API Changes in 2.1.0

`mpl_toolkits.axes_grid` has been deprecated

All functionallity from `mpl_toolkits.axes_grid` can be found in either

`mpl_toolkits.axes_grid1` or `mpl_toolkits.axisartist`. Axes classes from

`mpl_toolkits.axes_grid` based on `Axis` from `mpl_toolkits.axisartist` can be

found in `mpl_toolkits.axisartist`

Improved toggling of the axes grids

The `g` key binding now switches the states of the `x` and `y` grids

independently (by cycling through all four on/off combinations).

The new `G` key binding switches the states of the minor grids.

Both bindings are disabled if only a subset of the grid lines (in either

direction) is visible, to avoid making irreversible changes to the figure.

Removal of warning on empty legends

``plt.legend`` used to issue a warning when no labeled artist could be

found. This warning has been removed.

More accurate legend autopositioning

Automatic positioning of legends now prefers using the area surrounded

by a `Line2D` rather than placing the legend over the line itself.

Cleanup of stock sample data

The sample data of stocks has been cleaned up to remove redundancies and

increase portability. The ``AAPL.dat.gz``, ``INTC.dat.gz`` and ``aapl.csv``

files have been removed entirely and will also no longer be available from

`matplotlib.cbook.get_sample_data`. If a CSV file is required, we suggest using

the ``msft.csv`` that continues to be shipped in the sample data. If a NumPy

binary file is acceptable, we suggest using one of the following two new files.

The ``aapl.npy.gz`` and ``goog.npy`` files have been replaced by ``aapl.npz``

and ``goog.npz``, wherein the first column's type has changed from

`datetime.date` to `np.datetime64` for better portability across Python

versions. Note that matplotlib does not fully support `np.datetime64` as yet.

Updated qhull to 2015.2

The version of qhull shipped with Matplotlib, which is used for

Delaunay triangulation, has been updated from version 2012.1 to

2015.2.

Use backports.functools_lru_cache instead of functools32

It's better maintained and more widely used (by pylint, jaraco, etc).

`cbook.is_numlike` only performs an instance check, `cbook.is_string_like` is deprecated

`cbook.is_numlike` now only checks that its argument is an instance of

``(numbers.Number, np.Number)``. In particular, this means that arrays are now

not num-like.

`cbook.is_string_like` and `cbook.is_sequence_of_strings` have been

deprecated. Use ``isinstance(obj, six.string_types)`` and ``iterable(obj) and

all(isinstance(o, six.string_types) for o in obj)`` instead.

Elliptical arcs now drawn between correct angles

The `matplotlib.patches.Arc` patch is now correctly drawn between the given

angles.

Previously a circular arc was drawn and then stretched into an ellipse,

so the resulting arc did not lie between *theta1* and *theta2*.

Changes to PDF backend methods

The methods `embedTeXFont` and `tex_font_mapping` of

`matplotlib.backend_pdf.PdfFile` have been removed.

It is unlikely that external users would have called

these methods, which are related to the font system

internal to the PDF backend.

``-d$backend`` no longer sets the backend

It is no longer possible to set the backend by passing ``-d$backend`` at the command line. Use the ``MPLBACKEND`` environment variable instead.

Path.intersects_bbox always treats the bounding box as filled

Previously, when ``Path.intersects_bbox`` was called with ``filled`` set to

``False``, it would treat both the path and the bounding box as unfilled. This

behavior was not well documented and it is usually not the desired behavior,

since bounding boxes are used to represent more complex shapes located inside

the bounding box. This behavior has now been changed: when ``filled`` is

``False``, the path will be treated as unfilled, but the bounding box is still

treated as filled. The old behavior was arguably an implementation bug.

When ``Path.intersects_bbox`` is called with ``filled`` set to ``True``

(the default value), there is no change in behavior. For those rare cases where

``Path.intersects_bbox`` was called with ``filled`` set to ``False`` and where

the old behavior is actually desired, the suggested workaround is to call

``Path.intersects_path`` with a rectangle as the path::

Removed resolution kwarg from PolarAxes

The kwarg `resolution` of `matplotlib.projections.polar.PolarAxes` has been

removed. It has triggered a deprecation warning of being with no effect

beyond version `0.98.x`.

Deprecation of `GraphicsContextBase`\'s ``linestyle`` property.

The ``GraphicsContextBase.get_linestyle`` and

``GraphicsContextBase.set_linestyle`` methods, which effectively had no effect,

have been deprecated.

NavigationToolbar2.dynamic_update is deprecated

Use `FigureCanvas.draw_idle` instead.

Unique identifier added to `RendererBase` classes

Since ``id()`` is not guaranteed to be unique between objects that exist at

different times, a new private property ``_uid`` has been added to

`RendererBase` which is used along with the renderer's ``id()`` to cache

certain expensive operations.

If a custom renderer does not subclass `RendererBase` or `MixedModeRenderer`,

it is not required to implement this ``_uid`` property, but this may produce

incorrect behavior when the renderers' ``id()`` clashes.

WX no longer calls generates ``IdleEvent`` events or calls ``idle_event``

Removed unused private method ``_onIdle`` from ``FigureCanvasWx``.

The ``IdleEvent`` class and ``FigureCanvasBase.idle_event`` method

will be removed in 2.2

Correct scaling of :func:`magnitude_spectrum()`

The functions :func:`matplotlib.mlab.magnitude_spectrum()` and :func:`matplotlib.pyplot.magnitude_spectrum()` implicitly assumed the sum

of windowing function values to be one. In Matplotlib and Numpy the

standard windowing functions are scaled to have maximum value of one,

which usually results in a sum of the order of n/2 for a n-point

signal. Thus the amplitude scaling :func:`magnitude_spectrum()` was

off by that amount when using standard windowing functions (`Bug 8417

<https://github.com/matplotlib/matplotlib/issues/8417>`_ ). Now the

behavior is consistent with :func:`matplotlib.pyplot.psd()` and

:func:`scipy.signal.welch()`. The following example demonstrates the

new and old scaling::

Default behavior of log scales changed to mask <= 0 values

Calling `matplotlib.axes.Axes.set_xscale` or `matplotlib.axes.Axes.set_yscale`

now uses 'mask' as the default method to handle invalid values (as opposed to

'clip'). This means that any values <= 0 on a log scale will not be shown.

Previously they were clipped to a very small number and shown.

Code Removal

matplotlib.delaunay

Remove the delaunay triangulation code which is now handled by Qhull

via ``matplotlib.tri``

qt4_compat.py

Moved to ``qt_compat.py``. Renamed because it now handles Qt5 as well.

Deprecated methods

The ``GraphicsContextBase.set_graylevel``, ``FigureCanvasBase.onHilite`` and

``mpl_toolkits.axes_grid1.mpl_axes.Axes.toggle_axisline`` methods have been

removed.

The ``ArtistInspector.findobj`` method, which was never working due to the lack

of a ``get_children`` method, has been removed.

The deprecated ``point_in_path``, ``get_path_extents``,

``point_in_path_collection``, ``path_intersects_path``,

``convert_path_to_polygons``, ``cleanup_path`` and ``clip_path_to_rect``

functions in the ``matplotlib.path`` module have been removed. Their

functionality remains exposed as methods on the ``Path`` class.

`Axes.set_aspect("normal")`

Support for setting an ``Axes``' aspect to ``"normal"`` has been removed, in

favor of the synonym ``"auto"``.

``shading`` kwarg to ``pcolor``

The ``shading`` kwarg to ``pcolor`` has been removed. Set ``edgecolors``

appropriately instead.

Removed internal functions

The ``matplotlib.backends.backend_ps.seq_allequal`` function has been removed.

Use ``np.array_equal`` instead.

The deprecated ``matplotlib.rcsetup.validate_maskedarray``,

``matplotlib.rcsetup.deprecate_savefig_extension`` and

``matplotlib.rcsetup.validate_tkpythoninspect`` functions, and associated

``savefig.extension`` and ``tk.pythoninspect`` rcparams entries have been

removed.

Deprecations

- `matplotlib.testing.noseclasses` is deprecated and will be removed in 2.3

Functions removed from the `lines` module

The `matplotlib.lines` module no longer imports the `pts_to_prestep`,

`pts_to_midstep` and `pts_to_poststep` functions from the `matplotlib.cbook`

module.