Recap:PCA Minimize(x-龙)2 As close as possible encode decode W hidden layer Input layer (linear） output layer Bottleneck later Output of the hidden layer is the codeRecap: PCA 𝑥 Input layer 𝑊 𝑥 ො 𝑊𝑇 output layer hidden layer (linear) 𝑐 As close as possible Minimize 𝑥 − 𝑥 ො 2 Bottleneck later Output of the hidden layer is the code encode decode