[R] dist

[Paulo Justiniano Ribeiro Jr]

Hi Agustin
You mingth not need this after Brain's reply but just in case...
The package geoR has a function which might help 
loccoords(coords, locations)

where the arguments are 2 column matrices with coordinates.
The function which returns the distance between each element of coords
(centroids) to each element of locations(individuals)

The function is just a "wrapper" to a piece of C code

Cheers
P.J.


On Mon, 19 Nov 2001, Agustin Lobo wrote:

> 
> Hi list!
> 
> I'm computing multivar. distances from a set of centroids
> to a (large) set of individuals. I'm now just using rbind
> to create a matrix (x) with the centroid and the individuals,
> then run as.matrix(dist(x)) and finally select the appropriate columns,
> as I'm not interested on the distances among individuals.
> Therefore, this procedure implies a waste of computing time.
> Is there any way to use dist only between each individual
> and the centroids (avoiding loops in R)? or should I just go and try to
> make
> a modified version of dist by hacking the C code?
> 
> Thanks
> 
> Dr. Agustin Lobo
> Instituto de Ciencias de la Tierra (CSIC)
> Lluis Sole Sabaris s/n
> 08028 Barcelona SPAIN
> tel 34 93409 5410
> fax 34 93411 0012
> alobo at ija.csic.es
> 
> 
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Paulo Justiniano Ribeiro Jr
Dept Maths & Stats  -  Fylde College
Lancaster University
Lancaster LA1 4YF   -  U.K.

e-mail: Paulo.Ribeiro at est.ufpr.br
http://www.maths.lancs.ac.uk/~ribeiro

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