Time-scrolling interface in matplotlib

Question

I've create a simple interface for viewing a time-series as it changes over time in matplotlib. You can pause, reset or click/drag on the time-line to change the view. Have I used the matplotlib API as effectively as possible?

import numpy as np
from collections import deque
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from matplotlib.widgets import Button, Slider
class AnalogPlot:
 def __init__(self, data, display_len):
 self.buff = deque(np.zeros(display_len))
 self.display_len = display_len
 self.data = data
 # set up the plot
 self.fig = plt.figure()
 self.ax = self.fig.add_subplot(111, xlim=(0, t_max), ylim=(-1, 1))
 self.ax.set_xticks((0, t_max))
 self.lines = self.ax.plot([], [])
 # setup the animation
 self.cur_frame = 0
 self.anim = animation.FuncAnimation(self.fig, self._update,
 interval=1.0)
 # setup the animation control
 self.anim_running = True
 def _add_to_buff(self, buf, val):
 if len(buf) < self.display_len:
 buf.appendLeft(val)
 else:
 buf.popleft()
 buf.append(val)
 def _update(self, frame):
 frame = self.cur_frame
 self._add_to_buff(self.buff, self.data[frame:frame+1])
 self.lines[0].set_data(range(self.display_len), self.buff)
 self.ax.set_xticklabels((str(frame), str(frame+self.display_len)))
 self.time_slider.eventson = False
 self.time_slider.set_val(frame)
 self.time_slider.eventson = True
 self.cur_frame += 1
 return self.lines
 def _pause(self, event):
 if self.anim_running:
 self.anim.event_source.stop()
 self.anim_running = False
 else:
 self.anim.event_source.start()
 self.anim_running = True
 def _reset(self, event):
 self._set_val(0)
 def _set_val(self, frame=0):
 frame = int(frame)
 self.cur_frame = frame
 new_start = frame - self.display_len
 if new_start >= 0:
 self.buff = deque(self.data[new_start:frame])
 else:
 self.buff = deque(np.concatenate((np.zeros(np.abs(new_start)),
 self.data[:frame])))
 self.anim.event_source.stop()
 self.anim = animation.FuncAnimation(self.fig, self._update,
 interval=1.0)
 self.anim_running = True
 def animate(self):
 pause_ax = self.fig.add_axes((0.7, 0.025, 0.1, 0.04))
 pause_button = Button(pause_ax, 'pause', hovercolor='0.975')
 pause_button.on_clicked(self._pause)
 reset_ax = self.fig.add_axes((0.8, 0.025, 0.1, 0.04))
 reset_button = Button(reset_ax, 'reset', hovercolor='0.975')
 reset_button.on_clicked(self._reset)
 slider_ax = self.fig.add_axes((0.1, 0.025, 0.5, 0.04))
 self.time_slider = Slider(slider_ax, label='Time',
 valmin=0, valmax=self.data.shape[0],
 valinit=0.0)
 self.time_slider.on_changed(self._set_val)
 plt.show()
t_max = 100
lin_sig = np.linspace(0, 1, 1000)
analog_plot = AnalogPlot(lin_sig, t_max)
analog_plot.animate()

Answer 1

Looks good to me.

Ship it.

(Consider using flake8, and burying the last four lines within if __name__ == '__main__':.)