New in matplotlib 1.5 ¶

Table of Contents

New in matplotlib 1.5

Note

matplotlib 1.5 supports Python 2.7, 3.4, and 3.5

Interactive OO usage ¶

All Artists now keep track of if their internal state has been changed but not reflected in the display ('stale') by a call to draw. It is thus possible to pragmatically determine if a given Figure needs to be re-drawn in an interactive session.

To facilitate interactive usage a draw_all method has been added to pyplot which will redraw all of the figures which are 'stale'.

To make this convenient for interactive use matplotlib now registers a function either with IPython's 'post_execute' event or with the displayhook in the standard python REPL to automatically call plt.draw_all just before control is returned to the REPL. This ensures that the draw command is deferred and only called once.

The upshot of this is that for interactive backends (including %matplotlib notebook) in interactive mode (with plt.ion())

import matplotlib.pyplot as plt
fig, ax = plt.subplots()
ln, = ax.plot([0, 1, 4, 9, 16])
plt.show()
ln.set_color('g')

will automatically update the plot to be green. Any subsequent modifications to the Artist objects will do likewise.

This is the first step of a larger consolidation and simplification of the pyplot internals.

Working with labeled data like pandas DataFrames ¶

Plot methods which take arrays as inputs can now also work with labeled data and unpack such data.

This means that the following two examples produce the same plot:

Example

df = pandas.DataFrame({"var1":[1,2,3,4,5,6], "var2":[1,2,3,4,5,6]})
plt.plot(df["var1"], df["var2"])

Example

plt.plot("var1", "var2", data=df)

This works for most plotting methods, which expect arrays/sequences as inputs. data can be anything which supports __getitem__ (dict, pandas.DataFrame, h5py, ...) to access array like values with string keys.

In addition to this, some other changes were made, which makes working with labeled data (ex pandas.Series) easier:

For plotting methods with label keyword argument, one of the data inputs is designated as the label source. If the user does not supply a label that value object will be introspected for a label, currently by looking for a name attribute. If the value object does not have a name attribute but was specified by as a key into the data kwarg, then the key is used. In the above examples, this results in an implicit label="var2" for both cases.
plot() now uses the index of a Series instead of np.arange(len(y)), if no x argument is supplied.

Added `axes.prop_cycle` key to rcParams ¶

This is a more generic form of the now-deprecated axes.color_cycle param. Now, we can cycle more than just colors, but also linestyles, hatches, and just about any other artist property. Cycler notation is used for defining property cycles. Adding cyclers together will be like you are zip-ing together two or more property cycles together:

axes.prop_cycle: cycler('color', 'rgb') + cycler('lw', [1, 2, 3])

You can even multiply cyclers, which is like using itertools.product on two or more property cycles.

Color Cycle¶

New Colormaps ¶

All four of the colormaps proposed as the new default are available as 'viridis' (the new default in 2.0), 'magma', 'plasma', and 'inferno'

(Source code, png, pdf)

Styles ¶

Several new styles have been added, including many styles from the Seaborn project. Additionally, in order to prep for the upcoming 2.0 style-change release, a 'classic' and 'default' style has been added. For this release, the 'default' and 'classic' styles are identical. By using them now in your scripts, you can help ensure a smooth transition during future upgrades of matplotlib, so that you can upgrade to the snazzy new defaults when you are ready!

import matplotlib.style
matplotlib.style.use('classic')

The 'default' style will give you matplotlib's latest plotting styles:

matplotlib.style.use('default')

Backends ¶

New backend selection¶

The environment variable MPLBACKEND can now be used to set the matplotlib backend.

wx backend has been updated¶

The wx backend can now be used with both wxPython classic and Phoenix.

wxPython classic has to be at least version 2.8.12 and works on Python 2.x. As of May 2015 no official release of wxPython Phoenix is available but a current snapshot will work on Python 2.7+ and 3.4+.

If you have multiple versions of wxPython installed, then the user code is responsible setting the wxPython version. How to do this is explained in the comment at the beginning of the example Embedding in wx #2.

Configuration (rcParams)¶

Some parameters have been added, others have been improved.

Parameter	Description
`rcParams["xaxis.labelpad"]`, `rcParams["yaxis.labelpad"]`	mplot3d now respects these parameters
`rcParams["axes.labelpad"]` (default: `4.0`)	Default space between the axis and the label
`rcParams["errorbar.capsize"]` (default: `0.0`)	Default length of end caps on error bars
`rcParams["xtick.minor.visible"]` (default: `False`), `rcParams["ytick.minor.visible"]` (default: `False`)	Default visibility of minor x/y ticks
`rcParams["legend.framealpha"]` (default: `0.8`)	Default transparency of the legend frame box
`rcParams["legend.facecolor"]` (default: `'inherit'`)	Default facecolor of legend frame box (or `'inherit'` from `rcParams["axes.facecolor"]` (default: `'white'`))
`rcParams["legend.edgecolor"]` (default: `'0.8'`)	Default edgecolor of legend frame box (or `'inherit'` from `rcParams["axes.edgecolor"]` (default: `'black'`))
`rcParams["figure.titlesize"]` (default: `'large'`)	Default font size for figure suptitles
`rcParams["figure.titleweight"]` (default: `'normal'`)	Default font weight for figure suptitles
`rcParams["image.composite_image"]` (default: `True`)	Whether a vector graphics backend should composite several images into a single image or not when saving. Useful when needing to edit the files further in Inkscape or other programs.
`rcParams["markers.fillstyle"]` (default: `'full'`)	Default fillstyle of markers. Possible values are `'full'` (the default), `'left'`, `'right'`, `'bottom'`, `'top'` and `'none'`
`rcParams["toolbar"]` (default: `'toolbar2'`)	Added `'toolmanager'` as a valid value, enabling the experimental `ToolManager` feature.

Widgets ¶

Active state of Selectors¶

All selectors now implement set_active and get_active methods (also called when accessing the active property) to properly update and query whether they are active.

Adds enable/disable feature to MultiCursor¶

A MultiCursor object can be disabled (and enabled) after it has been created without destroying the object. Example:

multi_cursor.active = False

Allow Artists to Display Pixel Data in Cursor¶

Adds get_cursor_data and format_cursor_data methods to artists which can be used to add zdata to the cursor display in the status bar. Also adds an implementation for Images.

New plotting features ¶

Auto-wrapping Text¶

Added the keyword argument "wrap" to Text, which automatically breaks long lines of text when being drawn. Works for any rotated text, different modes of alignment, and for text that are either labels or titles. This breaks at the Figure, not Axes edge.

(Source code, png, pdf)

Contour plot corner masking¶

Ian Thomas rewrote the C++ code that calculates contours to add support for corner masking. This is controlled by a new keyword argument corner_mask in the functions contour() and contourf(). The previous behaviour, which is now obtained using corner_mask=False, was for a single masked point to completely mask out all four quads touching that point. The new behaviour, obtained using corner_mask=True, only masks the corners of those quads touching the point; any triangular corners comprising three unmasked points are contoured as usual. If the corner_mask keyword argument is not specified, the default value is taken from rcParams.

Contour Corner Mask¶

Mostly unified linestyles for `Line2D`, `Patch` and `Collection`¶

The handling of linestyles for Lines, Patches and Collections has been unified. Now they all support defining linestyles with short symbols, like "--", as well as with full names, like "dashed". Also the definition using a dash pattern ((0., [3., 3.])) is supported for all methods using Line2D, Patch or Collection.

Legend marker order¶

Added ability to place the label before the marker in a legend box with markerfirst keyword

Support for legend for PolyCollection and stackplot¶

Added a legend_handler for PolyCollection as well as a labels argument to stackplot().

Support for alternate pivots in mplot3d quiver plot¶

Added a pivot kwarg to quiver() that controls the pivot point around which the quiver line rotates. This also determines the placement of the arrow head along the quiver line.

Logit Scale¶

Added support for the 'logit' axis scale, a nonlinear transformation

\[x -> \log10(x / (1-x))\]

for data between 0 and 1 excluded.

Add step kwargs to fill_between¶

Added step kwarg to Axes.fill_between to allow to fill between lines drawn using the 'step' draw style. The values of step match those of the where kwarg of Axes.step. The asymmetry of of the kwargs names is not ideal, but Axes.fill_between already has a where kwarg.

This is particularly useful for plotting pre-binned histograms.

Filled Step¶

Square Plot¶

Implemented square plots feature as a new parameter in the axis function. When argument 'square' is specified, equal scaling is set, and the limits are set such that xmax-xmin == ymax-ymin.

(Source code, png, pdf)

Updated figimage to take optional resize parameter¶

Added the ability to plot simple 2D-Array using plt.figimage(X, resize=True). This is useful for plotting simple 2D-Array without the Axes or whitespacing around the image.

(Source code, png, pdf)

Updated Figure.savefig() can now use figure's dpi¶

Added support to save the figure with the same dpi as the figure on the screen using dpi='figure':.

Example:

f = plt.figure(dpi=25)  # dpi set to 25
S = plt.scatter([1,2,3],[4,5,6])
f.savefig('output.png', dpi='figure')  # output savefig dpi set to 25 (same as figure)

Updated Table to control edge visibility¶

Added the ability to toggle the visibility of lines in Tables. Functionality added to the pyplot.table factory function under the keyword argument "edges". Values can be the strings "open", "closed", "horizontal", "vertical" or combinations of the letters "L", "R", "T", "B" which represent left, right, top, and bottom respectively.

Example:

table(..., edges="open")  # No line visible
table(..., edges="closed")  # All lines visible
table(..., edges="horizontal")  # Only top and bottom lines visible
table(..., edges="LT")  # Only left and top lines visible.

Zero r/cstride support in plot_wireframe¶

Adam Hughes added support to mplot3d's plot_wireframe to draw only row or column line plots.

(Source code, png, pdf)

Plot bar and barh with labels¶

Added kwarg tick_label to bar and barh to support plotting bar graphs with a text label for each bar.

(Source code, png, pdf)

Added center and frame kwargs to pie¶

These control where the center of the pie graph are and if the Axes frame is shown.

Fixed 3D filled contour plot polygon rendering¶

Certain cases of 3D filled contour plots that produce polygons with multiple holes produced improper rendering due to a loss of path information between PolyCollection and Poly3DCollection. A function set_verts_and_codes() was added to allow path information to be retained for proper rendering.

Dense colorbars are rasterized¶

Vector file formats (pdf, ps, svg) are efficient for many types of plot element, but for some they can yield excessive file size and even rendering artifacts, depending on the renderer used for screen display. This is a problem for colorbars that show a large number of shades, as is most commonly the case. Now, if a colorbar is showing 50 or more colors, it will be rasterized in vector backends.

DateFormatter strftime¶

DateFormatter's __call__() method will format a datetime.datetime object with the format string passed to the formatter's constructor. This method accepts datetimes with years before 1900, unlike datetime.datetime.strftime().

Artist-level {get,set}_usetex for text¶

Add {get,set}_usetex methods to Text objects which allow artist-level control of LaTeX rendering vs. the internal mathtex rendering.

`Axes.remove()` works as expected¶

As with artists added to an Axes, Axes objects can be removed from their figure via remove().

API Consistency fix within Locators set_params() function¶

set_params() function, which sets parameters within a Locator type instance, is now available to all Locator types. The implementation also prevents unsafe usage by strictly defining the parameters that a user can set.

To use, call set_params() on a Locator instance with desired arguments:

loc = matplotlib.ticker.LogLocator()
# Set given attributes for loc.
loc.set_params(numticks=8, numdecs=8, subs=[2.0], base=8)
# The below will error, as there is no such parameter for LogLocator
# named foo
# loc.set_params(foo='bar')

Date Locators¶

Date Locators (derived from DateLocator) now implement the tick_values method. This is expected of all Locators derived from Locator.

The Date Locators can now be used easily without creating axes

from datetime import datetime
from matplotlib.dates import YearLocator
t0 = datetime(2002, 10, 9, 12, 10)
tf = datetime(2005, 10, 9, 12, 15)
loc = YearLocator()
values = loc.tick_values(t0, tf)

OffsetBoxes now support clipping¶

Artists draw onto objects of type OffsetBox through DrawingArea and TextArea. The TextArea calculates the required space for the text and so the text is always within the bounds, for this nothing has changed.

However, DrawingArea acts as a parent for zero or more Artists that draw on it and may do so beyond the bounds. Now child Artists can be clipped to the bounds of the DrawingArea.

OffsetBoxes now considered by tight_layout¶

When tight_layout() or Figure.tight_layout or GridSpec.tight_layout() is called, OffsetBoxes that are anchored outside the axes will not get chopped out. The OffsetBoxes will also not get overlapped by other axes in case of multiple subplots.

Per-page pdf notes in multi-page pdfs (PdfPages)¶

Add a new method attach_note() to the PdfPages class, allowing the attachment of simple text notes to pages in a multi-page pdf of figures. The new note is visible in the list of pdf annotations in a viewer that has this facility (Adobe Reader, OSX Preview, Skim, etc.). Per default the note itself is kept off-page to prevent it to appear in print-outs.

PdfPages.attach_note needs to be called before savefig in order to be added to the correct figure.

Updated fignum_exists to take figure name¶

Added the ability to check the existence of a figure using its name instead of just the figure number. Example:

figure('figure')
fignum_exists('figure') #true

ToolManager ¶

Federico Ariza wrote the new ToolManager that comes as replacement for NavigationToolbar2

ToolManager offers a new way of looking at the user interactions with the figures. Before we had the NavigationToolbar2 with its own tools like zoom/pan/home/save/... and also we had the shortcuts like yscale/grid/quit/..... ToolManager relocate all those actions as Tools (located in backend_tools), and defines a way to access/trigger/reconfigure them.

The Toolbars are replaced for ToolContainers that are just GUI interfaces to trigger the tools. But don't worry the default backends include a ToolContainer called toolbar

Note

At the moment, we release this primarily for feedback purposes and should be treated as experimental until further notice as API changes will occur. For the moment the ToolManager works only with the GTK3 and Tk backends. Make sure you use one of those. Port for the rest of the backends is coming soon.

To activate the ToolManager include the following at the top of your file

>>> matplotlib.rcParams['toolbar'] = 'toolmanager'

Interact with the ToolContainer¶

The most important feature is the ability to easily reconfigure the ToolContainer (aka toolbar). For example, if we want to remove the "forward" button we would just do.

>>> fig.canvas.manager.toolmanager.remove_tool('forward')

Now if you want to programmatically trigger the "home" button

>>> fig.canvas.manager.toolmanager.trigger_tool('home')

New Tools for ToolManager¶

It is possible to add new tools to the ToolManager

A very simple tool that prints "You're awesome" would be:

from matplotlib.backend_tools import ToolBase
class AwesomeTool(ToolBase):
    def trigger(self, *args, **kwargs):
        print("You're awesome")

To add this tool to ToolManager

>>> fig.canvas.manager.toolmanager.add_tool('Awesome', AwesomeTool)

If we want to add a shortcut ("d") for the tool

>>> fig.canvas.manager.toolmanager.update_keymap('Awesome', 'd')

To add it to the toolbar inside the group 'foo'

>>> fig.canvas.manager.toolbar.add_tool('Awesome', 'foo')

There is a second class of tools, "Toggleable Tools", this are almost the same as our basic tools, just that belong to a group, and are mutually exclusive inside that group. For tools derived from ToolToggleBase there are two basic methods enable and disable that are called automatically whenever it is toggled.

A full example is located in Tool Manager

cbook.is_sequence_of_strings recognizes string objects ¶

This is primarily how pandas stores a sequence of strings

import pandas as pd
import matplotlib.cbook as cbook

a = np.array(['a', 'b', 'c'])
print(cbook.is_sequence_of_strings(a))  # True

a = np.array(['a', 'b', 'c'], dtype=object)
print(cbook.is_sequence_of_strings(a))  # True

s = pd.Series(['a', 'b', 'c'])
print(cbook.is_sequence_of_strings(s))  # True

Previously, the last two prints returned false.

New `close-figs` argument for plot directive ¶

Matplotlib has a sphinx extension plot_directive that creates plots for inclusion in sphinx documents. Matplotlib 1.5 adds a new option to the plot directive - close-figs - that closes any previous figure windows before creating the plots. This can help avoid some surprising duplicates of plots when using plot_directive.

Support for URL string arguments to `imread`¶

The imread() function now accepts URL strings that point to remote PNG files. This circumvents the generation of a HTTPResponse object directly.

Display hook for animations in the IPython notebook ¶

Animation instances gained a _repr_html_ method to support inline display of animations in the notebook. The method used to display is controlled by the animation.html rc parameter, which currently supports values of none and html5. none is the default, performing no display. html5 converts the animation to an h264 encoded video, which is embedded directly in the notebook.

Users not wishing to use the _repr_html_ display hook can also manually call the to_html5_video method to get the HTML and display using IPython's HTML display class:

from IPython.display import HTML
HTML(anim.to_html5_video())

Prefixed pkg-config for building ¶

Handling of pkg-config has been fixed in so far as it is now possible to set it using the environment variable PKG_CONFIG. This is important if your toolchain is prefixed. This is done in a simpilar way as setting CC or CXX before building. An example follows.

export PKG_CONFIG=x86_64-pc-linux-gnu-pkg-config

New backend selection¶

wx backend has been updated¶

Active state of Selectors¶

Moved ignore, set_active, and get_active methods to base class Widget¶

Adds enable/disable feature to MultiCursor¶

Improved RectangleSelector and new EllipseSelector Widget¶

Allow Artists to Display Pixel Data in Cursor¶

Auto-wrapping Text¶

Contour plot corner masking¶

Mostly unified linestyles for Line2D, Patch and Collection¶

Legend marker order¶

Support for legend for PolyCollection and stackplot¶

Support for alternate pivots in mplot3d quiver plot¶

Logit Scale¶

Add step kwargs to fill_between¶

Square Plot¶

Updated figimage to take optional resize parameter¶

Updated Figure.savefig() can now use figure's dpi¶

Updated Table to control edge visibility¶

Zero r/cstride support in plot_wireframe¶

Plot bar and barh with labels¶

Added center and frame kwargs to pie¶

Fixed 3D filled contour plot polygon rendering¶

Dense colorbars are rasterized¶

DateFormatter strftime¶

Artist-level {get,set}_usetex for text¶

Axes.remove() works as expected¶

API Consistency fix within Locators set_params() function¶

Date Locators¶

OffsetBoxes now support clipping¶

OffsetBoxes now considered by tight_layout¶

Per-page pdf notes in multi-page pdfs (PdfPages)¶

Updated fignum_exists to take figure name¶

Interact with the ToolContainer¶

New Tools for ToolManager¶

Moved `ignore`, `set_active`, and `get_active` methods to base class `Widget`¶

Mostly unified linestyles for `Line2D`, `Patch` and `Collection`¶

`Axes.remove()` works as expected¶