Re: [idvusers] Simple difference a-b with data from two netcdf files

Hi Hilde-

Hilde Fagerli wrote:
I am a new idv user, trying to do something that apparently should be easy.
I am loading two netcdf files with multiple 2D fields. I simply want to subtract one field in one file from another field in another file. I load and plot both fields with Color-shaded Plan View, that works fine.

I then use Data->Formulas->Miscellaneous->Simple difference a-b
and choose Colour-Shaded Plan View again. Now I get a window where I can choose a and b. The problem is that I can only choose the files, not the fields in the files. At the same time, idv seems to get very busy. I thought it might try to load all the data again, but the files are not very big, and even if I wait a long time, nothing happens. So when I then click 'ok' I get

The dialog should show the two data sources and allow you to
expand them to show the Fields in each file by clicking on the
little icon to the left of the name.  If that's not the
case, could you send a screen shot of the dialog to
support-idv@xxxxxxxxxxxxxxxx so we can check it out?

An error has occurred:
Creating display: Color-Shaded Plan View
No data selected

How do I get around this problem?

It should work as you expect, so I'm not quite sure what's
going on.

Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307