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https://issues.apache.org/jira/browse/MATH-1092?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13917559#comment-13917559
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Bruce A Johnson commented on MATH-1092:
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Couldn't we have another constructor that takes a fourth argument (the initial
upper limit for the bracket search). The current constructor could default to
1.0 for that value so existing tests would pass.
The problem I'm working on is the energy minimization of a complex molecule.
I'm sure there are many local minima and if the bracket is too large it finds a
minimum that is not as good as one near the origin of the search. So it seems
essential to be able to specify the size of the search region. (As an aside, I
use the CMAESOptimizer to initially search in this complex landscape, but (when
I can use gradients) the ConjugateGradientOptimizer is useful to quickly refine
the solution.
> NonLinearConjugateGradientOptimizer's Line search is a gradient search
> returns obviously suboptimal point.
> ----------------------------------------------------------------------------------------------------------
>
> Key: MATH-1092
> URL: https://issues.apache.org/jira/browse/MATH-1092
> Project: Commons Math
> Issue Type: Bug
> Reporter: Ajo Fod
> Attachments: MATH-1092.patch
>
>
> In package : org.apache.commons.math3.optim.nonlinear.scalar.gradient
> In a minimization problem, a line search should not return a point where the
> value is greater than the values at the edges of the interval. The line
> search violates this obvious requirement by focusing solely on solving for
> gradient=0 and ignoring the value.
> Moreover LineSearchFunction is something that can be used in other contexts,
> so perhaps this should be a standalone class.
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