legend 标注定义的图像import matplotlib as plt
import numpy as np
x = np.linspace(-3, 3, 50)
y1 = 2*x + 1
y2 = x**2
plt.figure()
# set x limits
plt.xlim((-1, 2))
plt.ylim((-2, 3))
# set new sticks
Microsoft PowerPoint provides a suite of basic image-editing tools, including the ability to change the opacity of an object or photo. If you want, you can even change the transparency of only a
