iraf.net

I'm having a problem trying to use flatcombine. I'm using quadproc, an adaptation of ccdproc for four chips together. I was able to process the biases---overscan and trim--and make a master bias. Overscanning, trimming, and bias-correcting the flats went okay. But when I tried to run flatcombine I got the message Error on line 47: Illegal file name operand (null string) flatcombine ()I am pretty sure I've run this routine before on the same computer without this error message. Any suggestions? Thanks.

This usually means that a filename parameter someplace has been specified using a space instead of an empty string, e.g. quadproc.flat=" " instead of quadprc.flat="". Doing an 'lpar' list will show this pretty clearly and you can simply edit the parameter. Keep in mind some of these are script tasks based on CCDPROC, so check the parameters for FLATCOMBINE as well as CCDPROC. You can either unlearn individual tasks, the entire package, or to be really thorough do a new MKIRAF and reinitialize your uparm directory.If that doesn't explain it, please post lpar listings of the tasks.Cheers,
-Mike

Mike,
The problem seems to have been permissions--we tried removing spaces and that didn't help. But after changing the permissions it works fine. Thanks for the suggestions!