about Cox-Box transformation
On Thu, 9 Feb 2006, Petr Pikal wrote:
Hi 1. upgrade 2. read Introduction to R shipped with the distribution 3. read documentation to MASS 4. packages not libraries 5. use library(MASS) to make functions from MASS package available 6. now you can use boxcox() but not on vectors AFAIK
You can by boxcox(y ~ 1) but car's box.cox does similar things. (I did not mention that as adding packages to R 1.8.0 is unlikely to be easy.)
probably not completely correct but this
box.cox <- function(x, lambda,inv=F)
{ if (!inv)
{if(missing(lambda))
log(x)
else (x^lambda - 1)/lambda}
else (lambda*x+1)^(1/lambda)
}
you can use to perform Box-Cox transformation on vectors.
HTH
Petr
On 9 Feb 2006 at 11:51, Stefano Sofia wrote:
From: Stefano Sofia <stefano.sofia at regione.marche.it>
To: r-help at stat.math.ethz.ch
Date sent: Thu, 09 Feb 2006 11:51:02 +0000
Subject: [R] about Cox-Box transformation
Dear R-users, I am using R version 1.8.0-1 under Suse 8.2. I need to use the boxcox command because I want to apply a Cox-Box transformation to a vector of rainfall values. Within the libraries, the MASS library is present, but I don't know whether this means that is automatically installed or not. The command doesn't work. What do I have to do in order to make it working? Is just a problem of installation or simply of recalling the right command? thank you for your help Stefano
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595