[Rcpp-devel] passing function
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>