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Next: Taking the Bus: Alternative Schemes Previous: At The Very Beginning of Your Run: obsinit

Keeping Your Data Organized: Directories, Subdirectories, and Pixel Files

  Those of us who have been at one time or another labeled ``organizationally impaired" find that it is useful to keep our images separated by different nights. There are a couple ways of doing this:

  1. You could use a separate root-name for each night, i.e., ``a" for the first night, ``b" for the second night, and so on.

  2. You could create a separate subdirectory for each night. To do this,

    1. Use mkdir subdirectory_name to create a subdirectory that is named subdirectory_name.

    2. Move to that directory by doing a cd subdirectory name. You will need to do this in each of your IRAF windows (both ``Data Acquisition" and ``Data Reduction").

You can always find what directory you are in by doing a path. To return to your ``home" directory, do a cd (no argument).

When you take data, the image headers are actually all that wind up in the current directory. The pixel files (i.e., the actual data) wind up in a special ``image directory" called imdir. However, by setting the image directory to the special designation ``HDR$pixels/" when you ran obsinit, you have assured that your pixels will wind up on the same disk as your headers, stored in a subdirectory called ``pixels" of whatever directory you happen to be in when you take an image.

The fact that the pixels and the headers are stored on the same disk makes it very easy to see whether or not you are in danger of running out of disk-space. If you type diskspace you will see a listing of the percentage used on each disk area; the one to pay attention to is the one labeled data1.

By executive fiat, the disk-names have been made sensible and consistent across the mountain-top. When you log onto the SUN computer in your dome and do a path you will see that your home directory is called


I.e., if you are logged onto ``taupe" as ``36inch" the home directory is


At each telescope, the data-acquisition disk is /data1 is physically attached to the data-taking computer. There may also be a smaller disk, /data2, which is ``cross-mounted" from a second (data-reduction) computer in some of the domes (cocoa, royal, rust). Given the limitations of cross-mounted disks, we suggest that you use /data2 only as a reduction area, and that you access it primarily from the second computer. If you attempt to take data using /data2 (by changing directories to this disk), you may find that things are incredibly slow. (A normal 310 read-down of T2KB took 530 on /data2.) It takes less time to keep your taping up to date!

To make a duplicate copy of your images on /data2 you can do the following:

imcopy *.imh /data2/4meter/

Note that this has to be done while in the directory where the images you wish to copy currently sit.

next previous contents
Next: Taking the Bus: Alternative Schemes Previous: At The Very Beginning of Your Run: obsinit
Tue Feb 14 07:48:00 MST 1995