RE: [R] formula restriction in multinom?

From: Berton Gunter <gunter.berton_at_gene.com>
Date: Tue 10 May 2005 - 05:09:25 EST


Note: multinom() is in nnet package.

In any case, the answer is, yes, this is "normal" behavior:

x^2 <==> x:x <==> x in S language linear model notation. So if you want a quadratic you must use I(x^2). S-Plus does this silently, but it is not required by the language definition.

"The business of the statistician is to catalyze the scientific learning process." - George E. P. Box    

> -----Original Message-----
> From: r-help-bounces@stat.math.ethz.ch
> [mailto:r-help-bounces@stat.math.ethz.ch] On Behalf Of Berry, Mark R
> Sent: Monday, May 09, 2005 11:33 AM
> To: 'r-help@stat.math.ethz.ch'
> Subject: [R] formula restriction in multinom?
>
> Good Day: When I used:
> multinom(formula = Y ~ X1 + X2 + X3 + X1:X2 + X1:X3 + X3:X2 +
> X1^2 + X2^2 +
> X3^2, data = DATASET),
> I get estimates and AIC for the model containing main effects and
> interactions only (no squared terms)...and FYI, all predictors are
> continuous. Is this "normal" behavior? If I run this in S-Plus I get
> estimates and AIC for the model containing all
> terms(including the squared
> terms).
>
> Thanks,
> Mark Berry
>
>
>
>
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R-help@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 Received on Tue May 10 05:19:40 2005

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