如何在图中添加曲线y=0?
#matplotlib inline
import numpy as np
import matplotlib.pyplot as plt
from pylab import *
x=np.arange(-0.1,4.1,0.1)
#plt.ylim(-100,100)
y1=np.cos(x)
y2=np.sin(x)
y3=abs(x-1)*tan(x-3)/(x-1)*(x-2)*square(x-3)
plt.rcParams['figure.figsize']=(10,5) #reParams设置图片尺寸
plt.plot(x,y1,color='blue',linewidth=1.5,linestyle='-',marker='.')
plt.plot(x,y2,color='green',linewidth=1.5,linestyle='-',marker='*')
plt.plot(x,y3,color='purple',linewidth=1.5,linestyle='-')
plt.legend(['cos(x)','sin(x)','im the target'],loc='upper right') #对好顺序
plt.show()