Extremely simple continuously animated line using Python and matplotlib

animate_line.py

import numpy as np
from collections import deque

import matplotlib.pyplot as plt
import matplotlib.animation as animation


class AnalogPlot:
    def __init__(self, data, display_len):
        self.buff = deque([0.0]*display_len)
        self.display_len = display_len
        self.data = data

    def add_to_buff(self, buf, val):
        if len(buf) < self.display_len:
            buf.append(val)
        else:
            buf.pop()
            buf.appendleft(val)

    def update(self, frame, a0, ax):
        self.add_to_buff(self.buff, self.data[frame:frame+1])
        a0[0].set_data(range(self.display_len), self.buff)

        ax.set_xticklabels((str(frame), str(frame+self.display_len)))

        return a0



def main():

    t_max = 100
    sin_sig = np.sin(np.linspace(0, 20*np.pi, 1000))
    analog_plot = AnalogPlot(sin_sig, t_max)

    # set up animation
    fig = plt.figure()
    ax = fig.add_subplot(111, xlim=(0, t_max), ylim=(-1, 1))
    ax.set_xticks((0,t_max))
    a0 = ax.plot([], [])
    anim = animation.FuncAnimation(fig, analog_plot.update, 
                                   fargs=(a0, ax), 
                                   interval=1.0)

    plt.show()


if __name__ == '__main__':
    main()