Hi, It seems the ublas::matrix don't have begin() and end() that the ordinary STL container would have. It do have begin1(), begin2(), end1(), end2(), but it only traverse a row or a column. So, how could I use the iterators rather than hand-crafted for-loop to traverse the whole matrix? e.g., copy( matrix.begin(), matrix.end(), ostream_iterator<element_type>(cout, " ") ) ; // ERROR: won't compile: matrix don't have begin & end (I know matrix have overloaded the operator<<, it's only an example )