sigmoid 函数

目录

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公式
$ g(z) = frac{1}{1+e^{-z}} $

• (g:mathbb{R} o [0,1])
• (g(0)=0.5)
• (g(- infty)=0)
• (g(+ infty)=1)

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

nums = np.arange(-10, 10, step=1) #creates a vector containing 20 equally spaced values from -10 to 10
fig, ax = plt.subplots(figsize=(12,4))
ax.plot(nums, sigmoid(nums), 'r')