matplotlib Code

Unit tests run correctly by buildout

This requires plugin support in pbp.recipe.noserunner, which will
hopefully be added in 0.2.7.

Add an empty matplotlibrc to the tests/ directory so that running the test suite uses the default matplotlib config.

support collective.buildbot by enabling buildout support

add script to consolidate difference images

save difference image between failed image and baseline image

Axis.grid(): allow use of which='major,minor' to have grid on major and minor ticks

convert Axis.grid() docstrings to use complete sentences

Move code for wrapping negative frequencies from specgram() into _spectral_helper(), so that psd(), csd(), and cohere() can benefit from this functionality as well. While this changes API a little, this is much more sensible behavior.

Fix the linespacing bug of multiline text (#1239682)

Add *annotation_clip* attr. for text.Annotation class