* +-======-+ 
*  Copyright (c) 2003-2007 United States Government as represented by 
*  the Admistrator of the National Aeronautics and Space Administration.  
*  All Rights Reserved.
*  
*  THIS OPEN  SOURCE  AGREEMENT  ("AGREEMENT") DEFINES  THE  RIGHTS  OF USE,
*  REPRODUCTION,  DISTRIBUTION,  MODIFICATION AND REDISTRIBUTION OF CERTAIN 
*  COMPUTER SOFTWARE ORIGINALLY RELEASED BY THE UNITED STATES GOVERNMENT AS 
*  REPRESENTED BY THE GOVERNMENT AGENCY LISTED BELOW ("GOVERNMENT AGENCY").  
*  THE UNITED STATES GOVERNMENT, AS REPRESENTED BY GOVERNMENT AGENCY, IS AN 
*  INTENDED  THIRD-PARTY  BENEFICIARY  OF  ALL  SUBSEQUENT DISTRIBUTIONS OR 
*  REDISTRIBUTIONS  OF THE  SUBJECT  SOFTWARE.  ANYONE WHO USES, REPRODUCES, 
*  DISTRIBUTES, MODIFIES  OR REDISTRIBUTES THE SUBJECT SOFTWARE, AS DEFINED 
*  HEREIN, OR ANY PART THEREOF,  IS,  BY THAT ACTION, ACCEPTING IN FULL THE 
*  RESPONSIBILITIES AND OBLIGATIONS CONTAINED IN THIS AGREEMENT.
*  
*  Government Agency: National Aeronautics and Space Administration
*  Government Agency Original Software Designation: GSC-15354-1
*  Government Agency Original Software Title:  GEOS-5 GCM Modeling Software
*  User Registration Requested.  Please Visit http://opensource.gsfc.nasa.gov
*  Government Agency Point of Contact for Original Software:  
*  			Dale Hithon, SRA Assistant, (301) 286-2691
*  
* +-======-+ 
function stdiff (args)
field = subwrd  (args,1)
type  = subwrd  (args,2)
tag1  = subwrd  (args,3)
tag2  = subwrd  (args,4)
cint  = subwrd  (args,5)
 
if( type = std ) ; string = "Std.Dev.  (Forecast-Analysis)"           ; endif
if( type = var ) ; string = "Variance  (Forecast-Analysis)"           ; endif
if( type = rms ) ; string = "RMS  (Forecast-Analysis)"                ; endif
if( type = fma ) ; string = "MEAN  (Forecast-Analysis)"               ; endif
if( type = fmc ) ; string = "MEAN  (Forecast-Climatology)"            ; endif
if( type = mse ) ; string = "Mean_Square_Error  (Forecast-Analysis)"  ; endif
if( type = mes ) ; string = "Mean_Error_Squared  (Forecast-Analysis)" ; endif

'getinfo level'
         level = result

'run getinfo tinc'
             tinc = result
if( tinc = "NULL" ) ; tinc = 6 ; endif
'run getinfo time'
             time = result
             hour = (time-1)*tinc
if( hour < 10  ) ; hour = 0hour ; endif
if( hour < 100 ) ; hour = 0hour ; endif


'set vpage off'
'set grid  off'
'set grads off'
'set gxout shaded'
'set ccols 92 0'
'set clevs 0.5'
'd mask'
'define diff = regrid2( 'field''type''tag1'-'field''type''tag2',.25, .25, bs_p1, 0, -90 )'

'define NHEM = aave( diff,lon=0,lon=360,lat= 20,lat= 80 )'
'define SHEM = aave( diff,lon=0,lon=360,lat=-80,lat=-20 )'
'define GLOB = aave( diff,lon=0,lon=360,lat=-90,lat= 90 )'
'define TROP = aave( diff,lon=0,lon=360,lat=-20,lat= 20 )'
'd NHEM'
   NHEM = subwrd(result,4)
'd SHEM'
   SHEM = subwrd(result,4)
'd GLOB'
   GLOB = subwrd(result,4)
'd TROP'
   TROP = subwrd(result,4)

if( cint = '' )
        'stats 'diff
         aGLOB = subwrd(result,2)
'getint 'aGLOB
      cint = result
 if( aGLOB = 0 ) ; cint = 1 ; endif
         n = 0
     while( cint = 0 )
     say 'N: 'n'  CINT: 'cint'  aGLOB: 'aGLOB
*    say 'Hit ENTER to continue'
*    pull flag
            n = n + 1
        aGLOB = 10*aGLOB
       'getint 'aGLOB
         cint = result
      endwhile
      'd pow(10,'n')'
      fact = subwrd(result,4)
      cint = cint/fact
endif

clevs = ''
n = -9
while ( n <= 9 )
  val = n * cint
if( n != 0 ) ; clevs = clevs' 'val ; endif
    n = n + 1
endwhile
'set ccols 59   57   55   47   44   37   36   34   33    0     21   22   23   24   25   26   27   28   29'

'set clevs 'clevs
'd maskout( diff,abs(diff)-'cint' )'
'cbarn -snum 0.75'
'draw title 'tag1'  minus  'tag2
'set string 1 c 6'

'getinfo month' 
         month = result
'getinfo year'
         year  = result

'set vpage off'
'set string 1 c 6'
'set strsiz 0.14'
'draw string 5.5 7.9 'month' 'year'   Forecast Hour: 'hour
'draw string 5.42238 8.20392 'level'-mb 'field'  'string

'set string 1 l 6'
'set strsiz 0.12'
'draw string 9.0 8.10 NHEM: 'NHEM
'draw string 9.0 7.90 SHEM: 'SHEM
'draw string 9.0 7.70 GLOB: 'GLOB
'draw string 9.0 7.50 TROP: 'TROP