[R] exponential correlation?

[Spencer Graves]

      The "nlme" package has "corExp" for estimating the nuggett effect 
n and the range d for an exponential spatial correlation structure = n + 
(1-n)*exp(-r/d), where r = distance between two observations.  See 
library(nlme);  ?corExp, plus Pinheiro and Bates (2000) Mixed-Effects 
Models for S and S-Plus (Springer). 

      Is this what you want? 

      hope this helps. 
      spencer graves
p.s.  If this is NOT adequate, please read the posting guide! 
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TRAMIER Blaise wrote:

>Hello,
>	I have been asked to perform a exponential correlation on a data set.
>Unfortunately, i did not find any simple example on how to do that with R. 
>If the correlation is significant, one asked me to also find the thresold 
>of the acceleration slope.
>
>Have any of you a little example or a good link to get me started?
>
>Best regards
>
>Blaise
>  
>

-- 
Spencer Graves, PhD, Senior Development Engineer
O:  (408)938-4420;  mobile:  (408)655-4567