Given a set of data:> names(data)[1] "city" "house" "visit" "value" I am looking for a way to compute the variance components of the nested model (ie, visit 1 at house 2 at city 3 isn't related to visit 1 and house 2 at city 4), but different houses in the same city may be related, and different visits to the same house are probably related. I want to be able to compute how much of the total variance of "value" is explained by each of these. How can I do that in R? Thanks! -- Russell Senior ``shtal latta wos ba padre u prett tu nashtonfi seniorr at aracnet.com mrlosh'' -- Bashgali Kafir for ``If you have had diarrhoea many days you will surely die.''
On 26 Oct 2003, Russell Senior wrote:> > Given a set of data: > > > names(data) > [1] "city" "house" "visit" "value" > > I am looking for a way to compute the variance components of the > nested model (ie, visit 1 at house 2 at city 3 isn't related to visit > 1 and house 2 at city 4), but different houses in the same city may be > related, and different visits to the same house are probably related. > I want to be able to compute how much of the total variance of "value" > is explained by each of these. How can I do that in R?With lme or (if balanced) aov with an Error term. There are lots of examples about, e.g. in the MASS and nlme scripts from the associated books. -- 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
lme should do the job (r1,r2,r3 are your random factors):
library(nlme)
y.lme <- lme(y ~ 1,random = ~ 1 | r1/r2/r3)
summary(y.lme)
This is equivalent to a call to varcomp in S-Plus
Pascal
--
Dr. Pascal A. Niklaus
Institute of Botany
University of Basel
Sch?nbeinstrasse 6
CH-4056 Basel / Switzerland
Russell Senior wrote:
>Given a set of data:
>
>
>
>>names(data)
>>
>>
>[1] "city" "house" "visit"
"value"
>
>I am looking for a way to compute the variance components of the
>nested model (ie, visit 1 at house 2 at city 3 isn't related to visit
>1 and house 2 at city 4), but different houses in the same city may be
>related, and different visits to the same house are probably related.
>I want to be able to compute how much of the total variance of
"value"
>is explained by each of these. How can I do that in R?
>
>Thanks!
>
>
>
>