Re: [Databionic-ESOM-User] Bray-Curtis distances

[Niko E. <ne...@Ma...>]

On Wednesday 14 May 2008, rimet frederic wrote:
> Hello,
> I've tried your eSOM program on ecological data (phytoplancton counts
> of a french lake). It produces interesting maps and groups.
> Nevertheless I wanted to know if you plan to add in the data space
> distance function other distances more adapted to ecological data, as
> for instance Sorensen (Bray & Curtis) Distance or Jaccard Distance ?
> Thanks for your answer,
> Frédéric RIMET

Hello,

as far as I know there are no such plans. However adding this metrics 
should not be wery hard. You just have to implement them as 
	
	cern.colt.function.ThresholdVectorVectorFunction
 	cern.colt.function.VectorVectorFunction

objects and add them to 
	
	databionics.math.DistanceFactory
	databionics.esom.Train

and that schould be about it (my crystal ball reads ~100 lines of code). 
Please consider submiting a patch if you do add them.


Greats Niko