RE : RE : RE : [matplotlib-devel] Re: Speed of dynamic_image

[Gregory L. <gre...@ff...>]

> > You are right, I should definitely install pygtk on my 
> system to check 
> > that, I wonder how a 3X increase in FPS is possible: after all, 
> > de-activating blit in the TkAgg produce only a 1.5X 
> increase (and no 
> > image of course ;-) ): something else than Agg must hold Tk 
> (and Fltk) 
> > back then: I have to test the FPS one have without Agg drawing and 
> > blitting, only canvas update, with GTK, Tk and Fltk, to be sure...
> > 
> I guess I'm surprised at that. How are you disabling the 
> blit? If no blit is being done, where else is the time going 
> if not for agg?

In the draw method of the FigureCanvasTkAgg class (in
matplotlib/backends/backend_tkagg.py file), I just commented out the
second line, going from:

def draw(self):
        FigureCanvasAgg.draw(self)
        tkagg.blit(self._tkphoto, self.renderer._renderer, 2)
        self._master.update_idletasks()


To:


def draw(self):
        FigureCanvasAgg.draw(self)
        #tkagg.blit(self._tkphoto, self.renderer._renderer, 2)
        self._master.update_idletasks()

This makes the image dissapear from screen of course, but still draw the
image in the in-memory Agg buffer...and ask the Tk canvas to redraw
itself (allways with the same empty image), I guess...so I indeed
suspect that the Tk canvas updating is causing the slow down somehow...I
will check that tomorrow for sure! 

Greg, puzzled too ;-)