Le 25/03/10 13:16, Abhisek a écrit :
Hi, Im not sure if this is the right place to post this.
It is not. The Rcpp-devel mailing list is the right place:
https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
I am using Xubuntu
Karmic Koala and am trying to use the Rcpp package. I am testing it using a
simple code that takes in a vector and adds 1 to each element:
#include<Rcpp.h>
// This file takes in a vector and adds one to each entry
RcppExport SEXP addone(SEXP vec){
// create a local copy of vec
Rcpp::NumericVector orig(vec);
// create an output vector
Rcpp::NumericVector vecout(orig.size());
for(i=0;i<orig.size();i++) {
vecout[i] = orig[i]+1;
}
Rcpp::Pairlist
res(Rcpp::Named("result",vecout),Rcpp::Named("original",orig));
return res;
}
You need some flags set up :
export PKG_LIBS=`Rscript -e "Rcpp:::LdFlags()"`
export PKG_CXXFLAGS=`Rscript -e "Rcpp:::CxxFlags()"`
R CMD SHLIB addone.cpp
also, your code is not correct since the i variable is not declared, so
I get this when I try to compile it:
addone.cpp: In function ‘SEXPREC* addone(SEXPREC*)’:
addone.cpp:12: error: ‘i’ was not declared in this scope
make: *** [addone.o] Error 1
The inline package can help you with this when prototyping your code,
check the cfunction in the inline package, specifically its arguments
"verbose" and "Rcpp".
Personally I would code this using stl algorithms rather than raw looping:
#include <Rcpp.h>
template <typename T>
inline T add_one( T x){
return x + 1 ;
}
// This file takes in a vector and adds one to each entry
RcppExport SEXP addone(SEXP vec){
// original object
Rcpp::NumericVector orig(vec);
// output vector
Rcpp::NumericVector vecout(orig.size());
std::transform(
orig.begin(), orig.end(),
vecout.begin(),
add_one<double> ) ;
return vecout ;
}
or maybe you don't even have to write the tedious add_one template and
you can do it like this:
#include <Rcpp.h>
// This file takes in a vector and adds one to each entry
RcppExport SEXP addone(SEXP vec){
// original object
Rcpp::NumericVector orig(vec);
// output vector
Rcpp::NumericVector vecout(orig.size());
std::transform(
orig.begin(), orig.end(),
vecout.begin(),
std::bind2nd( std::plus<double>(), 1.0 )
) ;
return vecout ;
}
I then try to use - R CMD SHLIB addone.cpp
that didnt work. the error said there was no such file - "Rcpp.h" .
Then i came across Dirk Eddelbeutel's beamer presentation and followed the
suggestion to copy Rcpp.h to /usr/loca/include and libRcpp.so to
/usr/local/lib
Then i tried R CMD SHLIB addone.cpp again but got many errors. Here is a
small selection:
/usr/local/include/Rcpp.h:34:32: error: RcppDatetimeVector.h: No such file
or directory
/usr/local/include/Rcpp.h:35:23: error: RcppFrame.h: No such file or
directory
/usr/local/include/Rcpp.h:36:26: error: RcppFunction.h: No such file or
directory
/usr/local/include/Rcpp.h:37:22: error: RcppList.h: No such file or
directory
could someone help? im afraid im new both to linux and Rcpp!
best,
abhisek
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