Hi Eric,

Thanks for your work on this.  I've tried your latest changes and I
think they're a big improvement.

I've attached another org-mode file for you to try.  It illustrates
the use of double blank lines in the first table (called block_data)
to inform gnuplot that there're two separate data sets in the single
data file.  The first code block (gnuplot_1) plots these two data sets
as red and green surfaces.  It's really nice that gnuplot can now be
used in this way from within org-mode.

One slight drawback, however, is that there still doesn't seem to be a
way to specify missing values in the org table in the way they're
frequently used by gnuplot.  An illustration of what I mean by this is
given in the table block_data_missing in the attached org file.
You'll see that I've inserted two '?' characters for missing z-values.
 If you execute the second and third code blocks (gnuplot_2 and
gnuplot_3) you'll see that neither give the desired result.

If the block_data_missing table were exported exactly as it is except
for the removal of the '|' characters and "set datafile missing '?'"
were specified in the gnuplot script this would enable gnuplot to plot
the red and green surfaces with the missing values.  To see this try
executing the last code block (gnuplot_4) which plots the data which
is first "cleaned" by the shell command you suggested in a previous
post.  This would also remove the need to have the :missing header
argument.

Kind regards,

Paul