Namespace Math::Matrix::Banded

Hi all,

I am working on a set of modules dealing with banded matrices (aka
band matrices or band diagonal matrices). These are a certain kind
of sparse matrices where all entries are known to be 0 except close
to the main diagonal. Obviously, this condition can be exploited for
efficient storage and algorithms.

I am planning to use the Math::Matrix::Banded namespace. However, I
require separate namespaces for rectangular (i.e. non-square) and
symmetric systems because they are stored differently and allow a
distinct set of algorithms.

I have considered
Math::Matrix::Banded
Math::Matrix::BandedRectangular
Math::Matrix::BandedSymmetric

What I don't like about this option is that the package name would
be Math-Matrix-Banded, but it would use namespaces outside the top
level namespace.

An obvious alternative would be
Math::Matrix::Banded
Math::Matrix::Banded::Rectangular
Math::Matrix::Banded::Symmetric

What I don't like here is that it suggests that the latter two
classes are subclasses of the first, which is not the case.

The third option I came up with is
Math::Matrix::Banded::Square
Math::Matrix::Banded::Rectangular
Math::Matrix::Banded::Symmetric

This is all within the Math::Matrix::Banded namespace and reflects
the sibling relationship between the three classes. What I can see
as a disadvantage - apart from long names - is that the package
would still be called Math-Matrix-Banded, but there is no class
occupying the top level namespace, which might be confusing for
users.

Do you have any thoughts on this matter?
Thank you and best wishes,
Lutz