FXCOR: Bus error

jchavez wrote on Sep 17, 2010

Hi,

I'm not sure if this is a pyraf issue, or a problem with the IRAF task, but I'm getting a bus error when I run fxcor. It works for some object images, but not others. I don't see any obvious differences in the headers of the two images.

Thank you,
-Joy Chavez

Error message:
Killing IRAF task 'fxcor'
Traceback (innermost last):
File "<CL script CL1>", line 1, in <module>
File "<string>", line 1 in <module>
File "<CL script CL2>", line42, in string_proc
IrafError: Error running IRAF task fxcor
IRAF task terminated abnormally
ERROR (501, "bus error")

I just updated to PyRAF 1.9, Python 2.5.4 on a Mac 10.5.8

Here is the script I am running:
noao
rv
.#unlearn fxcor
!rm *.txt

fxcor.apertures='40,42,49,50,52-70'
fxcor.continuum='both'
fxcor.filter='none'
fxcor.rebin='object'
fxcor.pixcorr=no # Do a pixel-only correlation
fxcor.osample='*' #object regions to be correlated
fxcor.rsample='*'
fxcor.apodize=0.2
fxcor.function="gaussian"
fxcor.width=INDEF #Width of fitting region in pixels
fxcor.height=0. #Starting height of fit
fxcor.peak=no #Is height relative to ccf peak?
fxcor.minwidth=3.0
fxcor.maxwidth=21.0
fxcor.weights=1.0
fxcor.background=0.0
fxcor.window=INDEF
fxcor.wincenter=INDEF
fxcor.verbose='long'
fxcor.imupdate=no
fxcor.graphics='stdgraph'
fxcor.interactive=no
fxcor.autowrite=yes
fxcor.autodraw=yes
fxcor.ccftype='image'
fxcor.observatory='lco'

fxcor.output='hd108177'
fxcor pmj11584-4155red_multi.fits hd108177red_multi.fits

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Mike Fitzpatrick wrote on Sep 17, 2010

The message indicates a crash in FXCOR but there are no known issues and not enough information to say specifically what's going wrong. You might try resetting the 'apertures' or 'continuum' parameter to see if you can narrow down the behavior to a specific setting, but it might just as well be something specific to the data itself. Does it reliably crash on specific images or randomly? Does it crash for these images when run interactively?

I'll need to be able to reproduce the problem to fix it. If you find a test image that can reliably do this could you upload the image (and template image) to the anonftp on iraf.noao.edu?

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jchavez wrote on Sep 17, 2010

Hi again,

Since I was running this in PyRAF, I also asked for help from STScI. They suggested I try running it in IRAF - and it still crashed.

I've uploaded to ftp://iraf.noao.edu/pub the script (fxcorprob.cl), the template (fxcortemp.fits), and a good star (fxcorgood.fits), and the one where it crashes (fxcorbad.fits).

Thank you for your help,
-Joy

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Mike Fitzpatrick wrote on Sep 17, 2010

Thanks for the files. I can reproduce the problem with a v2.14 system but not on the v2.15 development system. I'll post back once I track it down.

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jchavez wrote on Sep 17, 2010

Are you talking about the IRAF version when you say v2.14? That is the version I am running. I recently updated the PyRAF package distributed by STScI for Mac OS X, but not IRAF.

Thanks,
-Joy

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jchavez wrote on Sep 17, 2010

Should I update my IRAF? PyRAF is only tested up through IRAF 2.14, so I'm slightly worried about updating it, and then PyRAF be buggy.

Is there something in the data that would cause a bus error? There are several times when a fit doesn't converge, but fxcor is able to scratch that order and move on. But with the bus error crash, I don't know how to get it to run smoothly through all my data.

Thanks,
-Joy

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Last post on Sep 17, 2010