Question

I never think to use Reduce but I have a problem I thought it would be good for. I want to make sure the size of each iterative element of a vector is equal to or larger than the previous element. I can do this with sapply but my attempt with Reduce fails. How can I use this with Reduce?

#This works
y <- c(1,2,3,2,4,4)
sapply(seq_along(y)[-length(y)], function(i) y[i] <= y[i+1])

#attempts
Reduce('<', c(1,2,3,2,4,4)), accumulate = TRUE)
Reduce('<', c(1,2,3,2,4,4)))

Answer 1

Desparately bored? I was:

myFun <- function(x,z){
  if(is.null(names(z))) names(z) <- z
  if(is.null(names(x))) names(x) <- x
  if(as.numeric(names(x)) < as.numeric(names(z))) res <- TRUE else res <- FALSE
  names(res) <- names(z)
  return(res)
}
as.logical(Reduce(myFun, y, accumulate = TRUE)[-1])
# [1]  TRUE  TRUE FALSE  TRUE  TRUE