Visualizing the content of a 2D array

Let's start with the most basic scenario. We have a 2D array, and we want to visualize its content. As an example, we will visualize the Mandelbrot set. The Mandelbrot set, a famous fractal shape, associates a number of iterations to each point on the plane.

How to do it...

We will first fill a 2D square array with values and then call pyplot.imshow() to visualize it, as shown in the following code:

import numpy as np
import matplotlib.cm as cm
from matplotlib import pyplot as plt 

def iter_count(C, max_iter): 
  X = C 
  for n in range(max_iter): 
    if abs(X) > 2.: 
      return n 
    X = X ** 2 + C 
  return max_iter 

N = 512 
max_iter = 64 
xmin, xmax, ymin, ymax = -2.2, .8, -1.5, 1.5 
X = np.linspace(xmin, xmax, N) 
Y = np.linspace(ymin, ymax, N) 
Z = np.empty((N, N)) 

for i, y in enumerate(Y): 
  for j, x in enumerate(X): 
    Z[i, j] = iter_count(complex(x, y), max_iter)

plt.imshow(Z, cmap = cm.gray)
plt.show()

This script might take a few...