Re: files v5d with SpreadSheet.

• To: "From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>" <billh@xxxxxxxxxxxxx>
• Subject: Re: files v5d with SpreadSheet.
• From: Don Murray <dmurray@xxxxxxxxxxxxxxxx>
• Date: Thu, 14 Jun 2001 11:27:49 -0600

Hi Gianluca-

Bill is correct that the Vis5D GUI is tailored to Vis5D file schema
while the SpreadSheet GUI is tailored to generically handle any of the
datatypes that VisAD reads.  However, I've been able to display Vis5D
files in the SpreadSheet.  It does take a little bit of tweaking (and a
lot of memory since Vis5D files tend to be large).  If you read in a
Vis5D file to the SpreadSheet, you will probably have to use the extract
function to pull out the variable you want to display into a separate
cell.  Then use the SpreadSheet mapping tool set up the appropriate
ScalarMaps.  It's best to turn off autodetection of mappings to speed up
the display

For example, if you got the Vis5D Eta run for this morning:

http://sgi62.wwb.noaa.gov:8080/V_AVN3H/eta/eta_01061412.v5d

You could read it into the SpreadSheet:

1) run java -Xmx128m -jar visad.jar
2) Under the "Options" menu, deselect "Autodetect mappings"
3) Under the "File" menu, select "Import data...." (or click on the file
open icon)
4) Once the file has been read in, look at the MathType in the "Edit
mappings..." option (Under the "Cell" menu).  This will show a MathType
of something like:

(Time -> (((row, col, Height) -> P),
          ((row, col, Height) -> T),
           ...(other "3D" params)....,
          ((row, col) -> (PMSL, SFCZ, .... "2D" params....)
5) Close the mapping dialog
6) Use the extract function to place the data in another cell:
   - click on cell B1
   - type extract(A1d1,1) to extract the 2nd parameter (T in this case)
7) Open the mapping dialog for this cell and set up mappings:
   row -> Y
   col -> X
   height -> Z
   T -> Iso-Contour
   Time -> Animation
8) Using the contour widget to select the temperature isosurface.  Then
start the animation.
9) If you download the North American map from the FTP server
(ftp://www.ssec.wisc.edu/pub/visad/OUTLUSAM), you could add that to the
cell.  You would need to change your mappings to be Latitude -> Y and
Longitude -> X and Height_2 to Z.

So, this is not to imply that the SpreadSheet is a replacement for
Vis5D, but just to show that you can do some of the same things here and
it could be used for a quick look.  As Bill mentioned, VisAD is an API,
but the SpreadSheet shows that the desired capabilities are available,
just that someone has to build an application on the API. The 3-D
Gridded data viewer that Unidata has developed is an example of a Vis5D
like application that can be build using VisAD.  It does not (yet) read
Vis5D files though.

Don Murray 
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
*************************************************************

• References:
  • Re: files v5d with SpreadSheet.
    • From: From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>