import numpy as np

import matplotlib.pylab as plt

def step_function(x):

y = x > 0

return y.astype(np.int)

def sigmoid_function(x):

return 1 / (1 + np.exp(-x)) #broadcast

x = np.arange(-5.0, 5.0, 0.1)

y1 = step_function(x)

y2 = sigmoid_function(x)

plt.plot(x, y1)

plt.plot(x, y2)

plt.ylim(-0.1, 1.1) #y축의 범위 지정

plt.show()