Hi, I have a ublas vector (or it can be std::vector also). Where I want to perform certain operation as a rotating basis. The program below illustrates it. std::vector<int> v; v+=1,2,3,4,5,6,7,8,9; ublas::vector<int> v1(v.size()); std::copy(v.begin(),v.end(),v1.begin()); std::cout<<ublas::sum(ublas::subrange(v1,1,3))<<std::endl; std::cout<<ublas::sum(ublas::subrange(v1,7,2))<<std::endl; In the first case I got a sum for [1 ,3) , I also want to get a sum for [7, 2) in a wrapped (circular )way. So is there any range functionality provides it in that way ? I also want some std algorithms to perform over some iterator adapter in a wrapped way .I can write such iterators , but are they already exist in boost ? Thanks abir basak -- Abir Basak, Member IEEE Software Engineer, Read Ink Technologies B. Tech, IIT Kharagpur email: abir@abirbasak.com homepage: www.abirbasak.com