[Rd] array indexes in C

[Benjamin Tyner]

Tamas,

You could write convenience functions, but I have used the C99 mechanism 
for variable length arrays with no problems calling from R. One thing 
you have to keep in mind though is that (as far as I know) the 
dimensions must be passed before the array reference. So for example,

r <- .C("foo",
              as.integer(ni),
              as.integer(nj),
              x = double(ni * nj),
              ...)

with your function defined as

void foo(int *ni, int *nj, double x[*ni][*nj])
{
...

Then in C you can access elements of x via x[3][4], for example.

Ben