[SAC-HELP] SPARC/Solaris to PC/SuSE problems

[Kris Walker]

On Dec 27, 2005, at 10:16 AM, jim at okgeosurvey1.gov wrote:

> We have changed from SPARC/Solaris to PC/SuSE Linux.

Congrats.  As you probably know, you may not experience immediate 
benefits, except maybe for the speed factor, but they'll start to shine 
through as you climb the linux learning curve.

> Since this change we have several problems with
> SAC. The problems persist for the following
> versions of SAC: 00.59.48 100.00
> and the following SuSE OS: 8.0pro,
> 8.2pro 9.3pro.
>
> Problem 1. Whenever a SAC graphics
> window is covered totaly or partly,
> and is reexposed, the reexposed
> parts are blank. Putting the
> window "always on top" or frequent
> replotting are the only workarounds
> we have found.

I had same experience with redhat versions >=6.2 if I recall.  I don't 
recall my experience with redhat v. <6.2.  I think this is due to the 
graphics drivers.  If there were better graphics drivers used, it 
probably wouldn't be a problem.

>
> Perhaps this is an XFree86
> config problem. I have not found
> any other application which acts
> this way.
> Problem 2. After "plotpk" the
> SAC window will only display a
> small "+", not a full crosshairs.
>

I don't remember what happens on my linux boxes (and can't access them 
currently), but on my mac os X, I get the full crosshairs, but then get 
the small "+" after I type "q" to quick picking.

> Problem 3. I can't use rollback.
> It always gives "out of memory"
> and sometimes other statements.
> Because most of our Linux boxes
> have ca 1GB RAM and ca 1GB swap,
> but will not rollback even one
> tiny SAC file, I do not believe
> we are truly out of either RAM
> or swap.

Interesting.  I've never used this command before, but I have found 
other similar memory-flavor bugs as well.  
http://sail.ucsd.edu/~walker/andmore.htm (look for SAC link--but will 
be down until Jan. 3 for security reasons).  I recall the specific 
problem of spectrograms calls and do loops crashing sac2000.  It would 
be a good if the developers of SAC could use a good memory leak finder 
like "purify" during testing on each supported platform.

>
> Problem 4. The "color" statement
> seems to have little or no effect.
> I seem to only be able to plot
> black and white.

I've never been able to plot color.

>
> Problem 5. Help followed by a
> SAC command which is mispelled
> exits with "segmentation fault".

I recall having this problem on some installations but not on others.

You will no doubt encounter more similar pains and annoyances as you 
further program in SAC.  I have found that using shell scripts to do 
most of the data flow/processing organization (piping suites of sac 
commands output with "echo" into sac) is a way to get around most of 
the memory-related problems, which are the most severe problems for me. 
  As far as graphics go, I'm not sure there is any workaround.

Best,
kris

================================================================
Dr. Kristoffer T. Walker            http://sail.ucsd.edu/~walker
Green Scholar                       email: walker at ucsd.edu
IGPP, Scripps MC 0225               phone: 858-534-0126
University of California, San Diego fax:   858-534-9873
La Jolla, CA 92093-0225             room:  2201 Revelle Lab
================================================================