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IRAF/PHOT problems on Mac OS X 10.4 (Tiger)

graffke wrote on Sep 16, 2008

I'm using IRAF with my MacBook 2.2GHz, 4GB RAM. Everything seemed ok, till I started IRAF/PHOT package to calculate magnitudes from FITS image. I am doing some stellar photometry, and everything seemed ok, till I started IRAF/PHOT package to calculate magnitudes from FITS image.
When I start PHOT package to run, it runs normaly until it's output file (some_file.mag) reaches size that is equal to x_apphot service virtual memory size. Maybe it sounds a bit strange.. I tried to run PHOT in the other computer (OpenSuse OS) and everything went allright. PHOT computed 100000 objects in about 1-2 minutes. My computer does this job in about 1-2 hours..

Mike Fitzpatrick wrote on Sep 16, 2008

Sorry for the slow reply, I was hoping somebody else had an idea or could offer advice on images with so many objects.

I think you may actually be running into a per-process limit imposed by the operating system on how much memory you can use. Specifically, the 'datasize' limit is set to 6144Kb on Tiger by default but is generally 'unlimited' on linux systems. To check this, use the "limit" command at the unix prompt to print the current values, and "limit datasize unlimited" to reset it (if you use a Bash shell instead of C-shell, use "ulimit" and "ulimit -d unlimited" instead).

Otherwise, are you talking about the PHOT task in the APPHOT package or the DAOPHOT version? The latter is subject to the 'maxnstars' parameter set in the DAOPARS pset which you may be exceeding. Hope this helps.

Cheers,
-Mike

grf wrote on Sep 16, 2008

fitz

Sorry for the slow reply, I was hoping somebody else had an idea or could offer advice on images with so many objects.

I think you may actually be running into a per-process limit imposed by the operating system on how much memory you can use. Specifically, the 'datasize' limit is set to 6144Kb on Tiger by default but is generally 'unlimited' on linux systems. To check this, use the "limit" command at the unix prompt to print the current values, and "limit datasize unlimited" to reset it (if you use a Bash shell instead of C-shell, use "ulimit" and "ulimit -d unlimited" instead).

Otherwise, are you talking about the PHOT task in the APPHOT package or the DAOPHOT version? The latter is subject to the 'maxnstars' parameter set in the DAOPARS pset which you may be exceeding. Hope this helps.

Cheers,
-Mike


Limit is unlimited, checked that. I'm talking about PHOT in the DAOPHOT package, so there is no maxstars..

Last post on Sep 16, 2008