镜子

例如，使用鼠标事件模拟用于检查数据的镜子。

镜子示例

  1. import numpy as np
  2. import matplotlib.pyplot as plt
  3. import matplotlib.patches as patches
  5. # Fixing random state for reproducibility
  6. np.random.seed(19680801)
  8. x, y = np.random.rand(2, 200)
  10. fig, ax = plt.subplots()
  11. circ = patches.Circle((0.5, 0.5), 0.25, alpha=0.8, fc='yellow')
  12. ax.add_patch(circ)
  15. ax.plot(x, y, alpha=0.2)
  16. line, = ax.plot(x, y, alpha=1.0, clip_path=circ)
  17. ax.set_title("Left click and drag to move looking glass")
  20. class EventHandler(object):
  21.     def __init__(self):
  22.         fig.canvas.mpl_connect('button_press_event', self.onpress)
  23.         fig.canvas.mpl_connect('button_release_event', self.onrelease)
  24.         fig.canvas.mpl_connect('motion_notify_event', self.onmove)
  25.         self.x0, self.y0 = circ.center
  26.         self.pressevent = None
  28.     def onpress(self, event):
  29.         if event.inaxes != ax:
  30.             return
  32.         if not circ.contains(event)[0]:
  33.             return
  35.         self.pressevent = event
  37.     def onrelease(self, event):
  38.         self.pressevent = None
  39.         self.x0, self.y0 = circ.center
  41.     def onmove(self, event):
  42.         if self.pressevent is None or event.inaxes != self.pressevent.inaxes:
  43.             return
  45.         dx = event.xdata - self.pressevent.xdata
  46.         dy = event.ydata - self.pressevent.ydata
  47.         circ.center = self.x0 + dx, self.y0 + dy
  48.         line.set_clip_path(circ)
  49.         fig.canvas.draw()
  51. handler = EventHandler()
  52. plt.show()

下载这个示例