[IDV #XVT-855811]: IDv problems

Hi Bill-

What version of the IDV are you using?  See the Help->About menu dialog.

> Thanks.  I tried the sample displays and they seemed to work fine.  When I
> tried the catalog via data choosers (NSF-ATM), it seemed to hang and
> eventually a window popped up saying,
> 
> Could not load catalog:
> http://thredds.cise-nsf.gov:8080/thredds/idv/models.xml
> 
> I exited and tried again later and still had this problem.

In that case you shouldn't have needed to exit.  Can you access the catalog
now?  I'm not aware of any problems on that server and I can get to it
from my system.

> I eventually went in to motherlode, and was able to do things like
> isosurfaces of humidity and height.  However, I also noticed it wouldn't
> display the current data, even after I removed the data sources from those
> sample bundles --- as though it was confused because those cases were in
> different years?  I had to exit IDV and then could bring up current data.

The IDV will only load data from the data sources that are selected so
if you removed the data from the old bundle and selected the current
NAM data that you loaded in, that's what you should get.

> I also am confused because when I told it to do an isosurface of
> geopotential height, expecting to see a 500 mb map come up, instead it
> seems to show a map of constant height in gpm -- and it looked like the
> hills/ridges are where trofs/lows should be at 500 mb -- almost as though
> everything was reversed/opposite.  

An isosurface is a surface connecting points of equal value.  So
an isosurface of geopotential height will connect point of equal
geopotential height, not points of equal pressure.  The vertical
domain of pressure of these grids is plotted at the height of that
pressure in the standard atmosphere.  Thus, for an isosurface of
geopotential height, the troughs and ridges show the variation of
pressure for that particular value.

> So, I went back to try the color-filled
> contour plan over topography, which is the thing that has never worked
> this past month, but it is the thing I saw a colleague do a month ago to
> get the nice 500 mb display where trofs and ridges showed up nicely.
> Again, this did not seem to load and I did not get any data.  A little
> window pops up asking something about what topography to use and the
> choices are either "formulas" or the NAM data I had chosen.  When I select
> the NAM, nothing happened (it appears the NAM was the default).

You need to select the particular parameter that is the height value.  Expand
the NAM tab in the dialog an then select the 3D grid->Geopotential height @ 
isobaric
field.  See the section on Doing more with Grids in the IDV Workshop materials 
at:

http://www.unidata.ucar.edu/software/idv/docs/workshop/datadisplays/grid/DoingMoreWithGrids.html

> So, it might be that the problem I am having is with this color-filled
> plan over topography.  However, what seems odd is that today, when I click
> on create display, it appears nothing at all is happening.  The past
> month, the problem was that it appeared like it wsa trying to load forever
> with nothing ever showing up.

I can't think of why you don't get prompted for anything when you 
click the Create Display button.  Do you have a field and display
selected?

> My machine has 4GB of memory, although only 3 GB are being seen by the
> kernel.  Daryl said that he hopes the next kernel update will allow all 4
> GB to be seen/accessed/whatever (I don't know what all of this means)

This shouldn't be a problem.  The default runIDV script only uses 512 Mb.
You can change that to use 1Gb if you want.  Follow the instructions in the
IDV FAQ at:

http://www.unidata.ucar.edu/software/idv/docs/userguide/Faq.html#memory

Don



Ticket Details
===================
Ticket ID: XVT-855811
Department: Support IDV
Priority: Normal
Status: Open