[R] model.matrix()

[Thomas Lumley]

On Mon, 30 Aug 1999, Thomas Yee wrote:

> Hi,
> 
> In R I get the following:
> 
> > x <- 1:9
> > f <- as.factor(1:9)
> > i <- model.matrix(~x+f)
> > 
> > attr(i, "assign")
>  [1] 0 1 2 2 2 2 2 2 2 2
> 
> whereas in S I get the following:
> 
> >  attr(i, "assign")
> $"(Intercept)":
> [1] 1
> 
> $x:
> [1] 2
> 
> $f:
> [1]  3  4  5  6  7  8  9 10
> 
> Has anybody written a model.matrix function to get the same
> result as S? It's just that S's output is what I want, viz.,
> 


As well as the previous suggestions, you will find in library(survival5) a
function attrassign() that converts an 'assign' attribute to the new
style.  

	-thomas

Thomas Lumley
Assistant Professor, Biostatistics
University of Washington, Seattle

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