使用 matplotlib 存储鼠标单击事件坐标

2022-01-09 00:00:00 python matplotlib mouseevent onclick

问题描述

我正在尝试在 matplotlib 中实现一个简单的鼠标单击事件.我希望绘制一个图形，然后使用鼠标选择积分的下限和上限.到目前为止，我能够将坐标打印到屏幕上，但不能存储它们以供以后在程序中使用.我也想在第二次鼠标点击后退出与图的连接.

I am trying to implement a simple mouse click event in matplotlib. I wish to plot a figure then use the mouse to select the lower and upper limits for integration. So far I am able to print the coordinates to screen but not store them for later use in the program. I would also like to exit the connection to the figure after the second mouse click.

下面是当前绘制然后打印坐标的代码.

Below is the code which currently plots and then prints the coordinates.

我的问题:

如何将图形中的坐标存储到列表中?即点击 = [xpos, ypos]

How can I store coordinates from the figure to list? i.e. click = [xpos, ypos]

是否有可能获得两组 x 坐标以便对该段线进行简单的积分?

Is it possible to get two sets of x coordinates in order to do a simple integration over that section of line?

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(-10,10)
y = x**2

fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(x,y)

def onclick(event):
    global ix, iy
    ix, iy = event.xdata, event.ydata
    print 'x = %d, y = %d'%(
        ix, iy)

    global coords
    coords = [ix, iy]

    return coords


for i in xrange(0,1):

    cid = fig.canvas.mpl_connect('button_press_event', onclick)


plt.show()

解决方案

mpl_connect 只需调用一次即可将事件连接到事件处理程序.它将开始监听点击事件，直到您断开连接.你可以使用

mpl_connect needs to be called just once to connect the event to event handler. It will start listening to click event until you disconnect. And you can use 

fig.canvas.mpl_disconnect(cid)

断开事件挂钩.

你想做的是这样的:

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(-10,10)
y = x**2

fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(x,y)

coords = []

def onclick(event):
    global ix, iy
    ix, iy = event.xdata, event.ydata
    print 'x = %d, y = %d'%(
        ix, iy)

    global coords
    coords.append((ix, iy))

    if len(coords) == 2:
        fig.canvas.mpl_disconnect(cid)

    return coords
cid = fig.canvas.mpl_connect('button_press_event', onclick)

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