从motion_notify_event获取当前坐标轴

Question

我有一个包含多个子图的图。每个子图都有不同的数据。我也希望在悬停时显示数据标签，以捕捉motion_notify_event。如何从事件中捕获当前子图轴？

import random 
import matplotlib.pyplot as plt 

def on_move(event): 
    if event.inaxes is not None: 
     # Which subplot am I hovering over? 
     pass 

fig = plt.figure() 
ax1 = plt.subplot2grid((4, 4), (0, 0), colspan=3) 
ax2 = plt.subplot2grid((4, 4), (1, 0), colspan=3, rowspan=3) 
ax3 = plt.subplot2grid((4, 4), (1, 3), rowspan=3) 

ax1.plot(random.sample(xrange(100), 10), random.sample(xrange(100), 10), 'ro') 
ax2.plot(random.sample(xrange(100), 10), random.sample(xrange(100), 10), 'bo') 
ax3.plot(random.sample(xrange(100), 10), random.sample(xrange(100), 10), 'go') 

on_move_id = fig.canvas.mpl_connect('motion_notify_event', on_move) 

plt.show() 

Answer 1

event是LocationEvent一个实例，从而event.inaxes包含已经次要情节轴。试试：

def on_move(event): 
    if event.inaxes is not None: 
     x = event.xdata 
     y = event.ydata 
     event.inaxes.plot(x,y,'ro') 
     event.canvas.draw()