R help - Mar 2012 - a question about writing C extensions to functions

Dear R People:

I'm not sure if I should ask this here or in Rcpp, but I thought I'd
start here first.

If I'm writing a C program, when do I know to use SEXP vs. int or float,
please?

Thanks,
Erin


-- 
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: erinm.hodgess at gmail.com

On 16.03.2012 18:08, Erin Hodgess wrote:
> Dear R People:
>
> I'm not sure if I should ask this here or in Rcpp,
Why is this related to Rcpp?
> but I thought I'd
> start here first.
>
> If I'm writing a C program, when do I know to use SEXP vs. int or
float, please?
For very short:

If you want keep some things internal to your C code, use int etc. , but 
if it makes sense to use R objects (e.g. because you return things or 
make use of otehr R functionality), use SEXP objects. If the latter, you 
already decided to use the .Call() interface.

There is more in Writing R Extensions.

Uwe

> Thanks,
> Erin
>
>