[R] exponential correlation?

Spencer Graves spencer.graves at pdf.com
Sat Sep 25 22:21:34 CEST 2004

      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! 
"http://www.R-project.org/posting-guide.html".  This might help you 
answer some questions for yourself, thereby getting you quicker answers 
than otherwise.  Moreover, it could increase your chances of getting a 
response that actually helps solve your problem.  In particular, please 
provide a toy example showing something that a reader can easily copy 
from an email and paste into R to try something just a little different. 

TRAMIER Blaise wrote:

>	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

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

More information about the R-help mailing list