Matplotlib饼图-如何居中放置标签？

Question

我在饼图中添加了旋转标签，并希望默认情况下标签将位于饼图的每个切片中。但这不是

如何将标签居中？

这是我的后端代码：

from PyQt5 import QtCore, QtGui, QtWidgets
import sys
from PyQt5.QtWidgets import QMainWindow, QApplication, QWidget
from frontend import Ui_MainWindow
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
import matplotlib.pyplot as plt

class Ui_MainWindow(QMainWindow, Ui_MainWindow):

    def __init__(self, parent=None):
        super(Ui_MainWindow, self).__init__(parent)
        self.setupUi(self)
        self.graph = MyCanvas()      
        self.gridLayout.addWidget(self.graph, 0, 0, 1, 1)
        self.graph.figure.clf()
        self.axes = self.graph.figure.add_subplot(111)
        self.y = [1,2,3, 4,8,16,32]
        self.label = ['1.52%', '3.03%', '4.55%', '6.06%', '12.12%', '24.24%', '48.48%']
        self.axes.pie(self.y, labels=self.label, labeldistance=0.6, rotatelabels =True)

class MyCanvas(FigureCanvas):
    def __init__(self, *args, **kwargs):
        self.figure = plt.figure()
        FigureCanvas.__init__(self, self.figure)
        self.figure.patch.set_facecolor("None")
        self.figure.subplots_adjust(left=0.08, bottom=0.10, right=0.99, top=0.97)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    prog = Ui_MainWindow()
    prog.show()
    sys.exit(app.exec_())

Answer 1

查看documentation，您可以使用textprops关键字将专用选项传递给饼图中的文本对象。 textprops接受dict，它显然接受matplotlib.text.Text接受的所有选项。向其提供选项rotation_mode='anchor'，va='center'和ha='left'可获得很好的效果：

import matplotlib.pyplot as plt

figure = plt.figure()
figure.patch.set_facecolor("None")
figure.subplots_adjust(left=0.08, bottom=0.10, right=0.99, top=0.97)
figure.clf()
axes = figure.add_subplot(111)
axes.set_aspect(1)
y = [1,2,3, 4,8,16,32]
label = ['1.52%', '3.03%', '4.55%', '6.06%', '12.12%', '24.24%', '48.48%']
axes.pie(
    y, labels=label, labeldistance=0.6, rotatelabels =True,
    textprops = dict(rotation_mode = 'anchor', va='center', ha='left'),
)

plt.show()

代码的结果如下：

请注意，我添加了ax.set_aspect(1)以使饼图成为圆形。如果您不希望这样做，则请忽略该行。