	REAL FUNCTION R_CGRID_SIZE_DELTA ( cx )

*  This software was developed by the Thermal Modeling and Analysis
*  Project(TMAP) of the National Oceanographic and Atmospheric
*  Administration''s (NOAA) Pacific Marine Environmental Lab(PMEL),
*  hereafter referred to as NOAA/PMEL/TMAP.
*
*  Access and use of this software shall impose the following
*  obligations and understandings on the user. The user is granted the
*  right, without any fee or cost, to use, copy, modify, alter, enhance
*  and distribute this software, and any derivative works thereof, and
*  its supporting documentation for any purpose whatsoever, provided
*  that this entire notice appears in all copies of the software,
*  derivative works and supporting documentation.  Further, the user
*  agrees to credit NOAA/PMEL/TMAP in any publications that result from
*  the use of this software or in any product that includes this
*  software. The names TMAP, NOAA and/or PMEL, however, may not be used
*  in any advertising or publicity to endorse or promote any products
*  or commercial entity unless specific written permission is obtained
*  from NOAA/PMEL/TMAP. The user also understands that NOAA/PMEL/TMAP
*  is not obligated to provide the user with any support, consulting,
*  training or assistance of any kind with regard to the use, operation
*  and performance of this software nor to provide the user with any
*  updates, revisions, new versions or "bug fixes".
*
*  THIS SOFTWARE IS PROVIDED BY NOAA/PMEL/TMAP "AS IS" AND ANY EXPRESS
*  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
*  ARE DISCLAIMED. IN NO EVENT SHALL NOAA/PMEL/TMAP BE LIABLE FOR ANY SPECIAL,
*  INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
*  RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
*  CONTRACT, NEGLIGENCE OR OTHER TORTUOUS ACTION, ARISING OUT OF OR IN
*  CONNECTION WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE. 
*
*
* Real-number version of cgrid_size_delta.
* determine the number of values in a 2D grid that lies within the plane
* of the specified context
* Unlike CGRID_SIZE this routine *IS* sensitive to cx_delta values

* Ansley Manke 9/2014

        IMPLICIT NONE
        include 'tmap_dims.parm'
	include 'ferret.parm'
	include 'xcontext.cmn'

* calling argument declarations
	INTEGER	cx

* internal variable declarations
	INTEGER	idim
	REAL size, delta

* determine the delta product
	size = 1
	DO 10 idim = 1, nferdims
	  IF (cx_delta(idim,cx) .NE. unspecified_val8) THEN
	    delta = cx_delta(idim,cx)
	  ELSE
	    delta = 1.
	  ENDIF
          IF ( (cx_hi_ss(cx,idim) .GE. cx_lo_ss(cx,idim)) .AND.
     .         (cx_hi_ss(cx,idim) .NE. unspecified_int4)  .AND.
     .         (cx_lo_ss(cx,idim) .NE. unspecified_int4)  ) THEN
              size = size * 
     .          (FLOAT(cx_hi_ss(cx,idim)-cx_lo_ss(cx,idim))/delta + 1.)
          ENDIF
 10 	CONTINUE

* the result
	R_CGRID_SIZE_DELTA = size

	RETURN
	END
