Not a bug, this is expected behaviour. If you pass a matrix of ints to the NumericVector ctor, Rcpp has no choice but to coerce the data to a matrix of double, which means new data, hence the original data does not get modified.
If you pass a matrix of double, no copy is required, therefore Rcpp operates directly on the data. Those are features. Le 4 nov. 2011 à 08:01, Darren Cook <dar...@dcook.org> a écrit : >> I.e. the point of his code was to show that a matrix of doubles gets >> modified, a matrix of ints does not. > > Or change the first line from NumericMatrix to: > Rcpp::IntegerMatrix r_m(mem); > > Then the behaviour is reversed. The matrix of doubles does not get > modified, but the matrix of ints does! > > Dirk, Romain, this is a bug-in-waiting. Is there any way to generate a > warning when the implicit deep copy happens? Or alternatively when the > pointer is being used implicitly... but my hunch is that I want to know > when there is any implicit conversion between int and double: modern C++ > style is to explicitly declare all type conversions with static_cast<> > and friends. > > Darren > _______________________________________________ > 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
