SMatrix: a generic fixed size D1 x D2 Matrix class.
The class is template on the scalar type, on the matrix sizes:
D1 = number of rows and D2 = number of columns
amd on the representation storage type.
By default the representation is MatRepStd<T,D1,D2> (standard D1xD2 of type T),
but it can be of type MatRepSym<T,D> for symmetric matrices DxD, where the storage is only
D*(D+1)/2.
See \ref SMatrixDoc.
Original author is Thorsten Glebe
HERA-B Collaboration, MPI Heidelberg (Germany)
@ingroup SMatrixSVector
@authors T. Glebe, L. Moneta and J. Palacios
SMatrix: column-wise storage