Proximal gradient methods for learning

term_id: proximal_gradient_methods_for_learning

Category: training_techniques

Definition

Proximal gradient methods are iterative optimization techniques used when the loss function includes a differentiable smooth term and a non-differentiable regularizer, such as L1 norm. The algorithm combines gradient descent steps on the smooth part with a proximal operator that handles the non-smooth part. This makes them particularly useful for sparse learning and regularization tasks where traditional gradient descent fails due to non-differentiability.

Summary

Optimization algorithms designed to minimize composite objective functions containing both smooth and non-smooth components.

Key Concepts

  • composite optimization
  • proximal operator
  • L1 regularization
  • non-smooth convexity

Use Cases

  • Sparse feature selection
  • Lasso regression
  • Structured prediction models