[R] compare linear regressions

[Jeff Newmiller]

Just because your model specification is valid does not mean your data can be analyzed using that particular model specification.
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Sent from my phone. Please excuse my brevity.

Holger Taschenberger <Holger.Taschenberger at mpi-bpc.mpg.de> wrote:

>Thank you. I was confused because the output of the line
>"summary(lm(formula
>=..." reads:
>
>"Coefficients: (1 not defined because of singularities)",
>
>which did not look like a normal message (which can safely be ignored)
>to me.
>
>--Holger
>
>On Tue, 8 Nov 2011 15:06:28 +0100
>Peter Konings <peter.l.e.konings at gmail.com> wrote:
>
>> On Tue, Nov 8, 2011 at 2:52 PM, Holger Taschenberger <
>> Holger.Taschenberger at mpi-bpc.mpg.de> wrote:
>> <snip>
>> 
>> > summary(lm(formula = y ~ x - 1 + x:g, dta))
>> > ##################
>> > I assume that the last line is the correct way to specify a linear
>model
>> > without intercept. But I'm not certain about that. Can someone
>please
>> > confirm?
>> 
>> 
>> Yes, that's true. See chapter 11 of the "Introduction To R" manual
>that was
>> installed with R for an overview of model specification in R.
>> 
>> HTH
>> Peter.
>
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