Expectation Maximization

Gaussian Mixture Model & Expectation Maximization

Gaussian Mixture Model & Expectation Maximization #

A Gaussian Mixture Model represents data as a weighted combination of multiple Gaussian distributions.

It is commonly used for soft clustering and density estimation.

Key takeaway:
K-means gives hard cluster membership.

GMM gives probabilities of belonging to each cluster.

  • Gaussian Mixture Model
  • soft clustering
  • mixing coefficients
  • latent variables
  • likelihood and log-likelihood
  • Expectation-Maximization algorithm
  • E-step and M-step
  • responsibilities
  • convergence

Motivation ☆ #

Many real datasets are not described well by one Gaussian distribution.