Plotting or real-time data with the Matplotlib animation API. Source: http://stackoverflow.com/a/15724978/183995

realtimeplot.py

#!/usr/bin/env python

import numpy as np
import time
import matplotlib
matplotlib.use('TKAgg')
#matplotlib.use('GTKAgg')
from matplotlib import pyplot as plt


def randomwalk(dims=(256, 256), n=20, sigma=5, alpha=0.95, seed=1):
    """ A simple random walk with memory """

    r, c = dims
    gen = np.random.RandomState(seed)
    pos = gen.rand(2, n) * ((r,), (c,))
    old_delta = gen.randn(2, n) * sigma

    while True:
        delta = (1. - alpha) * gen.randn(2, n) * sigma + alpha * old_delta
        pos += delta
        for ii in range(n):
            if not (0. <= pos[0, ii] < r):
                pos[0, ii] = abs(pos[0, ii] % r)
            if not (0. <= pos[1, ii] < c):
                pos[1, ii] = abs(pos[1, ii] % c)
        old_delta = delta
        yield pos


def run(niter=10000):
    """
    Display the simulation using matplotlib, using blit() for speed
    """

    fig, ax = plt.subplots(1, 1)
    ax.set_aspect('equal')
    ax.set_xlim(0, 255)
    ax.set_ylim(0, 255)
    ax.hold(True)
    rw = randomwalk()
    x, y = next(rw)

    plt.show(False)
    plt.draw()

    # cache the background
    background = fig.canvas.copy_from_bbox(ax.bbox)

    points = ax.plot(x, y, 'o')[0]
    tic = time.time()

    for ii in range(niter):

        # update the xy data
        x, y = next(rw)
        points.set_data(x, y)

        # restore background
        fig.canvas.restore_region(background)

        # redraw just the points
        ax.draw_artist(points)

        # fill in the axes rectangle
        fig.canvas.blit(ax.bbox)

    plt.close(fig)
    print("Average FPS: {:.2f}".format(niter / (time.time() - tic)))

if __name__ == '__main__':
    run()