Ccdmask..bad pixel mask

Nishkin wrote on Jul 11, 2006

It's me again...

When I try to use ccdmask to make a bad pixel mask with a division of flat field...I get the error "Invalid floating point operation"

I had flat fields of 20s and 4s..I normalized them both with imsurfit and divided them with imarith (which I named Sflatdiv).

When I run ccdmask on Sflatdiv..I get the error..

Any help will be appreciated!

Thanks!

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Mike Fitzpatrick wrote on Jul 11, 2006

Without seeing the image and knowing particulars like the iraf/OS version it isn't really obvious what the problem is. FPE errors like this are usually data related, e.g. a zero pixel where the task wasn't expecting it, near-zero values in the denominator of a division, etc. Have you done an IMSTAT to see whether the pixel stats look reasonable? Does changing/unlearning some of the parameters change anything?

If that doesn't help feel free to post a URL to the image and let me know what kind of system you're on. Frank may also chime in with suggestions if this sounds familiar to him as well.

Cheers,
-Mike

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Last post on Jul 11, 2006