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pylab_examples example code: shading_example.pyΒΆ

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../../_images/shading_example.png
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.colors import LightSource

# example showing how to make shaded relief plots
# like Mathematica
# (http://reference.wolfram.com/mathematica/ref/ReliefPlot.html)
# or Generic Mapping Tools
# (http://gmt.soest.hawaii.edu/gmt/doc/gmt/html/GMT_Docs/node145.html)

# test data
X,Y=np.mgrid[-5:5:0.05,-5:5:0.05]
Z=np.sqrt(X**2+Y**2)+np.sin(X**2+Y**2)
# create light source object.
ls = LightSource(azdeg=0,altdeg=65)
# shade data, creating an rgb array.
rgb = ls.shade(Z,plt.cm.copper)
# plot un-shaded and shaded images.
plt.figure(figsize=(12,5))
plt.subplot(121)
plt.imshow(Z,cmap=plt.cm.copper)
plt.title('imshow')
plt.xticks([]); plt.yticks([])
plt.subplot(122)
plt.imshow(rgb)
plt.title('imshow with shading')
plt.xticks([]); plt.yticks([])
plt.show()

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