Scaled Relative Graph: Nonexpansive operators via 2D Euclidean Geometry

Abstract: Many iterative methods in applied mathematics can be thought of as fixed-point iterations, and such algorithms are usually analyzed analytically, with inequalities. In this work, we present a geometric approach to analyzing contractive and nonexpansive fixed point iterations with a new tool called the scaled relative graph (SRG). The SRG provides a rigorous correspondence between nonlinear operators and subsets of the 2D plane. Under this framework, a geometric argument in the 2D plane becomes a rigorous proof of contractiveness of the corresponding operator.

optimization and control

Audience: researchers in the topic

Variational Analysis and Optimisation Webinar

Series comments: Register on www.mocao.org/va-webinar/ to receive information about the zoom connection.