[R] newbie question about index

[sun]

Thanks for all these replies, all work perfectly.

Sun
--- Petr Pikal <petr.pikal at precheza.cz>дµÀ:

> Hallo
> 
> probably there are other options but
> 
> outer(1:3,a, "==")*1
> 
> can do what you want.
> 
> HTH
> Petr
> 
> 
> 
> On 31 Aug 2006 at 22:41, z s wrote:
> 
> Date sent:      	Thu, 31 Aug 2006 22:41:27 +0800
> (CST)
> From:           	z s <flyhyena at yahoo.com.cn>
> To:             	r-help at stat.math.ethz.ch
> Subject:        	[R] newbie question about index
> 
> > Hi,
> >
> >   I am trying to convert a variable a =
> sample(1:3,100,rep = T)
> >   represents choices into a 3X100 dummy varible b
> with corresponding
> >   element set to 1 otherwise 0.
> > eg.
> >
> > a: 1 3 2 1 2 3 1 1....
> >
> > b: 1 0 0 1 0 0 1 1..
> >     0 0 1 0 1 0 0 0...
> >     0 1 0 0 0 1 0 0...
> >
> >  Is there something like b[a] =1 existing? I could
> not figure this out
> >  myself.
> >
> >
> > ---------------------------------
> >  Mp3è¿ñˁ-иèÈȸè¸ßËÙÏÂ
> >  [[alternative HTML version deleted]]
> >
> >
> 
> Petr Pikal
> petr.pikal at precheza.cz
> 
> 



		
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