Function factorial

inst/include/Rcpp/sugar/functions/math.h:55–55

namespace Rcpp{
    namespace internal{
        extern "C" inline double factorial( double x ){ return ::Rf_gammafn( x + 1.0 ) ; }
        extern "C" inline double lfactorial( double x ){ return ::Rf_lgammafn( x + 1.0 ) ; }
    }
}