<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title></title><style type="text/css">.felamimail-body-blockquote {margin: 5px 10px 0 3px;padding-left: 10px;border-left: 2px solid #000088;} </style></head><body>On Aug 17, 2018 3:45:01 PM, Sri Nandini wrote:
<br><blockquote class="felamimail-body-blockquote"><div>Hello</div><div><br></div><div>I am plotting a simple mean evaporation panel plot with extreme values. As such i decided to use a non linear color scale for this to try to focus on the smaller changes and use white to "mask" the larger variability because that's not important and i want the reader to focus on the smaller changes.</div><div><br></div><div>But i cannot seem to really distribute a good color scheme to highlight the smaller changes reasonably and i am trying to not use green. I think it becomes clearer once you view the attached plot. I have attached the plotting resources used in my script below.<br></div><div>I have tried to change the ExplicitLevels values many times as well as the ;res@cnFillPalette = (/"Snow","Black","Blue","PaleTurquoise","PaleGreen","SeaGreen3" ,"Yellow","Pink","Red","Orange","Brown"/) colors = (/"white", "black", "PeachPuff", "MintCream", "SlateBlue", \<br> ; "Khaki", "OliveDrab","BurlyWood", "LightSalmon", "Coral", \<br> ; "HotPink", "LemonChiffon", "AliceBlue", "LightGrey", \<br> ; "MediumTurquoise", "DarkSeaGreen", "Peru", "Tomato", \<br> ; "Orchid","PapayaWhip"/)</div><div><br></div><div>I would b grateful for any advice on selecting a colormap for extreme values.</div><div><br></div><div><br>;==================================================================<br>;Here is a section of my code that draws a color fill plot<br>;===================================================================<br><br> wks = gsn_open_wks("pdf","all_Evaporation_diff1")</div><div> gsn_define_colormap(wks,"prcp_1")<br><br> res = True<br><br> res@cnFillOn = True ; turn on color<br> ;res@gsnSpreadColors = True ; use full colormap<br><br> res@cnLinesOn = False ; turn off contour lines<br> res@cnLevelSelectionMode = "ExplicitLevels" ; set manual contour levels<br> res@cnLevels = (/-1.5,-1.,-0.6,-0.4,-0.3,-0.2,-0.1,0,0.1,0.2,0.3,0.4,0.5/) ; set levels<br><br> ;res@cnFillPalette =(/"Snow"/)</div><div><br></div><div>;res@cnFillPalette =(/"Snow","Black","Blue", "DarkSeaGreen","PaleTurquoise","PaleGreen","SeaGreen3" ,"OliveDrab","Snow","Snow","BurlyWood","Pink","Salmon","Orange","Red"/)<br><br> ;res@cnLevels = (/ -3,-1.,-0.5,-0.4,-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1.,3./) ; set levels<br> ;res@cnLevels = (/ -4,-1.5,-1.,-0.5,-0.4,-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1./) ; set levels<br> <br> res@gsnDraw = False ; Do not draw plot<br> res@gsnFrame = False ; Do not advance frome<br> res@lbLabelBarOn = False ; turn off individual label bars<br> res@tiMainString = " "<br> ;res@tiMainOffsetYF = 0.02 ; Move title up a little<br> res@gsnCenterString = " "<br> res@gsnLeftString = " "<br> res@gsnRightString = " "<br> res@cnRasterModeOn = True ; Raster mode shows grid cells<br> ;gsn_reverse_colormap(wks) <br><br> minlat = 30. ; min lat to mask<br> maxlat = 80. ; max lat to mask<br> minlon = -10. ; min lon to mask<br> maxlon = 100. ; max lon to mask<br><br> res@mpProjection = "LambertConformal" ; choose projection<br><br>;---masked plot<br> res@gsnAddCyclic = True ; regional plot<br><br> res@mpMinLatF = minlat ; min lat to mask<br> res@mpMaxLatF = maxlat ; max lat to mask<br> res@mpMinLonF = minlon ; min lon to mask<br> res@mpMaxLonF = maxlon ; max lon to mask<br><br></div></blockquote><br></body></html>