<div dir="ltr"><div class="gmail_default" style="font-size:small">Hi Tabish,</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">Here's a some extra information on colors in NCL:</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">-------------------------------------------------------------------------<br></div><div class="gmail_default" style="font-size:small">When you use a predefined colormap, like "rainbow" or "amwg", it is not defined by named colors, by rather by RGBA quadruplets. </div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">RGBA arrays are N x 4 floating point arrays of values that go from 0 to 1, where the 'RGB' represents fractions of red, green, and blue, and the 'A' represents the 'alpha' value which designates the opacity of the color.<br></div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">For example:</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">The color (/1.0,0.,0.,1./) represents red, because you have full red (1.0), no green (0.0), no blue (0.0), and full opacity (1.0).</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">The color (/0.0,1.0,0.0,1./) represents green, with full opacity.</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"><div class="gmail_default">The color (/0.0,0.0,1.0,0.5/) represents blue, with half opacity.</div><div class="gmail_default"><br></div><div class="gmail_default"><div class="gmail_default">The color (/1.0,1.0,0.0,0.25/) represents yellow, with a quarter opacity.</div><div><br></div></div><div class="gmail_default">etc.</div><div><br></div></div><div class="gmail_default" style="font-size:small">In NCL, when you specify a color resource like:</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"> res@gsMarkerColor = "red"</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">you can use named colors, but you can also use direct RGBA values:</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"> res@gsMarkerColor = (/1.,0.,0.,1./) ; fully opaque red marker<br></div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">The nice thing about using RGBA values is it allows you to control the opacity, for example:</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style=""><div class="gmail_default" style="font-size:small"> res@gsMarkerColor = (/1.,0.,0.,0.25/) ; mostly transparent red marker</div><div class="gmail_default" style="font-size:small">---------------------------------------------------------------------</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">Anyway, you can mimic the colors that NCL uses in your WRF plot, by using span_color_rgba. You need to give this function the same levels that you are using for the contour plot, and it will return the same colors being used by the contour plot. Note, you could accomplish the same thing by calling "getvalues" on the smoothed contour plot to retrieve the levels and the colors.</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">See the attached script, which creates a filled contour plot of SLP, and then randomly grabs points from SLP to mimic an observational data set, but draws these values using filled square markers.</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">You can get the dataset from:</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style=""><a href="http://www.ncl.ucar.edu/Applications/Data/cdf/wrfout_d01_2003-07-15_00:00:00">http://www.ncl.ucar.edu/Applications/Data/cdf/wrfout_d01_2003-07-15_00:00:00</a><br></div><div class="gmail_default" style=""><br></div><div class="gmail_default" style="">--Mary</div><div class="gmail_default" style=""><br></div></div><div class="gmail_default" style="font-size:small"><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Aug 27, 2016 at 9:38 PM, Tabish Ansari <span dir="ltr"><<a href="mailto:tabishumaransari@gmail.com" target="_blank">tabishumaransari@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_default" style="font-family:trebuchet ms,sans-serif">Hi<br><br></div><div class="gmail_default" style="font-family:trebuchet ms,sans-serif">I'm trying to compare wrf model output (contour plot) with some station data (scattered observations). I am trying to color the markers of the station data based on their values and create a similar legend bar as the wrf-contour. However, this is not very straightforward as I'm using predefined colormap for wrf-contour but have to explicitly specify the name of the color for each range in case of station data. <br><br></div><div class="gmail_default" style="font-family:trebuchet ms,sans-serif">This will be very easy if I know the exact name of each shade used in the legend bar of wrf-contour (out of the 650 named colors in NCL). Is there a way to print the names of these colors used in the legendbar?<br><br></div><div class="gmail_default" style="font-family:trebuchet ms,sans-serif">Thanks<br><br></div><div class="gmail_default" style="font-family:trebuchet ms,sans-serif">Tabish<br><br clear="all"></div><div><div data-smartmail="gmail_signature"><div dir="ltr"><div><div><font size="1"><span style="font-family:tahoma,sans-serif">Tabish U Ansari<br></span></font></div><font size="1"><span style="font-family:tahoma,sans-serif">PhD student, Lancaster Environment Center<br></span></font></div><font size="1"><span style="font-family:tahoma,sans-serif">Lancaster Univeristy<br> <span>Bailrigg</span>, <span>Lancaster</span>, <br><span>LA1 4YW</span>, <span>United Kingdom</span></span></font><br></div></div></div>
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