File:Fold catastrophe animation.gif

from mpl_toolkits import mplot3d import numpy as np import matplotlib.pyplot as plt import matplotlib.animation as animation

video_length = 10 # in seconds video_fps = 30 num_frames = video_fps * video_length angle_per_frame = (360 / num_frames)

stride = 5 width = 3

a = np.linspace(-width, width, 500) b = a x, y = np.meshgrid(a, b) z = -y**2- 0.1 * x**4

plt.tick_params(left = False) fig = plt.figure(figsize= (10,10)) ax = plt.axes(projection ='3d') frame = ax.plot_wireframe(x, y, z, color ='#4a5a90', rstride=stride, cstride=stride)

def init():

   ax.set_box_aspect((1,1,1))
   ax.view_init(0, -90)
   ax.axis('off')
   ax.set_xlim(-1,1)
   ax.set_ylim(-1,1)
   ax.set_zlim(-1, 1)
   return frame,

1. animation function. This is called sequentially

def animate(i):

   ax.view_init(angle_per_frame * i, -90)
   return frame,

1. call the animator. blit=True means only re-draw the parts that have changed.

anim = animation.FuncAnimation(fig, animate, init_func=init,

                              frames=num_frames, blit=True)

anim.save('fold.mp4', fps=video_fps, extra_args=['-vcodec', 'libx264'])

plt.show()