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Commit ca664a1

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ImportanceOfBeingErnestImportanceOfBeingErnest
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marker-transforms
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‎examples/lines_bars_and_markers/scatter_piecharts.py

Copy file name to clipboardExpand all lines: examples/lines_bars_and_markers/scatter_piecharts.py
+57-7Lines changed: 57 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -3,15 +3,19 @@
33
Scatter plot with pie chart markers
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===================================
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6-
This example makes custom 'pie charts' as the markers for a scatter plot.
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Thanks to Manuel Metz for the example.
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This example shows two methods to make custom 'pie charts' as the markers
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for a scatter plot.
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"""
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##########################################################################
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# Manually creating marker vertices
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# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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#
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1115
import numpy as np
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import matplotlib.pyplot as plt
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# first define the ratios
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# first define the cumulative ratios
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r1 = 0.2 # 20%
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r2 = r1 + 0.4 # 40%
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@@ -36,10 +40,54 @@
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s3 = np.abs(xy3).max()
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fig, ax = plt.subplots()
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ax.scatter(range(3), range(3), marker=xy1, s=s1**2 * sizes, facecolor='blue')
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ax.scatter(range(3), range(3), marker=xy2, s=s2**2 * sizes, facecolor='green')
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ax.scatter(range(3), range(3), marker=xy3, s=s3**2 * sizes, facecolor='red')
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ax.scatter(range(3), range(3), marker=xy1, s=s1**2 * sizes, facecolor='C0')
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ax.scatter(range(3), range(3), marker=xy2, s=s2**2 * sizes, facecolor='C1')
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ax.scatter(range(3), range(3), marker=xy3, s=s3**2 * sizes, facecolor='C2')
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plt.show()
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##########################################################################
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# Using wedges as markers
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# ~~~~~~~~~~~~~~~~~~~~~~~
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#
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# An alternative is to create custom markers from the `~.path.Path` of a
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# `~.patches.Wedge`, which might be more versatile.
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#
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import numpy as np
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import matplotlib.pyplot as plt
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from matplotlib.patches import Wedge
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from matplotlib.markers import MarkerStyle
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# first define the ratios
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r1 = 0.2 # 20%
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r2 = r1 + 0.3 # 50%
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r3 = 1 - r1 - r2 # 30%
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def markers_from_ratios(ratios, width=1):
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markers = []
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angles = 360*np.concatenate(([0], np.cumsum(ratios)))
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for i in range(len(angles)-1):
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# create a Wedge within the unit square in between the given angles...
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w = Wedge((0, 0), 0.5, angles[i], angles[i+1], width=width/2)
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# ... and create a custom Marker from its path.
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markers.append(MarkerStyle(w.get_path(), normalize_path=False))
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return markers
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# define some sizes of the scatter marker
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sizes = np.array([100, 200, 400, 800])
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# collect the markers and some colors
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markers = markers_from_ratios([r1, r2, r3], width=0.6)
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colors = plt.cm.tab10.colors[:len(markers)]
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fig, ax = plt.subplots()
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for marker, color in zip(markers, colors):
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ax.scatter(range(len(sizes)), range(len(sizes)), marker=marker, s=sizes,
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edgecolor="none", facecolor=color)
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ax.margins(0.1)
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plt.show()
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#############################################################################
@@ -55,3 +103,5 @@
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import matplotlib
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matplotlib.axes.Axes.scatter
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matplotlib.pyplot.scatter
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matplotlib.patches.Wedge
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matplotlib.markers.MarkerStyle

‎lib/matplotlib/markers.py

Copy file name to clipboardExpand all lines: lib/matplotlib/markers.py
+19-6Lines changed: 19 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -201,7 +201,7 @@ class MarkerStyle:
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# TODO: Is this ever used as a non-constant?
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_point_size_reduction = 0.5
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def __init__(self, marker=None, fillstyle=None):
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def __init__(self, marker=None, fillstyle=None, normalize_path=True):
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"""
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Attributes
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----------
@@ -213,12 +213,19 @@ def __init__(self, marker=None, fillstyle=None):
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Parameters
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----------
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marker : str or array-like, optional, default: None
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marker : str, array-like, `~.path.Path`, or `~.markers.MarkerStyle`,
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default: None
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See the descriptions of possible markers in the module docstring.
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fillstyle : str, optional, default: 'full'
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'full', 'left", 'right', 'bottom', 'top', 'none'
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normalize_path : bool, default: True
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Whether to normalize a custom paths that are provided as array of
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vertices or `~.path.Path`. If True, the marker is normalized to the
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unit square.
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"""
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self._normalize = normalize_path
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self._marker_function = None
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self.set_fillstyle(fillstyle)
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self.set_marker(marker)
@@ -302,6 +309,13 @@ def get_path(self):
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def get_transform(self):
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return self._transform.frozen()
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def set_transform(self, transform):
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"""
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Sets the transform of the marker. This is the transform by which the
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marker path is transformed.
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"""
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self._transform = transform
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def get_alt_path(self):
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return self._alt_path
@@ -316,8 +330,9 @@ def _set_nothing(self):
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self._filled = False
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def _set_custom_marker(self, path):
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rescale = np.max(np.abs(path.vertices)) # max of x's and y's.
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self._transform = Affine2D().scale(0.5 / rescale)
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if self._normalize:
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rescale = np.max(np.abs(path.vertices)) # max of x's and y's.
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self._transform = Affine2D().scale(0.5 / rescale)
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self._path = path
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323338
def _set_path_marker(self):
@@ -349,8 +364,6 @@ def _set_tuple_marker(self):
349364
def _set_mathtext_path(self):
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"""
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Draws mathtext markers '$...$' using TextPath object.
352-
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Submitted by tcb
354367
"""
355368
from matplotlib.text import TextPath
356369

‎lib/matplotlib/tests/test_marker.py

Copy file name to clipboardExpand all lines: lib/matplotlib/tests/test_marker.py
+24Lines changed: 24 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,10 @@
11
import numpy as np
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from matplotlib import markers
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from matplotlib.path import Path
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from matplotlib.transforms import Affine2D
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import matplotlib.pyplot as plt
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from matplotlib.testing.decorators import check_figures_equal
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import pytest
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710

@@ -26,3 +29,24 @@ def test_marker_path():
2629
path = Path([[0, 0], [1, 0]], [Path.MOVETO, Path.LINETO])
2730
# Checking this doesn't fail.
2831
marker_style.set_marker(path)
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33+
34+
@check_figures_equal(extensions=["png"])
35+
def test_marker_normalization(fig_test, fig_ref):
36+
plt.style.use("mpl20")
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38+
ax = fig_ref.subplots()
39+
ax.margins(0.3)
40+
ax.scatter([0, 1], [0, 0], s=400, marker="s", c="C2")
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42+
ax = fig_test.subplots()
43+
ax.margins(0.3)
44+
# test normalize
45+
p = Path([[0, 0], [1, 0], [1, 1], [0, 1], [0, 0]], closed=True)
46+
p1 = p.transformed(Affine2D().translate(-.5, -.5).scale(20))
47+
m1 = markers.MarkerStyle(p1, normalize_path=False)
48+
ax.scatter([0], [0], s=1, marker=m1, c="C2")
49+
# test transform
50+
m2 = markers.MarkerStyle("s")
51+
m2.set_transform(m2.get_transform() + Affine2D().scale(20))
52+
ax.scatter([1], [0], s=1, marker=m2, c="C2")

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