Stuck on rfits

andrewkbradshaw wrote on May 31, 2008

Hello, big IRAF newby here. I'm trying to do the exercises in the iraf.noao.edu ftp archive and I'm stuck, sadly, on the first part of the first exercise. Hopefully my question is really basic and easily fixed.

The introduction asks us to:
"Before proceeding further we need to unpack the images that will be used during
this exercise. This can be done using the RFITS task. New files will be
created with a .imh extension - these files are in the IRAF image format and
consist of a header (.imh) and pixel (.pix) file for each image.

cl> dir # list the files in the current directory
cl> unlearn rfits
cl> rfits fintro* "" junk old+ "

From the dir command I get the files they provided, of course, which are fintro001 and fintro002 . Then the rfits command supposedly gives back an .imh file and .pix file, but all I receive back are im010.fits and im011.fits in the same directory.

Any insight at all? I'm sure any tidbits will help me very much; unfortunately I couldn't find anything already posted about it. Could the problem be that I'm doing the exercises for 2.11 with IRAF version 2.14? I couldn't find an exercise for 2.14.

Thanks,
Andrew

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Mike Fitzpatrick wrote on May 31, 2008

In V2.14 the default imtype was reset to 'fits' meaning that all new images would be FITS. To explicitly use 'imh' you need to either specify the file extension when creating the image (e.g. "imcopy dev$pix foo.imh"), or you can

cl> reset imtype = "imh" ; flpr 0             # zero, not oh

This can also be done in your login.cl file.

Note that FITS images can be used directly provided they have an extension. The tutorial images don't have an explicit extension, but you can add one using something like

cl> rename fsp* fits field=extn

With that done, you can use the FITS files directly in the exercises.

Cheers,
-Mike

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Last post on May 31, 2008