Somehow the table didn't come in the email as I had visualized. But I hope you are able to understand the columns. They are
1. Obs number
2. Male Type
3. Female Type
4. Response variable
Male type can take three values 1, 2 and 3
Female type can take three values 1, 2 and 3
Note that to consider the above variables as factors and not covariates - you need to apply "as.factor" to those variables in R.
Then you can run fit the linear model with or without interaction term and study the ANOVA table.
Hope this helps.
Regards,
Indrajit
________________________________
To: Austin Paul
Cc: "r-help@r-project.org"
Sent: Tuesday, September 27, 2011 12:10 PM
Subject: Re: [R] two-way anova help
Hi Paul,
There should not be any problem. Here is how I visualize the data table looks like:
Obs Male_type
Female_type
Response
1 1 1 34
2 1 1 44
3 1 2 38
… … … …
If your data frame has the above structure, R will automatically understand that there is replication. Your model form will remain the same.
Regards,
Indrajit
________________________________
From: Austin Paul
Cc: "r-help@r-project.org"
Sent: Tuesday, September 27, 2011 10:57 AM
Subject: Re: [R] two-way anova help
Hi,
Yes. As I explained, the three male and three female types were crossed in all combinations (9 ways). For each of the 9 types, I have 5 replicate tanks (45 total tanks). And from each of the 45 tanks I have 50 observations for size. So the 5 replicates are somehow nested within the two-way interaction? If there was just 1 tank for each of the 9 crosses, yes, it would be very easy to code the two-way anova. It may still be very easy, but I'm not quite sure how to account for the replicate tanks.
Hope this makes more sense.
Austin
On Mon, Sep 26, 2011 at 10:21 PM, Indrajit Sengupta wrote:
Can you explain what do you mean by "5 replicate tanks"?
>
>
>Doing a two way anova is very simple in R. You would need to fit a linear model (lm function).
>
>
>
>Eg.:
>
>
>> model <- lm(y ~ male + female + male:female, data =)
>
>
>
>
>Regards,
>Indrajit
>
>
>
>
>
>________________________________
> From: Austin Paul
>To: r-help@r-project.org
>Sent: Tuesday, September 27, 2011 6:13 AM
>Subject: [R] two-way anova help
>
>
>Hello,
>
>I am having some trouble coding a two-way anova due to replicated
>treatments.
>
>I have a factorial design with three male parents and three female parents.
>They were mated in all combinations and their babies were grown out and
>measured for size. 50 babies were measured for each of the 9 crosses. If I
>stopped here, I would have no troubles. But I also have 5 replicate tanks
>for each of the 9 crosses. My question is how to I code in the 5 replicate
>tanks per treatment?
>
>Thanks,
>Austin
>
> [[alternative HTML version deleted]]
>
>______________________________________________
>R-help@r-project.org 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.
>
>
>
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org 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.
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