[R] relative euclidean distance

[Gavin Simpson]

On Wed, 2011-07-06 at 14:50 +0100, Sarah Leclaire wrote:
> Hi,
> 
> I would like to calculate the RELATIVE euclidean distance. Is there a 
> function in R which does it ?
> 
> (I calculated the abundance of 94 chemical compounds in secretion of 
> several individuals, and I would like to have the chemical distance 
> between 2 individuals as expressed by the relative euclidean distance. 
> Some compounds are in very low abundance whereas others are in high 
> abundance, that's why I would like to correct for the abundance)
> 
> Thanks,
> Sarah

A simple solution to this is to transform the data and then compute the
Euclidean distance using dist().

decostand(foo, method = "normalize") and

disttransform(foo, method = "chord") in package BiodiversityR 

can do this for you without you having to write a function yourself.
Pass the returned object to dist() to get the distances you want.

HTH

G

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