Matplotlib演示代碼不起作用

Question

我正在嘗試從Matplotlib運行演示代碼： legend_picking示例 。

單擊圖例時，此代碼應該隱藏和顯示繪圖線。

當我單擊圖例上的行時，似乎未觸發事件“ pick_event”。 我對簡單的揀貨示例沒有任何問題

"""
# Enable picking on the legend to toggle the legended line on and off
"""
import numpy as np
import matplotlib.pyplot as plt

t = np.arange(0.0, 0.2, 0.1)
y1 = 2*np.sin(2*np.pi*t)
y2 = 4*np.sin(2*np.pi*2*t)

fig = plt.figure()
ax = fig.add_subplot(111)
ax.set_title('Click on legend line to toggle line on/off')
line1, = ax.plot(t, y1, lw=2, color='red', label='1 HZ')
line2, = ax.plot(t, y2, lw=2, color='blue', label='2 HZ')
leg = ax.legend(loc='upper left', fancybox=True, shadow=True)
leg.get_frame().set_alpha(0.4)


# we will set up a dict mapping legend line to orig line, and enable
# picking on the legend line
lines = [line1, line2]
lined = dict()
for legline, origline in zip(leg.get_lines(), lines):
    legline.set_picker(5)  # 5 pts tolerance
    lined[legline] = origline


def onpick(event):
    # on the pick event, find the orig line corresponding to the
    # legend proxy line, and toggle the visibilit
    legline = event.artist
    origline = lined[legline]
    vis = not origline.get_visible()
    origline.set_visible(vis)
    # Change the alpha on the line in the legend so we can see what lines
    # have been toggled
    if vis:
        legline.set_alpha(1.0)
    else:
        legline.set_alpha(0.2)
    fig.canvas.draw()

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

plt.show()

Answer 1

您正在運行哪個版本的matplotlib ？ 對我來說很好（版本1.1.0 ）。 sourceforge網站上有多個示例，這些示例不適用於1.0以下的版本。 要查找版本號，請使用

import matplotlib
print matplotlib.__version__

Answer 2

確實有效。 只需單擊圖例中的行即可。

該腳本應該通過單擊圖例中的線條來切換圖形的透明度。