[R] string/character to number

[Liaw, Andy]

You can do indexing by name:

> x <- c("a", "b", "a", "b")
> v <- c(a=1, b=-1)
> v[x]
 a  b  a  b 
 1 -1  1 -1 

Andy 

> From: Jake Michaelson
> 
> Duh!
> 
> sub()
> 
> --Jake
> 
> On Jun 22, 2005, at 3:35 PM, Jake Michaelson wrote:
> 
> > I did a very quick search of the archive and couldn't find a readily
> > available answer to this one:
> >
> > I'd like to convert, for example:
> >
> > c("a", "b", "a", "b")
> >
> > to
> >
> > c(1, -1, 1, -1)
> >
> > In the case of the first vector, it may be any length, but 
> will always
> > only have two unique values.  It must always be replaced by
> > corresponding values of 1 and -1.
> >
> > Any thoughts?
> >
> > Thanks in advance,
> >
> > Jake
> >
> > ______________________________________________
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> >
> 
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> 
>