Duality Between Subgradient and Conditional Gradient Methods

Duality between subgradient and conditional gradient methods

Given a convex optimization problem and its dual, there are many possible firstorder algorithms. In this paper, we show the equivalence between mirror descent algorithms and algorithms generalizing the conditional gradient method. This is done through convex duality and implies notably that for certain problems, such as for supervised machine learning problems with nonsmooth losses or problems ...

On Stochastic Gradient and Subgradient Methods with Adaptive Steplength Sequences

Traditionally, stochastic approximation (SA) schemes have been popular choices for solving stochastic optimization problems. However, the performance of standard SA implementations can vary significantly based on the choice of the steplength sequence, and in general, little guidance is provided about good choices. Motivated by this gap, in the first part of the paper, we present two adaptive st...

Subgradient Optimization, Generalized Programming, and Nonconvex Duality

Subgradient Methods

3 Convergence proof 4 3.1 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Some basic inequalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.3 A bound on the suboptimality bound . . . . . . . . . . . . . . . . . . . . . . 7 3.4 A stopping criterion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.5 Numerical examp...

Cutting Plane Methods and Subgradient Methods

Interior point methods have proven very successful at solving linear programming problems. When an explicit linear programming formulation is either not available or is too large to employ directly, a column generation approach can be used. Examples of column generation approaches include cutting plane methods for integer programming and decomposition methods for many classes of optimization pr...