r - Passing arguments to iterated function through apply

Question

I have a function like this dummy-one:

FUN <- function(x, parameter){
  if (parameter == 1){
      z <- DO SOMETHING WITH "x"}
  if (parameter ==2){
      z <- DO OTHER STUFF WITH "x"}
return(z)
}

Now, I would like to use the function on a dataset using apply. The problem is, that apply(data,1,FUN(parameter=1))

wont work, as FUN doesn't know what "x" is. Is there a way to tell apply to call FUN with "x" as the current row/col? `

Answer 1

You want apply(data,1,FUN,parameter=1). Note the ... in the function definition:

> args(apply)
function (X, MARGIN, FUN, ...) 
NULL

and the corresponding entry in the documentation:

...: optional arguments to ‘FUN’.