forked from 170010011/fr
1216 lines
46 KiB
Python
1216 lines
46 KiB
Python
"""
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The legend module defines the Legend class, which is responsible for
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drawing legends associated with axes and/or figures.
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.. important::
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It is unlikely that you would ever create a Legend instance manually.
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Most users would normally create a legend via the `~.Axes.legend`
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function. For more details on legends there is also a :doc:`legend guide
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</tutorials/intermediate/legend_guide>`.
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The `Legend` class is a container of legend handles and legend texts.
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The legend handler map specifies how to create legend handles from artists
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(lines, patches, etc.) in the axes or figures. Default legend handlers are
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defined in the :mod:`~matplotlib.legend_handler` module. While not all artist
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types are covered by the default legend handlers, custom legend handlers can be
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defined to support arbitrary objects.
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See the :doc:`legend guide </tutorials/intermediate/legend_guide>` for more
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information.
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"""
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import itertools
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import logging
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import time
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import numpy as np
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import matplotlib as mpl
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from matplotlib import cbook, docstring, colors
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from matplotlib.artist import Artist, allow_rasterization
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from matplotlib.cbook import silent_list
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from matplotlib.font_manager import FontProperties
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from matplotlib.lines import Line2D
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from matplotlib.patches import Patch, Rectangle, Shadow, FancyBboxPatch
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from matplotlib.collections import (LineCollection, RegularPolyCollection,
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CircleCollection, PathCollection,
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PolyCollection)
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from matplotlib.transforms import Bbox, BboxBase, TransformedBbox
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from matplotlib.transforms import BboxTransformTo, BboxTransformFrom
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from matplotlib.offsetbox import HPacker, VPacker, TextArea, DrawingArea
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from matplotlib.offsetbox import DraggableOffsetBox
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from matplotlib.container import ErrorbarContainer, BarContainer, StemContainer
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from . import legend_handler
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class DraggableLegend(DraggableOffsetBox):
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def __init__(self, legend, use_blit=False, update="loc"):
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"""
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Wrapper around a `.Legend` to support mouse dragging.
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Parameters
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----------
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legend : `.Legend`
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The `.Legend` instance to wrap.
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use_blit : bool, optional
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Use blitting for faster image composition. For details see
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:ref:`func-animation`.
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update : {'loc', 'bbox'}, optional
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If "loc", update the *loc* parameter of the legend upon finalizing.
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If "bbox", update the *bbox_to_anchor* parameter.
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"""
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self.legend = legend
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cbook._check_in_list(["loc", "bbox"], update=update)
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self._update = update
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DraggableOffsetBox.__init__(self, legend, legend._legend_box,
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use_blit=use_blit)
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def finalize_offset(self):
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if self._update == "loc":
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self._update_loc(self.get_loc_in_canvas())
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elif self._update == "bbox":
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self._bbox_to_anchor(self.get_loc_in_canvas())
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def _update_loc(self, loc_in_canvas):
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bbox = self.legend.get_bbox_to_anchor()
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# if bbox has zero width or height, the transformation is
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# ill-defined. Fall back to the default bbox_to_anchor.
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if bbox.width == 0 or bbox.height == 0:
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self.legend.set_bbox_to_anchor(None)
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bbox = self.legend.get_bbox_to_anchor()
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_bbox_transform = BboxTransformFrom(bbox)
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self.legend._loc = tuple(_bbox_transform.transform(loc_in_canvas))
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def _update_bbox_to_anchor(self, loc_in_canvas):
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loc_in_bbox = self.legend.axes.transAxes.transform(loc_in_canvas)
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self.legend.set_bbox_to_anchor(loc_in_bbox)
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docstring.interpd.update(_legend_kw_doc="""
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loc : str or pair of floats, default: :rc:`legend.loc` ('best' for axes, \
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'upper right' for figures)
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The location of the legend.
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The strings
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``'upper left', 'upper right', 'lower left', 'lower right'``
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place the legend at the corresponding corner of the axes/figure.
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The strings
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``'upper center', 'lower center', 'center left', 'center right'``
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place the legend at the center of the corresponding edge of the
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axes/figure.
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The string ``'center'`` places the legend at the center of the axes/figure.
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The string ``'best'`` places the legend at the location, among the nine
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locations defined so far, with the minimum overlap with other drawn
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artists. This option can be quite slow for plots with large amounts of
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data; your plotting speed may benefit from providing a specific location.
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The location can also be a 2-tuple giving the coordinates of the lower-left
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corner of the legend in axes coordinates (in which case *bbox_to_anchor*
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will be ignored).
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For back-compatibility, ``'center right'`` (but no other location) can also
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be spelled ``'right'``, and each "string" locations can also be given as a
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numeric value:
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=============== =============
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Location String Location Code
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=============== =============
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'best' 0
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'upper right' 1
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'upper left' 2
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'lower left' 3
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'lower right' 4
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'right' 5
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'center left' 6
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'center right' 7
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'lower center' 8
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'upper center' 9
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'center' 10
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=============== =============
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bbox_to_anchor : `.BboxBase`, 2-tuple, or 4-tuple of floats
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Box that is used to position the legend in conjunction with *loc*.
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Defaults to `axes.bbox` (if called as a method to `.Axes.legend`) or
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`figure.bbox` (if `.Figure.legend`). This argument allows arbitrary
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placement of the legend.
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Bbox coordinates are interpreted in the coordinate system given by
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*bbox_transform*, with the default transform
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Axes or Figure coordinates, depending on which ``legend`` is called.
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If a 4-tuple or `.BboxBase` is given, then it specifies the bbox
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``(x, y, width, height)`` that the legend is placed in.
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To put the legend in the best location in the bottom right
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quadrant of the axes (or figure)::
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loc='best', bbox_to_anchor=(0.5, 0., 0.5, 0.5)
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A 2-tuple ``(x, y)`` places the corner of the legend specified by *loc* at
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x, y. For example, to put the legend's upper right-hand corner in the
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center of the axes (or figure) the following keywords can be used::
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loc='upper right', bbox_to_anchor=(0.5, 0.5)
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ncol : int, default: 1
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The number of columns that the legend has.
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prop : None or `matplotlib.font_manager.FontProperties` or dict
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The font properties of the legend. If None (default), the current
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:data:`matplotlib.rcParams` will be used.
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fontsize : int or {'xx-small', 'x-small', 'small', 'medium', 'large', \
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'x-large', 'xx-large'}
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The font size of the legend. If the value is numeric the size will be the
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absolute font size in points. String values are relative to the current
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default font size. This argument is only used if *prop* is not specified.
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labelcolor : str or list
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Sets the color of the text in the legend. Can be a valid color string
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(for example, 'red'), or a list of color strings. The labelcolor can
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also be made to match the color of the line or marker using 'linecolor',
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'markerfacecolor' (or 'mfc'), or 'markeredgecolor' (or 'mec').
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numpoints : int, default: :rc:`legend.numpoints`
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The number of marker points in the legend when creating a legend
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entry for a `.Line2D` (line).
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scatterpoints : int, default: :rc:`legend.scatterpoints`
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The number of marker points in the legend when creating
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a legend entry for a `.PathCollection` (scatter plot).
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scatteryoffsets : iterable of floats, default: ``[0.375, 0.5, 0.3125]``
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The vertical offset (relative to the font size) for the markers
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created for a scatter plot legend entry. 0.0 is at the base the
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legend text, and 1.0 is at the top. To draw all markers at the
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same height, set to ``[0.5]``.
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markerscale : float, default: :rc:`legend.markerscale`
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The relative size of legend markers compared with the originally
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drawn ones.
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markerfirst : bool, default: True
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If *True*, legend marker is placed to the left of the legend label.
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If *False*, legend marker is placed to the right of the legend label.
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frameon : bool, default: :rc:`legend.frameon`
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Whether the legend should be drawn on a patch (frame).
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fancybox : bool, default: :rc:`legend.fancybox`
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Whether round edges should be enabled around the `~.FancyBboxPatch` which
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makes up the legend's background.
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shadow : bool, default: :rc:`legend.shadow`
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Whether to draw a shadow behind the legend.
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framealpha : float, default: :rc:`legend.framealpha`
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The alpha transparency of the legend's background.
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If *shadow* is activated and *framealpha* is ``None``, the default value is
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ignored.
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facecolor : "inherit" or color, default: :rc:`legend.facecolor`
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The legend's background color.
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If ``"inherit"``, use :rc:`axes.facecolor`.
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edgecolor : "inherit" or color, default: :rc:`legend.edgecolor`
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The legend's background patch edge color.
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If ``"inherit"``, use take :rc:`axes.edgecolor`.
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mode : {"expand", None}
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If *mode* is set to ``"expand"`` the legend will be horizontally
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expanded to fill the axes area (or *bbox_to_anchor* if defines
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the legend's size).
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bbox_transform : None or `matplotlib.transforms.Transform`
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The transform for the bounding box (*bbox_to_anchor*). For a value
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of ``None`` (default) the Axes'
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:data:`~matplotlib.axes.Axes.transAxes` transform will be used.
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title : str or None
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The legend's title. Default is no title (``None``).
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title_fontsize : int or {'xx-small', 'x-small', 'small', 'medium', 'large', \
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'x-large', 'xx-large'}, default: :rc:`legend.title_fontsize`
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The font size of the legend's title.
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borderpad : float, default: :rc:`legend.borderpad`
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The fractional whitespace inside the legend border, in font-size units.
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labelspacing : float, default: :rc:`legend.labelspacing`
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The vertical space between the legend entries, in font-size units.
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handlelength : float, default: :rc:`legend.handlelength`
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The length of the legend handles, in font-size units.
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handletextpad : float, default: :rc:`legend.handletextpad`
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The pad between the legend handle and text, in font-size units.
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borderaxespad : float, default: :rc:`legend.borderaxespad`
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The pad between the axes and legend border, in font-size units.
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columnspacing : float, default: :rc:`legend.columnspacing`
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The spacing between columns, in font-size units.
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handler_map : dict or None
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The custom dictionary mapping instances or types to a legend
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handler. This *handler_map* updates the default handler map
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found at `matplotlib.legend.Legend.get_legend_handler_map`.
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""")
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class Legend(Artist):
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"""
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Place a legend on the axes at location loc.
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"""
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codes = {'best': 0, # only implemented for axes legends
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'upper right': 1,
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'upper left': 2,
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'lower left': 3,
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'lower right': 4,
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'right': 5,
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'center left': 6,
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'center right': 7,
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'lower center': 8,
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'upper center': 9,
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'center': 10,
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}
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zorder = 5
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def __str__(self):
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return "Legend"
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@docstring.dedent_interpd
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def __init__(self, parent, handles, labels,
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loc=None,
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numpoints=None, # the number of points in the legend line
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markerscale=None, # the relative size of legend markers
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# vs. original
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markerfirst=True, # controls ordering (left-to-right) of
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# legend marker and label
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scatterpoints=None, # number of scatter points
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scatteryoffsets=None,
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prop=None, # properties for the legend texts
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fontsize=None, # keyword to set font size directly
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labelcolor=None, # keyword to set the text color
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# spacing & pad defined as a fraction of the font-size
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borderpad=None, # the whitespace inside the legend border
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labelspacing=None, # the vertical space between the legend
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# entries
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handlelength=None, # the length of the legend handles
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handleheight=None, # the height of the legend handles
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handletextpad=None, # the pad between the legend handle
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# and text
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borderaxespad=None, # the pad between the axes and legend
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# border
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columnspacing=None, # spacing between columns
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ncol=1, # number of columns
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mode=None, # mode for horizontal distribution of columns.
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# None, "expand"
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fancybox=None, # True use a fancy box, false use a rounded
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# box, none use rc
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shadow=None,
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title=None, # set a title for the legend
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title_fontsize=None, # the font size for the title
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framealpha=None, # set frame alpha
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edgecolor=None, # frame patch edgecolor
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facecolor=None, # frame patch facecolor
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bbox_to_anchor=None, # bbox that the legend will be anchored.
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bbox_transform=None, # transform for the bbox
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frameon=None, # draw frame
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handler_map=None,
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):
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"""
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Parameters
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----------
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parent : `~matplotlib.axes.Axes` or `.Figure`
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The artist that contains the legend.
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handles : list of `.Artist`
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A list of Artists (lines, patches) to be added to the legend.
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labels : list of str
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A list of labels to show next to the artists. The length of handles
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and labels should be the same. If they are not, they are truncated
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to the smaller of both lengths.
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Other Parameters
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----------------
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%(_legend_kw_doc)s
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Notes
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-----
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Users can specify any arbitrary location for the legend using the
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*bbox_to_anchor* keyword argument. *bbox_to_anchor* can be a
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`.BboxBase` (or derived therefrom) or a tuple of 2 or 4 floats.
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See `set_bbox_to_anchor` for more detail.
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The legend location can be specified by setting *loc* with a tuple of
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2 floats, which is interpreted as the lower-left corner of the legend
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in the normalized axes coordinate.
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"""
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# local import only to avoid circularity
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from matplotlib.axes import Axes
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from matplotlib.figure import Figure
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Artist.__init__(self)
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if prop is None:
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if fontsize is not None:
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self.prop = FontProperties(size=fontsize)
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else:
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self.prop = FontProperties(
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size=mpl.rcParams["legend.fontsize"])
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else:
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self.prop = FontProperties._from_any(prop)
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if isinstance(prop, dict) and "size" not in prop:
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self.prop.set_size(mpl.rcParams["legend.fontsize"])
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self._fontsize = self.prop.get_size_in_points()
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self.texts = []
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self.legendHandles = []
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self._legend_title_box = None
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#: A dictionary with the extra handler mappings for this Legend
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#: instance.
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self._custom_handler_map = handler_map
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locals_view = locals()
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for name in ["numpoints", "markerscale", "shadow", "columnspacing",
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"scatterpoints", "handleheight", 'borderpad',
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'labelspacing', 'handlelength', 'handletextpad',
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'borderaxespad']:
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if locals_view[name] is None:
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value = mpl.rcParams["legend." + name]
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else:
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value = locals_view[name]
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setattr(self, name, value)
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del locals_view
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# trim handles and labels if illegal label...
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_lab, _hand = [], []
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for label, handle in zip(labels, handles):
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if isinstance(label, str) and label.startswith('_'):
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cbook._warn_external('The handle {!r} has a label of {!r} '
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'which cannot be automatically added to'
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' the legend.'.format(handle, label))
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else:
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_lab.append(label)
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_hand.append(handle)
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labels, handles = _lab, _hand
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handles = list(handles)
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if len(handles) < 2:
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ncol = 1
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self._ncol = ncol
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if self.numpoints <= 0:
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raise ValueError("numpoints must be > 0; it was %d" % numpoints)
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# introduce y-offset for handles of the scatter plot
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if scatteryoffsets is None:
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self._scatteryoffsets = np.array([3. / 8., 4. / 8., 2.5 / 8.])
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else:
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self._scatteryoffsets = np.asarray(scatteryoffsets)
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reps = self.scatterpoints // len(self._scatteryoffsets) + 1
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self._scatteryoffsets = np.tile(self._scatteryoffsets,
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reps)[:self.scatterpoints]
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# _legend_box is a VPacker instance that contains all
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# legend items and will be initialized from _init_legend_box()
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# method.
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self._legend_box = None
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if isinstance(parent, Axes):
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self.isaxes = True
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self.axes = parent
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self.set_figure(parent.figure)
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elif isinstance(parent, Figure):
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self.isaxes = False
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self.set_figure(parent)
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else:
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raise TypeError("Legend needs either Axes or Figure as parent")
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self.parent = parent
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self._loc_used_default = loc is None
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if loc is None:
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loc = mpl.rcParams["legend.loc"]
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if not self.isaxes and loc in [0, 'best']:
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loc = 'upper right'
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if isinstance(loc, str):
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if loc not in self.codes:
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raise ValueError(
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"Unrecognized location {!r}. Valid locations are\n\t{}\n"
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.format(loc, '\n\t'.join(self.codes)))
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else:
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loc = self.codes[loc]
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if not self.isaxes and loc == 0:
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raise ValueError(
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"Automatic legend placement (loc='best') not implemented for "
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"figure legend.")
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self._mode = mode
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self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)
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# We use FancyBboxPatch to draw a legend frame. The location
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# and size of the box will be updated during the drawing time.
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if facecolor is None:
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facecolor = mpl.rcParams["legend.facecolor"]
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if facecolor == 'inherit':
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facecolor = mpl.rcParams["axes.facecolor"]
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if edgecolor is None:
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edgecolor = mpl.rcParams["legend.edgecolor"]
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if edgecolor == 'inherit':
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edgecolor = mpl.rcParams["axes.edgecolor"]
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if fancybox is None:
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fancybox = mpl.rcParams["legend.fancybox"]
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self.legendPatch = FancyBboxPatch(
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xy=(0, 0), width=1, height=1,
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facecolor=facecolor, edgecolor=edgecolor,
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# If shadow is used, default to alpha=1 (#8943).
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alpha=(framealpha if framealpha is not None
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else 1 if shadow
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else mpl.rcParams["legend.framealpha"]),
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|
# The width and height of the legendPatch will be set (in draw())
|
|
# to the length that includes the padding. Thus we set pad=0 here.
|
|
boxstyle=("round,pad=0,rounding_size=0.2" if fancybox
|
|
else "square,pad=0"),
|
|
mutation_scale=self._fontsize,
|
|
snap=True,
|
|
visible=(frameon if frameon is not None
|
|
else mpl.rcParams["legend.frameon"])
|
|
)
|
|
self._set_artist_props(self.legendPatch)
|
|
|
|
# init with null renderer
|
|
self._init_legend_box(handles, labels, markerfirst)
|
|
|
|
tmp = self._loc_used_default
|
|
self._set_loc(loc)
|
|
self._loc_used_default = tmp # ignore changes done by _set_loc
|
|
|
|
# figure out title fontsize:
|
|
if title_fontsize is None:
|
|
title_fontsize = mpl.rcParams['legend.title_fontsize']
|
|
tprop = FontProperties(size=title_fontsize)
|
|
self.set_title(title, prop=tprop)
|
|
self._draggable = None
|
|
|
|
# set the text color
|
|
|
|
color_getters = { # getter function depends on line or patch
|
|
'linecolor': ['get_color', 'get_facecolor'],
|
|
'markerfacecolor': ['get_markerfacecolor', 'get_facecolor'],
|
|
'mfc': ['get_markerfacecolor', 'get_facecolor'],
|
|
'markeredgecolor': ['get_markeredgecolor', 'get_edgecolor'],
|
|
'mec': ['get_markeredgecolor', 'get_edgecolor'],
|
|
}
|
|
if labelcolor is None:
|
|
pass
|
|
elif isinstance(labelcolor, str) and labelcolor in color_getters:
|
|
getter_names = color_getters[labelcolor]
|
|
for handle, text in zip(self.legendHandles, self.texts):
|
|
for getter_name in getter_names:
|
|
try:
|
|
color = getattr(handle, getter_name)()
|
|
text.set_color(color)
|
|
break
|
|
except AttributeError:
|
|
pass
|
|
elif np.iterable(labelcolor):
|
|
for text, color in zip(self.texts,
|
|
itertools.cycle(
|
|
colors.to_rgba_array(labelcolor))):
|
|
text.set_color(color)
|
|
else:
|
|
raise ValueError("Invalid argument for labelcolor : %s" %
|
|
str(labelcolor))
|
|
|
|
def _set_artist_props(self, a):
|
|
"""
|
|
Set the boilerplate props for artists added to axes.
|
|
"""
|
|
a.set_figure(self.figure)
|
|
if self.isaxes:
|
|
# a.set_axes(self.axes)
|
|
a.axes = self.axes
|
|
|
|
a.set_transform(self.get_transform())
|
|
|
|
def _set_loc(self, loc):
|
|
# find_offset function will be provided to _legend_box and
|
|
# _legend_box will draw itself at the location of the return
|
|
# value of the find_offset.
|
|
self._loc_used_default = False
|
|
self._loc_real = loc
|
|
self.stale = True
|
|
self._legend_box.set_offset(self._findoffset)
|
|
|
|
def _get_loc(self):
|
|
return self._loc_real
|
|
|
|
_loc = property(_get_loc, _set_loc)
|
|
|
|
def _findoffset(self, width, height, xdescent, ydescent, renderer):
|
|
"""Helper function to locate the legend."""
|
|
|
|
if self._loc == 0: # "best".
|
|
x, y = self._find_best_position(width, height, renderer)
|
|
elif self._loc in Legend.codes.values(): # Fixed location.
|
|
bbox = Bbox.from_bounds(0, 0, width, height)
|
|
x, y = self._get_anchored_bbox(self._loc, bbox,
|
|
self.get_bbox_to_anchor(),
|
|
renderer)
|
|
else: # Axes or figure coordinates.
|
|
fx, fy = self._loc
|
|
bbox = self.get_bbox_to_anchor()
|
|
x, y = bbox.x0 + bbox.width * fx, bbox.y0 + bbox.height * fy
|
|
|
|
return x + xdescent, y + ydescent
|
|
|
|
@allow_rasterization
|
|
def draw(self, renderer):
|
|
# docstring inherited
|
|
if not self.get_visible():
|
|
return
|
|
|
|
renderer.open_group('legend', gid=self.get_gid())
|
|
|
|
fontsize = renderer.points_to_pixels(self._fontsize)
|
|
|
|
# if mode == fill, set the width of the legend_box to the
|
|
# width of the parent (minus pads)
|
|
if self._mode in ["expand"]:
|
|
pad = 2 * (self.borderaxespad + self.borderpad) * fontsize
|
|
self._legend_box.set_width(self.get_bbox_to_anchor().width - pad)
|
|
|
|
# update the location and size of the legend. This needs to
|
|
# be done in any case to clip the figure right.
|
|
bbox = self._legend_box.get_window_extent(renderer)
|
|
self.legendPatch.set_bounds(bbox.x0, bbox.y0, bbox.width, bbox.height)
|
|
self.legendPatch.set_mutation_scale(fontsize)
|
|
|
|
if self.shadow:
|
|
Shadow(self.legendPatch, 2, -2).draw(renderer)
|
|
|
|
self.legendPatch.draw(renderer)
|
|
self._legend_box.draw(renderer)
|
|
|
|
renderer.close_group('legend')
|
|
self.stale = False
|
|
|
|
# _default_handler_map defines the default mapping between plot
|
|
# elements and the legend handlers.
|
|
|
|
_default_handler_map = {
|
|
StemContainer: legend_handler.HandlerStem(),
|
|
ErrorbarContainer: legend_handler.HandlerErrorbar(),
|
|
Line2D: legend_handler.HandlerLine2D(),
|
|
Patch: legend_handler.HandlerPatch(),
|
|
LineCollection: legend_handler.HandlerLineCollection(),
|
|
RegularPolyCollection: legend_handler.HandlerRegularPolyCollection(),
|
|
CircleCollection: legend_handler.HandlerCircleCollection(),
|
|
BarContainer: legend_handler.HandlerPatch(
|
|
update_func=legend_handler.update_from_first_child),
|
|
tuple: legend_handler.HandlerTuple(),
|
|
PathCollection: legend_handler.HandlerPathCollection(),
|
|
PolyCollection: legend_handler.HandlerPolyCollection()
|
|
}
|
|
|
|
# (get|set|update)_default_handler_maps are public interfaces to
|
|
# modify the default handler map.
|
|
|
|
@classmethod
|
|
def get_default_handler_map(cls):
|
|
"""
|
|
A class method that returns the default handler map.
|
|
"""
|
|
return cls._default_handler_map
|
|
|
|
@classmethod
|
|
def set_default_handler_map(cls, handler_map):
|
|
"""
|
|
A class method to set the default handler map.
|
|
"""
|
|
cls._default_handler_map = handler_map
|
|
|
|
@classmethod
|
|
def update_default_handler_map(cls, handler_map):
|
|
"""
|
|
A class method to update the default handler map.
|
|
"""
|
|
cls._default_handler_map.update(handler_map)
|
|
|
|
def get_legend_handler_map(self):
|
|
"""
|
|
Return the handler map.
|
|
"""
|
|
|
|
default_handler_map = self.get_default_handler_map()
|
|
|
|
if self._custom_handler_map:
|
|
hm = default_handler_map.copy()
|
|
hm.update(self._custom_handler_map)
|
|
return hm
|
|
else:
|
|
return default_handler_map
|
|
|
|
@staticmethod
|
|
def get_legend_handler(legend_handler_map, orig_handle):
|
|
"""
|
|
Return a legend handler from *legend_handler_map* that
|
|
corresponds to *orig_handler*.
|
|
|
|
*legend_handler_map* should be a dictionary object (that is
|
|
returned by the get_legend_handler_map method).
|
|
|
|
It first checks if the *orig_handle* itself is a key in the
|
|
*legend_handler_map* and return the associated value.
|
|
Otherwise, it checks for each of the classes in its
|
|
method-resolution-order. If no matching key is found, it
|
|
returns ``None``.
|
|
"""
|
|
try:
|
|
return legend_handler_map[orig_handle]
|
|
except (TypeError, KeyError): # TypeError if unhashable.
|
|
pass
|
|
for handle_type in type(orig_handle).mro():
|
|
try:
|
|
return legend_handler_map[handle_type]
|
|
except KeyError:
|
|
pass
|
|
return None
|
|
|
|
def _init_legend_box(self, handles, labels, markerfirst=True):
|
|
"""
|
|
Initialize the legend_box. The legend_box is an instance of
|
|
the OffsetBox, which is packed with legend handles and
|
|
texts. Once packed, their location is calculated during the
|
|
drawing time.
|
|
"""
|
|
|
|
fontsize = self._fontsize
|
|
|
|
# legend_box is a HPacker, horizontally packed with
|
|
# columns. Each column is a VPacker, vertically packed with
|
|
# legend items. Each legend item is HPacker packed with
|
|
# legend handleBox and labelBox. handleBox is an instance of
|
|
# offsetbox.DrawingArea which contains legend handle. labelBox
|
|
# is an instance of offsetbox.TextArea which contains legend
|
|
# text.
|
|
|
|
text_list = [] # the list of text instances
|
|
handle_list = [] # the list of text instances
|
|
handles_and_labels = []
|
|
|
|
label_prop = dict(verticalalignment='baseline',
|
|
horizontalalignment='left',
|
|
fontproperties=self.prop,
|
|
)
|
|
|
|
# The approximate height and descent of text. These values are
|
|
# only used for plotting the legend handle.
|
|
descent = 0.35 * fontsize * (self.handleheight - 0.7)
|
|
# 0.35 and 0.7 are just heuristic numbers and may need to be improved.
|
|
height = fontsize * self.handleheight - descent
|
|
# each handle needs to be drawn inside a box of (x, y, w, h) =
|
|
# (0, -descent, width, height). And their coordinates should
|
|
# be given in the display coordinates.
|
|
|
|
# The transformation of each handle will be automatically set
|
|
# to self.get_transform(). If the artist does not use its
|
|
# default transform (e.g., Collections), you need to
|
|
# manually set their transform to the self.get_transform().
|
|
legend_handler_map = self.get_legend_handler_map()
|
|
|
|
for orig_handle, lab in zip(handles, labels):
|
|
handler = self.get_legend_handler(legend_handler_map, orig_handle)
|
|
if handler is None:
|
|
cbook._warn_external(
|
|
"Legend does not support {!r} instances.\nA proxy artist "
|
|
"may be used instead.\nSee: "
|
|
"https://matplotlib.org/users/legend_guide.html"
|
|
"#creating-artists-specifically-for-adding-to-the-legend-"
|
|
"aka-proxy-artists".format(orig_handle))
|
|
# We don't have a handle for this artist, so we just defer
|
|
# to None.
|
|
handle_list.append(None)
|
|
else:
|
|
textbox = TextArea(lab, textprops=label_prop,
|
|
multilinebaseline=True,
|
|
minimumdescent=True)
|
|
handlebox = DrawingArea(width=self.handlelength * fontsize,
|
|
height=height,
|
|
xdescent=0., ydescent=descent)
|
|
|
|
text_list.append(textbox._text)
|
|
# Create the artist for the legend which represents the
|
|
# original artist/handle.
|
|
handle_list.append(handler.legend_artist(self, orig_handle,
|
|
fontsize, handlebox))
|
|
handles_and_labels.append((handlebox, textbox))
|
|
|
|
if handles_and_labels:
|
|
# We calculate number of rows in each column. The first
|
|
# (num_largecol) columns will have (nrows+1) rows, and remaining
|
|
# (num_smallcol) columns will have (nrows) rows.
|
|
ncol = min(self._ncol, len(handles_and_labels))
|
|
nrows, num_largecol = divmod(len(handles_and_labels), ncol)
|
|
num_smallcol = ncol - num_largecol
|
|
# starting index of each column and number of rows in it.
|
|
rows_per_col = [nrows + 1] * num_largecol + [nrows] * num_smallcol
|
|
start_idxs = np.concatenate([[0], np.cumsum(rows_per_col)[:-1]])
|
|
cols = zip(start_idxs, rows_per_col)
|
|
else:
|
|
cols = []
|
|
|
|
columnbox = []
|
|
for i0, di in cols:
|
|
# pack handleBox and labelBox into itemBox
|
|
itemBoxes = [HPacker(pad=0,
|
|
sep=self.handletextpad * fontsize,
|
|
children=[h, t] if markerfirst else [t, h],
|
|
align="baseline")
|
|
for h, t in handles_and_labels[i0:i0 + di]]
|
|
# minimumdescent=False for the text of the last row of the column
|
|
if markerfirst:
|
|
itemBoxes[-1].get_children()[1].set_minimumdescent(False)
|
|
else:
|
|
itemBoxes[-1].get_children()[0].set_minimumdescent(False)
|
|
|
|
# pack columnBox
|
|
alignment = "baseline" if markerfirst else "right"
|
|
columnbox.append(VPacker(pad=0,
|
|
sep=self.labelspacing * fontsize,
|
|
align=alignment,
|
|
children=itemBoxes))
|
|
|
|
mode = "expand" if self._mode == "expand" else "fixed"
|
|
sep = self.columnspacing * fontsize
|
|
self._legend_handle_box = HPacker(pad=0,
|
|
sep=sep, align="baseline",
|
|
mode=mode,
|
|
children=columnbox)
|
|
self._legend_title_box = TextArea("")
|
|
self._legend_box = VPacker(pad=self.borderpad * fontsize,
|
|
sep=self.labelspacing * fontsize,
|
|
align="center",
|
|
children=[self._legend_title_box,
|
|
self._legend_handle_box])
|
|
self._legend_box.set_figure(self.figure)
|
|
self.texts = text_list
|
|
self.legendHandles = handle_list
|
|
|
|
def _auto_legend_data(self):
|
|
"""
|
|
Return display coordinates for hit testing for "best" positioning.
|
|
|
|
Returns
|
|
-------
|
|
bboxes
|
|
List of bounding boxes of all patches.
|
|
lines
|
|
List of `.Path` corresponding to each line.
|
|
offsets
|
|
List of (x, y) offsets of all collection.
|
|
"""
|
|
assert self.isaxes # always holds, as this is only called internally
|
|
ax = self.parent
|
|
lines = [line.get_transform().transform_path(line.get_path())
|
|
for line in ax.lines]
|
|
bboxes = [patch.get_bbox().transformed(patch.get_data_transform())
|
|
if isinstance(patch, Rectangle) else
|
|
patch.get_path().get_extents(patch.get_transform())
|
|
for patch in ax.patches]
|
|
offsets = []
|
|
for handle in ax.collections:
|
|
_, transOffset, hoffsets, _ = handle._prepare_points()
|
|
for offset in transOffset.transform(hoffsets):
|
|
offsets.append(offset)
|
|
return bboxes, lines, offsets
|
|
|
|
def get_children(self):
|
|
# docstring inherited
|
|
return [self._legend_box, self.get_frame()]
|
|
|
|
def get_frame(self):
|
|
"""Return the `~.patches.Rectangle` used to frame the legend."""
|
|
return self.legendPatch
|
|
|
|
def get_lines(self):
|
|
r"""Return the list of `~.lines.Line2D`\s in the legend."""
|
|
return [h for h in self.legendHandles if isinstance(h, Line2D)]
|
|
|
|
def get_patches(self):
|
|
r"""Return the list of `~.patches.Patch`\s in the legend."""
|
|
return silent_list('Patch',
|
|
[h for h in self.legendHandles
|
|
if isinstance(h, Patch)])
|
|
|
|
def get_texts(self):
|
|
r"""Return the list of `~.text.Text`\s in the legend."""
|
|
return silent_list('Text', self.texts)
|
|
|
|
def set_title(self, title, prop=None):
|
|
"""
|
|
Set the legend title. Fontproperties can be optionally set
|
|
with *prop* parameter.
|
|
"""
|
|
self._legend_title_box._text.set_text(title)
|
|
if title:
|
|
self._legend_title_box._text.set_visible(True)
|
|
self._legend_title_box.set_visible(True)
|
|
else:
|
|
self._legend_title_box._text.set_visible(False)
|
|
self._legend_title_box.set_visible(False)
|
|
|
|
if prop is not None:
|
|
self._legend_title_box._text.set_fontproperties(prop)
|
|
|
|
self.stale = True
|
|
|
|
def get_title(self):
|
|
"""Return the `.Text` instance for the legend title."""
|
|
return self._legend_title_box._text
|
|
|
|
def get_window_extent(self, renderer=None):
|
|
# docstring inherited
|
|
if renderer is None:
|
|
renderer = self.figure._cachedRenderer
|
|
return self._legend_box.get_window_extent(renderer=renderer)
|
|
|
|
def get_tightbbox(self, renderer):
|
|
"""
|
|
Like `.Legend.get_window_extent`, but uses the box for the legend.
|
|
|
|
Parameters
|
|
----------
|
|
renderer : `.RendererBase` subclass
|
|
renderer that will be used to draw the figures (i.e.
|
|
``fig.canvas.get_renderer()``)
|
|
|
|
Returns
|
|
-------
|
|
`.BboxBase`
|
|
The bounding box in figure pixel coordinates.
|
|
"""
|
|
return self._legend_box.get_window_extent(renderer)
|
|
|
|
def get_frame_on(self):
|
|
"""Get whether the legend box patch is drawn."""
|
|
return self.legendPatch.get_visible()
|
|
|
|
def set_frame_on(self, b):
|
|
"""
|
|
Set whether the legend box patch is drawn.
|
|
|
|
Parameters
|
|
----------
|
|
b : bool
|
|
"""
|
|
self.legendPatch.set_visible(b)
|
|
self.stale = True
|
|
|
|
draw_frame = set_frame_on # Backcompat alias.
|
|
|
|
def get_bbox_to_anchor(self):
|
|
"""Return the bbox that the legend will be anchored to."""
|
|
if self._bbox_to_anchor is None:
|
|
return self.parent.bbox
|
|
else:
|
|
return self._bbox_to_anchor
|
|
|
|
def set_bbox_to_anchor(self, bbox, transform=None):
|
|
"""
|
|
Set the bbox that the legend will be anchored to.
|
|
|
|
Parameters
|
|
----------
|
|
bbox : `~matplotlib.transforms.BboxBase` or tuple
|
|
The bounding box can be specified in the following ways:
|
|
|
|
- A `.BboxBase` instance
|
|
- A tuple of ``(left, bottom, width, height)`` in the given
|
|
transform (normalized axes coordinate if None)
|
|
- A tuple of ``(left, bottom)`` where the width and height will be
|
|
assumed to be zero.
|
|
- *None*, to remove the bbox anchoring, and use the parent bbox.
|
|
|
|
transform : `~matplotlib.transforms.Transform`, optional
|
|
A transform to apply to the bounding box. If not specified, this
|
|
will use a transform to the bounding box of the parent.
|
|
"""
|
|
if bbox is None:
|
|
self._bbox_to_anchor = None
|
|
return
|
|
elif isinstance(bbox, BboxBase):
|
|
self._bbox_to_anchor = bbox
|
|
else:
|
|
try:
|
|
l = len(bbox)
|
|
except TypeError as err:
|
|
raise ValueError("Invalid argument for bbox : %s" %
|
|
str(bbox)) from err
|
|
|
|
if l == 2:
|
|
bbox = [bbox[0], bbox[1], 0, 0]
|
|
|
|
self._bbox_to_anchor = Bbox.from_bounds(*bbox)
|
|
|
|
if transform is None:
|
|
transform = BboxTransformTo(self.parent.bbox)
|
|
|
|
self._bbox_to_anchor = TransformedBbox(self._bbox_to_anchor,
|
|
transform)
|
|
self.stale = True
|
|
|
|
def _get_anchored_bbox(self, loc, bbox, parentbbox, renderer):
|
|
"""
|
|
Place the *bbox* inside the *parentbbox* according to a given
|
|
location code. Return the (x, y) coordinate of the bbox.
|
|
|
|
Parameters
|
|
----------
|
|
loc : int
|
|
A location code in range(1, 11). This corresponds to the possible
|
|
values for ``self._loc``, excluding "best".
|
|
bbox : `~matplotlib.transforms.Bbox`
|
|
bbox to be placed, in display coordinates.
|
|
parentbbox : `~matplotlib.transforms.Bbox`
|
|
A parent box which will contain the bbox, in display coordinates.
|
|
|
|
"""
|
|
assert loc in range(1, 11) # called only internally
|
|
|
|
BEST, UR, UL, LL, LR, R, CL, CR, LC, UC, C = range(11)
|
|
|
|
anchor_coefs = {UR: "NE",
|
|
UL: "NW",
|
|
LL: "SW",
|
|
LR: "SE",
|
|
R: "E",
|
|
CL: "W",
|
|
CR: "E",
|
|
LC: "S",
|
|
UC: "N",
|
|
C: "C"}
|
|
|
|
c = anchor_coefs[loc]
|
|
|
|
fontsize = renderer.points_to_pixels(self._fontsize)
|
|
container = parentbbox.padded(-self.borderaxespad * fontsize)
|
|
anchored_box = bbox.anchored(c, container=container)
|
|
return anchored_box.x0, anchored_box.y0
|
|
|
|
def _find_best_position(self, width, height, renderer, consider=None):
|
|
"""
|
|
Determine the best location to place the legend.
|
|
|
|
*consider* is a list of ``(x, y)`` pairs to consider as a potential
|
|
lower-left corner of the legend. All are display coords.
|
|
"""
|
|
assert self.isaxes # always holds, as this is only called internally
|
|
|
|
start_time = time.perf_counter()
|
|
|
|
bboxes, lines, offsets = self._auto_legend_data()
|
|
|
|
bbox = Bbox.from_bounds(0, 0, width, height)
|
|
if consider is None:
|
|
consider = [self._get_anchored_bbox(x, bbox,
|
|
self.get_bbox_to_anchor(),
|
|
renderer)
|
|
for x in range(1, len(self.codes))]
|
|
|
|
candidates = []
|
|
for idx, (l, b) in enumerate(consider):
|
|
legendBox = Bbox.from_bounds(l, b, width, height)
|
|
badness = 0
|
|
# XXX TODO: If markers are present, it would be good to take them
|
|
# into account when checking vertex overlaps in the next line.
|
|
badness = (sum(legendBox.count_contains(line.vertices)
|
|
for line in lines)
|
|
+ legendBox.count_contains(offsets)
|
|
+ legendBox.count_overlaps(bboxes)
|
|
+ sum(line.intersects_bbox(legendBox, filled=False)
|
|
for line in lines))
|
|
if badness == 0:
|
|
return l, b
|
|
# Include the index to favor lower codes in case of a tie.
|
|
candidates.append((badness, idx, (l, b)))
|
|
|
|
_, _, (l, b) = min(candidates)
|
|
|
|
if self._loc_used_default and time.perf_counter() - start_time > 1:
|
|
cbook._warn_external(
|
|
'Creating legend with loc="best" can be slow with large '
|
|
'amounts of data.')
|
|
|
|
return l, b
|
|
|
|
def contains(self, event):
|
|
inside, info = self._default_contains(event)
|
|
if inside is not None:
|
|
return inside, info
|
|
return self.legendPatch.contains(event)
|
|
|
|
def set_draggable(self, state, use_blit=False, update='loc'):
|
|
"""
|
|
Enable or disable mouse dragging support of the legend.
|
|
|
|
Parameters
|
|
----------
|
|
state : bool
|
|
Whether mouse dragging is enabled.
|
|
use_blit : bool, optional
|
|
Use blitting for faster image composition. For details see
|
|
:ref:`func-animation`.
|
|
update : {'loc', 'bbox'}, optional
|
|
The legend parameter to be changed when dragged:
|
|
|
|
- 'loc': update the *loc* parameter of the legend
|
|
- 'bbox': update the *bbox_to_anchor* parameter of the legend
|
|
|
|
Returns
|
|
-------
|
|
`.DraggableLegend` or *None*
|
|
If *state* is ``True`` this returns the `.DraggableLegend` helper
|
|
instance. Otherwise this returns *None*.
|
|
"""
|
|
if state:
|
|
if self._draggable is None:
|
|
self._draggable = DraggableLegend(self,
|
|
use_blit,
|
|
update=update)
|
|
else:
|
|
if self._draggable is not None:
|
|
self._draggable.disconnect()
|
|
self._draggable = None
|
|
return self._draggable
|
|
|
|
def get_draggable(self):
|
|
"""Return ``True`` if the legend is draggable, ``False`` otherwise."""
|
|
return self._draggable is not None
|
|
|
|
|
|
# Helper functions to parse legend arguments for both `figure.legend` and
|
|
# `axes.legend`:
|
|
def _get_legend_handles(axs, legend_handler_map=None):
|
|
"""
|
|
Return a generator of artists that can be used as handles in
|
|
a legend.
|
|
|
|
"""
|
|
handles_original = []
|
|
for ax in axs:
|
|
handles_original += (ax.lines + ax.patches +
|
|
ax.collections + ax.containers)
|
|
# support parasite axes:
|
|
if hasattr(ax, 'parasites'):
|
|
for axx in ax.parasites:
|
|
handles_original += (axx.lines + axx.patches +
|
|
axx.collections + axx.containers)
|
|
|
|
handler_map = Legend.get_default_handler_map()
|
|
|
|
if legend_handler_map is not None:
|
|
handler_map = handler_map.copy()
|
|
handler_map.update(legend_handler_map)
|
|
|
|
has_handler = Legend.get_legend_handler
|
|
|
|
for handle in handles_original:
|
|
label = handle.get_label()
|
|
if label != '_nolegend_' and has_handler(handler_map, handle):
|
|
yield handle
|
|
|
|
|
|
def _get_legend_handles_labels(axs, legend_handler_map=None):
|
|
"""
|
|
Return handles and labels for legend, internal method.
|
|
|
|
"""
|
|
handles = []
|
|
labels = []
|
|
|
|
for handle in _get_legend_handles(axs, legend_handler_map):
|
|
label = handle.get_label()
|
|
if label and not label.startswith('_'):
|
|
handles.append(handle)
|
|
labels.append(label)
|
|
return handles, labels
|
|
|
|
|
|
def _parse_legend_args(axs, *args, handles=None, labels=None, **kwargs):
|
|
"""
|
|
Get the handles and labels from the calls to either ``figure.legend``
|
|
or ``axes.legend``.
|
|
|
|
``axs`` is a list of axes (to get legend artists from)
|
|
"""
|
|
log = logging.getLogger(__name__)
|
|
|
|
handlers = kwargs.get('handler_map', {}) or {}
|
|
extra_args = ()
|
|
|
|
if (handles is not None or labels is not None) and args:
|
|
cbook._warn_external("You have mixed positional and keyword "
|
|
"arguments, some input may be discarded.")
|
|
|
|
# if got both handles and labels as kwargs, make same length
|
|
if handles and labels:
|
|
handles, labels = zip(*zip(handles, labels))
|
|
|
|
elif handles is not None and labels is None:
|
|
labels = [handle.get_label() for handle in handles]
|
|
|
|
elif labels is not None and handles is None:
|
|
# Get as many handles as there are labels.
|
|
handles = [handle for handle, label
|
|
in zip(_get_legend_handles(axs, handlers), labels)]
|
|
|
|
# No arguments - automatically detect labels and handles.
|
|
elif len(args) == 0:
|
|
handles, labels = _get_legend_handles_labels(axs, handlers)
|
|
if not handles:
|
|
log.warning('No handles with labels found to put in legend.')
|
|
|
|
# One argument. User defined labels - automatic handle detection.
|
|
elif len(args) == 1:
|
|
labels, = args
|
|
if any(isinstance(l, Artist) for l in labels):
|
|
raise TypeError("A single argument passed to legend() must be a "
|
|
"list of labels, but found an Artist in there.")
|
|
|
|
# Get as many handles as there are labels.
|
|
handles = [handle for handle, label
|
|
in zip(_get_legend_handles(axs, handlers), labels)]
|
|
|
|
# Two arguments:
|
|
# * user defined handles and labels
|
|
elif len(args) >= 2:
|
|
handles, labels = args[:2]
|
|
extra_args = args[2:]
|
|
|
|
else:
|
|
raise TypeError('Invalid arguments to legend.')
|
|
|
|
return handles, labels, extra_args, kwargs
|