Matplotlib: simultaneous plotting in multiple threads

Why not just use multiprocessing? As far as I can tell from your description, threading won’t help you much, anyway…

Matplotlib already threads so that you can display and interact with multiple figures at once. If you want to speed up batch processing on a multicore machine, you’re going to need multiprocessing regardless.

As a basic example (Warning: This will create 20 small .png files in whatever directory you run it in!)

import multiprocessing
import matplotlib.pyplot as plt
import numpy as np

def main():
    pool = multiprocessing.Pool()
    num_figs = 20
    input = zip(np.random.randint(10,1000,num_figs), 
                range(num_figs))
    pool.map(plot, input)

def plot(args):
    num, i = args
    fig = plt.figure()
    data = np.random.randn(num).cumsum()
    plt.plot(data)
    plt.title('Plot of a %i-element brownian noise sequence' % num)
    fig.savefig('temp_fig_%02i.png' % i)

main()