Re: gnuplot functionallity in octave

[Olaf Till]

On Fri, Mar 19, 2010 at 12:27:52PM +0100, address@hidden wrote:
> Hello,
> 
> I just gave a colleague of mine a printed German Gnuplot tutorial
> (prepared by the computer center of Hannover, Germany). Actually he is
> working with a variety of lab devices. So he's dealing with many kinds of
> ascii data and has to create publication-ready plots.
> 
> I suggested him to use Octave because it might be more comfortable when it
> comes to data manipulation or some calculations. Although he was very
> interested, he was unsure about my suggestion since his English is not
> that good.
> 
> My question: Since until now I have not created plots for publishing
> through Octave is it in general possible to access all the functionallity
> of gnuplot via Octave? And, will the German Gnuplot manual still be
> helpfull for him?

I do not know if current Octave versions allow to control all Gnuplot
features with high level commands. But there were not all features
controllable previously, e.g. font size of tick-labels, if I remember
right. Some, including myself, use(d) to send Gnuplot commands
directly to Gnuplot from Octave to obtain publication-quality figures
of plots, similar to that, e.g.:


ofile = "figure.eps";
scale = .75;
settings = ["unset key\n", \
            "set xlabel 'independent variable [unit]'\n", \
            "set ylabel 'dependent variable'\n", \
            "set xrange [0:]\n", \
            sprintf ("setsize %f,%f\n", scale, scale)];
fmt = "with lines linetype 1 linewidth 3";

gnupl_fid = popen ("gnuplot - &> /dev/null", "w");
fprintf (gnupl_fid, settings);
fprintf (gnupl_fid, "set terminal postscript eps enhanced monochrome 22\n");
fprintf (gnupl_fid, sprintf ("set output '%s'\n", ofile));

n = ...; # number of traces in the plot

fprintf (gnupl_fid, sprintf ("plot '-' %s%s\n", fmt, \
                             repmat \
                             (sprintf (", '-' %s", fmt), 1, n - 1)));

for id = 1:n

  data = ...; # prepare your data, x in row 1, y in row 2
  fprintf (gnupl_fid, "%.16f %.16f\n", data);
  fprintf (gnupl_fid, "e\n");

endfor

fprintf (gnupl_fid, "exit\n");
pclose (gnupl_fid);


Note also that Etienne Grossmann has written Octave functions which
facilitate such a communication with Gnuplot. They are available at
his homepage.

So, with the above approach, the German Gnuplot manual _will_ be
useful for your colleague ...

Olaf