matplotlib pie：水平旋转标签

Question

使用 matplot 通过以下代码创建一个小仪表：

    group_size=[10,10,10,10,10,50]
    labels=['AAAA','BBBB','CCCC','DDDD','EEEE','']
    fig, ax = plt.subplots()
    ax.axis('equal')
    pie = ax.pie(group_size, radius=2.2, colors=['k'] ,startangle=180,counterclock=False)
    pie2 = ax.pie([10,10,10,10,10,50], radius=2,  labeldistance=0.7, labels=labels, rotatelabels = 270,
startangle=180,counterclock=False)
    plt.show()

我正在尝试让标签水平移动并与每个楔形的中点对齐（但楔形内的文本）：

使用 rotatelabel=True，我得到以下信息：

关于如何实现图表标签的水平旋转有什么想法吗？

Answer 1

您需要手动旋转饼图标签。为此，您可以遍历标签并根据需要设置旋转。

group_size=[10,10,10,10,10,50]
labels=['AAAA','BBBB','CCCC','DDDD','EEEE','']
fig, ax = plt.subplots()
ax.axis('equal')
pie = ax.pie(group_size, radius=2.2, colors=['k'] ,startangle=180,counterclock=False)
pie2 = ax.pie([10,10,10,10,10,50], radius=2,  labeldistance=0.9, labels=labels, 
              rotatelabels =True, startangle=180,counterclock=False)

plt.setp(pie2[1], rotation_mode="anchor", ha="center", va="center")
for tx in pie2[1]:
    rot = tx.get_rotation()
    tx.set_rotation(rot+90+(1-rot//180)*180)

plt.show()

Answer 2

我的解决方案与ImportanceOfBeingErnest接受的答案基本相似。不过我觉得里面的步骤比较容易掌握。

import matplotlib.pyplot as plt

group_size = [10, 10, 10, 10, 10, 50]
labels = ['AAAA', 'BBBB', 'CCCC', 'DDDD', 'EEEE', '']
fig, ax = plt.subplots()
ax.axis('equal')
pie = ax.pie(group_size, radius=2.2, colors=['k'], startangle=180, counterclock=False)

# ax.pie() returns wedges, labels
# Note that rotatelabels=False; so that, at this step ...
# all labels are not rotated; they will be rotated later
wedges, labels = ax.pie([10, 10, 10, 10, 10, 50], radius=2,  \
                      labeldistance=0.85, labels=labels, rotatelabels = False, \
                      startangle=180, counterclock=False)

# do the rotation of the labels
for ea, eb in zip(wedges, labels):
    mang =(ea.theta1 + ea.theta2)/2.  # get mean_angle of the wedge
    #print(mang, eb.get_rotation())
    eb.set_rotation(mang+270)         # rotate the label by (mean_angle + 270)
    eb.set_va("center")
    eb.set_ha("center")

plt.show()

生成的图像：

matplotlib pie：水平旋转标签

matplot pie: rotate labels horizontally

python

data-visualization

matplotlib

pie-chart