matplotlib：如何使用 fill_between 在雷达图中绘制闭合环？ （我的尝试留下了空白。）
matplotlib: How to plot a closed ring in a radar plot using fill_between? (My attempt leaves a gap.)
我正在尝试在雷达图中使用 fill_between 绘制“环”，遵循此处的 matplotlib 雷达示例：
https://matplotlib.org/3.1.0/gallery/specialty_plots/radar_chart.html
我保留 radar_factory 函数不变，除了一个额外的重载函数“fill_between”，遵循示例中已经存在的“fill”示例：
def fill_between(self, *args, closed=True, **kwargs):
"""Override fill_between so that lines are closed by default"""
return super().fill_between(closed=closed, *args, **kwargs)
据我了解，这应该将 closed=True 传递给 PolyCollection 对象。然而并没有。
这是重现问题的代码。它比最小的要长一点，但我认为与 matplotlib 文档中的示例保持接近很重要：
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.patches import Circle, RegularPolygon
from matplotlib.path import Path
from matplotlib.projections.polar import PolarAxes
from matplotlib.projections import register_projection
from matplotlib.spines import Spine
from matplotlib.transforms import Affine2D
def radar_factory(num_vars, frame='circle'):
# calculate evenly-spaced axis angles
theta = np.linspace(0, 2*np.pi, num_vars, endpoint=False)
class RadarAxes(PolarAxes):
name = 'radar'
# use 1 line segment to connect specified points
RESOLUTION = 1
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# rotate plot such that the first axis is at the top
self.set_theta_zero_location('N')
def fill(self, *args, closed=True, **kwargs):
"""Override fill so that line is closed by default"""
return super().fill(closed=closed, *args, **kwargs)
def fill_between(self, *args, closed=True, **kwargs):
"""
Override fill_between so that lines are closed by default
- CUSTOM ADDITION TO EXAMPLE -
"""
return super().fill_between(closed=closed, *args, **kwargs)
def plot(self, *args, **kwargs):
"""Override plot so that line is closed by default"""
lines = super().plot(*args, **kwargs)
for line in lines:
self._close_line(line)
def _close_line(self, line):
x, y = line.get_data()
# FIXME: markers at x[0], y[0] get doubled-up
if x[0] != x[-1]:
x = np.concatenate((x, [x[0]]))
y = np.concatenate((y, [y[0]]))
line.set_data(x, y)
def set_varlabels(self, labels):
self.set_thetagrids(np.degrees(theta), labels)
def _gen_axes_patch(self):
# The Axes patch must be centered at (0.5, 0.5) and of radius 0.5
# in axes coordinates.
if frame == 'circle':
return Circle((0.5, 0.5), 0.5)
elif frame == 'polygon':
return RegularPolygon((0.5, 0.5), num_vars,
radius=.5, edgecolor="k")
else:
raise ValueError("unknown value for 'frame': %s" % frame)
def _gen_axes_spines(self):
if frame == 'circle':
return super()._gen_axes_spines()
elif frame == 'polygon':
# spine_type must be 'left'/'right'/'top'/'bottom'/'circle'.
spine = Spine(axes=self,
spine_type='circle',
path=Path.unit_regular_polygon(num_vars))
# unit_regular_polygon gives a polygon of radius 1 centered at
# (0, 0) but we want a polygon of radius 0.5 centered at (0.5,
# 0.5) in axes coordinates.
spine.set_transform(Affine2D().scale(.5).translate(.5, .5)
+ self.transAxes)
return {'polar': spine}
else:
raise ValueError("unknown value for 'frame': %s" % frame)
register_projection(RadarAxes)
return theta
if __name__ == '__main__':
N = 5
theta = radar_factory(N, frame='polygon')
data1 = [2,1.5,3,3,2]
data2 = [1,0.5,2,2,1]
spoke_labels = ['A', 'B', 'C', 'D', 'E']
fig, ax = plt.subplots(figsize=(9, 9), nrows=1, ncols=1,
subplot_kw=dict(projection='radar'))
ax.plot(theta, data1, color='blue')
ax.plot(theta, data2, color='blue')
ax.fill_between(theta, y1=data1, y2=data2, color='red')
ax.fill(theta, data1, facecolor='blue', alpha=0.25)
ax.set_varlabels(spoke_labels)
plt.show()
及其输出。我希望红色区域会效仿蓝色区域并填充整个多边形。
如何关闭红色间隙？
这是我评论中建议的解决方案，它依赖于您提供 x、y1 和 y2 作为 args，而不是 kwargs :
....
def fill_between(self, *args, **kwargs):
"""
Override fill_between
- CUSTOM ADDITION TO EXAMPLE -
"""
if len(args) and args[0][0] != args[0][-1]:
args = list(args)
for i, arg in enumerate(args):
args[i] = np.append(arg, arg[0])
return super().fill_between(*args, **kwargs)
....
....
if __name__ == '__main__':
N = 5
theta = radar_factory(N, frame='polygon')
data1 = [2,1.5,3,3,2]
data2 = [1,0.5,2,2,1]
spoke_labels = ['A', 'B', 'C', 'D', 'E']
fig, ax = plt.subplots(figsize=(9, 9), nrows=1, ncols=1,
subplot_kw=dict(projection='radar'))
ax.plot(theta, data1, color='blue')
ax.plot(theta, data2, color='blue')
ax.fill_between(theta, data1, data2, color='red')
ax.fill(theta, data2, facecolor='blue', alpha=0.25)
ax.set_varlabels(spoke_labels)
plt.show()
示例输出：
如果需要，您也可以轻松实现 kwargs 解析以获得更大的灵活性，但显然，您失去了 matplotlib 解析的一些灵活性。但是，如果作为 len N 的 arg 或 len N+1 的 kwarg 提供，它仍然会解析 where:
#where array provided as arg of len N
ax.fill_between(theta, data1, data2, [True, True, False, True, True], color='red')
#or as kwarg of len N+1
#ax.fill_between(theta, data1, data2, where=[True, True, False, True, True, True], color='red')
输出：
我正在尝试在雷达图中使用 fill_between 绘制“环”，遵循此处的 matplotlib 雷达示例： https://matplotlib.org/3.1.0/gallery/specialty_plots/radar_chart.html
我保留 radar_factory 函数不变，除了一个额外的重载函数“fill_between”，遵循示例中已经存在的“fill”示例：
def fill_between(self, *args, closed=True, **kwargs):
"""Override fill_between so that lines are closed by default"""
return super().fill_between(closed=closed, *args, **kwargs)
据我了解，这应该将 closed=True 传递给 PolyCollection 对象。然而并没有。
这是重现问题的代码。它比最小的要长一点，但我认为与 matplotlib 文档中的示例保持接近很重要：
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.patches import Circle, RegularPolygon
from matplotlib.path import Path
from matplotlib.projections.polar import PolarAxes
from matplotlib.projections import register_projection
from matplotlib.spines import Spine
from matplotlib.transforms import Affine2D
def radar_factory(num_vars, frame='circle'):
# calculate evenly-spaced axis angles
theta = np.linspace(0, 2*np.pi, num_vars, endpoint=False)
class RadarAxes(PolarAxes):
name = 'radar'
# use 1 line segment to connect specified points
RESOLUTION = 1
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# rotate plot such that the first axis is at the top
self.set_theta_zero_location('N')
def fill(self, *args, closed=True, **kwargs):
"""Override fill so that line is closed by default"""
return super().fill(closed=closed, *args, **kwargs)
def fill_between(self, *args, closed=True, **kwargs):
"""
Override fill_between so that lines are closed by default
- CUSTOM ADDITION TO EXAMPLE -
"""
return super().fill_between(closed=closed, *args, **kwargs)
def plot(self, *args, **kwargs):
"""Override plot so that line is closed by default"""
lines = super().plot(*args, **kwargs)
for line in lines:
self._close_line(line)
def _close_line(self, line):
x, y = line.get_data()
# FIXME: markers at x[0], y[0] get doubled-up
if x[0] != x[-1]:
x = np.concatenate((x, [x[0]]))
y = np.concatenate((y, [y[0]]))
line.set_data(x, y)
def set_varlabels(self, labels):
self.set_thetagrids(np.degrees(theta), labels)
def _gen_axes_patch(self):
# The Axes patch must be centered at (0.5, 0.5) and of radius 0.5
# in axes coordinates.
if frame == 'circle':
return Circle((0.5, 0.5), 0.5)
elif frame == 'polygon':
return RegularPolygon((0.5, 0.5), num_vars,
radius=.5, edgecolor="k")
else:
raise ValueError("unknown value for 'frame': %s" % frame)
def _gen_axes_spines(self):
if frame == 'circle':
return super()._gen_axes_spines()
elif frame == 'polygon':
# spine_type must be 'left'/'right'/'top'/'bottom'/'circle'.
spine = Spine(axes=self,
spine_type='circle',
path=Path.unit_regular_polygon(num_vars))
# unit_regular_polygon gives a polygon of radius 1 centered at
# (0, 0) but we want a polygon of radius 0.5 centered at (0.5,
# 0.5) in axes coordinates.
spine.set_transform(Affine2D().scale(.5).translate(.5, .5)
+ self.transAxes)
return {'polar': spine}
else:
raise ValueError("unknown value for 'frame': %s" % frame)
register_projection(RadarAxes)
return theta
if __name__ == '__main__':
N = 5
theta = radar_factory(N, frame='polygon')
data1 = [2,1.5,3,3,2]
data2 = [1,0.5,2,2,1]
spoke_labels = ['A', 'B', 'C', 'D', 'E']
fig, ax = plt.subplots(figsize=(9, 9), nrows=1, ncols=1,
subplot_kw=dict(projection='radar'))
ax.plot(theta, data1, color='blue')
ax.plot(theta, data2, color='blue')
ax.fill_between(theta, y1=data1, y2=data2, color='red')
ax.fill(theta, data1, facecolor='blue', alpha=0.25)
ax.set_varlabels(spoke_labels)
plt.show()
及其输出。我希望红色区域会效仿蓝色区域并填充整个多边形。
如何关闭红色间隙？
这是我评论中建议的解决方案，它依赖于您提供 x、y1 和 y2 作为 args，而不是 kwargs :
....
def fill_between(self, *args, **kwargs):
"""
Override fill_between
- CUSTOM ADDITION TO EXAMPLE -
"""
if len(args) and args[0][0] != args[0][-1]:
args = list(args)
for i, arg in enumerate(args):
args[i] = np.append(arg, arg[0])
return super().fill_between(*args, **kwargs)
....
....
if __name__ == '__main__':
N = 5
theta = radar_factory(N, frame='polygon')
data1 = [2,1.5,3,3,2]
data2 = [1,0.5,2,2,1]
spoke_labels = ['A', 'B', 'C', 'D', 'E']
fig, ax = plt.subplots(figsize=(9, 9), nrows=1, ncols=1,
subplot_kw=dict(projection='radar'))
ax.plot(theta, data1, color='blue')
ax.plot(theta, data2, color='blue')
ax.fill_between(theta, data1, data2, color='red')
ax.fill(theta, data2, facecolor='blue', alpha=0.25)
ax.set_varlabels(spoke_labels)
plt.show()
示例输出：
如果需要，您也可以轻松实现 kwargs 解析以获得更大的灵活性，但显然，您失去了 matplotlib 解析的一些灵活性。但是，如果作为 len N 的 arg 或 len N+1 的 kwarg 提供，它仍然会解析 where:
#where array provided as arg of len N
ax.fill_between(theta, data1, data2, [True, True, False, True, True], color='red')
#or as kwarg of len N+1
#ax.fill_between(theta, data1, data2, where=[True, True, False, True, True, True], color='red')
输出：