Trifinder 事件演示

显示使用TriFinder对象的示例。当鼠标在三角测量上移动时，光标下方的三角形将突出显示，三角形的索引将显示在图表标题中。

Trifinder 事件演示

  1. import matplotlib.pyplot as plt
  2. from matplotlib.tri import Triangulation
  3. from matplotlib.patches import Polygon
  4. import numpy as np
  7. def update_polygon(tri):
  8.     if tri == -1:
  9.         points = [0, 0, 0]
  10.     else:
  11.         points = triang.triangles[tri]
  12.     xs = triang.x[points]
  13.     ys = triang.y[points]
  14.     polygon.set_xy(np.column_stack([xs, ys]))
  17. def motion_notify(event):
  18.     if event.inaxes is None:
  19.         tri = -1
  20.     else:
  21.         tri = trifinder(event.xdata, event.ydata)
  22.     update_polygon(tri)
  23.     plt.title('In triangle %i' % tri)
  24.     event.canvas.draw()
  27. # Create a Triangulation.
  28. n_angles = 16
  29. n_radii = 5
  30. min_radius = 0.25
  31. radii = np.linspace(min_radius, 0.95, n_radii)
  32. angles = np.linspace(0, 2 * np.pi, n_angles, endpoint=False)
  33. angles = np.repeat(angles[..., np.newaxis], n_radii, axis=1)
  34. angles[:, 1::2] += np.pi / n_angles
  35. x = (radii*np.cos(angles)).flatten()
  36. y = (radii*np.sin(angles)).flatten()
  37. triang = Triangulation(x, y)
  38. triang.set_mask(np.hypot(x[triang.triangles].mean(axis=1),
  39.                          y[triang.triangles].mean(axis=1))
  40.                 < min_radius)
  42. # Use the triangulation's default TriFinder object.
  43. trifinder = triang.get_trifinder()
  45. # Setup plot and callbacks.
  46. plt.subplot(111, aspect='equal')
  47. plt.triplot(triang, 'bo-')
  48. polygon = Polygon([[0, 0], [0, 0]], facecolor='y')  # dummy data for xs,ys
  49. update_polygon(-1)
  50. plt.gca().add_patch(polygon)
  51. plt.gcf().canvas.mpl_connect('motion_notify_event', motion_notify)
  52. plt.show()

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