variable metric

Accelerating Inexact Successive Quadratic Approximation for Regularized Optimization Through Manifold Identification

  • Ching-pei Lee
    • Categories Convex and Nonsmooth Optimization, Nonlinear Optimization Tags , , , ,

    For regularized optimization that minimizes the sum of a smooth term and a regularizer that promotes structured solutions, inexact proximal-Newton-type methods, or successive quadratic approximation (SQA) methods, are widely used for their superlinear convergence in terms of iterations. However, unlike the counter parts in smooth optimization, they suffer from lengthy running time in solving regularized … Read more

    A Proximal Interior Point Algorithm with Applications to Image Processing

  • Émilie Chouzenoux
  • Marie-Caroline Corbineau
  • Jean-Christophe Pesquet
    • Categories Constrained Nonlinear Optimization, Convex Optimization, Nonsmooth Optimization Tags , , , , , , , ,

    In this article, we introduce a new proximal interior point algorithm (PIPA). This algorithm is able to handle convex optimization problems involving various constraints where the objective function is the sum of a Lipschitz differentiable term and a possibly nonsmooth one. Each iteration of PIPA involves the minimization of a merit function evaluated for decaying … Read more

    Inexact Successive Quadratic Approximation for Regularized Optimization

  • Stephen Wright
  • Ching-pei Lee
    • Categories Nonlinear Optimization, Nonsmooth Optimization Tags , , , , , ,

    Successive quadratic approximations, or second-order proximal methods, are useful for minimizing functions that are a sum of a smooth part and a convex, possibly nonsmooth part that promotes regularization. Most analyses of iteration complexity focus on the special case of proximal gradient method, or accelerated variants thereof. There have been only a few studies of … Read more

    The proximal alternating direction method of multipliers in the nonconvex setting: convergence analysis and rates

  • Radu Ioan Bot
  • Dang-Khoa Nguyen
    • Categories Nonsmooth Optimization Tags , , , , , , ,

    We propose two numerical algorithms for minimizing the sum of a smooth function and the composition of a nonsmooth function with a linear operator in the fully nonconvex setting. The iterative schemes are formulated in the spirit of the proximal and, respectively, proximal linearized alternating direction method of multipliers. The proximal terms are introduced through … Read more

    Interior Proximal Algorithm with Variable Metric for Second-Order Cone Programming: Applications to Structural Optimization and Support Vector Machines

  • Felipe Álvarez
  • Julio López
  • Héctor Ramírez
    • Categories Second-Order Cone Programming Tags , , , , ,

    In this work, we propose an inexact interior proximal type algorithm for solving convex second-order cone programs. This kind of problems consists of minimizing a convex function (possibly nonsmooth) over the intersection of an affine linear space with the Cartesian product of second-order cones. The proposed algorithm uses a distance variable metric, which is induced … Read more

    A New Class of Interior Proximal Methods for Optimization over the Positive Orthant

  • Paulo Roberto Oliveira
  • Sissy da S. Souza
    • Categories Convex and Nonsmooth Optimization, Nonlinear Optimization Tags , , ,

    In this work we present a family of variable metric interior proximal methods for solving optimization problems under nonnegativity constraints. We define two algorithms, in the inexact and exact forms. The kernels are metrics generated by diagonal matrices in each iteration and the regularization parameters are conveniently chosen to force the iterates to be interior … Read more