[R] Step wise regression

[Frank E Harrell Jr]

walmir-rodrigues wrote:
> Dear Fellows,
> 
> How can I do to proced a step wise regression in R, if it´s 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))]

:-)   -Frank


-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University