[R] Function modification: how to calculate values for every combination?

[Lauri Nikkinen]

Hello,

I have a function like this:

fun <- function (x, y) {
          a <- log(10)*y
          b <- log(15)*x
          extr <- a-b
          extr
          }

fun(2,3)
[1] 1.491655

x <- c(1,2,3)
y <- c(4,5,6)
fun(x, y)
[1] 6.502290 6.096825 5.691360

How do I have to modify my function that I can calculate results using
every combination of x and y? I would like to produce a matrix which
includes the calculated values in every cell and names(x) and names(y)
as row and column headers respectively. Is the outer-function a way to
solution?

Best regards,
Lauri