[Rcpp-devel] [R] Error using Rcpp
Abhisek
shieks at gmail.com
Thu Mar 25 16:21:52 CET 2010
Many thanks Romain! It worked. And thanks for pointing out the errors.
best
abhisek
On Thu, Mar 25, 2010 at 12:45 PM, Romain Francois
<romain at r-enthusiasts.com>wrote:
> 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
>>
>
>
> --
> Romain Francois
> Professional R Enthusiast
> +33(0) 6 28 91 30 30
> http://romainfrancois.blog.free.fr
> |- http://tr.im/OIXN : raster images and RImageJ
> |- http://tr.im/OcQe : Rcpp 0.7.7
> `- http://tr.im/O1wO : highlight 0.1-5
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.r-forge.r-project.org/pipermail/rcpp-devel/attachments/20100325/fefcad15/attachment.htm
More information about the Rcpp-devel
mailing list