Quasicrystals in Python

quasicrystal.py

# -*- coding: utf-8 -*-
import bohrium as np
from math import pi
import matplotlib.pyplot as plt
import matplotlib.colors as colors

fig = plt.figure()
plt.xticks([])
plt.yticks([])

k       = 5    # number of plane waves
stripes = 37   # number of stripes per wave
N       = 512  # image size in pixels
ite     = 30   # iterations
phases  = np.arange(0, 2*pi, 2*pi/ite)

image = np.empty((N, N))

d = np.arange(-N/2, N/2, dtype=np.float64)

xv, yv = np.meshgrid(d, d)
theta  = np.arctan2(yv, xv)
r      = np.log(np.sqrt(xv*xv + yv*yv))
r[np.isinf(r) == True] = 0

tcos   = theta * np.cos(np.arange(0, pi, pi/k))[:, np.newaxis, np.newaxis]
rsin   = r * np.sin(np.arange(0, pi, pi/k))[:, np.newaxis, np.newaxis]
inner  = (tcos - rsin) * stripes

cinner = np.cos(inner)
sinner = np.sin(inner)

i = 0
for phase in phases:
    image[:] = np.sum(cinner * np.cos(phase) - sinner * np.sin(phase), axis=0) + k
    plt.imshow(image.copy2numpy(), cmap="RdGy")
    fig.savefig("quasi-{:03d}.png".format(i), bbox_inches='tight', pad_inches=0)
    i += 1

It's actually quite practical. The duration basically sets the speed of your gif (since it is looping) so it makes sense. As long as you are testing the animation, you make the rendering very quick by setting the fps to 5, and when you are happy with the result you set the fps to 30 and get a final, much fluider gif.

If you want to control the number of frames, is see these solutions:

• Set the fps automatically to n_frames / duration
• Use MoviePy's ImageSequenceClip, which lets you make a clip from a series of images or numpy arrays.
• Use Imageio, a library simpler than MoviePy (and used by MoviePy) which let you work frame by frame.

You may also be interested by these other examples.