[R] Posthoc tests for 3-way ANOVA analysis

[Torsten Hothorn]

On Tue, 24 Oct 2006, A Ezhil wrote:

> Hi Torsten,
>
> Thanks for your help. I have downloaded the 'multcomp'
> package (windows ver. 0.4-8, but the source is
> 0.991-1). When I tried with 'glht' function, it says
> 'object not found'. Am I missing anything?
>

just wait for version 0.991-1 being available for windows (should happen 
within the next hours) and have a look at ?glht

Best wishes,

Torsten


> Thanks again for your help.
>
> Regards,
> Ezhil
>
> --- Torsten Hothorn
> <Torsten.Hothorn at rzmail.uni-erlangen.de> wrote:
>
>>
>> On Tue, 24 Oct 2006, A Ezhil wrote:
>>
>>> Hi All,
>>>
>>> I have performed a 3-way ANOVA analysis for my
>>> experimental data using aov function. My simple R
>>> funtion for this is:
>>>
>>> 3aof <- function(x){
>>> m <- data.frame(R,S,T, x);
>>> anova(aov(x ~ R+S+T+R*S+R*T+S*T+R*S*T, m) )
>>> }
>>>
>>
>> you can use
>>
>> R> library("multcomp") ### check for version 0.991-1
>>
>> for some model
>>
>> R> amod <- aov(x ~ R+S+T+R*S+R*T+S*T+R*S*T, m)
>>
>> with, say, all-pair comparisons of the levels of
>> `T':
>>
>> R> posth <- glht(amod, linfct = mcp(T = "Tukey"))
>>
>> various adjusted p-values can be computed using
>>
>> R> summary(posth)
>>
>> and confidence intervals (adjusted and unadjusted)
>> are available from
>>
>> R> confint(posth)
>>
>>
>> Hope that helps,
>>
>> Torsten
>>
>>
>>> Now, I am getting P values for all the main and
>>> interactions effects. If I want to perform postdoc
>>> test on one of my main effects, say T, what method
>> I
>>> should use (i have unequal sample size)? Is there
>>> anyway I can extend my above '3aof' function to do
>>> this?
>>>
>>> I greatly appreciate your help. Thanks in Advance.
>>>
>>> Regards,
>>> Ezhil
>>> Ph.D Student
>>> School of Biotechnology
>>> AU, India.
>>>
>>> ______________________________________________
>>> R-help at stat.math.ethz.ch mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained,
>> reproducible code.
>>>
>>>
>>
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>