Introduction

Interactive programs have obvious advantages. The ability to see the results of a job immediately, and to be able to modify the parameters and try it again are just a couple. At SEP we have the hardware necessary to do a lot of interactive work, but only a small fraction of our software is interactive. Interactive programs are very time-consuming to write, and a programmer needs to know a lot about the particular software environment he is using (Sunview, X Windows, InterViews, etc.) before he can even get started. The result is that we have a few very nice but highly specialized interactive programs. For most of our work, we run in a ``batch'' mode. This means editing some file containing the names of programs and their parameters, launching a job, and waiting for the results. Thanks to SEP's vplot graphics system (see Cole and Dellinger, 1989), batch processing can be reasonably efficient. I can launch a job, see the results on my workstation screen, go back and change some parameters in a file, and try it again. When I'm happy with the results, I can send them off to a printer. But the process is still rather cumbersome if I want to experiment with different programs or parameters very much.