rcpp

looking at the rcpp documentation and Rcpp::DataFrame in the gallery I realized that I didn't know how to modify a DataFrame by reference. Googling a bit I found this post on SO and this post on the archive. There is nothing obvious so I suspect I miss something big like "It is already the case because" or "it does not make sense because". I tried the following which compiled but the data.frame object passed to updateDFByRef in R stayed untouched #include <Rcpp.h> using namespace Rcpp; // [[Rcpp::export]] void updateDFByRef(DataFrame& df) { int N = df.nrows(); NumericVector newCol(N,1.); df[

I have prepared a package in R by using RcppArmadillo and OpenMP libraries and following commands: RcppArmadillo.package.skeleton("mypackage") compileAttributes(verbose=TRUE) Also, in the DESCRIPTION file I added: Imports: Rcpp (>= 0.12.8), RcppArmadillo LinkingTo:Rcpp, RcppArmadillo Depends: RcppArmadillo and in the NAMESPACE file I added: import(RcppArmadillo) importFrom(Rcpp, evalCpp) Then I run the following codes in cmd : R CMD build mypackage R CMD INSTALL mypackage.tar.gz I build and install the package in my computer and I use it now. But my colleges and friends are not able to install

First of all, I am a novice user so forget my general ignorance. I am looking for a faster alternative to the %*% operator in R. Even though older posts suggest the use of RcppArmadillo, I have tried for 2 hours to make RcppArmadillo work without success. I always run into lexical issues that yield 'unexpected ...' errors. I have found the following function in Rcpp which I do can make work: library(Rcpp) func <- ' NumericMatrix mmult( NumericMatrix m , NumericMatrix v, bool byrow=true ) { if( ! m.nrow() == v.nrow() ) stop("Non-conformable arrays") ; if( ! m.ncol() == v.ncol() ) stop("Non

I wanted to know if there is a limit to the number of rows that can be read using the data.table fread function. I am working with a table with 4 billion rows, 4 columns, about 40 GB. It appears that fread will read only the first ~ 840 million rows. It does not give any errors but returns to the R prompt as if it had read all the data ! I understand that fread is not for "prod use" at the moment, and wanted to find out if there was any timeframe for implementation of a prod-release. The reason I am using data.table is that, for files of such sizes, it is extremely efficient at processing the

My task it to rewrite a R function in C++ to accelerate the while loops. All R codes has been rewritten in the help of Rcpp and Armadillo except the .Fortran() . I try to use Rinside to at first and it works at a very slow speed as Dirk indicated. (It is expensive for data to go through R -> C++ -> R -> Fortran) Since I don't want to rewrite the Fortran codes in C++ and vice versa, it looks natural to accelerate the programs by linking C++ directly to Fortran: R -> C++ -> Fortran. // [[Rcpp::depends(RcppArmadillo)]] #include <RcppArmadillo.h> using namespace Rcpp; extern "C"{ List f_(int *n

I have a ton of code using the base::order() command and I am really too lazy to code around that in rcpp. Since Rcpp only supports sort, but not order, I spent 2 minutes creating this function: // [[Rcpp::export]] Rcpp::NumericVector order_cpp(Rcpp::NumericVector invec){ int leng = invec.size(); NumericVector y = clone(invec); for(int i=0; i<leng; ++i){ y[sum(invec<invec[i])] = i+1; } return(y); } It somehow works. If the vectors are containing unique numbers, I get the same result as order(). If they are not unique, results are different, but not wrong (no unique solution really). Using it:

I am trying to convert RcppArmadillo vector (e.g. arma::colvec ) to a Rcpp vector ( NumericVector ). I know I can first convert arma::colvec to SEXP and then convert SEXP to NumericVector (e.g. as<NumericVector>(wrap(temp) ), assuming temp is an arma::colvec object). But what is a good way to do that? I want to do that simply because I am unsure if it is okay to pass arma::colvec object as a parameter to an Rcpp::Function object. I was trying to Evaluate a Rcpp::Function with argument arma::vec , it seems that it takes the argument in three forms without compilation errors. That is, if f is a