Re: [ncl-users] changes in lat/lon views

From: Dennis Shea (shea AT XXXXXX)
Date: Wed Aug 25 2004 - 16:17:51 MDT

  • Next message: Mary Haley: "Re: Contours not filled on part of plot"

    >From: Cathryn Meyer <cathryn.meyer AT yale.edu>
    >
    >Hello,
    >
    >I am attempting to plot CAM3.0 output to compare it to a GOES-west loop.
    > How do I get an image with a lat range of 10 to 60 and a lon range of
    >-170 to -100? The bulk of the code I am using was taken from an example
    >on the NCL website, cn05n.ncl, and here is the main chunk of it:
    >
    >-------------------------------------------------------------
    > do i = 0, NFRAMES
    >
    > print("Plotting 3-hr Timestep " + (i+1))
    > ; Read the next data field (next day).
    > setvalues field1
    > "sfDataArray" : RHavg(i,:,:,0)
    > end setvalues
    > d=i+1
    > ; Increment day string.
    > setvalues con1
    > "lbTitleString": "Hour " + d * 3
    > end setvalues
    > ; draw another plot.
    > draw(map)
    > draw(lbarlo)
    > draw(lbarhi)
    > frame(wks)
    > end do
    >-----------------------------------------------------------
    >
    >I already tried replacing the colons with {10,60}, {-170, -100}, however
    >I got this error message when I did that:
    >
    >fatal:syntax error: line 313 in file RH05nplay.ncl before or near ,
    > "sfDataArray" : RHavg(i,{10,
    >--------------------------------------------^
    >
    >
    >fatal:Error in subscript, normal subscripting is being used, make sure
    >named subscripting has not been used
    >fatal:Syntax Error in block, block not executed
    =============
    Hi Cathy

    I am not quite sure to which example you are referring.

    Hopefully, the following helps a bit.

    Since u r using geographical coordinates, I assume u want
    to plot the CCSM data with a map background. There are numerous
    variations. However, I'll make the assumption that u
    want the CCSM data on a cylindrical equidistant map.

    [1] http://www.cgd.ucar.edu/csm/support/
    [2] Click Graphics
    [3] Click Maps: Cylindrical Equidistant: ce_3
        Click Contour-on-Contour: conOncon_2.ncl

    [4] netCDF has the concept of "coordinate variables".
        Many NCL graphical routines implicitly understand this concept.
        
    [5] CAM data have longitude coordinate variables that start at the
        GM [0] and are positive. To use ranges between -180 to 180
        you can use a function in contributed.ncl. I'll also include
        the graphics hogh level interfaces.
        
        I will make the assumption the "t" [below] is (time,lev,lat,lon)
        
    load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
    load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
    load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
    begin
        
        f = addfile("CAM.nc","r")
        t = f->T
        printVarSummary(t) ; note that long span 0->357.5 or whatever]
        
        t = lonFlip(t) ; contributed.ncl function
                                  ; reorder longitude coordinate variable.
        printVarSummary(t) ; note longitude coord variable
        
    ;************************************************
    ; create plot
    ;************************************************
      wks = gsn_open_wks("ps" ,"ce") ; open a ps file
      gsn_define_colormap(wks,"BlAqGrYeOrRe") ; choose colormap

      res1 = True ; for "t"
      res1@cnFillOn = True ; turn on color fill
      res1@cnLinesOn = False ; turn of contour lines
      res1@gsnSpreadColors = True ; use full range of color map
      
      res1@mpCenterLonF = 180.
      res1@mpMinLatF = 10 ; range to zoom in on
      res1@mpMaxLatF = 60.
      res1@mpMinLonF = -170.
      res1@mpMaxLonF = -100.
      
      res2 = True ; goes resources

      nt = 0
      kl = 7
      

      plot = gsn_csm_contour_map_overlay(wks,t(nt,kl,:,:),\
                                         goes(?),res1,res2)
        
    end

    _______________________________________________
    ncl-talk mailing list
    ncl-talk AT ucar.edu
    http://mailman.ucar.edu/mailman/listinfo/ncl-talk



    This archive was generated by hypermail 2b29 : Wed Aug 25 2004 - 17:11:34 MDT