multiplying all elements of a vector in R

Question

I want a function to return the product of all the values in a vector, like sum but with multiplication instead of addition. I expected this to exist already, but if it does I can't find it. Here's my solution:

product <- function(vec){
    out <- 1
    for(i in 1:length(vec)){
         out <- out*vec[i]
    }
    out
}

This behaves the way I want it to. For example:

> product(1:3)
[1] 6

Is there a better way of doing this, either with an existing function or through an improvement to this custom one?

question from:https://stackoverflow.com/questions/3087145/multiplying-all-elements-of-a-vector-in-r

Answer 1

You want prod:

R> prod(1:3)
[1] 6