when the iterable is NOT the first argument of the function

Question

The problem is quite simple yet I can't find the answer.

I have myfun <- function(x, y). How can I sapply this function over a list of y?

To apply over x I would do this

iterables <- 1:10
sapply(iterables, myfun, y)

But I want the iterables to be y instead.

In reality, my function has more than 2 arguments though. I can't specify all the other arguments by hand. — Heisenberg, Mar 07 '14 at 23:45

score 8 · Accepted Answer · answered Mar 07 '14 at 23:41

8

You have several options - e.g. one mentioned by sgibb which relies on how R interprets function arguments, i.e. that myfun(y, x = x) is the same as myfun(x, y).

I prefer creating anonymous functions since it's easier to understand what's happening:

sapply(iterables, function(iter) myfun(x, iter))

answered Mar 07 '14 at 23:41

eddi

49,088
6
104
155

If `myfun` has, say, 5 arguments, can I do this? `sapply(iterables, function(iter) myfun(x1, x2, x3, iter, x4)`? – Heisenberg Mar 07 '14 at 23:47

when the iterable is NOT the first argument of the function

1 Answers1