This is more for CPAN-testers than anything else
Previously, 2D implicit domains would be explicitly created by PDL::Graphics::Gnuplot, and passed on down to the plotter. This is ineffient. This patch lets gnuplot construct the matrix. This is faster and allows contours to work. ASCII-only matrix support in this patch.
As a result, it's possible to make 2d plots that have a 2d implicit grid domain (useful for color maps)
When testing a plot command, some arbitrary data is sent to gnuplot. If the user asked for particular plot bounds (xmin, etc) then it was possible for the test plot to fail if the arbitrary data was out of bounds. I now have a whitelist of errors that are allowed during plot testing, and this error is now on that list. Furthermore, because I have this whitelist, I removed the extra logic that was a part of the tests, as it's unnecessary. Previously tests sent plot whatever; print 'xxxxxxx'; The print only runs if gnuplot thought the plot succeeded, so I was looking for the print output. I no longer need this. I simply run the plot, clear out any known errors, and barf if anything remains.
This allows an uninteresting case to produce uninteresting plots instead of failing