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<DIV>Another option if you're on Grads 1.8 would be to use fgvals to layer up each variable one at a time, being careful to select the order of how the variables are overlayed so that if there's overlap the desired variable ends up on top. Resolution of the input grib will result in a blocked output, depending on how zoomed in target area is, but it's better than nothing. </DIV>
<DIV>--<BR>Thanks, <BR>Mark</DIV>
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<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">-------------- Original message -------------- <BR>From: "Jennifer M. Adams" <jma@COLA.IGES.ORG> <BR>Assuming that areas of snow, rain, and freezing rain do not overlap, you could draw the first field (snow), then print the image to a file in the .png format. Next, you draw the second field (rain), but this time when you print the image to a file, you use the -b option to include your first plot in the background, and also use the -t option so that the areas of no rain would be transparent. Finally, you draw your third field (freezing rain), and print it using the -b option with the 2nd .png image file you created and the -t option with the transparent color belonging to the no-freezing-rain color. When you're done, you should have three layered images, with the middle and top images having a transparent color that allows the bottom and middle images to show through where there is no
rain
or freezing rain. I think the -t and -b options were added during the development of version 1.9, so this strategy won't work if you're using version 1.8.
<DIV>Jennifer</DIV>
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<DIV>On Dec 6, 2006, at 6:23 AM, Alessandro Mandelli wrote:</DIV><BR class=Apple-interchange-newline>
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<DIV style="MARGIN: 0px">Dan Leins ha scritto:</DIV>
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<DIV style="MARGIN: 0px">All,</DIV>
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<DIV style="MARGIN: 0px">I would like to create an image using GrADS of 3 separate model fields,</DIV></BLOCKQUOTE>
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<DIV style="MARGIN: 0px">I have the same question and the same problem.</DIV>
<DIV style="MARGIN: 0px">The only solution I could come up with is</DIV>
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<DIV style="MARGIN: 0px">d snow + rain*100 + freezingrain*10000</DIV>
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<DIV style="MARGIN: 0px">and associate three colors to 1, 100 and 10000 but I'm not really happy</DIV>
<DIV style="MARGIN: 0px">with that.</DIV>
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<DIV style="MARGIN: 0px">Cheers</DIV>
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<DIV>Jennifer M. Adams</DIV>
<DIV>IGES/COLA</DIV>
<DIV>4041 Powder Mill Road, Suite 302</DIV>
<DIV>Beltsville, MD 20705</DIV>
<DIV><A href="mailto:jma@cola.iges.org">jma@cola.iges.org</A></DIV>
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