[edit]
Convex Relaxation Regression: Black-Box Optimization of Smooth Functions by Learning Their Convex Envelopes
Proceedings of the 32nd Conference on Uncertainty in Artificial Intelligence, PMLR R14:266-275, 2016.
Abstract
Finding efficient and provable methods to solve nonconvex optimization problems is an outstanding challenge in machine learning and optimization theory. A popular approach used to tackle nonconvex problems is to use convex relaxation techniques to find a convex surrogate for the problem. Unfortunately, convex relaxations typically must be found on a problem-by-problem basis. Thus, providing a general-purpose strategy to estimate a convex relaxation would have a wide reaching impact. Here, we introduce Convex Relaxation Regression (CoRR), an approach for learning convex relaxations for a class of smooth functions. The idea behind our approach is to estimate the convex envelope of a function $f$ by evaluating $f$ at a set of $T$ random points and then fitting a convex function to these function evaluations. We prove that with probability greater than $1-\delta$, the solution of our algorithm converges to the global optimizer of $f$ with error $O \(\frac{\log(1/\delta) }{T} )^\alpha )$ for some $\alpha > 0$. Our approach enables the use of convex optimization tools to solve