Always not responding/freeze when use plot with QtOctave

Question

I'm new here. I've the same matter as this one but only using QtOctave; beside oct2mat pkg hasn't never been loaded on my pc. Typing:

pkg unload oct2mat

octave returns:

error: package oct2mat is not installed error: \share\octave\3.6.2\m\pkg\pkg.m at line 2170, column 9

Using plot function directly in Octave it works properly, very stange!

Can enybody help me? Thanks in advance.

Is this happening under Windows or another operating system? Please specify. — s-m-e, Dec 14 '12 at 21:15
This solution for El Capitan worked for me: http://stackoverflow.com/questions/35249881/octave-fontconfig-error/36259664#36259664 — kslstn, Jul 19 '16 at 07:08

score 2 · Answer 1 · edited May 23 '17 at 11:53

Addendum to @vinukn's answer, as it might be too cryptic.

Try this:

>>> graphics_toolkit
ans = fltk
>>> agts = available_graphics_toolkits
agts = 
{
  [1,1] = fltk
  [1,2] = gnuplot
}
>>> graphics_toolkit(agts{2})   % This sets the graphics toolkit.
>>> plot([1 2 3 4])

That is, the default was FLTK, and I've set Gnuplot. Try each, they look slightly different to each other.

This is on my default installation of Octave 3.6.2 on Windows Vista, with QtOctave. (I've tried the most recent build of Octave, with built-in GUI, but after starting it never drew in its windows, so it was unusable at this stage, which is a shame as there are probably a handful of lines of code that need to be changed to make it work... Will wait until that is fixed. In the meantime, Gnuplot doesn't freeze.)

Also, here is a list of keys to use in the Gnuplot window. Especially note:

Right-click to draw a zoom box.
a to autoscale (back to default zoom).
p to go back to the most recent previous zoom.

score 1 · Answer 2 · answered Dec 14 '12 at 22:28

Don't use QtOctave. It has been deprecated for a reason. See the GUI section in Octave FAQ to understand why the GUI doesn't work. It is specially true for things such as plots and dialog windows.

Take special note on the fact that QtOctave and others are specially sensitive to new versions of Octave. You are using Octave 3.6.2 while QtOctave was abandoned back in 3.2.X. Your options are (by order of what I recommend):

use Octave on its own, no QtOctave;
build from development sources to use the experimental GUI;
fix QtOctave (I actually don't recommend this one at all. Its website has been closed, and it would be too much work which would be better spent helping the Octave developers with the native GUI);

score 1 · Answer 3 · answered Dec 24 '12 at 16:23

Actually,the reason behind this problem is default graphics toolkit fltk or qt. Qtoctave works with pipe, fltk does nt support pipe, ie fltk works inside octave. Pipe does nt support both text and image(gui) same time. The solution is change default toolkit to gnuplot.

Always not responding/freeze when use plot with QtOctave

3 Answers3