[R-sig-ME] Split-plot Design
Kevin Wright
kw.statr at gmail.com
Thu Mar 20 23:23:19 CET 2008
Your question is not very clear, but if you are trying to match the
results in Kuehl, you need a fixed-effects model:
dat <- read.table("expl14-1.txt", header=TRUE)
dat$block <- factor(dat$block)
dat$nitro <- factor(dat$nitro)
dat$thatch <- factor(dat$thatch)
colnames(dat) <- c("block","nitro","thatch","chlor")
m1 <- aov(chlor~nitro*thatch+Error(block/nitro), data=dat)
summary(m1)
Mixed-effects models and degrees of freedom have been discussed many
times on this list....search the archives.
K Wright
On Thu, Mar 20, 2008 at 12:39 PM, <marcioestat at pop.com.br> wrote:
>
>
>
> Hi listers,
>
> I've been studying anova and at the book of Kuehl at the chapter
> about split-plot there is a experiment with the results... I am trying to
> understand the experiments and make the code in order to obtain the
> results... But there is something that I didn't understand yet...
> I have a split-plot design (2 blocks) with two facteurs, one
> facteur has 4 treatments and the other facteur is a measure
> taken in three years...
> I organize my data set as:
>
> Nitro Bloc Year Measure
> a
> x
> 1 3.8
> a
> x
> 2 3.9
> a x 3 2.0
> a y 1 3.7
> a y 2
> 2.4
> a y 3
> 1.2
> b x
> 1 4.0
> b x
> 2 2.5
> and so on...
>
>
> So, I am trying this code, because I want to test each factor and the
> interaction...
> lme=lme(measure ~ bloc + nitro + bloc*nitro, random= ~ 1|year,
> data=lme)
> summary(lme)
> The results that I am obtaining are not correct, because
> I calculated the degrees of fredom and they are not
> correct... According to this design I will get two errors one for the
> whole plot and other for the subplot....
>
> Well, as I told you, I am still learning... Any suggestions...
>
> Thanks in advance,
>
> Ribeiro
>
>
> [[alternative HTML version deleted]]
>
>
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