Hello everyone again,
How would you iterate over the i-th row or the j-th column of a mapped_matrix or a compressed_matrix? I got the feeling it's not possible to do it in a proper ( i.e: optimal) way.

In the case of a simple matrix, I would do something like this:

iterator1 it1 = this->begin1();
for( int x = 0; x < i; x++ )
    it1++;
iterator it2 = it1.begin();

Is this adequate?

Régis