"""Simple matshow() example."""
from matplotlib.pylab import *


def samplemat(dims):
    """Make a matrix with all zeros and increasing elements on the diagonal"""
    aa = zeros(dims)
    for i in range(min(dims)):
        aa[i, i] = i
    return aa


# Display 2 matrices of different sizes
dimlist = [(12, 12), (15, 35)]
for d in dimlist:
    matshow(samplemat(d))

# Display a random matrix with a specified figure number and a grayscale
# colormap
matshow(rand(64, 64), fignum=100, cmap=cm.gray)

show()