pcolor and "interp" [changeset-2]

[John W. Eaton]

On  2-Oct-2008, Ben Abbott wrote:

| Trying again. This time with the facecolor bug reported by Michael  
| included.

OK, I thought I had made the change, checked it in, and pushed it, but
I must have forgotten to push.  In any case, your latest changes
should be in the public archive now.

Now I see that for something like

  pcolor (peaks ())
  shading interp

I get an all green plot.  I'm using gnuplot 4.2.2.  I assumed that it
would just fail to do the interpolation, but now the plot changes to
something completely wrong.  I'm a bit surprised by that as I thought
the previous behavior was that "shading interp" simply had no effect.

However, if fixing this means distinguishing between versions of
gnuplot, then I think we should just not worry about it and encourage
the use of the fixed gnuplot.  OTOH, maybe it would be better for us
to do the version check if it is likely that Octave 3.2 is release
before a version of gnuplot with the fix is also released.

Thanks,

jwe