2,989 research outputs found

    Analogues of Dixon's and Powell's Theorems for Unconstrained Minimization with Inexact Line Searches

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    By modifying the way in which search directions are defined, we show how to relax the restrictive assumption that line searches must be exact in the theorems of Dixon and Powell. We show also that the BFGS algorithm modified in this way is equivalent to the three-term-recurrence (TTR) method for quadratic functions

    Experimental Comparisons of Derivative Free Optimization Algorithms

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    In this paper, the performances of the quasi-Newton BFGS algorithm, the NEWUOA derivative free optimizer, the Covariance Matrix Adaptation Evolution Strategy (CMA-ES), the Differential Evolution (DE) algorithm and Particle Swarm Optimizers (PSO) are compared experimentally on benchmark functions reflecting important challenges encountered in real-world optimization problems. Dependence of the performances in the conditioning of the problem and rotational invariance of the algorithms are in particular investigated.Comment: 8th International Symposium on Experimental Algorithms, Dortmund : Germany (2009

    SDLS: a Matlab package for solving conic least-squares problems

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    This document is an introduction to the Matlab package SDLS (Semi-Definite Least-Squares) for solving least-squares problems over convex symmetric cones. The package is shortly presented through the addressed problem, a sketch of the implemented algorithm, the syntax and calling sequences, a simple numerical example and some more advanced features. The implemented method consists in solving the dual problem with a quasi-Newton algorithm. We note that SDLS is not the most competitive implementation of this algorithm: efficient, robust, commercial implementations are available (contact the authors). Our main goal with this Matlab SDLS package is to provide a simple, user-friendly software for solving and experimenting with semidefinite least-squares problems. Up to our knowledge, no such freeware exists at this date
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