import  matplotlib.pyplot as plt
import  numpy as np

def step_function(x):
    return np.array(x>0,dtype =np.int)

def sigmoid(x):
    return 1/(1+np.exp(-x))

def relu(x):
    return np.maximum(0,x)

x =np.arange(-5.0,5.0,0.1)
# y =step_function(x)
y =sigmoid(x)
plt.plot(x,y)
plt.ylim(-0.1,1.1)#yの範囲を指定
plt.show()

