Matplotlib pyplot show() doesn't work once closed

Question

I have a loop like this

#!/usr/bin/env python
import matplotlib.pyplot as p

for i in xrange(N):
    # Create my_image here

    # Display this image
    p.fi         


        

Answer 1

It might be from a bug in previous versions of matplotlib. I was having a similar problem when I issued sequential show() commands -- only the first would show (and stay); but, when I updated matplotlib to 1.0.1 the problem went away.

Answer 2

There might be a better way to animate imshow's, but this should work in a pinch. It's a lightly modified version of an animation example from the docs.

# For detailed comments on animation and the techniqes used here, see
# the wiki entry http://www.scipy.org/Cookbook/Matplotlib/Animations

import matplotlib
matplotlib.use('TkAgg')

import matplotlib.pyplot as plt
import matplotlib.mlab as mlab
import matplotlib.cm as cm

import sys
import numpy as np
import time

ax = plt.subplot(111)
canvas = ax.figure.canvas

delta=0.025
x=y= np.arange(-3.0, 3.0, delta)
x,y=np.meshgrid(x, y)
z1=mlab.bivariate_normal(x, y, 1.0, 1.0, 0.0, 0.0)
z2=mlab.bivariate_normal(x, y, 1.5, 0.5, 1, 1)
z=z2-z1  # difference of Gaussians

def run(z):
    fig=plt.gcf()
    for i in range(10):
        plt.imshow(z, interpolation='bilinear', cmap=cm.gray,
                  origin='lower', extent=[-3,3,-3,3])
        canvas.draw()
        plt.clf()
        z**=2

manager = plt.get_current_fig_manager()
manager.window.after(100, run, z)
plt.show()

Answer 3

I have long been looking into this problem and I may have a solution although I haven't thoroughly tested it yet.

The key is in writing code more like MatLab, name your figures and then call them to show().

eg.

 from matplotlib import pyplot as plt

 fig1 = plt.figure()
 fig2 = plt.figure()

 fig1.show()
 fig2.show()

This might work for animations and plotting at different stages

Answer 4

After tinkering around with unutbu's example, I found a behavior that I could normally and debug with PyDev where I could progressively see the plots.

import time, threading
import numpy
from matplotlib.pyplot import *

x = numpy.linspace(0, 10)
y = x**2

def main():
    plot(x, x)
    draw()
    time.sleep(2)
    plot(x, y)
    draw()

thread = threading.Thread()
thread.run = main

manager = get_current_fig_manager()
manager.window.after(100, thread.start)
figure(1)
show()