Hello, just use:
double* values = input.begin() ; A NumericVector uses R allocated memory, and R allocates an array of doubles to store a numeric vector. You then need to remember you dońt own the pointer. So make sure your code does not eg delete[] it. The code you've used was very inefficient and will make many unecessary copies of the data, each time the std::vctor wants to grow. If you want a std:vector you can do something like this: std::vector<double> vec( input.begin(), input.end() ) ; Or: std::vector<double> vec = as< std::vector<double> >(input) ; Romain Le 29 juin 2013 à 12:08, Anwar Ludin <anwar.lu...@riskcetera.com> a écrit : > Hello, > > I need to interface some R code with a numerical library containing functions > taking as input double* > > What is the most efficient way to create an array of doubles from a > NumericVector. > > I was thinking of something like: > > > > > > > // input is of type Rcpp::NumericVector and passed from R > std::vector<double> vec; > std::copy(input.begin(), input.end(), std::back_inserter(vec)); > > double* values = &vec[0]; > > // now call function taking a double* > > > Regards, > > Anwar > _______________________________________________ > 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
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