Re: Plotting with 3.2.0 on Windows is SLOOOOOOWWWW

[John W. Eaton]

On 29-Jul-2009, Tatsuro MATSUOKA wrote:

| MMMMM It is really slow as you pointed out

Is it any faster if you make the following change?  This way,
communication with gnuplot will be one-way, using popen instead of
popen2.  However, some features will be disabled (anything that
requires getting information back from the gnuplot subprocess will
likely fail).  If you can determine that using popen2 is the cause of
the performance problem, then maybe the function that needs to be
fixed is octave_popen2 in liboctave/lo-sysdep.cc.  But I'm not a
Windows expert, so I have no clue if that is correct, or if it is,
what should be done, so someone else will have to work on this
problem.

jwe

diff --git a/scripts/plot/gnuplot_drawnow.m b/scripts/plot/gnuplot_drawnow.m
--- a/scripts/plot/gnuplot_drawnow.m
+++ b/scripts/plot/gnuplot_drawnow.m
@@ -79,7 +79,7 @@
     ##  Graphics terminal for display.
     plot_stream = get (h, "__plot_stream__");
     if (isempty (plot_stream))
-      plot_stream = __gnuplot_open_stream__ (2, h);
+      plot_stream = __gnuplot_open_stream__ (1, h);
       new_stream = true;
     else
       new_stream = false;