Replace PointND and Matrix classes
This is a follow-up and continues the discussion from issue #101 (closed). HyTeG offers two auxilliary classes
template < typename T, uint_t M, uint_t N > class Matrix
template<typename T, size_t N> class PointND
for small dense vectors and matrices. We would like to replace these by something that is better tested and (potentially) offers more functionality.
We are currently in favour of using Eigen for this. However, there is the issue that THE_INDEX_TYPE_MUST_BE_A_SIGNED_TYPE in Eigen, while our classes currently expect indices of type