Iterating the whole 2D-array#

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%matplotlib widget
import matplotlib.pyplot as plt
plt.rcParams['figure.dpi'] = 200

x_min, x_max = -2.5, 1.0
y_min, y_max = -1.25, 1.25
max_iterations = 100
resolution = 1000

We generate an array of complex numbers.

import numpy as np

x = np.linspace(x_min, x_max, resolution)
y = np.linspace(y_min, y_max, resolution)

c = x + y[:, None] * 1j

  • The inner function is modified to take the complex array

  • binary masking helps to just work on the necessary subset.

def mandelbrot_set(c, max_iterations):
    c0 = c.copy()
    iterations = np.zeros_like(c, dtype=np.uint)
    for index in range(max_iterations):
        mask = np.abs(c) < 2.0
        c[mask] = c[mask]**2 + c0[mask]
        iterations[mask] += 1
    return iterations

iterations = mandelbrot_set(c, max_iterations)
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fig, axes = plt.subplots()
axes.imshow(iterations[::-1], extent=(x_min, x_max, y_min, y_max), cmap="RdGy")
plt.tight_layout()