This filters created in this directory may be tested (at NCAR) as follows:

  ctrans -d ps.color ps.input.file > ps.output.file
  psblack < ps.output.file > ps.output.file.black
  pswhite < ps.output.file > ps.output.file.white
  ps.imagen ps.output.file
  ps.imagen ps.output.file.black
  ps.imagen ps.output.file.white
  rm ps.output.file*

It is questionable how valuable this test is, since these filters are only
intended for use with 3.00 and older metafiles.  It does verify that they
compile and execute.

The expected appearance of the plots is as follows:

  ps.output.file       - a zig-zag line, some plus signs arranged in a
			 zig-zag pattern, a nonagon, a rectangular
			 checkerboard, and the words "Example string,
			 centered in the center".
  ps.output.file.black - a rectangular checkerboard in white on black
  ps.output.file.white - a rectangular checkerboard in black on white
