Variational Inference

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Part 2: Scalable Approximate Inference Session 1: - Variational Inference Session 2: - Sampling methods Approximate and Scalable Inference for Complex Probabilistic Models in Recommender Systems

Transcript of Variational Inference

Page 1: Variational Inference

Part 2: Scalable Approximate Inference

Session 1:- Variational Inference

Session 2:- Sampling methods

Approximate and Scalable Inference for Complex Probabilistic Models in Recommender Systems

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Introduction

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Motivation: bayesian mixture model

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Main idea

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KL-Divergence

KL of the posterior

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KL-Divergence

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ELBO e KL-Divergence

Jensen inequality concave (log)

KL of the posterior

Evidence lower bound (ELBO)

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KL and ELBO

Choose family of variational distributions such that the expectations of log(q(z)) and log(p(x,z)) are computable

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Mean-field

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Optimizing a functional

Euler-lagrange equation

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Mean-field

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Structured variational inference