3d.py

# -*- coding: utf-8 -*-
# https://eli.thegreenplace.net/2016/drawing-animated-gifs-with-matplotlib/
import sys
import seaborn
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation

fig, ax = plt.subplots()
fig.set_tight_layout(True)

# Query the figure's on-screen size and DPI. Note that when saving the figure to
# a file, we need to provide a DPI for that separately.
print('fig size: {0} DPI, size in inches {1}'.format(
    fig.get_dpi(), fig.get_size_inches()))

# Plot a scatter that persists (isn't redrawn) and the initial line.
x = np.arange(0, 20, 0.1)
ax.scatter(x, x + np.random.normal(0, 3.0, len(x)))
line, = ax.plot(x, x - 5, 'r-', linewidth=2)

def update(i):
    label = 'timestep {0}'.format(i)
    print(label)
    # Update the line and the axes (with a new xlabel). Return a tuple of
    # "artists" that have to be redrawn for this frame.
    line.set_ydata(x - 5 + i)
    ax.set_xlabel(label)
    return line, ax

if __name__ == '__main__':
    # FuncAnimation will call the 'update' function for each frame; here
    # animating over 10 frames, with an interval of 200ms between frames.
    anim = FuncAnimation(fig, update, frames=10, interval=200)
    if len(sys.argv) > 1 and sys.argv[1] == 'save':
        anim.save('line.gif', dpi=80, writer='imagemagick')
    else:
        # plt.show() will just loop the animation forever.
        plt.show()