Function for finding matching values in two vectors.

a<-1:5;b<-1:9
a

b

intersect(a, b)

Hi,
You could use:
which(a%in%b)
#[1] 1 2 3 4 5

a1<-c(1,2,5)

b1<-c(1,3,4,5,7)
which(a1%in%b1)
#[1] 1 3
A.K.



Hello! I created the following function for calculating which elements
in vector a are existant in vector b. However, all I get is NA NA NA and I can?t figure out why. =/



fun <- function(a, b) {
  y <- rep(NA, length(a))
  x <- 0
  while (x <= length(b)) {
    x <- x + 1
    for (i in 1:length(a)) {
        y[i]<- (a[i] == b[x])
    }
  }
  return(y)
}

fun(a<-1:5,b<-1:9)


Thanks for any help!