Hello, I have very large matrices (not sparse), where I have to change each element. From the documentation I used the example with which two for-loops. I use for vectors: blas::vector<T> l_vec = p_vec; BOOST_FOREACH( T& i, l_vec) i = std::pow(i, p_exponent); Is there any way to process each element in the matrix with a loop and an iterator? Thanks Phil