Abstract

SPSS (Statistical Package for the Social Sciences) is a powerful, comprehensive, and flexible statistical analysis system. With SPSS you can perform highly complex data manipulations and analyses with surprisingly simple instructions. The version available on the Cunix Cluster is SPSS Version 6.1.4. Newer versions are available in the public CUIT labs and in EDS. Columbia University has site license agreements for purchasing individual copies.

Documentation

Paper manual are available for reference at the Electronic Data Service. Instructions for SPSS programming are in the manuals "SPSS Reference Guide," and "SPSS Base System User's Guide".

General Description

Because the version of Spss on cunix is so old, the only practical way to run it is in "batch mode." In batch mode, SPSS commands are executed from a file and output is sent to the screen or to an output file.

For example:

      spss -m  myprog.sps > myprog.lst

where "-m" is a "switch" (it says to run SPSS in batch mode), "myprog.sps" is your file of SPSS program statements, ">" is a standard UNIX directional command to send to output, and "myprog.lst" is your file for output. You can call the output file anything you want, but using the same name as the input file reduces confusion.

If the input file is very large and/or the program is going to take a long time to run, run it "in the background" by appending the "&" symbol after the command:

      spss -m  bigjob.sps > bigjob.lst  &

Now you can read your e-mail, do some other computer work, or go to lunch while the program is running.

Output from Batch Mode

SPSS will display some messages on your screen as it runs. Watch for them, but also check your output. Do not assume your program ran correctly just because no error messages appeared on the screen. Bring your output file into an editor (pico, emacs, vi) or view it by using the unix "more" command:

      more bigjob.lst

If there's a problem with your program, bring it back into an editor, make corrections, save the program, and run SPSS again. If you have lots of error messages, try fixing just the first one or two. They may be the cause of a lot of the subsequent error messages. If you are still stumped, send e-mail to eds@columbia.edu with the output file and we will help you.

Increasing Workspace

If your SPSS program has a large number of variables, variable values, or matrices, you may need to increase your workspace. The "-s" switch specifies the number of bytes SPSS uses as working space. The number is followed by k (kilobytes) or m (megabytes). For example:

      spss -m -s 2m  bigjob.sps > bigjob.lst  &

The default workspace is 256k. Note: A large number of cases usually will not require an increase in workspace since SPSS processes cases one by one.

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Sue Zayac
Electronic Data Service and CUIT
August, 2007