[R] Interaction

[Bert Gunter]

On Mon, Oct 29, 2012 at 7:09 PM, Jeff Newmiller
<jdnewmil at dcn.davis.ca.us> wrote:
> I thought addition was commutative. I am puzzled by your question.

1. This is not addition. These are model fomulae.

2, The model fitting function is unspecified by the OP. What is it? lm()?

3. In general, the coefficients should not depend on the order of the
coefficients,  However, inference will (sums of squares, etc.).

Cheers,
Bert

> ---------------------------------------------------------------------------
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> Sent from my phone. Please excuse my brevity.
>
> Silvano Cesar da Costa <silvano at uel.br> wrote:
>
>>Hi,
>>
>>I'm fitting a model with 3 variables: A, B and SNP.
>>The response variable is Y.
>>
>>I would like fit the following model, in this order:
>>
>>Y ~ A + B + A*B + SNP
>>
>>In general, the R sets of the form:
>>
>>Y ~ A + B + SNP + A*B
>>
>>How do this?
>>
>>
>>---------------------------------------------
>>Silvano Cesar da Costa
>>
>>Universidade Estadual de Londrina
>>Centro de Ciências Exatas
>>Departamento de Estatística
>>
>>Fone: (43) 3371-4346
>>
>>______________________________________________
>>R-help at 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.
>
> ______________________________________________
> R-help at 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.



-- 

Bert Gunter
Genentech Nonclinical Biostatistics

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