API Changes in 2.2.0

New dependency

kiwisolver is now a required dependency to support the new constrained_layout, see Constrained Layout Guide for more details.

Deprecations

Classes, functions, and methods

The unused and untested Artist.onRemove and Artist.hitlist methods have been deprecated.

The now unused mlab.less_simple_linear_interpolation function is deprecated.

The unused ContourLabeler.get_real_label_width method is deprecated.

The unused FigureManagerBase.show_popup method is deprecated. This introduced in e945059b327d42a99938b939a1be867fa023e7ba in 2005 but never built out into any of the backends.

backend_tkagg.AxisMenu is deprecated, as it has become unused since the removal of "classic" toolbars.

Changed function signatures

kwarg fig to GridSpec.get_subplot_params is deprecated, use figure instead.

Using pyplot.axes with an Axes as argument is deprecated. This sets the current axes, i.e. it has the same effect as pyplot.sca. For clarity plt.sca(ax) should be preferred over plt.axes(ax).

Using strings instead of booleans to control grid and tick visibility is deprecated. Using "on", "off", "true", or "false" to control grid and tick visibility has been deprecated. Instead, use normal booleans (True/False) or boolean-likes. In the future, all non-empty strings may be interpreted as True.

When given 2D inputs with non-matching numbers of columns, plot currently cycles through the columns of the narrower input, until all the columns of the wider input have been plotted. This behavior is deprecated; in the future, only broadcasting (1 column to n columns) will be performed.

rcparams

The rcParams["backend.qt4"] and rcParams["backend.qt5"] rcParams were deprecated in version 2.2. In order to force the use of a specific Qt binding, either import that binding first, or set the QT_API environment variable.

Deprecation of the nbagg.transparent rcParam. To control transparency of figure patches in the nbagg (or any other) backend, directly set figure.patch.facecolor, or the figure.facecolor rcParam.

Deprecated Axis.unit_data

Use Axis.units (which has long existed) instead.

Removals

Function Signatures

Contouring no longer supports legacy corner masking. The deprecated ContourSet.vmin and ContourSet.vmax properties have been removed.

Passing None instead of "none" as format to errorbar is no longer supported.

The bgcolor keyword argument to Axes has been removed.

Modules, methods, and functions

The matplotlib.finance, mpl_toolkits.exceltools and mpl_toolkits.gtktools modules have been removed. matplotlib.finance remains available at https://github.com/matplotlib/mpl_finance.

The mpl_toolkits.mplot3d.art3d.iscolor function has been removed.

The Axes.get_axis_bgcolor, Axes.set_axis_bgcolor, Bbox.update_from_data, Bbox.update_datalim_numerix, MaxNLocator.bin_boundaries methods have been removed.

mencoder can no longer be used to encode animations.

The unused FONT_SCALE and fontd attributes of the RendererSVG class have been removed.

color maps

The spectral colormap has been removed. The Vega* colormaps, which were aliases for the tab* colormaps, have been removed.

rcparams

The following deprecated rcParams have been removed:

• axes.color_cycle (see axes.prop_cycle),
• legend.isaxes,
• svg.embed_char_paths (see svg.fonttype),
• text.fontstyle, text.fontangle, text.fontvariant, text.fontweight, text.fontsize (renamed to text.style, etc.),
• tick.size (renamed to tick.major.size).

Only accept string-like for Categorical input

Do not accept mixed string / float / int input, only strings are valid categoricals.

Removal of unused imports

Many unused imports were removed from the codebase. As a result, trying to import certain classes or functions from the "wrong" module (e.g. Figure from matplotlib.backends.backend_agg instead of matplotlib.figure) will now raise an ImportError.

Axes3D.get_xlim, get_ylim and get_zlim now return a tuple

They previously returned an array. Returning a tuple is consistent with the behavior for 2D axes.

Exception type changes

If MovieWriterRegistry can't find the requested MovieWriter, a more helpful RuntimeError message is now raised instead of the previously raised KeyError.

auto_adjust_subplotpars now raises ValueError instead of RuntimeError when sizes of input lists don't match

Figure.set_figwidth and Figure.set_figheight default forward to True

matplotlib.Figure.set_figwidth and matplotlib.Figure.set_figheight had the kwarg forward=False by default, but Figure.set_size_inches now defaults to forward=True. This makes these functions conistent.

Do not truncate svg sizes to nearest point

There is no reason to size the SVG out put in integer points, change to out putting floats for the height, width, and viewBox attributes of the svg element.

Fontsizes less than 1 pt are clipped to be 1 pt.

FreeType doesn't allow fonts to get smaller than 1 pt, so all Agg backends were silently rounding up to 1 pt. PDF (other vector backends?) were letting us write fonts that were less than 1 pt, but they could not be placed properly because position information comes from FreeType. This change makes it so no backends can use fonts smaller than 1 pt, consistent with FreeType and ensuring more consistent results across backends.

Changes to Qt backend class MRO

To support both Agg and cairo rendering for Qt backends all of the non-Agg specific code previously in backend_qt5agg.FigureCanvasQTAggBase has been moved to backend_qt5.FigureCanvasQT so it can be shared with the cairo implementation. The FigureCanvasQTAggBase.paintEvent(), FigureCanvasQTAggBase.blit(), and FigureCanvasQTAggBase.print_figure() methods have moved to FigureCanvasQTAgg.paintEvent(), FigureCanvasQTAgg.blit(), and FigureCanvasQTAgg.print_figure(). The first two methods assume that the instance is also a QWidget so to use FigureCanvasQTAggBase it was required to multiple inherit from a QWidget sub-class.

Having moved all of its methods either up or down the class hierarchy FigureCanvasQTAggBase has been deprecated. To do this with out warning and to preserve as much API as possible, backend_qt5.FigureCanvasQTAggBase now inherits from backend_qt5.FigureCanvasQTAgg.

The MRO for FigureCanvasQTAgg and FigureCanvasQTAggBase used to be

[matplotlib.backends.backend_qt5agg.FigureCanvasQTAgg,
 matplotlib.backends.backend_qt5agg.FigureCanvasQTAggBase,
 matplotlib.backends.backend_agg.FigureCanvasAgg,
 matplotlib.backends.backend_qt5.FigureCanvasQT,
 PyQt5.QtWidgets.QWidget,
 PyQt5.QtCore.QObject,
 sip.wrapper,
 PyQt5.QtGui.QPaintDevice,
 sip.simplewrapper,
 matplotlib.backend_bases.FigureCanvasBase,
 object]

and

[matplotlib.backends.backend_qt5agg.FigureCanvasQTAggBase,
 matplotlib.backends.backend_agg.FigureCanvasAgg,
 matplotlib.backend_bases.FigureCanvasBase,
 object]

respectively. They are now

[matplotlib.backends.backend_qt5agg.FigureCanvasQTAgg,
 matplotlib.backends.backend_agg.FigureCanvasAgg,
 matplotlib.backends.backend_qt5.FigureCanvasQT,
 PyQt5.QtWidgets.QWidget,
 PyQt5.QtCore.QObject,
 sip.wrapper,
 PyQt5.QtGui.QPaintDevice,
 sip.simplewrapper,
 matplotlib.backend_bases.FigureCanvasBase,
 object]

and

[matplotlib.backends.backend_qt5agg.FigureCanvasQTAggBase,
 matplotlib.backends.backend_qt5agg.FigureCanvasQTAgg,
 matplotlib.backends.backend_agg.FigureCanvasAgg,
 matplotlib.backends.backend_qt5.FigureCanvasQT,
 PyQt5.QtWidgets.QWidget,
 PyQt5.QtCore.QObject,
 sip.wrapper,
 PyQt5.QtGui.QPaintDevice,
 sip.simplewrapper,
 matplotlib.backend_bases.FigureCanvasBase,
 object]

Axes.imshow clips RGB values to the valid range

When Axes.imshow is passed an RGB or RGBA value with out-of-range values, it now logs a warning and clips them to the valid range. The old behaviour, wrapping back in to the range, often hid outliers and made interpreting RGB images unreliable.

GTKAgg and GTKCairo backends deprecated

The GTKAgg and GTKCairo backends have been deprecated. These obsolete backends allow figures to be rendered via the GTK+ 2 toolkit. They are untested, known to be broken, will not work with Python 3, and their use has been discouraged for some time. Instead, use the GTK3Agg and GTK3Cairo backends for rendering to GTK+ 3 windows.