[R-SIG-Mac] Memory length in C

[Thomas Lumley]

On Mon, 4 Oct 2004, Maartje Raijmakers wrote:

>
>
> I suspect memory problems. Therefore I want to do the following, but I don't
> know how:
>
> I use C - routines which I call from R with .C (and C routines that are
> called from fortran by lsoda in the odesolve package)
> One of these C routines has as an argument a pointer to an array of doubles.
>
> Now, I want to check the length of this array within the C-routine.
> Does anyone know how I should do that?
>

You can't. The C pointer doesn't contain any information about the length 
of the array -- it has to be passed in as a separate argument.

To detect errors in the length of the array you can put extra entries on 
the end of the array and see if they are overwritten.

 	-thomas