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https://issues.apache.org/jira/browse/MATH-867?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13466253#comment-13466253
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Nikolaus Hansen commented on MATH-867:
--------------------------------------

just another motivation: inputSigma is related to the uncertainty on 
getStartPoint(), as we cannot intrinsically know whether this is in the order 
of 1 or 1e-4 or 1e4 or 10e23. 
                
> CMAESOptimizer with bounds fits finely near lower bound and coarsely near 
> upper bound. 
> ---------------------------------------------------------------------------------------
>
>                 Key: MATH-867
>                 URL: https://issues.apache.org/jira/browse/MATH-867
>             Project: Commons Math
>          Issue Type: Bug
>            Reporter: Frank Hess
>         Attachments: MATH867_patch, Math867Test.java
>
>
> When fitting with bounds, the CMAESOptimizer fits finely near the lower bound 
> and coarsely near the upper bound.  This is because it internally maps the 
> fitted parameter range into the interval [0,1].  The unit of least precision 
> (ulp) between floating point numbers is much smaller near zero than near one. 
>  Thus, fits have much better resolution near the lower bound (which is mapped 
> to zero) than the upper bound (which is mapped to one).  I will attach a 
> example program to demonstrate.

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