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Nikolaus Hansen commented on MATH-702: -------------------------------------- good point. However, if the encoding/decoding methods can be defined coordinate-wise differently or are even non-linear (I am not aware whether they can be or not), I am not sure you can come up with a sufficiently reasonable and comprehensible way to apply this transformation to sigma. sigma is a scalar and positive, so it is a different object than the encoding/decoding methods are operating on, right? The interplay between sigma and an encoding is an unfortunately delicate part in the user interface, but I don't really see a way to make it right *and* look entirely obvious to the user. On Mon, 07 Nov 2011 14:48:51 +0100, Luc Maisonobe (Created) (JIRA) -- Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool. So you have to be very careful about that. After you've not fooled yourself, it's easy not to fool other[ scientist]s. You just have to be honest in a conventional way after that. -- Richard P. Feynman Nikolaus Hansen INRIA, Research Centre Saclay – Ile-de-France Machine Learning and Optimization group (TAO) University Paris-Sud (Orsay) LRI (UMR 8623), building 490 91405 ORSAY Cedex, France Phone: +33-1-691-56495, Fax: +33-1-691-54240 URL: http://www.lri.fr/~hansen > CMA-ES optimizer input sigma should not be normalized by user > ------------------------------------------------------------- > > Key: MATH-702 > URL: https://issues.apache.org/jira/browse/MATH-702 > Project: Commons Math > Issue Type: Bug > Affects Versions: 3.0 > Reporter: Luc Maisonobe > Priority: Minor > Fix For: 3.0 > > > I am trying to use CMA-ES optimizer with simple boundaries. > It seems the inputSigma parameter should be normalized as it is checked > against the [0 - 1] range in the checkParameters private method and as its > value defaults to 0.3 if not not set in the initializeCMA private method. > I would have expected this value to be in the same units as the user > parameters and to be normalized as part of an internal processing step > instead of relying to the user doing this. I think the method need normalized > values internally, as per the encode/decode methods in the inner class > FitnessFunction suggest. > The optimizer should accept values in the same units as the other parameters > and use "encode" (or a similar function) to do the normalization. This way, > normalization is considered an internal implementation detail. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira