>>> # vim: ft=python foldmethod=marker foldlevel=0

...

... import numpy as np

... import matplotlib.pyplot as plt

>>> np.random.seed(42)

>>> for i in range(3):

... a = np.random.random((30,30))

... print(i, a.shape)

... plt.matshow(a)

... plt.show()

0 (30, 30)

1 (30, 30)

2 (30, 30)