Donald Goldfarb

  1. Structured Sparsity via Alternating Direction Methods.

    Authors: Donald Goldfarb, Zhiwei Qin
    Subjects: Optimization and Control
    Abstract

    We consider a class of sparse learning problems in high dimensional feature
    space regularized by a structured sparsity-inducing norm which incorporates
    prior knowledge of the group structure of the features. Such problems often
    pose a considerable challenge to optimization algorithms due to the
    non-smoothness and non-separability of the regularization term. In this paper,
    we focus on two commonly adopted sparsity-inducing regularization terms, the
    overlapping Group Lasso penalty $l_1/l_2$-norm and the $l_1/l_\infty$-norm.

  2. Sparse Inverse Covariance Selection via Alternating Linearization Methods.

    Authors: Donald Goldfarb, Shiqian Ma, Katya Scheinberg
    Subjects: Learning
    Abstract

    Gaussian graphical models are of great interest in statistical learning.
    Because the conditional independencies between different nodes correspond to
    zero entries in the inverse covariance matrix of the Gaussian distribution, one
    can learn the structure of the graph by estimating a sparse inverse covariance
    matrix from sample data, by solving a convex maximum likelihood problem with an
    $\ell_1$-regularization term.

  3. Fast Alternating Linearization Methods for Minimizing the Sum of Two Convex Functions.

    Authors: Donald Goldfarb, Shiqian Ma
    Subjects: Optimization and Control
    Abstract

    Splitting and alternating direction methods have been widely used for solving
    convex optimization problems. We present in this paper two first-order
    alternating linearization algorithms based on variable splitting and
    alternating linearization techniques for minimizing the sum of two convex
    functions. We prove that the number of iterations needed by the first algorithm
    is $O(1/\epsilon)$ to obtain an $\epsilon$-optimal solution.

  4. Fast Multiple Splitting Algorithms for Convex Optimization.

    Authors: Donald Goldfarb, Shiqian Ma
    Subjects: Optimization and Control
    Abstract

    We present in this paper two different classes of general $K$-splitting
    algorithms for solving convex optimization problems. We prove that the number
    of iterations needed by the first class of algorithms to obtain an
    $\epsilon$-optimal solution is $O(1/\epsilon)$. The algorithms in the second
    class are accelerated versions of those in the first class, where the
    complexity result is improved to $O(1/\sqrt{\epsilon})$ while the computational
    effort required at each iteration is almost unchanged.

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