Hi Ron,<br><br>I will second that suggestion. <br><br>In the meantime though what I typically end up doing is creating a rather roundabout solution to the situation and making use of ImageMagick's (<a href="http://www.imagemagick.org">http://www.imagemagick.org</a>) transparency feature (<a href="http://www.imagemagick.org/script/command-line-options.php#transparent">http://www.imagemagick.org/script/command-line-options.php#transparent</a>). You can draw the first variable and set the shading for the region you want to be transparent to a specific RGB value and then print that image to a file; clear the buffer and do the same for the other variable. You can then do something like the following:<br>
<br>mogrify -transparent rgb(<red value>,<green value>,<blue value>) first_image.gif<br>mogrify -transparent rgb(<red value>,<green value>,<blue value>) second_image.gif<br>composite atop first_image.gif second_image.gif combined_image.gif<br>
<br>I don't have any code samples in front of me but if anyone is in need of them let me know and I can send them out. Hope this helps.<br><br>Cheers,<br>Matt<br><br><div class="gmail_quote">On Tue, Jan 27, 2009 at 6:12 PM, Goodson,Ron [Edm] <span dir="ltr"><<a href="mailto:Ron.Goodson@ec.gc.ca">Ron.Goodson@ec.gc.ca</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div style="">
<div><span><font size="2" color="#0000ff" face="Arial">Just a
suggestion -- any chance of adding the ability to designate a colour number as
transparent when doing "gxout shaded" plots?</font></span></div>
<div><span><font size="2" color="#0000ff" face="Arial"></font></span> </div>
<div><span><font size="2" color="#0000ff" face="Arial">I know
you can set the lowest shade to the background colour so it "looks" like nothing
is being drawn (even though it is). But that doesn't help when you want to
have two separately shaded parameters (each between some limits so that neither
cover the entire graphic)... as drawing the 2nd parameter overwrite
the first.</font></span></div>
<div><span><font size="2" color="#0000ff" face="Arial"></font></span> </div>
<div><span><font size="2" color="#0000ff" face="Arial">I
currently do this by using maskout() to control what is valid data to
draw. But that leaves big-jagged edges based upon the resolution of my
grid so is neither accurate, nor visually appealing (understandable as I see
maskout as being more for calculations/analysis than for
display)</font></span></div>
<div><span><font size="2" color="#0000ff" face="Arial"></font></span> </div>
<div><span><font size="2" color="#0000ff" face="Arial">If a
colour could be marked as transparent - then I could use that for the colour of
my lower/upper limits of my shaded area and be able to smoothly overlay 2
different shaded areas. Perhaps it would simply set the operation to XOR
or something like that?</font></span></div>
<div><span><font size="2" color="#0000ff" face="Arial"></font></span> </div><font color="#888888">
<div><span><font size="2" color="#0000ff" face="Arial">ron</font></span></div></font></div>
</blockquote></div><br>