从图中选择n个数据点 [英] Select n data points from plot

问题描述

我想通过在图中单击om来选择点并将其存储在数组中.我想在n个选择之后停止选择点，例如通过按一个键.我怎样才能做到这一点?这就是我到目前为止所拥有的.

I want to select points by clicking om them in a plot and store the point in an array. I want to stop selecting points after n selections, by for example pressing a key. How can I do this? This is what I have so far.

import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)
ax.set_title('click on points')

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

def onpick(event):
    thisline = event.artist
    xdata = thisline.get_xdata()
    ydata = thisline.get_ydata()
    ind = event.ind
    points = tuple(zip(xdata[ind], ydata[ind]))
    print('onpick points:', points)


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

plt.show()

推荐答案

要具有GUI功能，您必须将绘图嵌入GUI框架中；但是，有一种简单的方法可以限制所选项目的数量:

To have GUI functionality, you will have to embed the plot in a GUI frame; however, there is a simple way to limit the number of selected items:

import matplotlib
matplotlib.use('TkAgg')

import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)
ax.set_title('click on points')

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

points = []
n = 5

def onpick(event):
    if len(points) < n:
        thisline = event.artist
        xdata = thisline.get_xdata()
        ydata = thisline.get_ydata()
        ind = event.ind
        point = tuple(zip(xdata[ind], ydata[ind]))
        points.append(point)
        print('onpick point:', point)
    else:
        print('already have {} points'.format(len(points)))


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

plt.show()

示例输出:

onpick point: ((54.0, 0.68482963903475647),)
onpick point: ((54.0, 0.68482963903475647),)
onpick point: ((54.0, 0.68482963903475647),)
onpick point: ((54.0, 0.68482963903475647),)
onpick point: ((54.0, 0.68482963903475647),)
already have 5 points

如果要选择唯一点，则可以使用集合来存储它们，而不是列表.

If you want to select unique points, you can use a set to store them instead of a list.

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