Selecting elements in vector

Hi

Consider the following code

x <- rep(1:13, 13)

y <- 1:3

I want to select all elements in x which are equal to 1, 2 or 3.

I know that I could use

sel <- x==y[1] | x==y[2] | x==y[3]
x[sel]

to obtain the values, but in my analysis, the y-vector is thousands of
elements long.

Is there any way, that I can do that easily?

Thanks

Rainer
-- 
Rainer M. Krug, Dipl. Phys. (Germany), MSc Conservation Biology (UCT)

Plant Conservation Unit Department of Botany
University of Cape Town
Rondebosch 7701
South Africa

Hi

 Consider the following code

 > x <- rep(1:13, 13)

 > y <- 1:3

 I want to select all elements in x which are equal to 1, 2 or 3.

 I know that I could use

 > sel <- x==y[1] | x==y[2] | x==y[3]
 > x[sel]

 to obtain the values, but in my analysis, the y-vector is thousands of
 elements long.

 Is there any way, that I can do that easily?

 Thanks

 Rainer
 --
 Rainer M. Krug, Dipl. Phys. (Germany), MSc Conservation Biology (UCT)

 Plant Conservation Unit Department of Botany
 University of Cape Town
 Rondebosch 7701
 South Africa

Try this:

 x[x %in% y]



 On 14/03/2008, Rainer M Krug <r.m.krug at gmail.com> wrote:

 > Hi
 >
 >  Consider the following code
 >

 >  > x <- rep(1:13, 13)

 >

 >  > y <- 1:3

 >
 >  I want to select all elements in x which are equal to 1, 2 or 3.
 >
 >  I know that I could use
 >

 >  > sel <- x==y[1] | x==y[2] | x==y[3]
 >  > x[sel]

 >
 >  to obtain the values, but in my analysis, the y-vector is thousands of
 >  elements long.
 >
 >  Is there any way, that I can do that easily?
 >
 >  Thanks
 >
 >  Rainer
 >  --
 >  Rainer M. Krug, Dipl. Phys. (Germany), MSc Conservation Biology (UCT)
 >
 >  Plant Conservation Unit Department of Botany
 >  University of Cape Town
 >  Rondebosch 7701
 >  South Africa
 >

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