Re: gnuplot zoom not functioning anymore in octave 2.9.10

[John W. Eaton]

On  6-Apr-2007, Francesco Potorti` wrote:

| >| This is quite a serious problem,
| >
| >I think a more serious problem was that Octave's plotting functions
| >were not compatible with Matlab.
| 
| In the long term, you are probably right :-(
| 
| >Precisely what feature of the old plot function are you missing that
| >seems essential?
| 
| I would simply like to have old scripts continue to plot the same way.
| As an example, look at <http://wnet.isti.cnr.it/software/damatfrc>.  You
| see a plot there, where the line colours are automatic, while the dot
| colours are chosen to match those of the lines.  Once 2.9.10 becomes the
| current version and I upgrade my system, that page will look ugly.
| 
| If I add text to that page making reference to the line colours as they
| are and to dots which are the same colours as the relevant lines, the
| text will become wrong.

I think the plotting part of your script is just a few lines:

  __gnuplot_raw__(sprintf("set terminal %s size %d,%d%s;\n",
                          fmt, imgw, imgh, imgd));
  __gnuplot_raw__(sprintf("set output \"%s\";\n", imgfilename));
  __gnuplot_raw__("set key left top;\n");
  plot(x, out, ";;", delayx, delayy, ";delay;",
       Frtime, tfrc(Frtime), "*g;feedback reports;",
       Datime, dama(Datime), "ob;DAMA allocations;");

The __gnuplot_raw__ commands will no longer do what you want, and I
think that we have been telling people for a long time now that these
commands are for internal use only (that's why they have the __x__
names) and that they are subject to change or removal.

I think the plot command itself will work much the same as before,
though the default color sequence for lines may have changed (but that
was always a potential problem with gnuplot anyway, which used to have
the possibility of using different colors for different terminal
types).

To make this code work completely with the new version of Octave, you
would need to write it as something like

  figure ("visible", "off");
  plot (x, out, ";;", delayx, delayy, ";delay;",
        Frtime, tfrc(Frtime), "*g;feedback reports;",
        Datime, dama(Datime), "ob;DAMA allocations;");
  legend (2);
  print (imgfilename, "-dpng");

I don't see that this is a significant problem given all the other
benefits.  We are talking about a MAJOR new version of Octave.  Think
of 2.9.10 as a 3.0 release candidate, not just a new point release.

| Same would happen to descriptions of plots with the 2.9.9 default
| legend.

You mean the "line 1", "line 2", ... legend?  I think that many more
people complained about that and asked how to turn it off than ever
said it was a good feature.

| I understand that your change is probably the right way to go everything
| considered, yet I would like to have a way to keep the old behaviour for
| existing scripts...

You can always use an older version of Octave that does what you
prefer.

jwe