[R] ANOVA problem

[Bert Gunter]

Rob:

On Fri, May 4, 2012 at 9:18 AM, robgriffin247 <rg.rforum at hotmail.co.uk> wrote:
> Hi,
> I need to create a data frame containing the results of a number of ANOVA's
> but I'm having some trouble setting it up (some being enough for me to spend
> 3 days trying with no progress and be left staring in to the abyss which
> some people call a weekend, and what I will call 2 quiet days in the
> office...)

I would suggest staying out of the office and consulting a local
statistician Monday morning. As a poor second choice, post on a
statistics Help list (e.g. stats.stackexchange.com).

I haven't gone through your post in detail, but it appears to have
little to do with R and a **lot** to do with your lack of statistical
understanding. It appears that you need to formulate a scientifically
appropriate mixed effect model (the problem is never "how to set up an
anova"), and interaction with a local consultant is the best way to do
that.

I suppose you could also post this on the r-sig-mixed-models list, as
they often go beyond the R issues to the statistical modeling. But
remote consulting is a risky business, as despite the best of
intentions on both sides, incomplete or mis- communication can lead to
errors of the third kind (right answer -- wrong question).

Best,
Bert

>
> The response variable is *V*.
> I need to do an ANOVA for each *G*.
> The fixed effect will be *S* ("M" or "F") whilst also having the *S*L* and
> *L* ("1" or "2") as random effects.
> The anova of *G* /AB01 /would be some thing like: y=V, fixed=S, Random= L &
> L*S...
> The new data frame would then compile all the variance components for each
> G, including total and residual variance.
>
> here is the example dataframe using 2 G's, with 2 S values, 2 L, and 2
> replicates for each.
>
> df<-as.data.frame(c("AB01","AB01","AB01","AB01","AB01","AB01","AB01","AB01","AB02","AB02","AB02","AB02","AB02","AB02","AB02","AB02"))
> names(df)<-"G"
> df$L<-as.numeric(c(1,1,1,1,2,2,2,2,1,1,1,1,2,2,2,2))
> df$S<-(c("m","m","f","f","m","m","f","f","m","m","f","f","m","m","f","f"))
> df$R<-as.numeric(c(1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2))
> df$V<-as.numeric(c(1,2,12,21,5,6,12,34,1,6,52,41,5,43,13,24))
>
> It is worth noting the actual data this will be used on is >10000*G's,
> 2*S's,  40*L's,  and 2*R's so hand writing an ANOVA for each G is not
> preferred...
>
> Here is a twitter link to a crudely drawn illustration of the aim
> illustrated (using 3 Ls) in case I have confused you with words (through my
> own poor understanding):
> https://twitter.com/#!/robgriffin247/status/198446041316593666/photo/1/large
> https://twitter.com/#!/robgriffin247/status/198446041316593666/photo/1/large
>
> Thanks in advance for your time,
> Rob
> (please save my weekend...)
>
> --
> View this message in context: http://r.789695.n4.nabble.com/ANOVA-problem-tp4609062.html
> Sent from the R help mailing list archive at Nabble.com.
>
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-- 

Bert Gunter
Genentech Nonclinical Biostatistics

Internal Contact Info:
Phone: 467-7374
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