自定义 Figure 子类

如果您想更改 figure 的默认行为,您可以将 Figure 子类传递给 pyplot.figure .

此示例定义了一个 Figure 子类 WatermarkFigure ,它接受一个额外的参数 watermark 来显示自定义水印文本.该 figure 使用 pyplot.figure 的 FigureClass 参数创建.额外的 watermark 参数会传递给子类构造函数.

import matplotlib.pyplot as plt
import numpy as np

from matplotlib.figure import Figure


class WatermarkFigure(Figure):
    """A figure with a text watermark."""

    def __init__(self, *args, watermark=None, **kwargs):
        super().__init__(*args, **kwargs)

        if watermark is not None:
            bbox = dict(boxstyle='square', lw=3, ec='gray',
                        fc=(0.9, 0.9, .9, .5), alpha=0.5)
            self.text(0.5, 0.5, watermark,
                      ha='center', va='center', rotation=30,
                      fontsize=40, color='gray', alpha=0.5, bbox=bbox)


x = np.linspace(-3, 3, 201)
y = np.tanh(x) + 0.1 * np.cos(5 * x)

plt.figure(FigureClass=WatermarkFigure, watermark='draft')
plt.plot(x, y)

参考

以下函数,方法,类和模块的用法在本例中显示:

• matplotlib.pyplot.figure

• matplotlib.figure.Figure

• matplotlib.figure.Figure.text

标签: component: figure plot-type: line level: intermediate purpose: showcase