Thank you for your reply, > If you always use vector< vector< double > > then I would start with > Rcpp::NumericMatrix, or arma::mat.
The problem is, that I want to offer the user a choice of using also data.frames and not just Matrices. So I can not really decide, with what I start, or am I wrong? Regarding the use of Rcpp:function: As the R objects used are very large (many MB to some GB), I would like to do the transformation into a usable format, in my case into the vector< vector< double > >, in CPP, as I imagine it to be much faster. I will have look into armadillo, but I hoped to avoid loading another library, to reduce the depencies of my script/package. Paul On 19.05.2016 12:07, Dirk Eddelbuettel wrote: > > On 19 May 2016 at 10:46, Paul Saary wrote: > | Hello, > | > | I have been trying to solve this problem for quite some time now, so I > | thought I'd ask here. > | > | I am trying to write a Cpp function, accepting multiple input types, > | such as matrices and dataframes. > | > | I understood that I could do this by accepting any SEXP object. > | > | The core problem now is to transform these object into something my > | software can use, which would be an object of type > | std::vector<vector<double>>. > > If you always use vector< vector< double > > then I would start with > Rcpp::NumericMatrix, or arma::mat. > > Do you know if you prefer rows or columns? It is pretty easy to pick off > either rows and columns, but you may save yourself a transpose. > > Lastly, maybe consider switching your code to arma::mat instead of vector< > vector< double > > which is really a fudge to make up for the lack of proper > Matrix classes in C++ itself. > > On 19 May 2016 at 11:12, Sameer D'Costa wrote: > | Have you considered using the function as.matrix? It is an R function but > you > | can call it from within your Rcpp code as well. Once you have a matrix you > can > | use your matrix solution. > > I'd consider Rcpp::Function as a last resort. You do not need it here. > > Dirk > _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
