20000504: sorry....

>From: address@hidden (Chris Hennon)
>Organization: UCAR/Unidata
>Keywords: 200005041522.e44FMGG28079

>Steve -
>
>Can you do me a favor?  Login to my machine and run the script
>/usr/local/gempak/scripts/models/eta_sfc.csh.  I now have Xvfb running so
>it is using display 1.  Can you let me know if you can successfully write
>a gif?  I keep getting the same SIGBUS errors as usual.  If you can write
>a gif, can you tell me exactly what you did when you logged in to be able
>to do this?  Thanks
>
>Chris
>
>PS - You will have to add your machine to the /etc/X1.hosts file or change
>the display within the script to 0.0
>
>
>


Chris,

I tracked down your trouble, ran the script and produced the
$MODHTML/models/eta/eta_sfc_f006.gif output file.

The problem stems from modifications made to the $GEMTBL/colors/coltbl.xw table.
I moved your locally edited version to coltbl.xw.osu and downloaded the
default table (and then changed the first entry from black to white
since you prefer white background images). The xw/gf drivers expect 32 color 
entries in the table, and by adding more, the data arrays were getting stepped 
on.

When you run ntl, it actually uses the $NAWIPS/tables/nawips.clr as the
table to initialize the common color set- and the xw/gf drivers do not
have to read the coltbl.xw table when the shared color table is installed.
So when you were creating gifs to :0 with ntl running, things still worked.
However, when you started trying to draw to the :1 Xvfb with no ntl running,
the drivers then load their color table by default from coltbl.xw. Running
gpend caused the gf driver to try to write the color table information to
the output file and that caused the dump. The first color in the coltbl.xw
will be installed as the background color- so I changed this so that your
gifs will be created with white backgrounds.

I have logged out of the gempak account, so you can change the password
as you wish.

Let me know if you have any questions.

Steve Chiswell