三种激活函数以及作图

import matplotlib.pyplot as plt
import  numpy as np
'''
'-'       solid line style
'--'      dashed line style
'-.'      dash-dot line style
':'       dotted line style

'''


plt.title("active functions")
x=np.linspace(-10,10,1000)

#simoid
y=np.array([ 1/(1+np.exp(-ele)) for ele in x])
plt.plot(x,y,color="black",linewidth=2.0,linestyle='--',label='sigmoid')

# tan
y1=np.array([(1-np.exp(-2*ele))/(1+np.exp(-2*ele)) for ele in x ])
plt.plot(x,y1,color="red",linewidth=2.0,linestyle=':',label='tan')

# relu
def relu(x):
    if x<0:
        return 0
    else:
        return x
y2=np.array([relu(ele) for ele in x])
plt.plot(x,y2,color="blue",linewidth=2.0,linestyle='--',label='relu')
plt.legend()
plt.show()