机器学习损失函数常用的函数
sigmoid
$\sigma(z) = \frac{1}{1+e^{-z}}$
1 import matplotlib.pyplot as plt 2 import numpy as np 3 import math 4 import pandas as pd 5 6 z = np.arange(-10.,10.,0.1) 7 fz = 1/(1 + np.exp(-z)) 8 9 plt.plot(z,fz) 10 plt.show()
$\sigma(z) = \frac{1}{1+e^{-z}}$
1 import matplotlib.pyplot as plt 2 import numpy as np 3 import math 4 import pandas as pd 5 6 z = np.arange(-10.,10.,0.1) 7 fz = 1/(1 + np.exp(-z)) 8 9 plt.plot(z,fz) 10 plt.show()