matplotlib - 交互式選擇點或位置？

Question

在R中，有一個功能locator，它與Matlab的ginput類似，您可以用鼠標單擊圖形並選擇任何x，y座標。另外，還有一個叫做identify(x,y)的函數，如果你給它一組已繪製的點x，y，然後單擊該圖，它將返回最接近的x，y點的索引（在一個可調容差）到您選擇的位置（或多個指標，如果選擇多個點）。 Matplotlib中有這樣的功能嗎？

Answer 1

您可能需要使用一個pick event：

fig = figure() 
ax1 = fig.add_subplot(111) 
ax1.set_title('custom picker for line data') 
line, = ax1.plot(rand(100), rand(100), 'o', picker=line_picker) 
fig.canvas.mpl_connect('pick_event', onpick2) 

公差通過選擇器參數有設置：

line, = ax1.plot(rand(100), 'o', picker=5) # 5 points tolerance 

Answer 2

from __future__ import print_function 
import matplotlib.pyplot as plt 
from matplotlib.lines import Line2D 
from matplotlib.patches import Rectangle 
from matplotlib.text import Text 
from matplotlib.image import AxesImage 
import numpy as np 
from numpy.random import rand 

if 1: 
    fig, ax = plt.subplots() 
    ax.set_title('click on points', picker=True) 
    ax.set_ylabel('ylabel', picker=True, bbox=dict(facecolor='red')) 
    line, = ax.plot(rand(100), 'o', picker=5) 

    def onpick1(event): 
     if isinstance(event.artist, Line2D): 
      thisline = event.artist 
      xdata = thisline.get_xdata() 
      ydata = thisline.get_ydata() 
      ind = event.ind 
      print 'X='+str(np.take(xdata, ind)[0]) # Print X point 
      print 'Y='+str(np.take(ydata, ind)[0]) # Print Y point 

    fig.canvas.mpl_connect('pick_event', onpick1)