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