RE: [R] Step wise regression

From: Liaw, Andy <andy_liaw_at_merck.com>
Date: Tue 03 May 2005 - 23:43:52 EST


> From: Frank E Harrell Jr
>
> walmir-rodrigues wrote:
> > Dear Fellows,
> >
> > How can I do to proced a step wise regression in R, if itīs
> possible ?
> >
> > Thanks,
> >
> > Walmir
>
> Here is an easy approach that will yield results only slightly less
> valid than one actually using the response variable:
>
> x <- data.frame(x1,x2,x3,x4,..., other potential predictors)
> x[,sample(ncol(x))]

Hmm... Shouldn't that be something like:

x[, sample(ncol(x), ceiling(ncol(x) * runif(1)))]

?

Cheers,
Andy  

> :-) -Frank
>
>
> --
> Frank E Harrell Jr Professor and Chair School of Medicine
> Department of Biostatistics
> Vanderbilt University
>
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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 Wed May 04 00:17:13 2005

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