matplotlib-users

[Matplotlib-users] slowdown when using pcolor and TkAgg; help?

[Russell E. O. <ro...@ce...>]

I have appended some code which draws a varying pcolor plot in a Tkinter 
window. The plot shows two 5x5 white rings which shrink to 3x3 and then 
1x3, then cycles through this repeatedly.

Unfortunately, it slows down with each cycle!!!

Are we doing something wrong? Or can we work around the problem somehow?

(By the way, I did not write the code, though I cleaned up some portions 
of it. I realize the data generation can be cleaned up, but it's not 
slowing things down).

-- Russell

P.S. At risk of distracting from the main problem: I am not entirely 
sure I'm commanding a redraw in the correct fashion. I'm fuzzy on the 
difference between show and plot. Using canvas.show() and canvas.plot() 
both seem to work. Just calling plot() doesn't. Any hints on this or 
pointers to documentation would be appreciated.

Also, is pcolor documented anywhere?

----- the code -----

import Tkinter as Tk
from matplotlib.pylab import *
import matplotlib.numerix as num
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, 
NavigationToolbar2TkAgg

root = Tk.Tk()
a =[ [0,1,2,3,4,5,6,\
90,91,92,93,94,95,96,15,30,45,\
60,75,21,36,51,66,81,\
8,9,10,11,12,13,14,98,99,\
100,101,102,103,104,\
23,38,53,68,83,29,44,59,74,89],\
[16,17,18,19,20,76,77,78,79,80,35,50,65,\
31,46,61,24,25,26,27,28,\
84,85,86,87,88,39,54,69,43,58,73],\
[32,33,34,62,63,64,47,49,40,41,42,\
70,71,72,55,57],\
[48,56] ]

ioff()
f = figure(figsize=(3,3))
sp = f.add_subplot(111)
canvas = FigureCanvasTkAgg(f, master=root)
canvas.get_tk_widget().pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)

def displayData(maxCount=20, delayTimeMS=20, count=0):
    fx = count % len(a)
    a[fx].sort()
    ra = []
    cnt = 0
    v = a[fx][cnt]
    for i in range(15*15):
        if i == v:
            ra.append(1)
            cnt += 1
            if cnt < len(a[fx]):
                v = a[fx][cnt]

        else:
            ra.append(0)

    z = num.reshape(ra, (15,15))
    sp.pcolor(transpose(z), cmap=cm.gray, norm=normalize())
    canvas.draw()
    count += 1
    if count < maxCount:
        root.after(delayTimeMS, displayData, maxCount, delayTimeMS, 
count)

displayData(maxCount=100, delayTimeMS=20)
root.mainloop()

Re: [Matplotlib-users] slowdown when using pcolor and TkAgg; help?

[Perry G. <pe...@st...>]

My guess is that the hold mode is true (that's the default). I think 
this means that every time you call .pcolor that you are just appending 
another one to the axes. You should either change the default hold mode 
or call the .clear() method of the axes object before calling the 
.pcolor method. If you don't do that it is rendering n previous 
versions and the time it takes grows linearly.

Perry

On Mar 16, 2005, at 2:47 PM, Russell E. Owen wrote:

> I have appended some code which draws a varying pcolor plot in a 
> Tkinter
> window. The plot shows two 5x5 white rings which shrink to 3x3 and then
> 1x3, then cycles through this repeatedly.
>
> Unfortunately, it slows down with each cycle!!!
>
> Are we doing something wrong? Or can we work around the problem 
> somehow?
>
> (By the way, I did not write the code, though I cleaned up some 
> portions
> of it. I realize the data generation can be cleaned up, but it's not
> slowing things down).
>
> -- Russell
>
> P.S. At risk of distracting from the main problem: I am not entirely
> sure I'm commanding a redraw in the correct fashion. I'm fuzzy on the
> difference between show and plot. Using canvas.show() and canvas.plot()
> both seem to work. Just calling plot() doesn't. Any hints on this or
> pointers to documentation would be appreciated.
>
> Also, is pcolor documented anywhere?
>
> ----- the code -----
>
> import Tkinter as Tk
> from matplotlib.pylab import *
> import matplotlib.numerix as num
> from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg,
> NavigationToolbar2TkAgg
>
> root = Tk.Tk()
> a =[ [0,1,2,3,4,5,6,\
> 90,91,92,93,94,95,96,15,30,45,\
> 60,75,21,36,51,66,81,\
> 8,9,10,11,12,13,14,98,99,\
> 100,101,102,103,104,\
> 23,38,53,68,83,29,44,59,74,89],\
> [16,17,18,19,20,76,77,78,79,80,35,50,65,\
> 31,46,61,24,25,26,27,28,\
> 84,85,86,87,88,39,54,69,43,58,73],\
> [32,33,34,62,63,64,47,49,40,41,42,\
> 70,71,72,55,57],\
> [48,56] ]
>
> ioff()
> f = figure(figsize=(3,3))
> sp = f.add_subplot(111)
> canvas = FigureCanvasTkAgg(f, master=root)
> canvas.get_tk_widget().pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)
>
> def displayData(maxCount=20, delayTimeMS=20, count=0):
>     fx = count % len(a)
>     a[fx].sort()
>     ra = []
>     cnt = 0
>     v = a[fx][cnt]
>     for i in range(15*15):
>         if i == v:
>             ra.append(1)
>             cnt += 1
>             if cnt < len(a[fx]):
>                 v = a[fx][cnt]
>
>         else:
>             ra.append(0)
>
>     z = num.reshape(ra, (15,15))
>     sp.pcolor(transpose(z), cmap=cm.gray, norm=normalize())
>     canvas.draw()
>     count += 1
>     if count < maxCount:
>         root.after(delayTimeMS, displayData, maxCount, delayTimeMS,
> count)
>
> displayData(maxCount=100, delayTimeMS=20)
> root.mainloop()
>
>
>
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Re: [Matplotlib-users] slowdown when using pcolor and TkAgg; help?

[John H. <jdh...@ac...>]

>>>>> "Perry" == Perry Greenfield <pe...@st...> writes:

    Perry> My guess is that the hold mode is true (that's the
    Perry> default). I think this means that every time you call
    Perry> .pcolor that you are just appending another one to the
    Perry> axes. You should either change the default hold mode or
    Perry> call the .clear() method of the axes object before calling
    Perry> the .pcolor method. If you don't do that it is rendering n
    Perry> previous versions and the time it takes grows linearly.

Good catch Perry.  You need

sp.hold(False)

    >> P.S. At risk of distracting from the main problem: I am not
    >> entirely sure I'm commanding a redraw in the correct
    >> fashion. I'm fuzzy on the difference between show and
    >> plot. Using canvas.show() and canvas.plot() both seem to
    >> work. Just calling plot() doesn't. Any hints on this or
    >> pointers to documentation would be appreciated.


Se  http://matplotlib.sourceforge.net/faq.html#SHOW


    >> Also, is pcolor documented anywhere?

From the python shell

  In [1]: fig = figure()
  In [2]: sp = fig.add_subplot(111)
  In [3]: help(sp.pcolor)

All the class docs can be found at
http://matplotlib.sourceforge.net/classdocs.html.  In particular,
http://matplotlib.sourceforge.net/matplotlib.axes.html#Axes-pcolor

    >> ----- the code -----

Your code was improperly line wrapped and hence I had to edit it to
test it.  Please check that when you paste code in, it does not
improperly wrap.

Hope this helps,
JDH

[Matplotlib-users] Re: slowdown when using pcolor and TkAgg; help?

[Russell E. O. <ro...@ce...>]

In article <m3r...@pe...>,
 John Hunter 
 <jdh...@ac...> wrote:

> >>>>> "Perry" == Perry Greenfield 
> >>>>> <pe...@st...> writes:
> 
>     Perry> My guess is that the hold mode is true (that's the
>     Perry> default). I think this means that every time you call
>     Perry> .pcolor that you are just appending another one to the
>     Perry> axes. You should either change the default hold mode or
>     Perry> call the .clear() method of the axes object before calling
>     Perry> the .pcolor method. If you don't do that it is rendering n
>     Perry> previous versions and the time it takes grows linearly.
> 
> Good catch Perry.  You need
> 
> sp.hold(False)

Thank you both very much. That did the trick. I put a hold on the figure 
and then a hold(False) on the one axis for which I wanted it and all 
works well now.

>     >> P.S. At risk of distracting from the main problem: I am not
>     >> entirely sure I'm commanding a redraw in the correct
>     >> fashion. I'm fuzzy on the difference between show and
>     >> plot. Using canvas.show() and canvas.plot() both seem to
>     >> work. Just calling plot() doesn't. Any hints on this or
>     >> pointers to documentation would be appreciated.
> 
> See  http://matplotlib.sourceforge.net/faq.html#SHOW

Thanks. That was helpful -- though also a bit confusing, in that I'm 
using the TkAgg back end and calling pylab.draw() doesn't update 
anything visible on my FigureCanvasAgg object. (As an aside, calling 
show() on my FigureCanvasAgg object seems to work -- the code originally 
did that when I got it -- but the manual and FAQ clearly point to using 
draw instead).

>     >> Also, is pcolor documented anywhere?
>...
> All the class docs can be found at
> http://matplotlib.sourceforge.net/classdocs.html.  In particular,

That's what I was really missing. Thanks! Now that I know about it, I'm 
not sure how I missed it the first time. Oh well...

-- Russell

Re: [Matplotlib-users] Re: slowdown when using pcolor and TkAgg; help?

[John H. <jdh...@ac...>]

>>>>> "Russell" == Russell E Owen <ro...@ce...> writes:

    Russell> Thanks. That was helpful -- though also a bit confusing,
    Russell> in that I'm using the TkAgg back end and calling
    Russell> pylab.draw() doesn't update anything visible on my
    Russell> FigureCanvasAgg object. (As an aside, calling show() on
    Russell> my FigureCanvasAgg object seems to work -- the code
    Russell> originally did that when I got it -- but the manual and
    Russell> FAQ clearly point to using draw instead).

I looked back over the code you posted previously and see that you are
using the API, eg making your own tk canvases.  In this case you
should not import pylab at all.  Do everything from the class API.
Call canvas.draw() rather than pylab.draw().

You can still use matplotlib.numerix to get all the Numeric/numarray
symbols, but the pylab interface doesn't mix well with the API
interface because pylab tries to manage figure creation and
destruction for you.

Instead of

  f = figure(figsize=(3,3))  # this is a pylab call
  sp = f.add_subplot(111)
  canvas = FigureCanvasTkAgg(f, master=root)

do 

from matplotlib.figure import Figure

  f = Figure(figsize=(3,3))  # this is an API call
  sp = f.add_subplot(111)
  canvas = FigureCanvasTkAgg(f, master=root)

See also examples/agg_oo.py and this post for a tutorial introduction
the matplotlib API

  http://sourceforge.net/mailarchive/message.php?msg_id=11033442

Hope this helps,
JDH