[ 
https://issues.apache.org/jira/browse/MATH-867?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13466309#comment-13466309
 ] 

Nikolaus Hansen commented on MATH-867:
--------------------------------------

{quote}
Hence, unless someone wants to try it out, we'll of course trust you  and leave 
the internal boundary handling in place.
{quote}
I spent several hundreds of hours (really!) to investigate (and try to 
understand) this with the greatest care I was able to. That of course doesn't 
mean there could be still surprises out there...

                
> 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.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to