convex interpolation

Inexactly Smooth Performance Estimation and New Optimized Gradient Methods

  • Aaron Zoll
  • Benjamin Grimmer
    • Categories Convex Optimization, Nonlinear Optimization, Nonsmooth Optimization Tags , , ,

      We consider a general class of “inexactly smooth” convex functions, providing a universal model capturing as special cases $L$-smooth, $M$-Lipschitz, and H\”older smooth functions, and any combination thereof. Such functions possess a calculus closely following that of smooth functions. Our main results provide inexactly smooth functions with interpolation theorems that are necessary and sufficient … Read more

    Exact Worst-case Performance of First-order Methods for Composite Convex Optimization

  • François Glineur
  • Julien M. Hendrickx
  • Adrien B. Taylor
    • Categories Convex Optimization, Nonsmooth Optimization Tags , , , , , , , , ,

    We provide a framework for computing the exact worst-case performance of any algorithm belonging to a broad class of oracle-based first-order methods for composite convex optimization, including those performing explicit, projected, proximal, conditional and inexact (sub)gradient steps. We simultaneously obtain tight worst-case guarantees and explicit instances of optimization problems on which the algorithm reaches this … Read more