[R] filling an array, vectorized

Tamas K Papp
Wed, 15 Nov 2006 19:16:11 -0000

Hi,

I am sure this has come up before, but my searches of the archive
didn't give any results (maybe I didn't use the right keywords, but if
I use too many, the search times out).

I have a vector of dimensions n, length is not fixed, eg

n <- c(4,5,7)

or

n <- c(19,4,5,7)

and a function f that takes a vector of indices, same length of n, and
gives a scalar.

I would like to fill the array

a <- array(dim=n)

so that (... is just notation, not R's ...)

a[i,j,k,...] <- f(list(i,j,k,...))

I would use loops, but since n can have different lengths, I don't
know how many loops I would need beforehand.  Is there a way to do
this?

Thanks,

Tamas