How to prevent freezing of plot window using qtOctave

( 8 Votes )

As the title says, each time I'm using plot function in qtOctave, plot window will show and draws successfully, but after that it will be always not responding. It means: I cannot touch to this again, and must shut down it.

Instead using plot in Octave it works properly.

Beside each time I use plot in qtOctave (not responding and close it), if I close qtOctave principal window it crashes too.

Actually the reason behind this problem is default graphics toolkit fltk or qt. qtOctave works with pipe, fltk doesn't support pipe. The solution is change default toolkit to gnuplot.

To check wich is your default tookit you have to type 


in qtOctave command line. From release 3.4.x of Octave default is fltk.

To switch the graphics toolkit to gnuplot only for the current work session you just have to type in command line:


While, in order to set up gnuplot as default, you have to edit the related row in the file named octaverc; you can find it in

(location of your octave directory)/share/octave/site/m/startup

I hope it could be usefull, pay attention at the difference between qtOctave and Octave in the text.