[Rcpp-devel] passing function

[Siddhartha Chib]

Thanks.

  I did not understand this code

  # C++ source code to operate on function and vector
  cpp<- '
   int n = as<int>(N);
   NumericVector numvec(xvec) ;
   Function f(fun) ;
   for( int i=0; i<n; i++){
    numvec = f( numvec ) ;
   }
   return numvec ;

  I see that f is a Function object but what is fun? And why the looping over numvec rather than elements of numvec? Finally, how to use RcppArmadillo to do the C++ computations on the R function?

  Best.



On 1/25/2011 12:17 PM, Dirk Eddelbuettel wrote:
> On 25 January 2011 at 12:01, Siddhartha Chib wrote:
> | Is it possible to pass a user defined function
> | written in R for use in rccparma.  For example, is it possible to have a
>
> (What is rccparma?)
>
> | function
> | SEXP myfunction(SEXP g, SEXP a)
> | where g is a function object and a is a
> | matrix, the argument of g?
>
> Have you looked at
>
>       examples/functionCallback/newApiExample.r
>
> which installed with your copy of Rcpp -- it uses Rcpp to sweep a
> user-supplied R function over a vector.  Doing this with a matrix is close.
>
> And just for completeness, there is more in other place; my RcppDE riff on
> the the DEoptim software allows you to pass objective functions as either R
> or C++ functions; the C++ side then needs external pointers.
>
> Hope this helps,  Dirk
>
>    

-- 
Siddhartha Chib
Harry C. Hartkopf Professor of Econometrics and Statistics
Olin Business School, Campus Box 1133
Washington University in St. Louis
1 Brookings Dr
St. Louis, MO 63130
(314) 935-4657;    (314) 935-6359 [Fax]
chib at wustl.edu
http://www.olin.wustl.edu/faculty/chib/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.r-forge.r-project.org/pipermail/rcpp-devel/attachments/20110126/f7bedadd/attachment.htm>