[R] Find multiple elements in a vector

[Chuck Cleland]

On 7/22/2009 3:32 PM, Michael Knudsen wrote:
> Hi,
> 
> Given a vector, say
> 
> x=sample(0:9,10)
> x
> [1] 0 6 3 5 1 9 7 4 8 2
> 
> I can find the location of an element by
> 
> which(x==2)
> [1] 10
> 
> but what if I want to find the location of more than one number? I could do
> 
> c(which(x==2),which(x==3))
> 
> but isn't there something more streamlined? My first guess was
> 
> y=c(2,3)
> which(x==y)
> integer(0)
> 
> which doesn't work. I haven't found any clue in the R manual.

  How about this?

which(x %in% c(2,3))

> Thanks! 

-- 
Chuck Cleland, Ph.D.
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