20060103: IDV - Parameter Tables

Hi Sean,

> I have two grib files of two different models.  One produces derived parameters 
> and the other does not.  The one that produces derived parameters has had its 
> parameter table embedded into the IDV 1.2 distribution by Unidata.  The other I 
> am not sure if it has.
>
> I am not sure if the parameter tables would cause this problem or is it 
> something else.
>
>  
Most likely the one grib file has parameter names that the IDV does not 
recognize.
The derived quantities are created by looking for particular parameter 
or parameter
groups based on names. e.g., dewpoint looks for some parameter called 
"TEMP" and
one called "RH"
These names are really canonical names. We use an alias mechanism to say 
that, for example,
the parameter name "foo_rh" is really an "RH". You can define your own
aliases for these canonical names through the alias editor:
http://www.unidata.ucar.edu/software/idv/docs/userguide/tools/AliasEditor.html

> Question 2:
>
> It was mentioned that documentation would be provided in the 1.2 release on how 
> to add/customize your own parameter tables.  I could not find the documentation.
>
>
>  
Sorry, we'll add that in. By default the idv looks in 
~/.metapps/DefaultIdv for the files:
grib1lookuptable.lst
and:
grib2lookuptable.lst

I am cc'ing this message to Robb Kambic who can better describe the 
format of those files.

Robb - do you have documentation somewhere on this and/or can you help 
Sean out?
Thanks.

-Jeff