hi, what's the best way to achieve x*=y? where x and y are vectors (or proxies) of identical size? although i wrote a function (below) i hope there's already some ublas related facility to do so. template<typename D> class Op_product_term_by_term{ public: Op_product_term_by_term(D& dest):iter(dest.begin()),end(dest.end()){}; void operator()(double elem); private: typename D::iterator iter; typename D::iterator end; }; template<typename D> void Op_product_term_by_term<D>::operator()(double elem){ if(iter<end){ *(iter++)*=elem; }else{ throw; }; }; template<typename D, typename B> void product_term_by_term(D& dest,const B& by){ if(dest.size()==by.size()){ for_each(by.begin(),by.end(),Op_product_term_by_term<D>(dest)); }else{ throw; }; }; ps: should i post this kind of ad in boost/ublas or boost/users?