Enhancements to polar plot

The polar axes transforms have been greatly re-factored to allow for more

customization of view limits and tick labelling. Additional options for view

limits allow for creating an annulus, a sector, or some combination of the two.

The :meth:`~matplotlib.axes.projections.polar.PolarAxes.set_rorigin` method may

be used to provide an offset to the minimum plotting radius, producing an

annulus.

The :meth:`~matplotlib.projections.polar.PolarAxes.set_theta_zero_location` now

has an optional :code:`offset` argument. This argument may be used to further

specify the zero location based on the given anchor point.

.. figure:: ../gallery/pie_and_polar_charts/images/sphx_glr_polar_scatter_001.png

:target: ../gallery/pie_and_polar_charts/polar_scatter.html

:align: center

:scale: 50

Polar Offset Demo

The :meth:`~matplotlib.axes.projections.polar.PolarAxes.set_thetamin` and

:meth:`~matplotlib.axes.projections.polar.PolarAxes.set_thetamax` methods may

be used to limit the range of angles plotted, producing sectors of a circle.

.. figure:: ../gallery/pie_and_polar_charts/images/sphx_glr_polar_scatter_002.png

:target: ../gallery/pie_and_polar_charts/polar_scatter.html

:align: center

:scale: 50

Polar Sector Demo

Previous releases allowed plots containing negative radii for which the

negative values are simply used as labels, and the real radius is shifted by

the configured minimum. This release also allows negative radii to be used for

grids and ticks, which were previously silently ignored.

Merge JSAnimation

Jake Vanderplas' JSAnimation package has been merged into matplotlib. This

adds to matplotlib the `~matplotlib.animation.HTMLWriter` class for

generating a javascript HTML animation, suitable for the IPython notebook.

This can be activated by default by setting the ``animation.html`` rc

parameter to ``jshtml``. One can also call the ``anim_to_jshtml`` function

to manually convert an animation. This can be displayed using IPython's

``HTML`` display class::

The `~matplotlib.animation.HTMLWriter` class can also be used to generate

an HTML file by asking for the ``html`` writer.