<div dir="ltr">One way you can do it is using the "tiling" option for creating custom colors in grads.<div>-However, if you want to use stars specifically, you will need to find or create a very small image file displaying the star and save it as a .png first.<div>-Then you can use 'set tile' (see <a href="http://cola.gmu.edu/grads/gadoc/gradcomdsettile.html">tiling</a>) to create the tile. Then apply that tile to a color by using 'set rgb <i>color#</i> tile <i>tile#</i>' as indicated in the documentation for set rgb.</div><div>-Finally, you can display a masked field in combination with 'set clevs' and 'set ccols' with your new color number and threshold level to get Grads to plot the stars in a hatching pattern where the field threshold is exceeded.</div><div><br></div><div>Another way is to literally search through your grid one point at a time and use 'draw string' to draw whatever character you want with whatever settings at that grid point if the field value at that grid point exceeds the threshold. This option would me more involved and require more coding and testing, but you would have a greater degree of control over how the end result looks.</div></div><div><br></div><div>Hope this helps. Ask questions if you need more information.</div><div><br></div><div>Jeff Duda</div></div><br><div class="gmail_quote"><div dir="ltr">On Thu, Dec 13, 2018 at 11:56 AM Tracey <<a href="mailto:tdorian10@gmail.com">tdorian10@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><div class="gmail_default"><font face="arial, helvetica, sans-serif">Hi GrADS users, </font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">I was wondering if anyone knew if there was a way to plot a large enough symbol on a global map in GrADS where a difference field exceeds a specific threshold?</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">For example, in my GrADS script I am plotting sea surface temperatures and masking out land areas:</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><div class="gmail_default"><font face="arial, helvetica, sans-serif">'set_parea 2 2 2 1 -margin 'margin</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">*'color -levs -15 -10 -5 5 10 15 -kind blue->white->red'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif" color="#0000ff"><b>'color -20 20 5 -kind blue->white-(0)->white->red'</b></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif" color="#0000ff"><b>'d (TMPsfc.2-TMPsfc.1)'</b></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">'q gxinfo'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">line3=sublin(result,3)</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">x1=subwrd(line3,4)</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">x2=subwrd(line3,6)</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">say ' (x1,x2) = ('x1','x2')'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">line4=sublin(result,4)</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">y1=subwrd(line4,4)</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">y2=subwrd(line4,6)</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">say ' (y1,y2) = ('y1','y2')'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">'xcbar 'x1' 'x2' 'y1-0.3' 'y1-0.2' -fw .06 -fh .06 -fs 1'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">*'cbarn'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">'draw title FV3-GFS'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">* 'set rgb 73 80 80 80'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">'set rgb 73 255 255 255'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">** Plots ocean temperatures and masks land **</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">'basemap L 73 1 M'</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">** Plots land temperatures and masks ocean **</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">*'basemap O 0 1 H'</font></div><div><br></div><div>I want to say in GrADS, look at all points on the global map (not including land) and plot a large enough star that the user can see anywhere in the globe where the difference in surface temperature exceeds 10 degrees Celsius, for example. Does anyone know how I can do this?</div><div><br></div><div>Thank you,</div><div>Tracey Dorian</div></div></div></div>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><font size="2"><span>Jeff Duda, Research Scientist</span></font></div><div dir="ltr"><font size="2"><span></span></font>University of Colorado Boulder</div><div dir="ltr"><font size="2"><span></span></font>Cooperative Institute for Research in Environmental Sciences</div><div dir="ltr">NOAA/OAR/ESRL/Global Systems Division<br><font size="2"><span>
<span>Boulder, CO<br></span></span></font>
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