Mandelbrot set: Difference between revisions

Actually the same, but more suitable for teaching. First without Numpy, only with floating point numbers.

<lang python>import matplotlib.pyplot as plt

def linspace(start, stop, num):

return [(stop*k + start*(num-k-1))/(num-1) for k in range(num)]

def zeros(rows, cols):

return [[0 for j in range(cols)] for i in range(rows)]

d, n = 100, 50 # pixel density & number of iterations

r = 2.5 # escape radius (must be greater than 2)

x = linspace(-2.5, 1.5, 4*d+1)

y = linspace(-1.5, 1.5, 3*d+1)

T = zeros(len(y), len(x))

for i, b in enumerate(y):

for j, a in enumerate(x):

u, v = 0.0, 0.0

for k in range(n):

u, v = u**2 - v**2 + a, 2*u*v + b

if not u**2 + v**2 < r**2:

break

T[i][j] = k + 1

plt.imshow(T, cmap=plt.cm.twilight_shifted)

plt.savefig('mandelbrot.png', dpi=200)</lang>

Second with Numpy and complex matrices.