Corner Limit in polar stereographic projection

Dear NCL talk,

I have some problem in zooming into a polar stereographic projection
over Southern Hemisphere by specifying a "Corner" Limit.
I read an array of binary data in native AMPS grid, then read a
auxiliary netcdf file to retrieve latitude and longitude. I then use the
function /gsn_csm_contour_map_polar/ with "opts" options where I set up
mpLimitMode to be Corners and mp Right/Left Corner Lat/Lon F to be the
values at the corners of the netcdf file. I got a message of
warning:MapSetTrans: map limits invalid - using maximal area such that
I've done something wrong and I need your help to solve it!
My check is that mpLeftCornerLonF < mpRightCornerLonF, and that
mpLeftCornerLatF and mpRightCornerLatF look correct, so I don't know...
Many thanks!

Yann MICHEL

Description of opts:

Variable: opts
Type: logical
Total Size: 4 bytes
            1 values
Number of Dimensions: 1
Dimensions and sizes: [1]
Coordinates:
Number Of Attributes: 19
  mpCenterLonF : 180
  mpRightCornerLonF : 215.9594
  mpRightCornerLatF : -22.03884
  mpLeftCornerLonF : 38.3541
  mpLeftCornerLatF : -24.93765
  mpLimitMode : Corners
  sfYArray : <ARRAY of 63291 elements>
  sfXArray : <ARRAY of 63291 elements>
  mpFillOn : False
  gsnPolar : SH
  mpProjection : Stereographic
  cnLinesOn : True
  cnFillOn : False
  cnLevelSelectionMode : ExplicitLevels
  cnLevels : ( 0.01, 0.05, 0.2, 0.5, 0.8 )
  gsnDraw : False
  gsnFrame : False
  gsnMaximize : True
  gsnContourLineThicknessesScale : 1
(0) True
warning:MapSetTrans: map limits invalid - using maximal area

Script:
; ----------------------------------------------*
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
;------------------------------------------------
begin
   ;------------------------------------------------
   ; read in data
   ;------------------------------------------------
  works="ps" ; open a ps file
  domain = "d01"
  type="tau"
  region = "ampsrt_"+domain
  dir = "/ptmp/yann/data/ampsrt/Oct2008_NL"+domain+"/working/"
  N_imp = 25
;----------------------------------------------------------------------------
; control_variables_3d=(/"psi","chi_u","t_u","rh", "ps_u"/)

   control_variables_3d=(/"ps_u"/)
   Nb_vars=dimsizes(control_variables_3d)
;----------------------------------------------------------------------------
   wks = gsn_open_wks (works,"impulse_recf_"+region+"_"+type) ; open
workstation

   res = True ; plot mods desired
   res_at_cnFillOn = False ; fill contour intervals
   res_at_cnLevelSelectionMode = "ExplicitLevels"
   res_at_cnLevels=(/10^(-2),0.05,0.2,0.5,0.8/)
   res_at_gsnDraw = False ; (a) donnot draw
   res_at_gsnFrame = False ; (b) donnot advance 'frame'
   res_at_gsnMaximize = True
   res_at_gsnContourLineThicknessesScale = 1.0 ; thickness
 
    ; create map from a given Netcdf auxiliary file
   nc_file =
addfile("/ptmp/yann/data/ampsrt/rc/2009052400/wrfinput_"+domain+".nc","r")
   lat = nc_file->XLAT(0,:,:)
   lon = nc_file->XLONG(0,:,:)
   print("netcdf size")
   print(dimsizes(lat))
   print(dimsizes(lon))
 ;----------------------------------------------------------------------------
   do kvar=0,Nb_vars-1
    
     filename =
dir+control_variables_3d(kvar)+"/impulse_response_"+type+"_"+control_variables_3d(kvar)+".dat"

     do l = 0, N_imp-1
   
       dim = fbinrecread (filename,2*l,4,"integer")
       ii = dim(0)
       jj = dim(1)
       ni = dim(2)
       nj = dim(3)
       print("test function at "+ii+","+jj+" size "+ni+" "+nj)
      
       test_function = fbinrecread (filename, 2*l+1, (/nj,ni/),"double")
    
       opts = res
       opts_at_cnLinesOn = True ; contour lines
       opts_at_mpProjection = "Stereographic"
       opts_at_gsnPolar = "SH"
  ; opts_at_mpEllipticalBoundary = True
       opts_at_mpFillOn = False
       opts_at_sfXArray = lon
       opts_at_sfYArray = lat

       opts_at_mpLimitMode = "Corners" ; choose map limits
       y1 = 0
       x1 = 0
       y2 = dim(3)-1
       x2 = dim(2)-1
       opts_at_mpLeftCornerLatF = lat(y1,x1)
       opts_at_mpLeftCornerLonF = lon(y1,x1)
       opts_at_mpRightCornerLatF = lat(y2,x2)
       opts_at_mpRightCornerLonF = lon(y2,x2)
       if ( opts_at_mpRightCornerLonF .lt. 0.0 ) then
         opts_at_mpRightCornerLonF = opts_at_mpRightCornerLonF + 360.0
       end if
       opts_at_mpCenterLonF = 180.0
       opts_at_mpGeophysicalLineColor = "black"
       opts_at_mpGridLineColor = "black"

       opts_at_cnLineLabelsOn = True
       opts_at_cnLineLabelFontQuality="High"
       opts_at_cnLineLabelPlacementMode="Computed"
       opts_at_cnLineLabelDensityF=0.6
    
       opts_at_sfDataArray = test_function

       plot = gsn_csm_contour_map_polar(wks,test_function,opts) ; create
plot

       draw(plot)
       frame(wks)
     end do
   end do
end
;----------------------------------------------------------------------------

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Received on Tue Jul 07 2009 - 11:00:40 MDT