Rounding problem R vs Excel

Does this script do what you want?

cround <- function(x,digits=0) {
  a <- ifelse(x>0,.5,-.5)
  if (digits==0) {
    floor(x+a)
  } else {
    m <- 10^digits
    floor(x*m+a)/m
  }
}

No, the problem is that R uses binary formats, and some numbers aren't
representable there.  So for example,

cround(0.145,2)

[1] 0.14

because 0.145 isn't representable exactly, and is actually being
represented as 0.14999999999 or something similar.

Duncan Murdoch