"""Produce custom labelling for a colorbar.

Contributed by Scott Sinclair
"""

import matplotlib.pyplot as plt
import numpy as np

from numpy.random import randn

# Make plot with vertical (default) colorbar
fig = plt.figure()
ax = fig.add_subplot(111)

data = np.clip(randn(250, 250), -1, 1)

cax = ax.imshow(data, interpolation='nearest')
ax.set_title('Gaussian noise with vertical colorbar')

# Add colorbar, make sure to specify tick locations to match desired ticklabels
cbar = fig.colorbar(cax, ticks=[-1, 0, 1])
cbar.ax.set_yticklabels(['< -1', '0', '> 1'])# vertically oriented colorbar

# Make plot with horizontal colorbar
fig = plt.figure()
ax = fig.add_subplot(111)

data = np.clip(randn(250, 250), -1, 1)

cax = ax.imshow(data, interpolation='nearest')
ax.set_title('Gaussian noise with horizontal colorbar')

cbar = fig.colorbar(cax, ticks=[-1, 0, 1], orientation='horizontal')
cbar.ax.set_xticklabels(['Low', 'Medium', 'High'])# horizontal colorbar

plt.show()