matplotlib/matplotlib — pull request #3283 by lpsinger (2014-07-21 18:19:17+00:00)
Title: Suppress invalid argument warnings in inverse Mollweide projection

The Mollweide inverse projection generates Numpy invalid value warnings for pixels outside of the projection. For example, the following code:

from matplotlib import pyplot as plt
plt.subplot(111, projection='mollweide')
plt.savefig('test.png')

produces this warning:

.../matplotlib/projections/geo.py:489:
RuntimeWarning: invalid value encountered in arcsin
theta = np.arcsin(y / np.sqrt(2))

This patch silences the warning by wrapping the inverse transformation in a `np.errstate` context.