Re: [idvusers] "Visible range" not showing image beneath

  • To: "Dan Grey" <dangrey@xxxxxxxxx>
  • Subject: Re: [idvusers] "Visible range" not showing image beneath
  • From: "Tom Whittaker" <whittaker@xxxxxxxx>
  • Date: Sun, 20 Apr 2008 14:51:38 -0500
Hi Dan --

I assume from your description that you tried to do a "change range"
on the theta-e plot.  In my example, the original range was perhaps you just tried changing the range to something
like 310-420K or something?

The behaviour of this is that it then treats all values from 250-309
as if there were equal to 310, for the purpose of mapping from the
data to the color table.

The way I know of to accomplish this is to edit the color table, click
on the "Transparency" radio button, set the transparency to 100%, and
then grab the slider above the "250" and drag it to the right (you
should see black/white checkboard pattern).  You will then get
something like the attached (I hope) image.

Hope that helps...


On Sun, Apr 20, 2008 at 12:42 PM, Dan Grey <dangrey@xxxxxxxxx> wrote:
> I've got a sat pic (from a server under "Images") on the surface, and
>  a colour-shaded plot of theta-e at 850 hPa from the GFS above. I
>  restrict the visible range of the theta-e to a value so only areas
>  above a certain value are shown (to illustrate a plume event). However
>  areas with theta-e below my range appear black, rather than showing
>  through the sat pic below.
>  Am I missing something simple, is this is intended behaviour, or is it a bug?
>  Dan
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Tom Whittaker
University of Wisconsin-Madison
Space Science & Engineering Center (SSEC)
Cooperative Institute for Meteorological Satellite Studies (CIMSS)
1225 W. Dayton Street
Madison, WI 53706 USA
ph: +1 608 262 2759

Attachment: thetae.jpg
Description: JPEG image