Re: __gnuplot_set__ fails as function call 2.9.1

[Daniel J Sebald]

John W. Eaton wrote:
> Perhaps we should also eliminate __gnuplot_plot__ and
> __gnuplot_splot__ and only have a function to send commands to the
> gnuplot stream.  Then we can eliminate the (always doomed to be broken
> in some way or another) parser.  That would mean that you would have
> to write out the data files yourself:
>
>   x = (-10:0.01:10)';
>   data = [x, sin(x)];
>
>   [fid, name] = mkstemp (sprintf ("%s/XXXXXX", P_tmpdir), 1);
>   fprintf (fid, "%f %f\n", data');
>   fclose (fid);
>
> (though we might want to provide some convenience functions for the
> common types of files).
>
> then issue commands like
>
>   gnuplot (sprintf ("plot \"%s\" using 1:2\n", name));
>
> Of course, if you want to do something simple like this, you should be
> using "plot" instead, and then these details would be hidden from you
> and your scripts would continue to work even if Octave's default
> plotting engine changes to something other than gnuplot.
>
> Comments?

Could you please clarify the big picture on this?  My understanding was that instead of having a 
plotting device at the core of Octave, it would be moved to the "__plot__", etc. m-scripts.  There 
there could be any plotting utility.  So what this would require is a unique set of m-scripts for, 
say, gnuplot commands.  In those scripts would be a way to launch gnuplot and do the things you 
mention above.

I assume there will be other types of graphics packages put together this way.

But how then does someone indicate their selection of which plotting utility to use?  Is this 
something selected when installing?

How does one close gnuplot if it is launched from a plotting m file?  Is there to be some hook into 
Octave that can call a command upon exit, just like .octaverc?

Dan