R devel - Feb 2010 - Portability of a C function

Hi the list,

In a package P1, I write a function f1 in C, potentially an internal 
function (not to be called from R).
In a package P2, I write a function f2 in C. The f2 function needs to 
use f1 from P1. Is it possible ?

--- 8< ---- In file P1.c ---------
double f1(x,y){
   ....
}

--- 8< ---- In file P2.c ---------
void f2(x,y,z){
   double result;
   ....
   result = f1(x,y);
   ....
}

Thanks
Christophe

Hello,

This was discussed this week in the thread "LinkingTo and C++".

It is possible, and documented in WRE section 5.4 : 
http://cran.r-project.org/doc/manuals/R-exts.html#Registering-native-routines

Romain

On 02/14/2010 12:58 PM, Christophe Genolini wrote:
>
> Hi the list,
>
> In a package P1, I write a function f1 in C, potentially an internal
> function (not to be called from R).
> In a package P2, I write a function f2 in C. The f2 function needs to
> use f1 from P1. Is it possible ?
>
> --- 8< ---- In file P1.c ---------
> double f1(x,y){
> ....
> }
>
> --- 8< ---- In file P2.c ---------
> void f2(x,y,z){
> double result;
> ....
> result = f1(x,y);
> ....
> }
>
> Thanks
> Christophe
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On 14 February 2010 at 12:58, Christophe Genolini wrote:
| Hi the list,
| 
| In a package P1, I write a function f1 in C, potentially an internal 
| function (not to be called from R).
| In a package P2, I write a function f2 in C. The f2 function needs to 
| use f1 from P1. Is it possible ?

Yes. See 'Writing R Extension' on LinkingTo. You can register f1 for use
by
the others, if P2 has a LinkingTo: on P1 then you're good.  The
'classic'
example is for lme4 using (large) parts of Matrix.

Dirk
 
| --- 8< ---- In file P1.c ---------
| double f1(x,y){
|    ....
| }
| 
| --- 8< ---- In file P2.c ---------
| void f2(x,y,z){
|    double result;
|    ....
|    result = f1(x,y);
|    ....
| }
| 
| Thanks
| Christophe
| 
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| R-devel at r-project.org mailing list
| https://stat.ethz.ch/mailman/listinfo/r-devel

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