between.R: checks if a number is between two other numbers (inclusive)

between.R

between <- function(x, a, b) {
    if(missing(b)) {
        if(length(a)==2) {
          a<-t(a)
       }
    } else {
        a <- unname(cbind(a,b))
    }
    a<-t(apply(a,1,sort, na.last=T))
    a[,1] <= x & x <= a[,2]
}

test.between,R

between(5,1,10)
between(5,c(1,10))
between(1:10, 4, 6)
between(1:10, c(4, 6))
between(1:3, c(0,4,2), 5)
between(7, 10, 6)