Greedy Newton: Newton's Method with Exact Line Search

Fuente: arXiv
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Main Authors: Shea, Betty, Schmidt, Mark
Format: Preprint
Published: 2024
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author Shea, Betty
Schmidt, Mark
author_facet Shea, Betty
Schmidt, Mark
contents {A defining characteristic of Newton's method is local superlinear convergence within a neighbourhood of a strict local minimum. However, outside this neighborhood Newton's method can converge slowly or even diverge. A common approach to dealing with non-convergence is using a step size that is set by an Armijo backtracking line search. With suitable initialization the line-search preserves local superlinear convergence, but may give sub-optimal progress when not near a solution. In this work we consider Newton's method under an exact line search, which we call ``greedy Newton'' (GN). We show that this leads to an improved global convergence rate, while retaining a local superlinear convergence rate. We empirically show that GN may work better than backtracking Newton by allowing significantly larger step sizes.
format Preprint
id arxiv_https___arxiv_org_abs_2401_06809
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Greedy Newton: Newton's Method with Exact Line Search
Shea, Betty
Schmidt, Mark
Optimization and Control
{A defining characteristic of Newton's method is local superlinear convergence within a neighbourhood of a strict local minimum. However, outside this neighborhood Newton's method can converge slowly or even diverge. A common approach to dealing with non-convergence is using a step size that is set by an Armijo backtracking line search. With suitable initialization the line-search preserves local superlinear convergence, but may give sub-optimal progress when not near a solution. In this work we consider Newton's method under an exact line search, which we call ``greedy Newton'' (GN). We show that this leads to an improved global convergence rate, while retaining a local superlinear convergence rate. We empirically show that GN may work better than backtracking Newton by allowing significantly larger step sizes.
title Greedy Newton: Newton's Method with Exact Line Search
topic Optimization and Control
url https://arxiv.org/abs/2401.06809