figure图像

import matplotlib.pyplot as plt
import numpy as np

x=np.linspace(-3,3,50)
y1=x*2+1
y2=x**2
plt.plot(x,y1)

plt.figure(num=3,figsize=(8,5))
plt.plot(x,y2)
plt.plot(x,y1,color="red",linewidth=1.0,linestyle="--")
plt.show()