19 Approximate Inference

19.1 Inference as Optimization

19.2 Expectation Maximization

19.3 MAP Inference and Sparse Coding

19.4 Variational Inference and Learning

19.4.1 Discrete Latent Variables

19.4.2 Calculus of Variations

19.4.3 Continuous Latent Variables

19.4.4 Interactions between Learning and Inference

19.5 Learned Approximate Inference

19.5.1 Wake-Sleep

19.5.2 Other Forms of Learning Inference