[Rcpp-devel] Rcpp: Error: not compatible with requested type

[Dirk Eddelbuettel]

Pierre,

It is not clear what your code is actually trying to do.  The following
should be equivalent (as best as I can tell), works (!!) and makes life a lot
easier via Attributes.

------- save this as eg /tmp/pierre.cpp -------------------------------------
#include <Rcpp.h>

// [[Rcpp::export]]
Rcpp::List newCompQuant(int n, int M, Rcpp::Function f) {
  Rcpp::Rcout << "n : " << n << std::endl
              << "M : " << M << std::endl;
  return Rcpp::List::create(Rcpp::Named("sample") = f,
                            Rcpp::Named("law.name") = " ",
                            Rcpp::Named("law.pars") = R_NilValue);
}  

/*** R
res <- newCompQuant(n=50, M=10^3, f=norm)
print(str(res))
*/
-----------------------------------------------------------------------------


In R, then do

R> Rcpp::sourceCpp("/tmp/pierre.cpp")

for which I then get:

R> sourceCpp("/tmp/pierre.cpp")

R> res <- newCompQuant(n=50, M=10^3, f=rnorm)
n : 50
M : 1000

R> print(str(res))
List of 3
 $ sample  :function (n, mean = 0, sd = 1) 
 $ law.name: chr " "
 $ law.pars: NULL
NULL
R> 


Attributes also take care of RNGScope, and past discussions here have seen it
help with repeated calls (with a 'big' N of number of repeats) where manually
dealing with scope and temp objects may otherwise create a wrinkle.

Hth,  Dirk


-- 
http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org