[ 969322 ] Set Missing problem with gnuplot 4.0

[Daniel J S. <dan...@ie...>]

I put a patch on

[ 969322 ] Set Missing problem with gnuplot 4.0

to address this bug.  Probably the best person to look at this is Ethan because he is familiar with that section of datafile code and could tell in a second if it is the correct thing to do.

Be sure to try behavior for with and without "?" set as the missing character for data files.  (See the text associated with the bug report.)  I've made it work the way that seems logical to me, e.g., if the user specifies a using field AND the missing character is not specified then it is treated as DF_UNDEFINED as opposed to simply ignoring the data point.

Really, there is the flexibility with DF_UNDEFINED and DF_MISSING, etc. to program it fairly easily to be any behavior.

I'll attach the patch here as well because I can't attach it to someone elses bug report and don't want to create another that references it.

There is the issue of what to do with 3D data, but let's address that after 2D.

Dan