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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

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<title>matplotlib.backend_bases — Matplotlib 3.1.0 documentation</title>

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<h1>Source code for matplotlib.backend_bases</h1><div class="highlight"><pre>

"""

Abstract base classes define the primitives that renderers and

graphics contexts must implement to serve as a matplotlib backend

:class:`RendererBase`

An abstract base class to handle drawing/rendering operations.

:class:`FigureCanvasBase`

The abstraction layer that separates the

:class:`matplotlib.figure.Figure` from the backend specific

details like a user interface drawing area

:class:`GraphicsContextBase`

An abstract base class that provides color, line styles, etc...

:class:`Event`

The base class for all of the matplotlib event

handling. Derived classes such as :class:`KeyEvent` and

:class:`MouseEvent` store the meta data like keys and buttons

pressed, x and y locations in pixel and

:class:`~matplotlib.axes.Axes` coordinates.

:class:`ShowBase`

The base class for the Show class of each interactive backend;

the 'show' callable is then set to Show.__call__, inherited from

ShowBase.

:class:`ToolContainerBase`

The base class for the Toolbar class of each interactive backend.

:class:`StatusbarBase`

The base class for the messaging area.

"""

from contextlib import contextmanager

from enum import IntEnum

import functools

import importlib

import io

import logging

import os

import sys

import time

from weakref import WeakKeyDictionary

import numpy as np

import matplotlib as mpl

from matplotlib import (

backend_tools as tools, cbook, colors, textpath, tight_bbox, transforms,

widgets, get_backend, is_interactive, rcParams)

from matplotlib._pylab_helpers import Gcf

from matplotlib.transforms import Affine2D

from matplotlib.path import Path

try:

from PIL import PILLOW_VERSION

from distutils.version import LooseVersion

if LooseVersion(PILLOW_VERSION) >= "3.4":

_has_pil = True

else:

_has_pil = False

del PILLOW_VERSION

except ImportError:

_has_pil = False

_log = logging.getLogger(__name__)

_default_filetypes = {

'ps': 'Postscript',

'eps': 'Encapsulated Postscript',

'pdf': 'Portable Document Format',

'pgf': 'PGF code for LaTeX',

'png': 'Portable Network Graphics',

'raw': 'Raw RGBA bitmap',

'rgba': 'Raw RGBA bitmap',

'svg': 'Scalable Vector Graphics',

'svgz': 'Scalable Vector Graphics'

}

_default_backends = {

'ps': 'matplotlib.backends.backend_ps',

'eps': 'matplotlib.backends.backend_ps',

'pdf': 'matplotlib.backends.backend_pdf',

'pgf': 'matplotlib.backends.backend_pgf',

'png': 'matplotlib.backends.backend_agg',

'raw': 'matplotlib.backends.backend_agg',

'rgba': 'matplotlib.backends.backend_agg',

'svg': 'matplotlib.backends.backend_svg',

'svgz': 'matplotlib.backends.backend_svg',

}

<div class="viewcode-block" id="register_backend"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.register_backend">[docs]</a>def register_backend(format, backend, description=None):

"""

Register a backend for saving to a given file format.

Parameters

----------

format : str

File extension

backend : module string or canvas class

Backend for handling file output

description : str, optional

Description of the file type. Defaults to an empty string

"""

if description is None:

description = ''

_default_backends[format] = backend

_default_filetypes[format] = description</div>

<div class="viewcode-block" id="get_registered_canvas_class"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.get_registered_canvas_class">[docs]</a>def get_registered_canvas_class(format):

"""

Return the registered default canvas for given file format.

Handles deferred import of required backend.

"""

if format not in _default_backends:

return None

backend_class = _default_backends[format]

if isinstance(backend_class, str):

backend_class = importlib.import_module(backend_class).FigureCanvas

_default_backends[format] = backend_class

return backend_class</div>

<div class="viewcode-block" id="RendererBase"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase">[docs]</a>class RendererBase(object):

"""An abstract base class to handle drawing/rendering operations.

The following methods must be implemented in the backend for full

functionality (though just implementing :meth:`draw_path` alone would

give a highly capable backend):

* :meth:`draw_path`

* :meth:`draw_image`

* :meth:`draw_gouraud_triangle`

The following methods *should* be implemented in the backend for

optimization reasons:

* :meth:`draw_text`

* :meth:`draw_markers`

* :meth:`draw_path_collection`

* :meth:`draw_quad_mesh`

"""

def __init__(self):

self._texmanager = None

self._text2path = textpath.TextToPath()

<div class="viewcode-block" id="RendererBase.open_group"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.open_group">[docs]</a> def open_group(self, s, gid=None):

"""

Open a grouping element with label *s* and *gid* (if set) as id.

Only used by the SVG renderer.

"""</div>

<div class="viewcode-block" id="RendererBase.close_group"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.close_group">[docs]</a> def close_group(self, s):

"""

Close a grouping element with label *s*

Only used by the SVG renderer.

"""</div>

<div class="viewcode-block" id="RendererBase.draw_path"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_path">[docs]</a> def draw_path(self, gc, path, transform, rgbFace=None):

"""

Draws a :class:`~matplotlib.path.Path` instance using the

given affine transform.

"""

raise NotImplementedError</div>

<div class="viewcode-block" id="RendererBase.draw_markers"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_markers">[docs]</a> def draw_markers(self, gc, marker_path, marker_trans, path,

trans, rgbFace=None):

"""

Draws a marker at each of the vertices in path. This includes

all vertices, including control points on curves. To avoid

that behavior, those vertices should be removed before calling

this function.

This provides a fallback implementation of draw_markers that

makes multiple calls to :meth:`draw_path`. Some backends may

want to override this method in order to draw the marker only

once and reuse it multiple times.

Parameters

----------

gc : `GraphicsContextBase`

The graphics context

marker_trans : `matplotlib.transforms.Transform`

An affine transform applied to the marker.

trans : `matplotlib.transforms.Transform`

An affine transform applied to the path.

"""

for vertices, codes in path.iter_segments(trans, simplify=False):

if len(vertices):

x, y = vertices[-2:]

marker_trans +

transforms.Affine2D().translate(x, y),

rgbFace)</div>

<div class="viewcode-block" id="RendererBase.draw_path_collection"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_path_collection">[docs]</a> def draw_path_collection(self, gc, master_transform, paths, all_transforms,

offsets, offsetTrans, facecolors, edgecolors,

linewidths, linestyles, antialiaseds, urls,

offset_position):

"""

Draws a collection of paths selecting drawing properties from

the lists *facecolors*, *edgecolors*, *linewidths*,

*linestyles* and *antialiaseds*. *offsets* is a list of

offsets to apply to each of the paths. The offsets in

*offsets* are first transformed by *offsetTrans* before being

applied. *offset_position* may be either "screen" or "data"

depending on the space that the offsets are in.

This provides a fallback implementation of

:meth:`draw_path_collection` that makes multiple calls to

:meth:`draw_path`. Some backends may want to override this in

order to render each set of path data only once, and then

reference that path multiple times with the different offsets,

colors, styles etc. The generator methods

:meth:`_iter_collection_raw_paths` and

:meth:`_iter_collection` are provided to help with (and

standardize) the implementation across backends. It is highly

recommended to use those generators, so that changes to the

behavior of :meth:`draw_path_collection` can be made globally.

"""

path_ids = [

(path, transforms.Affine2D(transform))

for path, transform in self._iter_collection_raw_paths(

master_transform, paths, all_transforms)]

for xo, yo, path_id, gc0, rgbFace in self._iter_collection(

gc, master_transform, all_transforms, path_ids, offsets,

offsetTrans, facecolors, edgecolors, linewidths, linestyles,

antialiaseds, urls, offset_position):

path, transform = path_id

transform = transforms.Affine2D(

transform.get_matrix()).translate(xo, yo)

self.draw_path(gc0, path, transform, rgbFace)</div>

<div class="viewcode-block" id="RendererBase.draw_quad_mesh"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_quad_mesh">[docs]</a> def draw_quad_mesh(self, gc, master_transform, meshWidth, meshHeight,

coordinates, offsets, offsetTrans, facecolors,

antialiased, edgecolors):

"""

This provides a fallback implementation of

:meth:`draw_quad_mesh` that generates paths and then calls

:meth:`draw_path_collection`.

"""

from matplotlib.collections import QuadMesh

paths = QuadMesh.convert_mesh_to_paths(

meshWidth, meshHeight, coordinates)

if edgecolors is None:

edgecolors = facecolors

linewidths = np.array([gc.get_linewidth()], float)

return self.draw_path_collection(

gc, master_transform, paths, [], offsets, offsetTrans, facecolors,

edgecolors, linewidths, [], [antialiased], [None], 'screen')</div>

<div class="viewcode-block" id="RendererBase.draw_gouraud_triangle"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_gouraud_triangle">[docs]</a> def draw_gouraud_triangle(self, gc, points, colors, transform):

"""

Draw a Gouraud-shaded triangle.

Parameters

----------

points : array_like, shape=(3, 2)

Array of (x, y) points for the triangle.

colors : array_like, shape=(3, 4)

RGBA colors for each point of the triangle.

transform : `matplotlib.transforms.Transform`

An affine transform to apply to the points.

"""

raise NotImplementedError</div>

<div class="viewcode-block" id="RendererBase.draw_gouraud_triangles"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_gouraud_triangles">[docs]</a> def draw_gouraud_triangles(self, gc, triangles_array, colors_array,

transform):

"""

Draws a series of Gouraud triangles.

Parameters

----------

points : array_like, shape=(N, 3, 2)

Array of *N* (x, y) points for the triangles.

colors : array_like, shape=(N, 3, 4)

Array of *N* RGBA colors for each point of the triangles.

transform : `matplotlib.transforms.Transform`

An affine transform to apply to the points.

"""

transform = transform.frozen()

for tri, col in zip(triangles_array, colors_array):

self.draw_gouraud_triangle(gc, tri, col, transform)</div>

def _iter_collection_raw_paths(self, master_transform, paths,

all_transforms):

"""

This is a helper method (along with :meth:`_iter_collection`) to make

it easier to write a space-efficient :meth:`draw_path_collection`

implementation in a backend.

This method yields all of the base path/transform

combinations, given a master transform, a list of paths and

list of transforms.

The arguments should be exactly what is passed in to

:meth:`draw_path_collection`.

The backend should take each yielded path and transform and

create an object that can be referenced (reused) later.

"""

Npaths = len(paths)

Ntransforms = len(all_transforms)

N = max(Npaths, Ntransforms)

if Npaths == 0:

return

transform = transforms.IdentityTransform()

for i in range(N):

path = paths[i % Npaths]

if Ntransforms:

transform = Affine2D(all_transforms[i % Ntransforms])

yield path, transform + master_transform

def _iter_collection_uses_per_path(self, paths, all_transforms,

offsets, facecolors, edgecolors):

"""

Compute how many times each raw path object returned by

_iter_collection_raw_paths would be used when calling

_iter_collection. This is intended for the backend to decide

on the tradeoff between using the paths in-line and storing

them once and reusing. Rounds up in case the number of uses

is not the same for every path.

"""

Npaths = len(paths)

if Npaths == 0 or len(facecolors) == len(edgecolors) == 0:

return 0

Npath_ids = max(Npaths, len(all_transforms))

N = max(Npath_ids, len(offsets))

return (N + Npath_ids - 1) // Npath_ids

def _iter_collection(self, gc, master_transform, all_transforms,

path_ids, offsets, offsetTrans, facecolors,

edgecolors, linewidths, linestyles,

antialiaseds, urls, offset_position):

"""

This is a helper method (along with

:meth:`_iter_collection_raw_paths`) to make it easier to write

a space-efficient :meth:`draw_path_collection` implementation in a

backend.

This method yields all of the path, offset and graphics

context combinations to draw the path collection. The caller

should already have looped over the results of

:meth:`_iter_collection_raw_paths` to draw this collection.

The arguments should be the same as that passed into

:meth:`draw_path_collection`, with the exception of

*path_ids*, which is a list of arbitrary objects that the

backend will use to reference one of the paths created in the

:meth:`_iter_collection_raw_paths` stage.

Each yielded result is of the form::

xo, yo, path_id, gc, rgbFace

where *xo*, *yo* is an offset; *path_id* is one of the elements of

*path_ids*; *gc* is a graphics context and *rgbFace* is a color to

use for filling the path.

"""

Ntransforms = len(all_transforms)

Npaths = len(path_ids)

Noffsets = len(offsets)

Nfacecolors = len(facecolors)

Nedgecolors = len(edgecolors)

Nlinewidths = len(linewidths)

Nlinestyles = len(linestyles)

Naa = len(antialiaseds)

Nurls = len(urls)

if (Nfacecolors == 0 and Nedgecolors == 0) or Npaths == 0:

return

if Noffsets:

toffsets = offsetTrans.transform(offsets)

gc0 = self.new_gc()

gc0.copy_properties(gc)

if Nfacecolors == 0:

rgbFace = None

if Nedgecolors == 0:

gc0.set_linewidth(0.0)

xo, yo = 0, 0

for i in range(N):

path_id = path_ids[i % Npaths]

if Noffsets:

xo, yo = toffsets[i % Noffsets]

if offset_position == 'data':

if Ntransforms:

transform = (

Affine2D(all_transforms[i % Ntransforms]) +

master_transform)

else:

transform = master_transform

xo, yo = transform.transform_point((xo, yo))

xp, yp = transform.transform_point((0, 0))

xo = -(xp - xo)

yo = -(yp - yo)

if not (np.isfinite(xo) and np.isfinite(yo)):

continue

if Nfacecolors:

rgbFace = facecolors[i % Nfacecolors]

if Nedgecolors:

if Nlinewidths:

gc0.set_linewidth(linewidths[i % Nlinewidths])

if Nlinestyles:

gc0.set_dashes(*linestyles[i % Nlinestyles])

fg = edgecolors[i % Nedgecolors]

if len(fg) == 4:

if fg[3] == 0.0:

gc0.set_linewidth(0)

else:

gc0.set_foreground(fg)

else:

gc0.set_foreground(fg)

if rgbFace is not None and len(rgbFace) == 4:

if rgbFace[3] == 0:

rgbFace = None

gc0.set_antialiased(antialiaseds[i % Naa])

if Nurls:

gc0.set_url(urls[i % Nurls])

yield xo, yo, path_id, gc0, rgbFace

gc0.restore()

<div class="viewcode-block" id="RendererBase.get_image_magnification"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.get_image_magnification">[docs]</a> def get_image_magnification(self):

"""

Get the factor by which to magnify images passed to :meth:`draw_image`.

Allows a backend to have images at a different resolution to other

artists.

"""

return 1.0</div>

<div class="viewcode-block" id="RendererBase.draw_image"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_image">[docs]</a> def draw_image(self, gc, x, y, im, transform=None):

"""

Draw an RGBA image.

Parameters

----------

gc : `GraphicsContextBase`

a graphics context with clipping information.

x : scalar

the distance in physical units (i.e., dots or pixels) from the left

hand side of the canvas.

y : scalar

the distance in physical units (i.e., dots or pixels) from the

bottom side of the canvas.

im : array_like, shape=(N, M, 4), dtype=np.uint8

An array of RGBA pixels.

transform : `matplotlib.transforms.Affine2DBase`

If and only if the concrete backend is written such that

:meth:`option_scale_image` returns ``True``, an affine

transformation *may* be passed to :meth:`draw_image`. It takes the

form of a :class:`~matplotlib.transforms.Affine2DBase` instance.

The translation vector of the transformation is given in physical

units (i.e., dots or pixels). Note that the transformation does not

override `x` and `y`, and has to be applied *before* translating

the result by `x` and `y` (this can be accomplished by adding `x`

and `y` to the translation vector defined by `transform`).

"""

raise NotImplementedError</div>

<div class="viewcode-block" id="RendererBase.option_image_nocomposite"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.option_image_nocomposite">[docs]</a> def option_image_nocomposite(self):

"""

Return whether image composition by Matplotlib should be skipped.

Raster backends should usually return False (letting the C-level

rasterizer take care of image composition); vector backends should

usually return ``not rcParams["image.composite_image"]``.

"""

return False</div>

<div class="viewcode-block" id="RendererBase.option_scale_image"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.option_scale_image">[docs]</a> def option_scale_image(self):

"""

Return whether arbitrary affine transformations in :meth:`draw_image`

are supported (True for most vector backends).

"""

return False</div>

<div class="viewcode-block" id="RendererBase.draw_tex"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_tex">[docs]</a> def draw_tex(self, gc, x, y, s, prop, angle, ismath='TeX!', mtext=None):

"""

"""

self._draw_text_as_path(gc, x, y, s, prop, angle, ismath="TeX")</div>

<div class="viewcode-block" id="RendererBase.draw_text"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.draw_text">[docs]</a> def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):

"""

Draw the text instance.

Parameters

----------

gc : `GraphicsContextBase`

The graphics context.

x : scalar

The x location of the text in display coords.

y : scalar

The y location of the text baseline in display coords.

s : str

The text string.

prop : `matplotlib.font_manager.FontProperties`

The font properties.

angle : scalar

The rotation angle in degrees.

mtext : `matplotlib.text.Text`

The original text object to be rendered.

Notes

-----

**backend implementers note**

When you are trying to determine if you have gotten your bounding box

right (which is what enables the text layout/alignment to work

properly), it helps to change the line in text.py::

if 0: bbox_artist(self, renderer)

to if 1, and then the actual bounding box will be plotted along with

your text.

"""

def _get_text_path_transform(self, x, y, s, prop, angle, ismath):

"""

Return the text path and transform.

Parameters

----------

prop : `matplotlib.font_manager.FontProperties`

The font property.

s : str

The text to be converted.

ismath : bool or "TeX"

If True, use mathtext parser. If "TeX", use *usetex* mode.

"""

text2path = self._text2path

fontsize = self.points_to_pixels(prop.get_size_in_points())

verts, codes = text2path.get_text_path(prop, s, ismath=ismath)

path = Path(verts, codes)

angle = np.deg2rad(angle)

if self.flipy():

transform = Affine2D().scale(fontsize / text2path.FONT_SCALE,

fontsize / text2path.FONT_SCALE)

transform = transform.rotate(angle).translate(x, self.height - y)

else:

fontsize / text2path.FONT_SCALE)

return path, transform

def _draw_text_as_path(self, gc, x, y, s, prop, angle, ismath):

"""

Draw the text by converting them to paths using textpath module.

Parameters

----------

prop : `matplotlib.font_manager.FontProperties`

The font property.

s : str

The text to be converted.

usetex : bool

Whether to use matplotlib usetex mode.

ismath : bool or "TeX"

If True, use mathtext parser. If "TeX", use *usetex* mode.

"""

path, transform = self._get_text_path_transform(

x, y, s, prop, angle, ismath)

color = gc.get_rgb()

gc.set_linewidth(0.0)

self.draw_path(gc, path, transform, rgbFace=color)

<div class="viewcode-block" id="RendererBase.get_text_width_height_descent"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.get_text_width_height_descent">[docs]</a> def get_text_width_height_descent(self, s, prop, ismath):

"""

Get the width, height, and descent (offset from the bottom

to the baseline), in display coords, of the string *s* with

:class:`~matplotlib.font_manager.FontProperties` *prop*

"""

if ismath == 'TeX':

# todo: handle props

texmanager = self._text2path.get_texmanager()

fontsize = prop.get_size_in_points()

w, h, d = texmanager.get_text_width_height_descent(

s, fontsize, renderer=self)

return w, h, d

dpi = self.points_to_pixels(72)

if ismath:

dims = self._text2path.mathtext_parser.parse(s, dpi, prop)

return dims[0:3] # return width, height, descent

flags = self._text2path._get_hinting_flag()

font = self._text2path._get_font(prop)

size = prop.get_size_in_points()

font.set_size(size, dpi)

# the width and height of unrotated string

font.set_text(s, 0.0, flags=flags)

w, h = font.get_width_height()

d = font.get_descent()

w /= 64.0 # convert from subpixels

h /= 64.0

d /= 64.0

return w, h, d</div>

<div class="viewcode-block" id="RendererBase.flipy"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.flipy">[docs]</a> def flipy(self):

"""

Return whether y values increase from top to bottom.

Note that this only affects drawing of texts and images.

"""

return True</div>

<div class="viewcode-block" id="RendererBase.get_canvas_width_height"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.get_canvas_width_height">[docs]</a> def get_canvas_width_height(self):

"""Return the canvas width and height in display coords."""

return 1, 1</div>

<div class="viewcode-block" id="RendererBase.get_texmanager"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.get_texmanager">[docs]</a> def get_texmanager(self):

"""Return the `.TexManager` instance."""

if self._texmanager is None:

from matplotlib.texmanager import TexManager

self._texmanager = TexManager()

return self._texmanager</div>

<div class="viewcode-block" id="RendererBase.new_gc"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.new_gc">[docs]</a> def new_gc(self):

"""Return an instance of a `GraphicsContextBase`."""

return GraphicsContextBase()</div>

<div class="viewcode-block" id="RendererBase.points_to_pixels"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.points_to_pixels">[docs]</a> def points_to_pixels(self, points):

"""

Convert points to display units.

You need to override this function (unless your backend

doesn't have a dpi, e.g., postscript or svg). Some imaging

systems assume some value for pixels per inch::

points to pixels = points * pixels_per_inch/72.0 * dpi/72.0

Parameters

----------

points : scalar or array_like

a float or a numpy array of float

Returns

-------

Points converted to pixels

"""

return points</div>

<div class="viewcode-block" id="RendererBase.strip_math"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.strip_math">[docs]</a> @cbook.deprecated("3.1", alternative="cbook.strip_math")

def strip_math(self, s):

return cbook.strip_math(s)</div>

<div class="viewcode-block" id="RendererBase.start_rasterizing"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.start_rasterizing">[docs]</a> def start_rasterizing(self):

"""

Switch to the raster renderer.

Used by `MixedModeRenderer`.

"""</div>

<div class="viewcode-block" id="RendererBase.stop_rasterizing"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.stop_rasterizing">[docs]</a> def stop_rasterizing(self):

"""

Switch back to the vector renderer and draw the contents of the raster

renderer as an image on the vector renderer.

Used by `MixedModeRenderer`.

"""</div>

<div class="viewcode-block" id="RendererBase.start_filter"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.start_filter">[docs]</a> def start_filter(self):

"""

Switch to a temporary renderer for image filtering effects.

Currently only supported by the agg renderer.

"""</div>

<div class="viewcode-block" id="RendererBase.stop_filter"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.RendererBase.stop_filter">[docs]</a> def stop_filter(self, filter_func):

"""

Switch back to the original renderer. The contents of the temporary

renderer is processed with the *filter_func* and is drawn on the

original renderer as an image.

Currently only supported by the agg renderer.

"""</div></div>

<div class="viewcode-block" id="GraphicsContextBase"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase">[docs]</a>class GraphicsContextBase(object):

"""An abstract base class that provides color, line styles, etc."""

def __init__(self):

self._alpha = 1.0

self._forced_alpha = False # if True, _alpha overrides A from RGBA

self._antialiased = 1 # use 0,1 not True, False for extension code

self._capstyle = 'butt'

self._cliprect = None

self._clippath = None

self._dashes = None, None

self._joinstyle = 'round'

self._linestyle = 'solid'

self._linewidth = 1

self._rgb = (0.0, 0.0, 0.0, 1.0)

self._hatch = None

self._hatch_color = colors.to_rgba(rcParams['hatch.color'])

self._hatch_linewidth = rcParams['hatch.linewidth']

self._url = None

self._gid = None

self._snap = None

self._sketch = None

<div class="viewcode-block" id="GraphicsContextBase.copy_properties"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.copy_properties">[docs]</a> def copy_properties(self, gc):

'Copy properties from gc to self'

self._alpha = gc._alpha

self._forced_alpha = gc._forced_alpha

self._antialiased = gc._antialiased

self._capstyle = gc._capstyle

self._cliprect = gc._cliprect

self._clippath = gc._clippath

self._dashes = gc._dashes

self._joinstyle = gc._joinstyle

self._linestyle = gc._linestyle

self._linewidth = gc._linewidth

self._rgb = gc._rgb

self._hatch = gc._hatch

self._hatch_color = gc._hatch_color

self._hatch_linewidth = gc._hatch_linewidth

self._url = gc._url

self._gid = gc._gid

self._snap = gc._snap

self._sketch = gc._sketch</div>

<div class="viewcode-block" id="GraphicsContextBase.restore"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.restore">[docs]</a> def restore(self):

"""

Restore the graphics context from the stack - needed only

for backends that save graphics contexts on a stack.

"""</div>

<div class="viewcode-block" id="GraphicsContextBase.get_alpha"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_alpha">[docs]</a> def get_alpha(self):

"""

Return the alpha value used for blending - not supported on

all backends.

"""

return self._alpha</div>

<div class="viewcode-block" id="GraphicsContextBase.get_antialiased"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_antialiased">[docs]</a> def get_antialiased(self):

"Return whether the object should try to do antialiased rendering."

return self._antialiased</div>

<div class="viewcode-block" id="GraphicsContextBase.get_capstyle"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_capstyle">[docs]</a> def get_capstyle(self):

"""

Return the capstyle as a string in ('butt', 'round', 'projecting').

"""

return self._capstyle</div>

<div class="viewcode-block" id="GraphicsContextBase.get_clip_rectangle"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_clip_rectangle">[docs]</a> def get_clip_rectangle(self):

"""

Return the clip rectangle as a `~matplotlib.transforms.Bbox` instance.

"""

return self._cliprect</div>

<div class="viewcode-block" id="GraphicsContextBase.get_clip_path"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_clip_path">[docs]</a> def get_clip_path(self):

"""

Return the clip path in the form (path, transform), where path

is a :class:`~matplotlib.path.Path` instance, and transform is

an affine transform to apply to the path before clipping.

"""

if self._clippath is not None:

return self._clippath.get_transformed_path_and_affine()

return None, None</div>

<div class="viewcode-block" id="GraphicsContextBase.get_dashes"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_dashes">[docs]</a> def get_dashes(self):

"""

Return the dash information as an offset dashlist tuple.

The dash list is a even size list that gives the ink on, ink

off in pixels.

See p107 of to PostScript `BLUEBOOK

<https://www-cdf.fnal.gov/offline/PostScript/BLUEBOOK.PDF>`_

for more info.

Default value is None

"""

return self._dashes</div>

<div class="viewcode-block" id="GraphicsContextBase.get_forced_alpha"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_forced_alpha">[docs]</a> def get_forced_alpha(self):

"""

Return whether the value given by get_alpha() should be used to

override any other alpha-channel values.

"""

return self._forced_alpha</div>

<div class="viewcode-block" id="GraphicsContextBase.get_joinstyle"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_joinstyle">[docs]</a> def get_joinstyle(self):

"""Return the line join style as one of ('miter', 'round', 'bevel')."""

return self._joinstyle</div>

<div class="viewcode-block" id="GraphicsContextBase.get_linewidth"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_linewidth">[docs]</a> def get_linewidth(self):

"""Return the line width in points."""

return self._linewidth</div>

<div class="viewcode-block" id="GraphicsContextBase.get_rgb"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_rgb">[docs]</a> def get_rgb(self):

"""Return a tuple of three or four floats from 0-1."""

return self._rgb</div>

<div class="viewcode-block" id="GraphicsContextBase.get_url"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_url">[docs]</a> def get_url(self):

"""Return a url if one is set, None otherwise."""

return self._url</div>

<div class="viewcode-block" id="GraphicsContextBase.get_gid"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_gid">[docs]</a> def get_gid(self):

"""Return the object identifier if one is set, None otherwise."""

return self._gid</div>

<div class="viewcode-block" id="GraphicsContextBase.get_snap"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.get_snap">[docs]</a> def get_snap(self):

"""

Returns the snap setting, which can be:

* True: snap vertices to the nearest pixel center

* False: leave vertices as-is

* None: (auto) If the path contains only rectilinear line segments,

round to the nearest pixel center

"""

return self._snap</div>

<div class="viewcode-block" id="GraphicsContextBase.set_alpha"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.set_alpha">[docs]</a> def set_alpha(self, alpha):

"""

Set the alpha value used for blending - not supported on all backends.

If ``alpha=None`` (the default), the alpha components of the

foreground and fill colors will be used to set their respective

transparencies (where applicable); otherwise, ``alpha`` will override

them.

"""

if alpha is not None:

self._alpha = alpha

self._forced_alpha = True

else:

self._alpha = 1.0

self._forced_alpha = False

self.set_foreground(self._rgb, isRGBA=True)</div>

<div class="viewcode-block" id="GraphicsContextBase.set_antialiased"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.set_antialiased">[docs]</a> def set_antialiased(self, b):

"""Set whether object should be drawn with antialiased rendering."""

# Use ints to make life easier on extension code trying to read the gc.

self._antialiased = int(bool(b))</div>

<div class="viewcode-block" id="GraphicsContextBase.set_capstyle"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.set_capstyle">[docs]</a> def set_capstyle(self, cs):

"""Set the capstyle to be one of ('butt', 'round', 'projecting')."""

if cs in ('butt', 'round', 'projecting'):

self._capstyle = cs

else:

raise ValueError('Unrecognized cap style. Found %s' % cs)</div>

<div class="viewcode-block" id="GraphicsContextBase.set_clip_rectangle"><a class="viewcode-back" href="../../api/backend_bases_api.html#matplotlib.backend_bases.GraphicsContextBase.set_clip_rectangle">[docs]</a> def set_clip_rectangle(self, rectangle):

"""

Set the clip rectangle with sequence (left, bottom, width, height)

"""

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