1.神经网络
1.1数据样式
1.2 单隐藏层神经网络
1.3 神经网络相关函数
For one example x(i)x^{(i)}x(i):
(1)z[1](i)=W[1]x(i)+b[1]z^{[1] (i)} = W^{[1]} x^{(i)} + b^{[1]}\tag{1}z[1](i)=W[1]x(i)+b[1](1)
(2)a[1](i)=tanh(z[1](i))a^{[1] (i)} = \tanh(z^{[1] (i)})\tag{2}a[1](i)=tanh(z[1](i))(2)
(3)z[2](i)=W[2]a[1](i)+b[2]z^{[2] (i)} = W^{[2]} a^{[1] (i)} + b^{[2]}\tag{3}z[2](i)=W[2]a[1](i)+b