Chuck, Internally, R is using 4-byte integers for indexing, and the length of a vector is thus constrained to 2-billion-ish elements. Two ways around this include packages ff and bigmemory, for example, or relying on database-like queries. However, the resulting objects can't be used with standard R functions (with some special exceptions).
Jay On Wed, Apr 13, 2011 at 2:05 PM, <ch...@chuckcode.com> wrote: > > Hi All, > > Thanks to Dirk Eddelbuettel and the other contributors for such a > wonderful package. Rcpp really transforms the way that I've been able to > incorporate c++ code into R. Makes it possible to speed up the critical > computations while keeping all the great flexibility and features of R. > > I've run into a problem lately with particularly large vectors in Rcpp. I > seem to be overflowing when my vectors get larger than 2^31 elements on a > 64 bit system. It looks from the code of both the classic (included below) > and the newer versions as though this is due to using ints rather than > something like size_t (http://en.wikipedia.org/wiki/Size_t) as the type for > size and indexing into the vector. It looks like RcppResultsSet's add() > functions may also be using ints. > > Curious to know if there is a particular reason for using ints rather than > something like size_t and if the project managers would be open to changing > to accomodate larger vectors. > > Thanks, > -Chuck Sugnet > > template <typename T> > class RcppVector { > public: > typedef T* iterator ; > typedef const T* const_iterator ; > > RcppVector(SEXP vec); > RcppVector(int len); > int size() const; > T& operator()(int i) const; > T *cVector() const; > std::vector<T> stlVector() const; > > inline const_iterator begin() const { return v ; } > inline const_iterator end() const { return v + len ; } > > inline iterator begin(){ return v ; } > inline iterator end(){ return v + len ; } > > private: > int len; > T *v; > }; > _______________________________________________ > 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 > -- John W. Emerson (Jay) Associate Professor of Statistics Department of Statistics Yale University http://www.stat.yale.edu/~jay _______________________________________________ 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
