> Le 20 oct. 2014 à 21:54, Dirk Eddelbuettel <e...@debian.org> a écrit : > > > Hi Gustaf, > > On 20 October 2014 at 15:17, Gustaf Granath wrote: > | Im trying to use some C++ functions in R. However, these functions are > | build around unsigned char* variables (1D array). I have for example a > | large matrix in R that represents black (e.g. 1-bit image, 0 and 1s). I > | cant find a solution to convert a character vector into unsigned char* > | within Rcpp. Im new to Rcpp and C++ so I might have missed something > > Rcpp builds a bridge between R and C++, and supports (in C++) the types that > R supports. Eg you won't find 'float' but only 'double' as that is what R > does. > > Here you will get character vectors easily. If they must be unsigned char, > you will probably have to cast them at the C++ level. > > | obvious here. Please direct me to resources on this topic (google did > | not help much). > | > | A start: > | > | SEXP test(SEXP cM){ > | CharacterVector Vc(cM); > | int n = Vr.size(); > | RawVector x(n); //is this the same as unsigned char* ? > > No, RawVector is for R 'raw' types -- see help("raw") in R,
Guess what raw is !!! > demangle( "RawVector::stored_type" ) [1] "unsigned char" > Dirk > > | //I tried to fill it with char*(Mr) but I > | didnt succeed > | } > | > | Thanks, > | > | Gustaf > | > | -- > | Gustaf Granath (PhD) > | Post doc > | McMaster University > | School of Geography & Earth Sciences > | > | _______________________________________________ > | 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 > > -- > http://dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org > _______________________________________________ > 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 _______________________________________________ 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