[Rcpp-devel] Error in Module

[Brötje David]

Hello,


I want to expose a C++ class to R through Rcpp. For that I want to try 
out a few examples from the note "Exposing C++ functions and classes 
with Rcpp modules" and the book "Seamless R and C++ Integration with 
Rpp". But I can't manage to get them work. It ends up with an error. 
So this is what I'm doing.

First I create a cpp file with the c++ code from the example. The full 
content of the cpp file is below.

------------------------------------------------------------------------------------
#include "Rcpp.h"
using namespace Rcpp;


std::string hello() { return "hello"; }

int bar( int x) { return x*2; }

double foo( int x, double y) { return x*y; }

void bla( ) { Rprintf( "hello\\n" ); }

void bla1( int x) {
Rprintf( "hello (x = %d)\\n", x );
}
void bla2( int x, double y) {
Rprintf( "hello (x = %d, y = %5.2f)\\n", x, y );
}


RCPP_MODULE(yada) {
using namespace Rcpp;
function( "hello" , &hello );
function( "bar" , &bar );
function( "foo" , &foo );
function( "bla" , &bla );
function( "bla1" , &bla1 );
function( "bla2" , &bla2 );
}
------------------------------------------------------------------------------------


Then I run this command:


PKG_CXXFLAGS=`Rscript -e 'Rcpp:::CxxFlags()'` PKG_LIBS=`Rscript -e 
'Rcpp:::LdFlags()'`  R CMD SHLIB test.cpp


Afterwards I start R and run these commands in R:


------------------------------------------------------------------------------------
require(Rcpp)
yada <- Module("yada")


yada$bar( 2L )
yada$foo( 2L, 10.0 )
yada$hello()
yada$bla()
yada$bla1( 2L)
yada$bla2( 2L, 5.0 )
------------------------------------------------------------------------------------


And it ends up with this error:


------------------------------------------------------------------------------------
Error in Module(module, mustStart = TRUE) :
   Failed to initialize module pointer: Error in 
FUN("_rcpp_module_boot_yada"[[1L]], ...): no such symbol 
_rcpp_module_boot_yada in package .GlobalEnv
------------------------------------------------------------------------------------


This happens all the time with modules. Did I overlook something or 
what am I doing wrong?


David