[R] RE: 1-way anova, nested model

About this list Date view Thread view Subject view Author view Attachment view

From: Federico Calboli (f.calboli@ucl.ac.uk)
Date: Thu 20 May 2004 - 00:14:58 EST


Message-id: <1084976098.2962.14.camel@monkey>


>From what I gather you have

2 treatments
6 samples nested in treatment
12 replicates in sample.

I do not know what your dependent veriable is, but I would:

code the two treatments as T1 and T2
code the 6 samples as a, b, c, d, e, f so the first three samples
belonging to T1 are not confused with the other three (coding them as
1,2,3 for T1 and 1,2,3 for T2 is a bad idea)
code the replicates as a1, a2, b1, b2....

here I am being extra paranoid in the coding, btw, but it helps and
saves grief later on, in my experience.

The model would be:

library(nlme) # needed!
mod<-lme(response ~ treatment, random = ~ 1|sample/replicate, mydata)

An anova test would give only one F test for the fixed factor, with 1
and 4 df (if I am not mistaken, double check!)

Federico

-- 

=================================

Federico C. F. Calboli

Dipartimento di Biologia Via Selmi 3 40126 Bologna Italy

tel (+39) 051 209 4187 fax (+39) 051 209 4286

f.calboli at ucl.ac.uk fcalboli at alma.unibo.it

______________________________________________ R-help@stat.math.ethz.ch mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html


About this list Date view Thread view Subject view Author view Attachment view

This archive was generated by hypermail 2.1.3 : Mon 31 May 2004 - 23:05:11 EST