Question

当用户点击某个特定点时，我正试图以动态方式将垂直线添加到matplotlib图中。

import matplotlib.pyplot as plt
import matplotlib.dates as mdate


class PointPicker(object):
    def __init__(self,dates,values):

        self.fig = plt.figure()
        self.ax = self.fig.add_subplot(111)

        self.lines2d, = self.ax.plot_date(dates, values, linestyle='-',picker=5)

        self.fig.canvas.mpl_connect('pick_event', self.onpick)
        self.fig.canvas.mpl_connect('key_press_event', self.onpress)

    def onpress(self, event):
        """define some key press events"""
        if event.key.lower() == 'q':
            sys.exit()

    def onpick(self,event):
        x = event.mouseevent.xdata
        y = event.mouseevent.ydata
        print self.ax.axvline(x=x, visible=True)
        x = mdate.num2date(x)
        print x,y,type(x)


if __name__ == '__main__':
    import numpy as np
    import datetime

    dates=[datetime.datetime.now()+i*datetime.timedelta(days=1) for i in range(100)]
    values = np.random.random(100)

    plt.ion()
    p = PointPicker(dates,values)
    plt.show()

这是一个（几乎）工作的例子。当我点击一个点时，确实调用了onpick方法并且数据看起来是正确的，但没有显示垂直线。我需要做什么才能显示垂直线？

由于

Answer 1

您需要更新画布图（self.fig.canvas.draw()）：

def onpick(self,event):
    x = event.mouseevent.xdata
    y = event.mouseevent.ydata
    L =  self.ax.axvline(x=x)
    self.fig.canvas.draw()

动态地向matplotlib图添加垂直线

1 个答案: