pylab_examples example code: hexbin_demo.py

(Source code, png)

"""
hexbin is an axes method or pyplot function that is essentially
a pcolor of a 2-D histogram with hexagonal cells.  It can be
much more informative than a scatter plot; in the first subplot
below, try substituting 'scatter' for 'hexbin'.
"""

import numpy as np
import matplotlib.pyplot as plt

np.random.seed(0)
n = 100000
x = np.random.standard_normal(n)
y = 2.0 + 3.0 * x + 4.0 * np.random.standard_normal(n)
xmin = x.min()
xmax = x.max()
ymin = y.min()
ymax = y.max()

plt.subplots_adjust(hspace=0.5)
plt.subplot(121)
plt.hexbin(x, y, cmap=plt.cm.YlOrRd_r)
plt.axis([xmin, xmax, ymin, ymax])
plt.title("Hexagon binning")
cb = plt.colorbar()
cb.set_label('counts')

plt.subplot(122)
plt.hexbin(x, y, bins='log', cmap=plt.cm.YlOrRd_r)
plt.axis([xmin, xmax, ymin, ymax])
plt.title("With a log color scale")
cb = plt.colorbar()
cb.set_label('log10(N)')

plt.show()

Keywords: python, matplotlib, pylab, example, codex (see Search examples)