R help - Apr 2012 - Return dynamic array from C to R

Hi Everyone,
I am new to R and I am trying to return array(dynamic) from C to R. But
when I print array(vector) in R it gives NA as output. When I print array
in C it gives correct o/p but some how it is not returned to R.

*Code in C:*
void test(double *vec,double *size){
vec = (double *)calloc(2 , sizeof(double));
        *(vec+0) = 1;
        *(vec+1) = 2;
        *size = 2;
}

*Code in R:*
test<-.C("test",vec=as.double(),size=as.integer())
print(test$vec[1:test$size])

Is there any other way to implement above thing?

Any help would be appreciated
Thanks

	[[alternative HTML version deleted]]

On 22/04/2012 04:52, Jaimin Dave wrote:
> Hi Everyone,
> I am new to R and I am trying to return array(dynamic) from C to R. But
> when I print array(vector) in R it gives NA as output. When I print array
> in C it gives correct o/p but some how it is not returned to R.
>
> *Code in C:*
> void test(double *vec,double *size){
> vec = (double *)calloc(2 , sizeof(double));
>          *(vec+0) = 1;
>          *(vec+1) = 2;
>          *size = 2;
> }
>
> *Code in R:*
> test<-.C("test",vec=as.double(),size=as.integer())
> print(test$vec[1:test$size])
>
> Is there any other way to implement above thing?
Use .Call.  As the documentation tells you, you cannot do this in .C 
(and you are likely to cause segfaults by trying).
>
> Any help would be appreciated
> Thanks
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
Which does say this is the wrong list for programming questions ....

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595