Sets the colors for a given list of color indexes and workstations.
procedure NhlSetColor ( workstations [*] : graphic, color_index [*] : integer, red [*] : float, green [*] : float, blue [*] : float )
An array of color indexes between 0 and 255. Must be dimensioned the same as red, blue, and green.red
Arrays of floating-point values between 0 and 1 inclusive. They must all be the same length.
For the color map of each workstation in workstations, the color indexes in color_index are set to the corresponding RGB triplets.
This procedure is different than the NhlNewColor function in that you are required to input color indexes for which to put the new colors. The NhlNewColor function adds the given color to the end of the existing color map, and returns the indexes used.
This example draws a filled contour plot over a map. It uses a "rainbow" colormap which has no gray in it. This causes the continents to be drawn in white. The NhlSetColor procedure is used to add gray to the end of the colormap. This example also shows how to remove this color using NhlFreeColor, and how it affects your plot.
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" begin datadir = ncargpath("data") datafile = datadir + "/cdf/meccatemp.cdf" ; ; Load a file record from the netCDF file ; as a read only data set. ; n = addfile(datafile,"r") t = n->t(0,:,:) type = "x11" type@wkColorMap = "rainbow" type@wkBackgroundColor = "white" type@wkForegroundColor = "black" wks = gsn_open_wks(type,"annotation") ; Open a workstation. ; ; If you don't set this color index, your continent colors ; will be white instead of gray. First, retrieve the length ; of the colormap, so we can add this color after the last one. ; getvalues wks "wkColorMapLen" : len end getvalues NhlSetColor(wks,len,0.8,0.8,0.8) ; ; Set some resources. ; res = True res@gsnSpreadColors = True res@gsnSpreadColorEnd = -2 res@gsnMaximize = True res@gsnAddCyclic = False res@cnLevelSelectionMode= "ManualLevels" res@cnMinLevelValF = 195.0 res@cnMaxLevelValF = 328.0 res@cnLevelSpacingF = 2.25 res@cnFillOn = True res@cnLinesOn = False res@mpGridAndLimbOn = False res@mpFillDrawOrder = "PostDraw" plot = gsn_csm_contour_map(wks,t,res) ; ; Now remove this color and see how it affects the plot. ; NhlFreeColor(wks,190) plot = gsn_csm_contour_map(wks,t,res) end