David H. Gutman

An Adaptive Proximal ADMM for Nonconvex Linearly-Constrained Composite Programs

  • Leandro Farias Maia
  • David H. Gutman
  • Renato D.C. Monteiro
  • Gilson Silva
    • Categories Convex and Nonsmooth Optimization, Global Optimization Theory, Nonlinear Optimization Tags , , , ,

    This paper develops an adaptive Proximal Alternating Direction Method of Multipliers (P-ADMM) for solving linearly-constrained, weakly convex, composite optimization problems. This method is adaptive to all problem parameters, including smoothness and weak convexity constants. It is assumed that the smooth component of the objective is weakly convex and possibly nonseparable, while the non-smooth component is … Read more

    Coordinate Descent Without Coordinates: Tangent Subspace Descent on Riemannian Manifolds

  • David H. Gutman
  • Nam Ho-Nguyen
    • Categories Convex and Nonsmooth Optimization, Nonlinear Optimization Tags , ,

    We extend coordinate descent to manifold domains, and provide convergence analyses for geodesically convex and non-convex smooth objective functions. Our key insight is to draw an analogy between coordinate blocks in Euclidean space and tangent subspaces of a manifold. Hence, our method is called tangent subspace descent (TSD). The core principle behind ensuring convergence of … Read more

    The condition number of a function relative to a set

  • David H. Gutman
  • Javier F. Peña
    • Categories Convex Optimization Tags , , ,

    The condition number of a differentiable convex function, namely the ratio of its smoothness to strong convexity constants, is closely tied to fundamental properties of the function. In particular, the condition number of a quadratic convex function is the square of the aspect ratio of a canonical ellipsoid associated to the function. Furthermore, the condition … Read more

    A unified framework for Bregman proximal methods: subgradient, gradient, and accelerated gradient schemes

  • David H. Gutman
  • Javier F. Peña
    • Categories Convex Optimization Tags , , , ,

    We provide a unified framework for analyzing the convergence of Bregman proximal first-order algorithms for convex minimization. Our framework hinges on properties of the convex conjugate and gives novel proofs of the convergence rates of the Bregman proximal subgradient, Bregman proximal gradient, and a new accelerated Bregman proximal gradient algorithm under fairly general and mild … Read more

    The condition of a function relative to a polytope

  • David H. Gutman
  • Javier F. Peña
    • Categories Convex and Nonsmooth Optimization, Convex Optimization Tags , ,

    The condition number of a smooth convex function, namely the ratio of its smoothness to strong convexity constants, is closely tied to fundamental properties of the function. In particular, the condition number of a quadratic convex function is precisely the square of the diameter-to-width ratio of a canonical ellipsoid associated to the function. Furthermore, the … Read more

    Convergence rates of proximal gradient methods via the convex conjugate

  • David H. Gutman
  • Javier F. Peña
    • Categories Convex Optimization Tags , ,

    We give a novel proof of the $O(1/k)$ and $O(1/k^2)$ convergence rates of the proximal gradient and accelerated proximal gradient methods for composite convex minimization. The crux of the new proof is an upper bound constructed via the convex conjugate of the objective function. Citation Technical Report, Carnegie Mellon University, January 2018. Article Download View … Read more