<div dir="ltr">Hi Sun,<div>Here's how I would do it:</div><div><span style="font-size:12.8px">gsn_define_colormap(wks,"</span><wbr style="font-size:12.8px"><span style="font-size:12.8px">ViBlGrWhYeOrRe”) </span></div><div><span style="font-size:12.8px">res = True</span></div><div><span style="font-size:12.8px">....</span></div><div><span style="font-size:12.8px">res@cnLevelSelectionMode = "ExplicitLevels"</span></div><div><span style="font-size:12.8px">res@cnLevels=(/-1000,-500,0,1000,5000,10000/) ; explicitly set contour levels</span></div><div><span style="font-size:12.8px">res@cnFillOn = True</span></div><div><span style="font-size:12.8px">res@cnFillColors = (/12,27,0,0,63,75,95/)</span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">Set the cnLevels to whatever you want, and then set the number of cnFillColors to one more than the number of cnLevels. The integers that I set in cnFillColors were chosen from the </span><span style="font-size:12.8px">ViBlGrWhYeOrRe colormap website here:</span></div><div><span style="font-size:12.8px"><a href="http://www.ncl.ucar.edu/Document/Graphics/ColorTables/ViBlGrWhYeOrRe.shtml">http://www.ncl.ucar.edu/Document/Graphics/ColorTables/ViBlGrWhYeOrRe.shtml</a></span><br></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">Color 12 is a blue, 27 is a blueish green, and so on. I set 0 (=background color/white) for all areas greater than or equal to -500 and less than 0, as well as all areas greater than or equal to 0 and less than 1000. (Note: I could have specified color 52 instead of 0 as 52 also looks white.) </span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">I don't know if you want to have -1000 and 10000 be the absolute minimum and maximum values on your labelbar. If so, see labelbar example #14 here (3rd panel):</span></div><div><span style="font-size:12.8px"><a href="http://www.ncl.ucar.edu/Applications/labelbar.shtml#ex14">http://www.ncl.ucar.edu/Applications/labelbar.shtml#ex14</a></span><br></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">Note that when you set lbLabelAlignment = "ExternalEdges" you will have to set the lbLabelStrings resource as the example shows. If you go with ExternalEdges some trial and error is likely needed to get the labelbar to exactly where you want it to be.</span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">Hope that helps. If you have further questions please respond to ncl-talk.</span></div><div><span style="font-size:12.8px">Adam</span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px"><br></span></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Sep 8, 2016 at 12:03 PM, mireiyue <span dir="ltr"><<a href="mailto:mireiyue@gmail.com" target="_blank">mireiyue@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Dear NCL users,<br>
<br>
I want to create a legend that shows minimum -1000 and maximum 10000. I want to have different interval for negative and positive values. And I am using gsn_define_colormap(wks,"<wbr>ViBlGrWhYeOrRe”) and I want to put white color for zero.<br>
<br>
I haven’t found any information about this work.<br>
<br>
I will appreciate any related helps and comments.<br>
<br>
Thank you<br>
Sun-<br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div><div><span><font color="#888888">Adam Phillips <br></font></span></div><span><font color="#888888">Associate Scientist, </font></span><span><font color="#888888">Climate and Global Dynamics Laboratory, NCAR<br></font></span></div></div><div><span><font color="#888888"><a href="http://www.cgd.ucar.edu/staff/asphilli/" target="_blank">www.cgd.ucar.edu/staff/asphilli/</a> </font></span><span><font color="#888888">303-497-1726 </font></span></div><span><font color="#888888"></font></span><div><div><span><font color="#888888"><br></font></span><div><span><font color="#888888"><a href="http://www.cgd.ucar.edu/staff/asphilli" target="_blank"></a></font></span></div></div></div></div></div></div></div></div></div></div></div>
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