Radar Plot Matplotlib Python：如何设置标签对齐

Question

我正在尝试将雷达图的标签与轴对齐，但我遇到了困难。

没有标签对齐，我的标签居中并超出了轴线。

当我将标签的前半部分（图的右侧）设置为左对齐，将后半部分设置为右对齐时，我得到了非 "circular" 对齐方式

为此，我在 xticklabels 中循环并设置水平对齐方式。

# Draw one axe per variable + add labels labels yet
plt.xticks(angles, categories)
for label,i in zip(ax.get_xticklabels(),range(0,len(angles))):
    if i<len(angles)/2:
        angle_text=angles[i]*(-180/pi)+90
        #label.set_horizontalalignment('left')

    else:
        angle_text=angles[i]*(-180/pi)-90
        #label.set_horizontalalignment('right')
    label.set_rotation(angle_text)

我想有一种正确的方法可以做到这一点，但我想不出来，因为我不知道它是否应该考虑偏移、平移或如何调整极坐标来做到这一点。

感谢您的帮助

保罗

完整代码如下

from math import pi
import matplotlib.pyplot as plt
%matplotlib inline
import pandas as pd

## Generate Data
labels_test=[]
for i in range(0,40):
    labels_test.append("Fooooooooo"+str(i))
pd_radar=pd.DataFrame(data=np.random.randint(low=0, high=10, size=(2, 40)),columns=labels_test)

# number of variable
categories=list(pd_radar)
N = len(categories)

# What will be the angle of each axis in the plot? (we divide the plot / number of variable)
angles = [n / float(N) * 2 * pi for n in range(N)]

# Initialise the spider plot
fig=plt.figure(figsize=(20,10))
ax = plt.subplot(111, polar=True)

# If you want the first axis to be on top:
ax.set_theta_offset(pi / 2)
ax.set_theta_direction(-1)

# Draw one axe per variable + add labels labels yet
plt.xticks(angles, categories)
for label,i in zip(ax.get_xticklabels(),range(0,len(angles))):
    if i<len(angles)/2:
        angle_text=angles[i]*(-180/pi)+90
        label.set_horizontalalignment('left')

    else:
        angle_text=angles[i]*(-180/pi)-90
        label.set_horizontalalignment('right')
    label.set_rotation(angle_text)
# Draw ylabels
ax.set_rlabel_position(0)


# ------- PART 2: Add plots

# Plot each line of the data 

# Ind1
values0=pd_radar.iloc[0].values.flatten().tolist()
ax.plot(angles, values0, linewidth=1, linestyle='solid', label="Label 1",color='yellow')
ax.fill(angles, values0, 'r', alpha=0.1,color='yellow')

# Ind2
values1=pd_radar.iloc[1].values.flatten().tolist()
ax.plot(angles, values1, linewidth=1, linestyle='solid', label="Label 2",color='deepskyblue')
ax.fill(angles, values1, 'r',color='deepskyblue', alpha=0.1)

# Add legend
plt.show()

Answer 1

我找到了一个看起来不太优雅的解决方案。主要思想是将垂直和水平对齐设置为角度的函数。

from math import pi
import matplotlib.pyplot as plt
%matplotlib inline
import pandas as pd
import numpy as np

## Generate Data
labels_test=[]
for i in range(0,40):
    labels_test.append("Fooooooooo"+str(i))
pd_radar=pd.DataFrame(data=np.random.randint(low=0, high=10, size=(2, 40)),columns=labels_test)


# number of variable
categories=list(pd_radar)
N = len(categories)

# What will be the angle of each axis in the plot? (we divide the plot / number of variable)
angles = [n / float(N) * 2 * pi for n in range(N)]

# Initialise the spider plot
fig=plt.figure(figsize=(20,10))
ax = plt.subplot(111, polar=True)

# If you want the first axis to be on top:
ax.set_theta_offset(pi / 2)
ax.set_theta_direction(-1)

# Draw one axe per variable + add labels labels yet
# idea is to add both vertical and horizontal alignment as a function of pi

plt.xticks(angles, categories)
for label,i in zip(ax.get_xticklabels(),range(0,len(angles))):

    angle_rad=angles[i]
    if angle_rad <= pi/2:
        ha= 'left'
        va= "bottom"
        angle_text=angle_rad*(-180/pi)+90
    elif pi/2 < angle_rad <= pi:
        ha= 'left'
        va= "top"
        angle_text=angle_rad*(-180/pi)+90
    elif pi < angle_rad <= (3*pi/2):
        ha= 'right'
        va= "top"  
        angle_text=angle_rad*(-180/pi)-90
    else:
        ha= 'right'
        va= "bottom"
        angle_text=angle_rad*(-180/pi)-90
    label.set_rotation(angle_text)
    label.set_verticalalignment(va)
    label.set_horizontalalignment(ha)


# Draw ylabels
ax.set_rlabel_position(0)


# ------- PART 2: Add plots

# Plot each line of the data 

# Ind1
values2=pd_radar.iloc[0].values.flatten().tolist()
ax.plot(angles, values2, linewidth=1, linestyle='solid', label="Label 1",color='yellow')
ax.fill(angles, values2, 'r', alpha=0.1,color='yellow')

# Ind2
values3=pd_radar.iloc[1].values.flatten().tolist()
ax.plot(angles, values3, linewidth=1, linestyle='solid', label="Label 2",color='deepskyblue')
ax.fill(angles, values3, 'r',color='deepskyblue', alpha=0.1)

# Add legend
plt.show()

Answer 2

当前代码does not run with matplotlib 2.2. The following solution works however with version 2.0.2 that the OP is using. For a workaround using newer versions, see .

matplotlib 中的文本有 rotation mode.

旋转方式可以是"default"，此时文字先旋转再对齐

也可以是"anchor"，在这种情况下文本先对齐然后旋转。

因此，为了使极坐标图上的刻度标签指向外，您需要将文本的对齐设置为 "left"，然后将旋转模式设置为 "anchor"。

for label,rot in zip(ax.get_xticklabels(),ticks):
    label.set_rotation(rot*180./np.pi)
    label.set_horizontalalignment("left")
    label.set_rotation_mode("anchor")

完整示例：

import numpy as np
import matplotlib.pyplot as plt

fig=plt.figure(figsize=(5,5))
ax = plt.subplot(111, polar=True)

ticks = np.linspace(0, 2*np.pi, 20, endpoint=False)
text = lambda : "".join(np.random.choice(list("manuladefil"), size=10))
labels = [text() for _ in range(len(ticks))]

plt.xticks(ticks, labels, size=16)
for label,rot in zip(ax.get_xticklabels(),ticks):
    label.set_rotation(rot*180./np.pi)
    label.set_horizontalalignment("left")
    label.set_rotation_mode("anchor")

plt.tight_layout()
plt.show()

Radar Plot Matplotlib Python：如何设置标签对齐

Radar Plot Matplotlib Python : how to set label alignment

python

matplotlib

alignment

radar-chart