  !   </DESCRIPTION>
  !   <IN NAME="name=" TYPE="CHARACTER(len=*)">File name.</IN>
  !   <IN NAME="tile_count" TYPE="INTEGER">Tile number.</IN>
  INTEGER FUNCTION find_file(name, tile_count)
    INTEGER, INTENT(in) :: tile_count
    CHARACTER(len=*), INTENT(in) :: name

    INTEGER :: i

    find_file = -1
    DO i = 1, num_files
       IF( TRIM(files(i)%name) == TRIM(name) .AND. tile_count == files(i)%tile_count ) THEN
          find_file = i
          RETURN
       END IF
    END DO
  END FUNCTION find_file
  ! </FUNCTION>
  ! </PRIVATE>

  ! <FUNCTION NAME="find_input_field">
  !   <OVERVIEW>
  !     Return the field number for the given module name, field name, and tile number.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     INTEGER FUNCTION find_input_field(module_name, field_name, tile_count)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Return the field number for the given module name, field name and tile number.  A return value of <TT>-1</TT> indicates
  !     the field was not found.
  !   </DESCRIPTION>
  !   <IN NAME="module_name" TYPE="CHARACTER(len=*)">Module name.</IN>
  !   <IN NAME="field_name" TYPE="CHARACTER(len=*)">field name.</IN>
  !   <IN NAME="tile_count" TYPE="INTEGER">Tile number.</IN>
  INTEGER FUNCTION find_input_field(module_name, field_name, tile_count)
    CHARACTER(len=*), INTENT(in) :: module_name, field_name
    INTEGER, INTENT(in) :: tile_count

    INTEGER :: i

    find_input_field = DIAG_FIELD_NOT_FOUND ! Default return value if not found.
    DO i = 1, num_input_fields
       IF(tile_count == input_fields(i)%tile_count .AND.&
            & TRIM(input_fields(i)%module_name) == TRIM(module_name) .AND.&
            & lowercase(TRIM(input_fields(i)%field_name)) == lowercase(TRIM(field_name))) THEN
          find_input_field = i
          RETURN
       END IF
    END DO
  END FUNCTION find_input_field
  ! </FUNCTION>

  ! <SUBROUTINE NAME="init_input_field">
  !   <OVERVIEW>
  !     Initialize the input field.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE init_input_field(module_name, field_name, tile_count)
  !   </TEMPLATE>
  !     Initialize the input field.
  !   <DESCRIPTION>
  !   </DESCRIPTION>
  !   <IN NAME="module_name" TYPE="CHARACTER(len=*)">Module name.</IN>
  !   <IN NAME="field_name" TYPE="CHARACTER(len=*)">Input field name.</IN>
  !   <IN NAME="tile_count" TYPE="INTEGER">Tile number.</IN>
  SUBROUTINE init_input_field(module_name, field_name, tile_count)
    CHARACTER(len=*),  INTENT(in) :: module_name, field_name
    INTEGER, INTENT(in) :: tile_count

    ! Get a number for this input_field if not already set up
    IF ( find_input_field(module_name, field_name, tile_count) < 0 ) THEN
       num_input_fields = num_input_fields + 1
       IF ( num_input_fields > max_input_fields ) THEN
          ! <ERROR STATUS="FATAL">max_input_fields exceeded, increase it via diag_manager_nml</ERROR>
          CALL error_mesg('diag_util_mod::init_input_field',&
               & 'max_input_fields exceeded, increase it via diag_manager_nml', FATAL)
       END IF
    ELSE
       ! If this is already initialized do not need to do anything
       RETURN
    END IF

    input_fields(num_input_fields)%module_name = TRIM(module_name)
    input_fields(num_input_fields)%field_name = TRIM(field_name)
    input_fields(num_input_fields)%num_output_fields = 0
    ! Set flag that this field has not been registered
    input_fields(num_input_fields)%register = .FALSE.
    input_fields(num_input_fields)%local = .FALSE.
    input_fields(num_input_fields)%standard_name = 'none'
    input_fields(num_input_fields)%tile_count = tile_count
    input_fields(num_input_fields)%numthreads = 1
    input_fields(num_input_fields)%active_omp_level = 0
    input_fields(num_input_fields)%time = time_zero
  END SUBROUTINE init_input_field
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="init_output_field">
  !   <OVERVIEW>
  !     Initialize the output field.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE init_output_field(module_name, field_name, output_name, output_file
  !     time_method, pack, tile_count, local_coord)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Initialize the output field.
  !   </DESCRIPTION>
  !   <IN NAME="module_name" TYPE="CHARACTER(len=*)">Module name.</IN>
  !   <IN NAME="field_name" TYPE="CHARACTER(len=*)">Output field name.</IN>
  !   <IN NAME="output_name" TYPE="CHARACTER(len=*)">Output name written to file.</IN>
  !   <IN NAME="output_file" TYPE="CHARACTER(len=*)">File where field should be written.</IN>
  !   <IN NAME="time_method" TYPE="CHARACTER(len=*)">
  !     Data reduction method.  See <LINK SRC="diag_manager.html">diag_manager_mod</LINK> for valid methods.</IN>
  !   <IN NAME="pack" TYPE="INTEGER">Packing method.</IN>
  !   <IN NAME="tile_count" TYPE="INTEGER">Tile number.</IN>
  !   <IN NAME="local_coord" TYPE="INTEGER, OPTIONAL">Region to be written.  If missing, then all data to be written.</IN>
  SUBROUTINE init_output_field(module_name, field_name, output_name, output_file,&
       & time_method, pack, tile_count, local_coord)
    CHARACTER(len=*), INTENT(in) :: module_name, field_name, output_name, output_file
    CHARACTER(len=*), INTENT(in) :: time_method
    INTEGER, INTENT(in) :: pack
    INTEGER, INTENT(in) :: tile_count
    TYPE(coord_type), INTENT(in), OPTIONAL :: local_coord
    INTEGER :: out_num, in_num, file_num, file_num_tile1
    INTEGER :: num_fields, i, method_selected, l1
    INTEGER :: ioerror
    REAL :: pow_value
    INTEGER :: grv !< Value used to determine if the region defined in the diag_table is for the whole axis, or a sub-axis
    CHARACTER(len=128) :: error_msg
    CHARACTER(len=50) :: t_method
    character(len=256) :: tmp_name

    ! Value to use to determine if a region is to be output on the full axis, or sub-axis
    ! get the value to compare to determine if writing full axis data
    IF ( region_out_use_alt_value ) THEN
       grv = GLO_REG_VAL_ALT
    ELSE
       grv = GLO_REG_VAL
    END IF


    ! Get a number for this output field
    num_output_fields = num_output_fields + 1
    IF ( num_output_fields > max_output_fields ) THEN
       ! <ERROR STATUS="FATAL">max_output_fields = <max_output_fields> exceeded.  Increase via diag_manager_nml</ERROR>
       WRITE (UNIT=error_msg,FMT=*) max_output_fields
       CALL error_mesg('diag_util_mod::init_output_field', 'max_output_fields = '//TRIM(error_msg)//' exceeded.&
            &  Increase via diag_manager_nml', FATAL)
    END IF
    out_num = num_output_fields

    ! First, find the index to the associated input field
    in_num = find_input_field(module_name, field_name, tile_count)
    IF ( in_num < 0 ) THEN
       IF ( tile_count > 1 ) THEN
          WRITE (error_msg,'(A,"/",A,"/",A)') TRIM(module_name),TRIM(field_name),&
               & "tile_count="//TRIM(string(tile_count))
       ELSE
          WRITE (error_msg,'(A,"/",A)') TRIM(module_name),TRIM(field_name)
       END IF
       ! <ERROR STATUS="FATAL">module_name/field_name <module_name>/<field_name>[/tile_count=<tile_count>] NOT registered</ERROR>
       CALL error_mesg('diag_util_mod::init_output_field',&
            & 'module_name/field_name '//TRIM(error_msg)//' NOT registered', FATAL)
    END IF

    ! Add this output field into the list for this input field
    input_fields(in_num)%num_output_fields =&
         & input_fields(in_num)%num_output_fields + 1
    IF ( input_fields(in_num)%num_output_fields > max_out_per_in_field ) THEN
       ! <ERROR STATUS="FATAL">
       !   MAX_OUT_PER_IN_FIELD = <MAX_OUT_PER_IN_FIELD> exceeded for <module_name>/<field_name>, increase MAX_OUT_PER_IN_FIELD
       !   in the diag_manager_nml namelist.
       ! </ERROR>
       WRITE (UNIT=error_msg,FMT=*) MAX_OUT_PER_IN_FIELD
       CALL error_mesg('diag_util_mod::init_output_field',&
        & 'MAX_OUT_PER_IN_FIELD exceeded for '//TRIM(module_name)//"/"//TRIM(field_name)//&
        &', increase MAX_OUT_PER_IN_FIELD in the diag_manager_nml namelist', FATAL)
    END IF
    input_fields(in_num)%output_fields(input_fields(in_num)%num_output_fields) = out_num

    ! Also put pointer to input field in this output field
    output_fields(out_num)%input_field = in_num

    ! Next, find the number for the corresponding file
    IF ( TRIM(output_file).EQ.'null' ) THEN
       file_num = max_files
    ELSE
       file_num = find_file(output_file, 1)
       IF ( file_num < 0 ) THEN
          ! <ERROR STATUS="FATAL">
          !   file <file_name> is NOT found in the diag_table.
          ! </ERROR>
          CALL error_mesg('diag_util_mod::init_output_field', 'file '&
               & //TRIM(output_file)//' is NOT found in the diag_table', FATAL)
       END IF
       IF ( tile_count > 1 ) THEN
          file_num_tile1 = file_num
          file_num = find_file(output_file, tile_count)
          IF(file_num < 0) THEN
             CALL init_file(files(file_num_tile1)%name, files(file_num_tile1)%output_freq,&
                  & files(file_num_tile1)%output_units, files(file_num_tile1)%format,&
                  & files(file_num_tile1)%time_units, files(file_num_tile1)%long_name,&
                  & tile_count, files(file_num_tile1)%new_file_freq,&
                  & files(file_num_tile1)%new_file_freq_units, files(file_num_tile1)%start_time,&
                  & files(file_num_tile1)%duration, files(file_num_tile1)%duration_units  )
             file_num = find_file(output_file, tile_count)
             IF ( file_num < 0 ) THEN
                ! <ERROR STATUS="FATAL">
                !   file <output_file> is not initialized for tile_count = <tile_count>
                ! </ERROR>
                CALL error_mesg('diag_util_mod::init_output_field', 'file '//TRIM(output_file)//&
                     & ' is not initialized for tile_count = '//TRIM(string(tile_count)), FATAL)
             END IF
          END IF
       END IF
    END IF

    ! Insert this field into list for this file
    files(file_num)%num_fields = files(file_num)%num_fields + 1
    IF ( files(file_num)%num_fields > MAX_FIELDS_PER_FILE ) THEN
       WRITE (UNIT=error_msg, FMT=*) MAX_FIELDS_PER_FILE
       ! <ERROR STATUS="FATAL">
       !   MAX_FIELDS_PER_FILE = <MAX_FIELDS_PER_FILE> exceeded.  Increase MAX_FIELDS_PER_FILE in diag_data.F90.
       ! </ERROR>
       CALL error_mesg('diag_util_mod::init_output_field',&
            & 'MAX_FIELDS_PER_FILE = '//TRIM(error_msg)//' exceeded.  Increase MAX_FIELDS_PER_FILE in diag_data.F90.', FATAL)
    END IF
    num_fields = files(file_num)%num_fields
    files(file_num)%fields(num_fields) = out_num

    ! Set the file for this output field
    output_fields(out_num)%output_file = file_num

    ! Enter the other data for this output field
    output_fields(out_num)%output_name = TRIM(output_name)
    output_fields(out_num)%pack = pack
    output_fields(out_num)%pow_value = 1
    output_fields(out_num)%num_axes = 0
    output_fields(out_num)%total_elements = 0
    output_fields(out_num)%region_elements = 0
    output_fields(out_num)%imax = 0
    output_fields(out_num)%jmax = 0
    output_fields(out_num)%kmax = 0
    output_fields(out_num)%imin = VERY_LARGE_AXIS_LENGTH
    output_fields(out_num)%jmin = VERY_LARGE_AXIS_LENGTH
    output_fields(out_num)%kmin = VERY_LARGE_AXIS_LENGTH

    ! initialize the size of the diurnal axis to 1
    output_fields(out_num)%n_diurnal_samples = 1

    ! Initialize all time method to false
    method_selected = 0
    output_fields(out_num)%time_average = .FALSE.
    output_fields(out_num)%time_rms = .FALSE.
    output_fields(out_num)%time_min = .FALSE.
    output_fields(out_num)%time_max = .FALSE.
    output_fields(out_num)%time_sum = .FALSE.
    output_fields(out_num)%time_ops = .FALSE.
    output_fields(out_num)%written_once = .FALSE.

    t_method = lowercase(time_method)
    ! cannot time average fields output every time
    IF ( files(file_num)%output_freq == EVERY_TIME ) THEN
       output_fields(out_num)%time_average = .FALSE.
       method_selected = method_selected+1
       t_method = 'point'
    ELSEIF ( INDEX(t_method,'diurnal') == 1 ) THEN
       ! get the integer number from the t_method
       READ (UNIT=t_method(8:LEN_TRIM(t_method)), FMT=*, IOSTAT=ioerror) output_fields(out_num)%n_diurnal_samples
       IF ( ioerror /= 0 ) THEN
          ! <ERROR STATUS="FATAL">
          !   could not find integer number of diurnal samples in string "<t_method>"
          ! </ERROR>
          CALL error_mesg('diag_util_mod::init_output_field',&
               & 'could not find integer number of diurnal samples in string "' //TRIM(t_method)//'"', FATAL)
       ELSE IF ( output_fields(out_num)%n_diurnal_samples <= 0 ) THEN
          ! <ERROR STATUS="FATAL">
          !   The integer value of diurnal samples must be greater than zero.
          ! </ERROR>
          CALL error_mesg('diag_util_mod::init_output_field',&
               & 'The integer value of diurnal samples must be greater than zero.', FATAL)
       END IF
       output_fields(out_num)%time_average = .TRUE.
       method_selected = method_selected+1
       t_method='mean'
    ELSEIF ( INDEX(t_method,'pow') == 1 ) THEN
       ! Get the integer number from the t_method
       READ (UNIT=t_method(4:LEN_TRIM(t_method)), FMT=*, IOSTAT=ioerror) pow_value
       IF ( ioerror /= 0 .OR. output_fields(out_num)%pow_value < 1  .OR. FLOOR(pow_value) /= CEILING(pow_value) ) THEN
          ! <ERROR STATUS="FATAL">
          !   Invalid power number in time operation "<t_method>".  Must be a positive integer.
          ! </ERROR>
          CALL error_mesg('diag_util_mod::init_output_field',&
               & 'Invalid power number in time operation "'//TRIM(t_method)//'".  Must be a positive integer', FATAL)
       END IF
       output_fields(out_num)%pow_value = INT(pow_value)
       output_fields(out_num)%time_average = .TRUE.
       method_selected = method_selected+1
       t_method = 'mean_pow('//t_method(4:LEN_TRIM(t_method))//')'
    ELSE
       SELECT CASE(TRIM(t_method))
       CASE ( '.true.', 'mean', 'average', 'avg' )
          output_fields(out_num)%time_average = .TRUE.
          method_selected = method_selected+1
          t_method = 'mean'
       CASE ( 'rms' )
          output_fields(out_num)%time_average = .TRUE.
          output_fields(out_num)%time_rms = .TRUE.
          output_fields(out_num)%pow_value = 2.0
          method_selected = method_selected+1
          t_method = 'root_mean_square'
       CASE ( '.false.', 'none', 'point' )
          output_fields(out_num)%time_average = .FALSE.
          method_selected = method_selected+1
          t_method = 'point'
       CASE ( 'maximum', 'max' )
          output_fields(out_num)%time_max = .TRUE.
          l1 = LEN_TRIM(output_fields(out_num)%output_name)
          if (l1 .ge. 3) then
              tmp_name = trim(adjustl(output_fields(out_num)%output_name(l1-2:l1)))
              IF (lowercase(trim(tmp_name)) /= 'max' ) then
                  output_fields(out_num)%output_name = TRIM(output_name)//'_max'
               endif
          endif
          method_selected = method_selected+1
          t_method = 'max'
       CASE ( 'minimum', 'min' )
          output_fields(out_num)%time_min = .TRUE.
          l1 = LEN_TRIM(output_fields(out_num)%output_name)
          if (l1 .ge. 3) then
              tmp_name = trim(adjustl(output_fields(out_num)%output_name(l1-2:l1)))
              IF (lowercase(trim(tmp_name)) /= 'min' ) then
                  output_fields(out_num)%output_name = TRIM(output_name)//'_min'
              endif
          endif
          method_selected = method_selected+1
          t_method = 'min'
       CASE ( 'sum', 'cumsum' )
          output_fields(out_num)%time_sum = .TRUE.
          l1 = LEN_TRIM(output_fields(out_num)%output_name)
          IF ( output_fields(out_num)%output_name(l1-2:l1) /= 'sum' )&
               & output_fields(out_num)%output_name = TRIM(output_name)//'_sum'
          method_selected = method_selected+1
          t_method = 'sum'
       END SELECT
    END IF

    ! reconcile logical flags
    output_fields(out_num)%time_ops = output_fields(out_num)%time_min.OR.output_fields(out_num)%time_max&
         & .OR.output_fields(out_num)%time_average .OR. output_fields(out_num)%time_sum

    output_fields(out_num)%phys_window = .FALSE.
    ! need to initialize grid_type = -1(start, end, l_start_indx,l_end_indx etc...)
    IF ( PRESENT(local_coord) ) THEN
       input_fields(in_num)%local = .TRUE.
       input_fields(in_num)%local_coord = local_coord
       IF ( INT(local_coord%xbegin) ==  grv .AND. INT(local_coord%xend) == grv .AND.&
            & INT(local_coord%ybegin) == grv .AND. INT(local_coord%yend) == grv ) THEN
          output_fields(out_num)%local_output = .FALSE.
          output_fields(out_num)%need_compute = .FALSE.
          output_fields(out_num)%reduced_k_range = .TRUE.
       ELSE
          output_fields(out_num)%local_output = .TRUE.
          output_fields(out_num)%need_compute = .FALSE.
          output_fields(out_num)%reduced_k_range = .FALSE.
       END IF

       output_fields(out_num)%output_grid%start(1) = local_coord%xbegin
       output_fields(out_num)%output_grid%start(2) = local_coord%ybegin
       output_fields(out_num)%output_grid%start(3) = local_coord%zbegin
       output_fields(out_num)%output_grid%end(1) = local_coord%xend
       output_fields(out_num)%output_grid%end(2) = local_coord%yend
       output_fields(out_num)%output_grid%end(3) = local_coord%zend
       DO i = 1, 3
          output_fields(out_num)%output_grid%l_start_indx(i) = -1
          output_fields(out_num)%output_grid%l_end_indx(i) = -1
          output_fields(out_num)%output_grid%subaxes(i) = -1
       END DO
    ELSE
       output_fields(out_num)%local_output = .FALSE.
       output_fields(out_num)%need_compute = .FALSE.
       output_fields(out_num)%reduced_k_range = .FALSE.
    END IF

    ! <ERROR STATUS="FATAL">
    !   improper time method in diag_table for output field <output_name>
    ! </ERROR>
    IF ( method_selected /= 1 ) CALL error_mesg('diag_util_mod::init_output_field',&
         &'improper time method in diag_table for output field:'//TRIM(output_name),FATAL)

    output_fields(out_num)%time_method = TRIM(t_method)

    ! allocate counters: NOTE that for simplicity we always allocate them, even
    ! if they are superceeded by 4D "counter" array. This isn't most memory
    ! efficient, approach, but probably tolerable since they are so small anyway
    ALLOCATE(output_fields(out_num)%count_0d(output_fields(out_num)%n_diurnal_samples))
    ALLOCATE(output_fields(out_num)%num_elements(output_fields(out_num)%n_diurnal_samples))
    output_fields(out_num)%count_0d(:) = 0
    output_fields(out_num)%num_elements(:) = 0
    output_fields(out_num)%num_attributes = 0
  END SUBROUTINE init_output_field
  ! </SUBROUTINE>

  ! <PRIVATE>
  ! <SUBROUTINE NAME="opening_file">
  !   <OVERVIEW>
  !     Open file for output.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE opening_file(file, time)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Open file for output, and write the meta data.  <BB>Warning:</BB> Assumes all data structures have been fully initialized.
  !   </DESCRIPTION>
  !   <IN NAME="file" TYPE="INTEGER">File ID.</IN>
  !   <IN NAME="tile" TYPE="TYPE(time_type)">Time for the file time stamp</IN>
  SUBROUTINE opening_file(file, time)
    ! WARNING: Assumes that all data structures are fully initialized
    INTEGER, INTENT(in) :: file
    TYPE(time_type), INTENT(in) :: time

    REAL, DIMENSION(2) :: DATA
    INTEGER :: j, field_num, input_field_num, num_axes, k
    INTEGER :: field_num1
    INTEGER :: position
    INTEGER :: dir, edges
    INTEGER :: ntileMe
    INTEGER :: year, month, day, hour, minute, second
    INTEGER, ALLOCATABLE :: tile_id(:)
    INTEGER, DIMENSION(1) :: time_axis_id, time_bounds_id
    ! size of this axes array must be at least max num. of
    ! axes per field + 2; the last two elements are for time
    ! and time bounds dimensions
    INTEGER, DIMENSION(6) :: axes
    INTEGER, ALLOCATABLE  :: axesc(:) ! indices if compressed axes associated with the field
    LOGICAL :: time_ops, aux_present, match_aux_name, req_present, match_req_fields
    LOGICAL :: all_scalar_or_1d
    CHARACTER(len=7) :: prefix
    CHARACTER(len=7) :: avg_name = 'average'
    CHARACTER(len=128) :: time_units, timeb_units, avg, error_string, filename, aux_name, req_fields, fieldname
    CHARACTER(len=128) :: suffix, base_name
    CHARACTER(len=32) :: time_name, timeb_name,time_longname, timeb_longname, cart_name
    CHARACTER(len=256) :: fname
    CHARACTER(len=24) :: start_date
    TYPE(domain1d) :: domain
    TYPE(domain2d) :: domain2
    TYPE(domainUG) :: domainU
    INTEGER :: is, ie, last, ind


    aux_present = .FALSE.
    match_aux_name = .FALSE.
    req_present = .FALSE.
    match_req_fields = .FALSE.

    ! Here is where time_units string must be set up; time since base date
    WRITE (time_units, 11) TRIM(time_unit_list(files(file)%time_units)), base_year,&
         & base_month, base_day, base_hour, base_minute, base_second
11  FORMAT(A, ' since ', I4.4, '-', I2.2, '-', I2.2, ' ', I2.2, ':', I2.2, ':', I2.2)
    base_name = files(file)%name
    IF ( files(file)%new_file_freq < VERY_LARGE_FILE_FREQ ) THEN
       position = INDEX(files(file)%name, '%')
       IF ( position > 0 )  THEN
          base_name = base_name(1:position-1)
       ELSE
          ! <ERROR STATUS="FATAL">
          !   filename <files(file)%name> does not contain % for time stamp string
          ! </ERROR>
          CALL error_mesg('diag_util_mod::opening_file',&
               & 'file name '//TRIM(files(file)%name)//' does not contain % for time stamp string', FATAL)
       END IF
       suffix = get_time_string(files(file)%name, time)
    ELSE
       suffix = ' '
    END IF

    ! Add ensemble ID to filename
    fname=base_name
    call get_instance_filename(fname, base_name)

    ! Set the filename
    filename = TRIM(base_name)//TRIM(suffix)

    ! prepend the file start date if prepend_date == .TRUE.
    IF ( prepend_date ) THEN
       call get_date(diag_init_time, year, month, day, hour, minute, second)
       write (start_date, '(1I20.4, 2I2.2)') year, month, day

       filename = TRIM(adjustl(start_date))//'.'//TRIM(filename)
    END IF

    ! Loop through all fields with this file to output axes
    ! JWD: This is a klooge; need something more robust
    domain2 = NULL_DOMAIN2D
    domainU = NULL_DOMAINUG
    all_scalar_or_1d = .TRUE.
    DO j = 1, files(file)%num_fields
       field_num = files(file)%fields(j)
       if (output_fields(field_num)%local_output .AND. .NOT. output_fields(field_num)%need_compute) CYCLE
       num_axes = output_fields(field_num)%num_axes
       IF ( num_axes > 1 ) THEN
          all_scalar_or_1d = .FALSE.
          domain2 = get_domain2d ( output_fields(field_num)%axes(1:num_axes) )
          domainU = get_domainUG ( output_fields(field_num)%axes(1) )
          IF ( domain2 .NE. NULL_DOMAIN2D ) EXIT
       ELSEIF (num_axes == 1) THEN
          if (domainU .EQ. null_domainUG) then
               domainU = get_domainUG ( output_fields(field_num)%axes(num_axes) )
          endif
       END IF
    END DO

    IF (.NOT. all_scalar_or_1d) THEN
        IF (domainU .NE. null_domainUG .AND. domain2 .NE. null_domain2D) THEN
            CALL error_mesg('diag_util_mod::opening_file', &
                            'Domain2 and DomainU are somehow both set.', &
                            FATAL)
        ELSEIF (domainU .EQ. null_domainUG) THEN
            IF (domain2 .EQ. NULL_DOMAIN2D) THEN
                CALL return_domain(domain2)
            ENDIF

            IF (domain2 .EQ. NULL_DOMAIN2D) THEN

                !Fix for the corner-case when you have a file that contains
                !2D field(s) that is not associated with a domain tile, as
                !is usually assumed.

                !This is very confusing, but I will try to explain.  The
                !all_scalar_or_1d flag determines if the file name is associated
                !with a domain (i.e. has ".tilex." in the file name).  A value
                !of .FALSE. for the all_scalar_or_1d flag signals that the
                !file name is associated with a domain tile.  Normally,
                !files that contain at least one two-dimensional field are
                !assumed to be associated with a specific domain tile, and
                !thus have the value of the all_scalar_or_1d flag set to
                !.FALSE.  It is possible, however, to have a file that contains
                !two-dimensional fields that is not associated with a domain tile
                !(i.e., if you make it into this branch.).  If that is the
                !case, then reset the all_scalar_or_1d flag back to .TRUE.
                !Got that?
                all_scalar_or_1d = .TRUE.

            ELSE
                ntileMe = mpp_get_current_ntile(domain2)
                ALLOCATE(tile_id(ntileMe))
                tile_id = mpp_get_tile_id(domain2)
                fname = TRIM(filename)
                IF ( mpp_get_ntile_count(domain2) > 1 ) THEN
                   CALL get_tile_string(filename, TRIM(fname)//'.tile' , tile_id(files(file)%tile_count))
                ELSEIF ( tile_id(1) > 1 ) then
                   CALL get_tile_string(filename, TRIM(fname)//'.tile' , tile_id(1))
                ENDIF
                DEALLOCATE(tile_id)
            ENDIF
        ENDIF
    ENDIF
    IF ( domainU .ne. null_domainUG) then
!          ntileMe = mpp_get_UG_current_ntile(domainU)
!          ALLOCATE(tile_id(ntileMe))
!          tile_id = mpp_get_UG_tile_id(domainU)
!          fname = TRIM(filename)
!           ntiles = mpp_get_UG_domain_ntiles(domainU)
!           my_tile_id = mpp_get_UG_domain_tile_id(domainU)
!          CALL get_tile_string(filename, TRIM(fname)//'.tile' , tile_id(files(file)%tile_count))
!          DEALLOCATE(tile_id)
          fname = TRIM(filename)
          CALL get_mosaic_tile_file_ug(fname,filename,domainU)
    ENDIF
    IF ( _ALLOCATED(files(file)%attributes) ) THEN
       CALL diag_output_init(filename, files(file)%format, global_descriptor,&
            & files(file)%file_unit, all_scalar_or_1d, domain2, domainU,&
            & attributes=files(file)%attributes(1:files(file)%num_attributes))
    ELSE
       CALL diag_output_init(filename, files(file)%format, global_descriptor,&
            & files(file)%file_unit, all_scalar_or_1d, domain2,domainU)
    END IF
    files(file)%bytes_written = 0
    ! Does this file contain time_average fields?
    time_ops = .FALSE.
    DO j = 1, files(file)%num_fields
       field_num = files(file)%fields(j)
       IF ( output_fields(field_num)%time_ops ) THEN
          time_ops = .TRUE.
          EXIT
       END IF
    END DO
    ! Loop through all fields with this file to output axes
    DO j = 1, files(file)%num_fields
       field_num = files(file)%fields(j)
       input_field_num = output_fields(field_num)%input_field
       IF (.NOT.input_fields(input_field_num)%register) THEN
          WRITE (error_string,'(A,"/",A)') TRIM(input_fields(input_field_num)%module_name),&
               & TRIM(input_fields(input_field_num)%field_name)
          IF(mpp_pe() .EQ. mpp_root_pe()) THEN
             ! <ERROR STATUS="WARNING">
             !   module/field_name (<input_fields(input_field_num)%module_name>/<input_fields(input_field_num)%field_name>)
             !   NOT registered
             ! </ERROR>
             CALL error_mesg('diag_util_mod::opening_file',&
                  & 'module/field_name ('//TRIM(error_string)//') NOT registered', WARNING)
          END IF
          CYCLE
       END IF
       if (output_fields(field_num)%local_output .AND. .NOT. output_fields(field_num)%need_compute) CYCLE

       ! Put the time axis in the axis field
       num_axes = output_fields(field_num)%num_axes
       axes(1:num_axes) = output_fields(field_num)%axes(1:num_axes)
       ! make sure that axis_id are not -1
       DO k = 1, num_axes
          IF ( axes(k) < 0 ) THEN
             WRITE(error_string,'(a)') output_fields(field_num)%output_name
             ! <ERROR STATUS="FATAL">
             !   ouptut_name <output_fields(field_num)%output_name> has axis_id = -1
             ! </ERROR>
             CALL error_mesg('diag_util_mod::opening_file','output_name '//TRIM(error_string)//&
                  & ' has axis_id = -1', FATAL)
          END IF
       END DO
       ! check if aux is present in any axes
       IF ( .NOT.aux_present ) THEN
          DO k = 1, num_axes
             aux_name = get_axis_aux(axes(k))
             IF ( TRIM(aux_name) /= 'none' ) THEN
                aux_present = .TRUE.
                EXIT
             END IF
          END DO
       END IF
       ! check if required fields are present in any axes
       IF ( .NOT.req_present ) THEN
          DO k = 1, num_axes
             req_fields = get_axis_reqfld(axes(k))
             IF ( TRIM(req_fields) /= 'none' ) THEN
                CALL error_mesg('diag_util_mod::opening_file','required fields found: '//&
                               &TRIM(req_fields)//' in file '//TRIM(files(file)%name),NOTE)
                req_present = .TRUE.
                EXIT
             END IF
          END DO
       END IF

       axes(num_axes + 1) = files(file)%time_axis_id
       CALL write_axis_meta_data(files(file)%file_unit, axes(1:num_axes + 1), time_ops)
       IF ( time_ops ) THEN
          axes(num_axes + 2) = files(file)%time_bounds_id
          CALL write_axis_meta_data(files(file)%file_unit, axes(1:num_axes + 2))
       END IF
       ! write metadata for axes used  in compression-by-gathering, e.g. for unstructured
       ! grid
       DO k = 1, num_axes
          IF (axis_is_compressed(axes(k))) THEN
             CALL get_compressed_axes_ids(axes(k), axesc) ! returns allocatable array
             CALL write_axis_meta_data(files(file)%file_unit, axesc)
             DEALLOCATE(axesc)
          ENDIF
       ENDDO

    END DO

    ! Looking for the first NON-static field in a file
    field_num1 = files(file)%fields(1)
    DO j = 1, files(file)%num_fields
       field_num = files(file)%fields(j)
       IF ( output_fields(field_num)%time_ops ) THEN
          field_num1 = field_num
          EXIT
       END IF
    END DO
    DO j = 1, files(file)%num_fields
       field_num = files(file)%fields(j)
       input_field_num = output_fields(field_num)%input_field
       IF (.NOT.input_fields(input_field_num)%register) CYCLE
       IF (output_fields(field_num)%local_output .AND. .NOT. output_fields(field_num)%need_compute) CYCLE
       ! Make sure that 1 file contains either time_average or instantaneous fields
       ! cannot have both time_average and instantaneous in 1 file
       IF ( .NOT.mix_snapshot_average_fields ) THEN
          IF ( (output_fields(field_num)%time_ops.NEQV.output_fields(field_num1)%time_ops) .AND.&
               & .NOT.output_fields(field_num1)%static .AND. .NOT.output_fields(field_num)%static) THEN
             IF ( mpp_pe() == mpp_root_pe() ) THEN
                ! <ERROR STATUS="FATAL">
                !   <files(file)%name> can NOT have BOTH time average AND instantaneous fields.
                !   Create a new file or set mix_snapshot_average_fields=.TRUE. in the namelist diag_manager_nml.
                ! </ERROR>
                CALL error_mesg('diag_util_mod::opening_file','file '//&
                     & TRIM(files(file)%name)//' can NOT have BOTH time average AND instantaneous fields.'//&
                     & ' Create a new file or set mix_snapshot_average_fields=.TRUE. in the namelist diag_manager_nml.' , FATAL)
             END IF
          END IF
       END IF
       ! check if any field has the same name as aux_name
       IF ( aux_present .AND. .NOT.match_aux_name ) THEN
          fieldname = output_fields(field_num)%output_name
          IF ( INDEX(aux_name, TRIM(fieldname)) > 0 ) match_aux_name = .TRUE.
       END IF
       ! check if any field has the same name as req_fields
       IF ( req_present .AND. .NOT.match_req_fields ) THEN
          fieldname = output_fields(field_num)%output_name
          is = 1; last = len_trim(req_fields)
          DO
            ind = index(req_fields(is:last),' ')
            IF (ind .eq. 0) ind = last-is+2
            ie = is+(ind-2)
            if (req_fields(is:ie) .EQ. trim(fieldname)) then
              match_req_fields = .TRUE.
             !CALL error_mesg('diag_util_mod::opening_file','matched required field: '//TRIM(fieldname),NOTE)
              EXIT
            END IF
            is = is+ind
            if (is .GT. last) EXIT
          END DO
       END IF

       ! Put the time axis in the axis field
       num_axes = output_fields(field_num)%num_axes
       axes(1:num_axes) = output_fields(field_num)%axes(1:num_axes)
       IF ( .NOT.output_fields(field_num)%static ) THEN
          num_axes=num_axes+1
          axes(num_axes) = files(file)%time_axis_id
       END IF
       IF(output_fields(field_num)%time_average) THEN
          avg = avg_name
       ELSE IF(output_fields(field_num)%time_max) THEN
          avg = avg_name
       ELSE IF(output_fields(field_num)%time_min) THEN
          avg = avg_name
       ELSE
          avg = " "
       END IF
       IF ( input_fields(input_field_num)%missing_value_present ) THEN
          IF ( LEN_TRIM(input_fields(input_field_num)%interp_method) > 0 ) THEN
             output_fields(field_num)%f_type = write_field_meta_data(files(file)%file_unit,&
                  & output_fields(field_num)%output_name, axes(1:num_axes),&
                  & input_fields(input_field_num)%units,&
                  & input_fields(input_field_num)%long_name,&
                  & input_fields(input_field_num)%range, output_fields(field_num)%pack,&
                  & input_fields(input_field_num)%missing_value, avg_name = avg,&
                  & time_method=output_fields(field_num)%time_method,&
                  & standard_name = input_fields(input_field_num)%standard_name,&
                  & interp_method = input_fields(input_field_num)%interp_method,&
                  & attributes=output_fields(field_num)%attributes,&
                  & num_attributes=output_fields(field_num)%num_attributes,&
                  & use_UGdomain=files(file)%use_domainUG)
          ELSE
             output_fields(field_num)%f_type = write_field_meta_data(files(file)%file_unit,&
                  & output_fields(field_num)%output_name, axes(1:num_axes),&
                  & input_fields(input_field_num)%units,&
                  & input_fields(input_field_num)%long_name,&
                  & input_fields(input_field_num)%range, output_fields(field_num)%pack,&
                  & input_fields(input_field_num)%missing_value, avg_name = avg,&
                  & time_method=output_fields(field_num)%time_method,&
                  & standard_name = input_fields(input_field_num)%standard_name,&
                  & attributes=output_fields(field_num)%attributes,&
                  & num_attributes=output_fields(field_num)%num_attributes,&
                  & use_UGdomain=files(file)%use_domainUG)
          END IF
          ! NEED TO TAKE CARE OF TIME AVERAGING INFO TOO BOTH CASES
       ELSE
          IF ( LEN_TRIM(input_fields(input_field_num)%interp_method) > 0 ) THEN
             output_fields(field_num)%f_type = write_field_meta_data(files(file)%file_unit,&
                  & output_fields(field_num)%output_name, axes(1:num_axes),&
                  & input_fields(input_field_num)%units,&
                  & input_fields(input_field_num)%long_name,&
                  & input_fields(input_field_num)%range, output_fields(field_num)%pack,&
                  & avg_name = avg,&
                  & time_method=output_fields(field_num)%time_method,&
                  & standard_name = input_fields(input_field_num)%standard_name,&
                  & interp_method = input_fields(input_field_num)%interp_method,&
                  & attributes=output_fields(field_num)%attributes,&
                  & num_attributes=output_fields(field_num)%num_attributes,&
                  & use_UGdomain=files(file)%use_domainUG)
          ELSE
             output_fields(field_num)%f_type = write_field_meta_data(files(file)%file_unit,&
                  & output_fields(field_num)%output_name, axes(1:num_axes),&
                  & input_fields(input_field_num)%units,&
                  & input_fields(input_field_num)%long_name,&
                  & input_fields(input_field_num)%range, output_fields(field_num)%pack,&
                  & avg_name = avg,&
                  & time_method=output_fields(field_num)%time_method,&
                  & standard_name = input_fields(input_field_num)%standard_name,&
                  & attributes=output_fields(field_num)%attributes,&
                  & num_attributes=output_fields(field_num)%num_attributes,&
                  & use_UGdomain=files(file)%use_domainUG)
          END IF
       END IF
    END DO

    ! If any of the fields in the file are time averaged, need to output the axes
    ! Use double precision since time axis is double precision
    IF ( time_ops ) THEN
       time_axis_id(1) = files(file)%time_axis_id
       files(file)%f_avg_start = write_field_meta_data(files(file)%file_unit,&
            & avg_name // '_T1', time_axis_id, time_units,&
            & "Start time for average period", pack=pack_size)
       files(file)%f_avg_end = write_field_meta_data(files(file)%file_unit,&
            & avg_name // '_T2', time_axis_id, time_units,&
            & "End time for average period", pack=pack_size)
       files(file)%f_avg_nitems = write_field_meta_data(files(file)%file_unit,&
            & avg_name // '_DT', time_axis_id,&
            & TRIM(time_unit_list(files(file)%time_units)),&
            & "Length of average period", pack=pack_size)
    END IF

    IF ( time_ops ) THEN
       time_axis_id(1) = files(file)%time_axis_id
       time_bounds_id(1) = files(file)%time_bounds_id
       CALL get_diag_axis( time_axis_id(1), time_name, time_units, time_longname,&
            & cart_name, dir, edges, Domain, domainU, DATA)
       CALL get_diag_axis( time_bounds_id(1), timeb_name, timeb_units, timeb_longname,&
            & cart_name, dir, edges, Domain, domainU, DATA)
       IF ( do_cf_compliance() ) THEN
          ! CF Compliance requires the unit on the _bnds axis is the same as 'time'
          files(file)%f_bounds =  write_field_meta_data(files(file)%file_unit,&
               & TRIM(time_name)//'_bnds', (/time_bounds_id,time_axis_id/),&
               & time_units, TRIM(time_name)//' axis boundaries', pack=pack_size)
       ELSE
          files(file)%f_bounds =  write_field_meta_data(files(file)%file_unit,&
               & TRIM(time_name)//'_bnds', (/time_bounds_id,time_axis_id/),&
               & TRIM(time_unit_list(files(file)%time_units)),&
               & TRIM(time_name)//' axis boundaries', pack=pack_size)
       END IF
    END IF
    ! Let lower levels know that all meta data has been sent
    CALL done_meta_data(files(file)%file_unit)
    IF( aux_present .AND. .NOT.match_aux_name ) THEN
       ! <ERROR STATUS="WARNING">
       !   one axis has auxiliary but the corresponding field is NOT
       !   found in file <file_name>
       ! </ERROR>
       IF ( mpp_pe() == mpp_root_pe() ) CALL error_mesg('diag_util_mod::opening_file',&
            &'one axis has auxiliary but the corresponding field is NOT found in file '//TRIM(files(file)%name), WARNING)
    END IF
    IF( req_present .AND. .NOT.match_req_fields ) THEN
       ! <ERROR STATUS="FATAL">
       !   one axis has required fields but the corresponding field is NOT
       !   found in file <file_name>
       ! </ERROR>
       IF ( mpp_pe() == mpp_root_pe() ) CALL error_mesg('diag_util_mod::opening_file',&
                  &'one axis has required fields ('//trim(req_fields)//') but the '// &
                  &'corresponding fields are NOT found in file '//TRIM(files(file)%name), FATAL)
    END IF
  END SUBROUTINE opening_file
  ! </SUBROUTINE>
  ! </PRIVATE>

  ! <PRIVATE>
  ! <FUNCTION NAME="get_time_string">
  !   <OVERVIEW>
  !     This function determines a string based on current time.
  !     This string is used as suffix in output file name
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     CHARACTER(len=128) FUNCTION get_time_string(filename, current_time)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     This function determines a string based on current time.
  !     This string is used as suffix in output file name
  !   </DESCRIPTION>
  !   <IN NAME="filename" TYPE="CHARACTER(len=128)">File name.</IN>
  !   <IN NAME="current_time" TYPE="TYPE(time_type)">Current model time.</IN>
  CHARACTER(len=128) FUNCTION get_time_string(filename, current_time)
    CHARACTER(len=128), INTENT(in) :: filename
    TYPE(time_type), INTENT(in) :: current_time

    INTEGER :: yr1, mo1, dy1, hr1, mi1, sc1  ! get from current time
    INTEGER :: yr2, dy2, hr2, mi2            ! for computing next_level time unit
    INTEGER :: yr1_s, mo1_s, dy1_s, hr1_s, mi1_s, sc1_s ! actual values to write string
    INTEGER :: abs_sec, abs_day              ! component of current_time
    INTEGER :: days_per_month(12) = (/31,28,31,30,31,30,31,31,30,31,30,31/)
    INTEGER :: julian_day, i, position, len, first_percent
    CHARACTER(len=1) :: width  ! width of the field in format write
    CHARACTER(len=10) :: format
    CHARACTER(len=20) :: yr, mo, dy, hr, mi, sc        ! string of current time (output)
    CHARACTER(len=128) :: filetail

    format = '("_",i*.*)'
    CALL get_date(current_time, yr1, mo1, dy1, hr1, mi1, sc1)
    len = LEN_TRIM(filename)
    first_percent = INDEX(filename, '%')
    filetail = filename(first_percent:len)
    ! compute year string
    position = INDEX(filetail, 'yr')
    IF ( position > 0 ) THEN
       width = filetail(position-1:position-1)
       yr1_s = yr1
       format(7:9) = width//'.'//width
       WRITE(yr, format) yr1_s
       yr2 = 0
    ELSE
       yr = ' '
       yr2 = yr1 - 1
    END IF
    ! compute month string
    position = INDEX(filetail, 'mo')
    IF ( position > 0 ) THEN
       width = filetail(position-1:position-1)
       mo1_s = yr2*12 + mo1
       format(7:9) = width//'.'//width
       WRITE(mo, format) mo1_s
    ELSE
       mo = ' '
    END IF
    ! compute day string
    IF ( LEN_TRIM(mo) > 0 ) THEN ! month present
       dy1_s = dy1
       dy2 = dy1_s - 1
    ELSE IF ( LEN_TRIM(yr) >0 )  THEN ! no month, year present
       ! compute julian day
       IF ( mo1 == 1 ) THEN
          dy1_s = dy1
       ELSE
          julian_day = 0
          DO i = 1, mo1-1
             julian_day = julian_day + days_per_month(i)
          END DO
          IF ( leap_year(current_time) .AND. mo1 > 2 ) julian_day = julian_day + 1
          julian_day = julian_day + dy1
          dy1_s = julian_day
       END IF
       dy2 = dy1_s - 1
    ELSE ! no month, no year
       CALL get_time(current_time, abs_sec, abs_day)
       dy1_s = abs_day
       dy2 = dy1_s
    END IF
    position = INDEX(filetail, 'dy')
    IF ( position > 0 ) THEN
       width = filetail(position-1:position-1)
       FORMAT(7:9) = width//'.'//width
       WRITE(dy, FORMAT) dy1_s
    ELSE
       dy = ' '
    END IF
    ! compute hour string
    IF ( LEN_TRIM(dy) > 0 ) THEN
       hr1_s = hr1
    ELSE
       hr1_s = dy2*24 + hr1
    END IF
    hr2 = hr1_s
    position = INDEX(filetail, 'hr')
    IF ( position > 0 ) THEN
       width = filetail(position-1:position-1)
       format(7:9) = width//'.'//width
       WRITE(hr, format) hr1_s
    ELSE
       hr = ' '
    END IF
    ! compute minute string
    IF ( LEN_TRIM(hr) > 0 ) THEN
       mi1_s = mi1
    ELSE
       mi1_s = hr2*60 + mi1
    END IF
    mi2 = mi1_s
    position = INDEX(filetail, 'mi')
    IF(position>0) THEN
       width = filetail(position-1:position-1)
       format(7:9) = width//'.'//width
       WRITE(mi, format) mi1_s
    ELSE
       mi = ' '
    END IF
    ! compute second string
    IF ( LEN_TRIM(mi) > 0 ) THEN
       sc1_s = sc1
    ELSE
       sc1_s = NINT(mi2*SECONDS_PER_MINUTE) + sc1
    END IF
    position = INDEX(filetail, 'sc')
    IF ( position > 0 ) THEN
       width = filetail(position-1:position-1)
       format(7:9) = width//'.'//width
       WRITE(sc, format) sc1_s
    ELSE
       sc = ' '
    ENDIF
    get_time_string = TRIM(yr)//TRIM(mo)//TRIM(dy)//TRIM(hr)//TRIM(mi)//TRIM(sc)
  END FUNCTION get_time_string
  ! </FUNCTION>
  ! </PRIVATE>

  ! <FUNCTION NAME="get_date_dif">
  !   <OVERVIEW>
  !     Return the difference between two times in units.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     REAL FUNCTION get_date_dif(t2, t1, units)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Calculate and return the difference between the two times given in the unit given using the function <TT>t2 - t1</TT>.
  !   </DESCRIPTION>
  !   <IN NAME="t2" TYPE="TYPE(time_type)">Most recent time.</IN>
  !   <IN NAME="t1" TYPE="TYPE(time_type)">Most distant time.</IN>
  !   <IN NAME="units" TYPE="INTEGER">Unit of return value.</IN>
  REAL FUNCTION get_date_dif(t2, t1, units)
    TYPE(time_type), INTENT(in) :: t2, t1
    INTEGER, INTENT(in) :: units

    INTEGER :: dif_seconds, dif_days
    TYPE(time_type) :: dif_time

    ! Compute time axis label value
    ! <ERROR STATUS="FATAL">
    !   variable t2 is less than in variable t1
    ! </ERROR>
    IF ( t2 < t1 ) CALL error_mesg('diag_util_mod::get_date_dif', &
         & 'in variable t2 is less than in variable t1', FATAL)

    dif_time = t2 - t1

    CALL get_time(dif_time, dif_seconds, dif_days)

    IF ( units == DIAG_SECONDS ) THEN
       get_date_dif = dif_seconds + SECONDS_PER_DAY * dif_days
    ELSE IF ( units == DIAG_MINUTES ) THEN
       get_date_dif = 1440 * dif_days + dif_seconds / SECONDS_PER_MINUTE
    ELSE IF ( units == DIAG_HOURS ) THEN
       get_date_dif = 24 * dif_days + dif_seconds / SECONDS_PER_HOUR
    ELSE IF ( units == DIAG_DAYS ) THEN
       get_date_dif = dif_days + dif_seconds / SECONDS_PER_DAY
    ELSE IF ( units == DIAG_MONTHS ) THEN
       ! <ERROR STATUS="FATAL">
       !   months not supported as output units
       ! </ERROR>
       CALL error_mesg('diag_util_mod::get_date_dif', 'months not supported as output units', FATAL)
    ELSE IF ( units == DIAG_YEARS ) THEN
       ! <ERROR STATUS="FATAL">
       !   years not suppored as output units
       ! </ERROR>
       CALL error_mesg('diag_util_mod::get_date_dif', 'years not supported as output units', FATAL)
    ELSE
       ! <ERROR STATUS="FATAL">
       !   illegal time units
       ! </ERROR>
       CALL error_mesg('diag_util_mod::diag_date_dif', 'illegal time units', FATAL)
    END IF
  END FUNCTION get_date_dif
  ! </FUNCTION>

  ! <SUBROUTINE NAME="diag_data_out">
  !   <OVERVIEW>
  !     Write data out to file.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE diag_data_out(file, field, dat, time, fianl_call_in, static_write_in)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Write data out to file, and if necessary flush the buffers.
  !   </DESCRIPTION>
  !   <IN NAME="file" TYPE="INTEGER">File ID.</IN>
  !   <IN NAME="field" TYPE="INTEGER">Field ID.</IN>
  !   <INOUT NAME="dat" TYPE="REAL, DIMENSION(:,:,:,:)">Data to write out.</INOUT>
  !   <IN NAME="time" TYPE="TYPE(time_type)">Current model time.</IN>
  !   <IN NAME="final_call_in" TYPE="LOGICAL, OPTIONAL"><TT>.TRUE.</TT> if this is the last write for file.</IN>
  !   <IN NAME="static_write_in" TYPE="LOGICAL, OPTIONAL"><TT>.TRUE.</TT> if static fields are to be written to file.</IN>
  SUBROUTINE diag_data_out(file, field, dat, time, final_call_in, static_write_in)
    INTEGER, INTENT(in) :: file, field
    REAL, DIMENSION(:,:,:,:), INTENT(inout) :: dat
    TYPE(time_type), INTENT(in) :: time
    LOGICAL, OPTIONAL, INTENT(in):: final_call_in, static_write_in

    LOGICAL :: final_call, do_write, static_write
    INTEGER :: i, num
    REAL :: dif, time_data(2, 1, 1, 1), dt_time(1, 1, 1, 1), start_dif, end_dif

    do_write = .TRUE.
    final_call = .FALSE.
    IF ( PRESENT(final_call_in) ) final_call = final_call_in
    static_write = .FALSE.
    IF ( PRESENT(static_write_in) ) static_write = static_write_in
    dif = get_date_dif(time, base_time, files(file)%time_units)
    ! get file_unit, open new file and close curent file if necessary
    IF ( .NOT.static_write .OR. files(file)%file_unit < 0 ) CALL check_and_open(file, time, do_write)
    IF ( .NOT.do_write ) RETURN  ! no need to write data
    CALL diag_field_out(files(file)%file_unit, output_fields(field)%f_type, dat, dif)
    ! record number of bytes written to this file
    files(file)%bytes_written = files(file)%bytes_written +&
         & (SIZE(dat,1)*SIZE(dat,2)*SIZE(dat,3))*(8/output_fields(field)%pack)
    IF ( .NOT.output_fields(field)%written_once ) output_fields(field)%written_once = .TRUE.
    ! *** inserted this line because start_dif < 0 for static fields ***
    IF ( .NOT.output_fields(field)%static ) THEN
       start_dif = get_date_dif(output_fields(field)%last_output, base_time,files(file)%time_units)
       IF ( .NOT.mix_snapshot_average_fields ) THEN
          end_dif = get_date_dif(output_fields(field)%next_output, base_time, files(file)%time_units)
       ELSE
          end_dif = dif
       END IF
    END IF

    ! Need to write average axes out;
    DO i = 1, files(file)%num_fields
       num = files(file)%fields(i)
       IF ( output_fields(num)%time_ops .AND. &
            input_fields(output_fields(num)%input_field)%register) THEN
          IF ( num == field ) THEN
             ! Output the axes if this is first time-averaged field
             time_data(1, 1, 1, 1) = start_dif
             CALL diag_field_out(files(file)%file_unit, files(file)%f_avg_start, time_data(1:1,:,:,:), dif)
             time_data(2, 1, 1, 1) = end_dif
             CALL diag_field_out(files(file)%file_unit, files(file)%f_avg_end, time_data(2:2,:,:,:), dif)
             ! Compute the length of the average
             dt_time(1, 1, 1, 1) = end_dif - start_dif
             CALL diag_field_out(files(file)%file_unit, files(file)%f_avg_nitems, dt_time(1:1,:,:,:), dif)

             ! Include boundary variable for CF compliance
             CALL diag_field_out(files(file)%file_unit, files(file)%f_bounds, time_data(1:2,:,:,:), dif)
             EXIT
          END IF
       END IF
    END DO

    ! If write time is greater (equal for the last call) than last_flush for this file, flush it
    IF ( final_call ) THEN
       IF ( time >= files(file)%last_flush ) THEN
          CALL diag_flush(files(file)%file_unit)
          files(file)%last_flush = time
       END IF
    ELSE
       IF ( time > files(file)%last_flush .AND. (flush_nc_files.OR.debug_diag_manager) ) THEN
          CALL diag_flush(files(file)%file_unit)
          files(file)%last_flush = time
       END IF
    END IF
  END SUBROUTINE diag_data_out
  ! </SUBROUTINE>

  ! <PRIVATE>
  ! <SUBROUTINE NAME="check_and_open">
  !   <OVERVIEW>
  !     Checks if it is time to open a new file.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE check_and_open(file, time, do_write)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Checks if it is time to open a new file. If yes, it first closes the
  !     current file, opens a new file and returns file_unit
  !     previous diag_manager_end is replaced by closing_file and output_setup by opening_file.
  !   </DESCRIPTION>
  !   <IN NAME="file" TYPE="INTEGER">File ID.</IN>
  !   <IN NAME="time" TYPE="TYPE(time_type)">Current model time.</IN>
  !   <OUT NAME="do_write" TYPE="LOGICAL"><TT>.TRUE.</TT> if file is expecting more data to write, <TT>.FALSE.</TT> otherwise.</OUT>
  SUBROUTINE check_and_open(file, time, do_write)
    INTEGER, INTENT(in) :: file
    TYPE(time_type), INTENT(in) :: time
    LOGICAL, INTENT(out) :: do_write

    IF ( time >= files(file)%start_time ) THEN
       IF ( files(file)%file_unit < 0 ) THEN ! need to open a new file
          CALL opening_file(file, time)
          do_write = .TRUE.
       ELSE
          do_write = .TRUE.
          IF ( time > files(file)%close_time .AND. time < files(file)%next_open ) THEN
             do_write = .FALSE. ! file still open but receives NO MORE data
          ELSE IF ( time > files(file)%next_open ) THEN ! need to close current file and open a new one
             CALL write_static(file)  ! write all static fields and close this file
             CALL opening_file(file, time)
             files(file)%start_time = files(file)%next_open
             files(file)%close_time =&
                  & diag_time_inc(files(file)%start_time,files(file)%duration, files(file)%duration_units)
             files(file)%next_open =&
                  & diag_time_inc(files(file)%next_open, files(file)%new_file_freq,&
                  & files(file)%new_file_freq_units)
             IF ( files(file)%close_time > files(file)%next_open ) THEN
                ! <ERROR STATUS="FATAL">
                !   <file_name> has close time GREATER than next_open time,
                !   check file duration and frequency
                ! </ERROR>
                CALL error_mesg('diag_util_mod::check_and_open',&
                     & files(file)%name//' has close time GREATER than next_open time, check file duration and frequency',FATAL)
             END IF
          END IF ! no need to open new file, simply return file_unit
       END IF
    ELSE
       do_write = .FALSE.
    END IF
  END SUBROUTINE check_and_open
  ! </SUBROUTINE>
  ! </PRIVATE>

  ! <SUBROUTINE NAME="write_static">
  !   <OVERVIEW>
  !     Output all static fields in this file
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE write_static(file)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Write the static data to the file.
  !   </DESCRIPTION>
  !   <IN NAME="file" TYPE="INTEGER">File ID.</IN>
  SUBROUTINE write_static(file)
    INTEGER, INTENT(in) :: file

    INTEGER :: j, i, input_num

    DO j = 1, files(file)%num_fields
       i = files(file)%fields(j)
       input_num = output_fields(i)%input_field
       ! skip fields that were not registered
       IF ( .NOT.input_fields(input_num)%register ) CYCLE
       IF ( output_fields(i)%local_output .AND. .NOT. output_fields(i)%need_compute) CYCLE
       ! only output static fields here
       IF ( .NOT.output_fields(i)%static ) CYCLE
       CALL diag_data_out(file, i, output_fields(i)%buffer, files(file)%last_flush, .TRUE., .TRUE.)
    END DO
    ! Close up this file
    IF ( files(file)%file_unit.NE.-1 ) then
      ! File is stil open.  This is to protect when the diag_table has no Fields
      ! going to this file, and it was never opened (b/c diag_data_out was not
      ! called)
      CALL mpp_close(files(file)%file_unit)
      files(file)%file_unit = -1
    END IF
  END SUBROUTINE write_static
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="check_duplicate_output_fields">
  !   <OVERVIEW>
  !     Checks to see if <TT>output_name</TT> and <TT>output_file</TT> are unique in <TT>output_fields</TT>.
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE check_duplicate_output_fields(err_msg)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Check to see if <TT>output_name</TT> and <TT>output_file</TT> are unique in <TT>output_fields</TT>.  An empty
  !     <TT>err_msg</TT> indicates no duplicates found.
  !   </DESCRIPTION>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*), OPTIONAL">Error message.  If empty, then no duplicates found.</OUT>
  SUBROUTINE check_duplicate_output_fields(err_msg)
    CHARACTER(len=*), INTENT(out), OPTIONAL :: err_msg

    INTEGER :: i, j, tmp_file
    CHARACTER(len=128) :: tmp_name
    CHARACTER(len=256) :: err_msg_local

    IF ( PRESENT(err_msg) ) err_msg=''
    ! Do the checking when more than 1 output_fileds present
    IF ( num_output_fields <= 1 ) RETURN
    err_msg_local = ''

    i_loop: DO i = 1, num_output_fields-1
       tmp_name = TRIM(output_fields(i)%output_name)
       tmp_file =  output_fields(i)%output_file
       DO j = i+1, num_output_fields
          IF ( (tmp_name == TRIM(output_fields(j)%output_name)) .AND. &
               &(tmp_file == output_fields(j)%output_file)) THEN
             err_msg_local = ' output_field "'//TRIM(tmp_name)//&
                  &'" duplicated in file "'//TRIM(files(tmp_file)%name)//'"'
             EXIT i_loop
          END IF
       END DO
    END DO i_loop
    IF ( err_msg_local /= '' ) THEN
       IF ( fms_error_handler(' ERROR in diag_table',err_msg_local,err_msg) ) RETURN
    END IF
  END SUBROUTINE check_duplicate_output_fields
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="attribute_init_field" INTERFACE="attribute_init">
  !   <OVERVIEW>
  !     Allocates the atttype in out_field
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE attribute_init(out_field, err_msg)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Allocates memory in out_field for the attributes.  Will <TT>FATAL</TT> if err_msg is not included
  !     in the subroutine call.
  !   </DESCRIPTION>
  !   <INOUT NAME="out_field" TYPE="TYPE(output_field_type)">output field to allocate memory for attribute</INOUT>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*), OPTIONAL">Error message, passed back to calling function</OUT>
  SUBROUTINE attribute_init_field(out_field, err_msg)
    TYPE(output_field_type), INTENT(inout) :: out_field
    CHARACTER(LEN=*), INTENT(out), OPTIONAL :: err_msg

    INTEGER :: istat

    ! Need to initialize err_msg if present
    IF ( PRESENT(err_msg) ) err_msg = ''

    ! Allocate memory for the attributes
    IF ( .NOT._ALLOCATED(out_field%attributes) ) THEN
       ALLOCATE(out_field%attributes(max_field_attributes), STAT=istat)
       IF ( istat.NE.0 ) THEN
          ! <ERROR STATUS="FATAL">
          !   Unable to allocate memory for attribute <name> to module/input_field <module_name>/<field_name>
          ! </ERROR>
          IF ( fms_error_handler('diag_util_mod::attribute_init_field',&
               & 'Unable to allocate memory for attributes', err_msg) ) THEN
             RETURN
          END IF
       ELSE
          ! Set equal to 0.  It will be increased when attributes added
          out_field%num_attributes = 0
       END IF
    END IF
  END SUBROUTINE attribute_init_field
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="prepend_attribute_field" INTERFACE="prepend_attribute">
  !   <OVERVIEW>
  !     Prepends the attribute value to an already existing attribute.  If the
  !     attribute isn't yet defined, then creates a new attribute
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE prepend_attribute(out_field, attribute, prepend_value)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Checks if the attribute already exists in the <TT>out_field</TT>.  If it exists,
  !     then prepend the <TT>prepend_value</TT>, otherwise, create the attribute
  !     with the <TT>prepend_value</TT>. <TT>err_msg</TT> indicates no duplicates found.
  !   </DESCRIPTION>
  !   <INOUT NAME="out_field" TYPE="TYPE(output_field_type)">output field that will get the attribute</INOUT>
  !   <IN NAME="att_name" TYPE="CHARACTER(len=*)">Name of the attribute</IN>
  !   <IN NAME="prepend_value" TYPE="CHARACTER(len=*)">Value to prepend</IN>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*), OPTIONAL">Error message, passed back to calling routine</OUT>
  SUBROUTINE prepend_attribute_field(out_field, att_name, prepend_value, err_msg)
    TYPE(output_field_type), INTENT(inout) :: out_field
    CHARACTER(len=*), INTENT(in) :: att_name, prepend_value
    CHARACTER(len=*), INTENT(out) , OPTIONAL :: err_msg

    INTEGER :: length, i, this_attribute
    CHARACTER(len=512) :: err_msg_local

    ! Initialize string characters
    err_msg_local=''
    IF ( PRESENT(err_msg) ) err_msg = ''

    ! Make sure the attributes for this out field have been initialized
    CALL attribute_init_field(out_field, err_msg_local)
    IF ( TRIM(err_msg_local) .NE. '' ) THEN
       IF ( fms_error_handler('diag_util_mod::prepend_attribute_field', TRIM(err_msg_local), err_msg) ) THEN
          RETURN
       END IF
    END IF

    ! Find if attribute exists
    this_attribute = 0
    DO i=1, out_field%num_attributes
       IF ( TRIM(out_field%attributes(i)%name) .EQ. TRIM(att_name) ) THEN
          this_attribute = i
          EXIT
       END IF
    END DO

    IF ( this_attribute > 0 ) THEN
       IF ( out_field%attributes(this_attribute)%type .NE. NF90_CHAR ) THEN
          ! <ERROR STATUS="FATAL">
          !   Attribute <name> is not a character attribute.
          ! </ERROR>
          IF ( fms_error_handler('diag_util_mod::prepend_attribute_field', &
               & 'Attribute "'//TRIM(att_name)//'" is not a character attribute.',&
               & err_msg) ) THEN
             RETURN
          END IF
       END IF
    ELSE
       ! Defining a new attribute
       ! Increase the number of field attributes
       this_attribute = out_field%num_attributes + 1
       IF ( this_attribute .GT. max_field_attributes ) THEN
          ! <ERROR STATUS="FATAL">
          !   Number of attributes exceeds max_field_attributes for attribute <name>.
          !   Increase diag_manager_nml:max_field_attributes.
          ! </ERROR>
          IF ( fms_error_handler('diag_util_mod::prepend_attribute_field',&
               & 'Number of attributes exceeds max_field_attributes for attribute "'&
               & //TRIM(att_name)//'".  Increase diag_manager_nml:max_field_attributes.',&
               & err_msg) ) THEN
             RETURN
          END IF
       ELSE
          out_field%num_attributes = this_attribute
          ! Set name and type
          out_field%attributes(this_attribute)%name = att_name
          out_field%attributes(this_attribute)%type = NF90_CHAR
          ! Initialize catt to a blank string, as len_trim doesn't always work on an uninitialized string
          out_field%attributes(this_attribute)%catt = ''
       END IF
    END IF

    ! Check if string is already included, and return if found
    IF ( INDEX(TRIM(out_field%attributes(this_attribute)%catt), TRIM(prepend_value)).EQ.0 ) THEN
       ! Check if new string length goes beyond the length of catt
       length = LEN_TRIM(TRIM(prepend_value)//" "//TRIM(out_field%attributes(this_attribute)%catt))
       IF ( length.GT.LEN(out_field%attributes(this_attribute)%catt) ) THEN
          ! <ERROR STATUS="FATAL">
          !   Prepend length for attribute <name> is longer than allowed.
          ! </ERROR>
          IF ( fms_error_handler('diag_util_mod::prepend_attribute_field',&
               & 'Prepend length for attribute "'//TRIM(att_name)//'" is longer than allowed.',&
               & err_msg) ) THEN
             RETURN
          END IF
       END IF
       ! Set fields
       out_field%attributes(this_attribute)%catt =&
            & TRIM(prepend_value)//' '//TRIM(out_field%attributes(this_attribute)%catt)
       out_field%attributes(this_attribute)%len = length
    END IF
  END SUBROUTINE prepend_attribute_field
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="attribute_init_file" INTERFACE="attribute_init">
  !   <OVERVIEW>
  !     Allocates the atttype in out_file
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE attribute_init(out_file, err_msg)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Allocates memory in out_file for the attributes.  Will <TT>FATAL</TT> if err_msg is not included
  !     in the subroutine call.
  !   </DESCRIPTION>
  !   <INOUT NAME="out_file" TYPE="TYPE(file_type)">output file to allocate memory for attribute</INOUT>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*), OPTIONAL">Error message, passed back to calling function</OUT>
  SUBROUTINE attribute_init_file(out_file, err_msg)
    TYPE(file_type), INTENT(inout) :: out_file
    CHARACTER(LEN=*), INTENT(out), OPTIONAL :: err_msg

    INTEGER :: istat

    ! Initialize err_msg
    IF ( PRESENT(err_msg) ) err_msg = ''

    ! Allocate memory for the attributes
    IF ( .NOT._ALLOCATED(out_file%attributes) ) THEN
       ALLOCATE(out_file%attributes(max_field_attributes), STAT=istat)
       IF ( istat.NE.0 ) THEN
          ! <ERROR STATUS="FATAL">
          !   Unable to allocate memory for file attributes
          ! </ERROR>
          IF ( fms_error_handler('diag_util_mod::attribute_init_file', 'Unable to allocate memory for file attributes', err_msg) ) THEN
             RETURN
          END IF
       ELSE
          ! Set equal to 0.  It will be increased when attributes added
          out_file%num_attributes = 0
       END IF
    END IF
  END SUBROUTINE attribute_init_file
  ! </SUBROUTINE>

  ! <SUBROUTINE NAME="prepend_attribute_file" INTERFACE="prepend_attribute">
  !   <OVERVIEW>
  !     Prepends the attribute value to an already existing attribute.  If the
  !     attribute isn't yet defined, then creates a new attribute
  !   </OVERVIEW>
  !   <TEMPLATE>
  !     SUBROUTINE prepend_attribute(out_file, attribute, prepend_value)
  !   </TEMPLATE>
  !   <DESCRIPTION>
  !     Checks if the attribute already exists in the <TT>out_file</TT>.  If it exists,
  !     then prepend the <TT>prepend_value</TT>, otherwise, create the attribute
  !     with the <TT>prepend_value</TT>. <TT>err_msg</TT> indicates no duplicates found.
  !   </DESCRIPTION>
  !   <INOUT NAME="out_file" TYPE="TYPE(file_type)">output file that will get the attribute</INOUT>
  !   <IN NAME="att_name" TYPE="CHARACTER(len=*)">Name of the attribute</IN>
  !   <IN NAME="prepend_value" TYPE="CHARACTER(len=*)">Value to prepend</IN>
  !   <OUT NAME="err_msg" TYPE="CHARACTER(len=*), OPTIONAL">Error message, passed back to calling routine</OUT>
  SUBROUTINE prepend_attribute_file(out_file, att_name, prepend_value, err_msg)
    TYPE(file_type), INTENT(inout) :: out_file
    CHARACTER(len=*), INTENT(in) :: att_name, prepend_value
    CHARACTER(len=*), INTENT(out) , OPTIONAL :: err_msg

    INTEGER :: length, i, this_attribute
    CHARACTER(len=512) :: err_msg_local

    ! Initialize string variables
    err_msg_local = ''
    IF ( PRESENT(err_msg) ) err_msg = ''

    ! Make sure the attributes for this out file have been initialized
    CALL attribute_init_file(out_file, err_msg_local)
    IF ( TRIM(err_msg_local) .NE. '' ) THEN
       IF ( fms_error_handler('diag_util_mod::prepend_attribute_file', TRIM(err_msg_local), err_msg) ) THEN
          RETURN
       END IF
    END IF

    ! Find if attribute exists
    this_attribute = 0
    DO i=1, out_file%num_attributes
       IF ( TRIM(out_file%attributes(i)%name) .EQ. TRIM(att_name) ) THEN
          this_attribute = i
          EXIT
       END IF
    END DO

    IF ( this_attribute > 0 ) THEN
       IF ( out_file%attributes(this_attribute)%type .NE. NF90_CHAR ) THEN
          ! <ERROR STATUS="FATAL">
          !   Attribute <name> is not a character attribute.
          ! </ERROR>
          IF ( fms_error_handler('diag_util_mod::prepend_attribute_file',&
               & 'Attribute "'//TRIM(att_name)//'" is not a character attribute.',&
               & err_msg) ) THEN
             RETURN
          END IF
       END IF
    ELSE
       ! Defining a new attribute
       ! Increase the number of file attributes
       this_attribute = out_file%num_attributes + 1
       IF ( this_attribute .GT. max_file_attributes ) THEN
          ! <ERROR STATUS="FATAL">
          !   Number of attributes exceeds max_file_attributes for attribute <name>.
          !   Increase diag_manager_nml:max_file_attributes.
          ! </ERROR>
          IF ( fms_error_handler('diag_util_mod::prepend_attribute_file',&
               & 'Number of attributes exceeds max_file_attributes for attribute "'&
               &//TRIM(att_name)//'".  Increase diag_manager_nml:max_file_attributes.',&
               & err_msg) ) THEN
             RETURN
          END IF
       ELSE
          out_file%num_attributes = this_attribute
          ! Set name and type
          out_file%attributes(this_attribute)%name = att_name
          out_file%attributes(this_attribute)%type = NF90_CHAR
          ! Initialize catt to a blank string, as len_trim doesn't always work on an uninitialized string
          out_file%attributes(this_attribute)%catt = ''
       END IF
    END IF

    ! Only add string only if not already defined
    IF ( INDEX(TRIM(out_file%attributes(this_attribute)%catt), TRIM(prepend_value)).EQ.0 ) THEN
       ! Check if new string length goes beyond the length of catt
       length = LEN_TRIM(TRIM(prepend_value)//" "//TRIM(out_file%attributes(this_attribute)%catt))
       IF ( length.GT.LEN(out_file%attributes(this_attribute)%catt) ) THEN
          ! <ERROR STATUS="FATAL">
          !   Prepend length for attribute <name> is longer than allowed.
          ! </ERROR>
          IF ( fms_error_handler('diag_util_mod::prepend_attribute_file',&
               & 'Prepend length for attribute "'//TRIM(att_name)//'" is longer than allowed.',&
               & err_msg) ) THEN
             RETURN
          END IF
       END IF
       ! Set files
       out_file%attributes(this_attribute)%catt =&
            & TRIM(prepend_value)//' '//TRIM(out_file%attributes(this_attribute)%catt)
       out_file%attributes(this_attribute)%len = length
    END IF
  END SUBROUTINE prepend_attribute_file
  ! </SUBROUTINE>
END MODULE diag_util_mod