Implementation of class "polyMatrix" for storing a matrix of polynomials and implements
basic matrix operations; including a determinant and characteristic polynomial.
It is based on the package 'polynom' and uses a lot of its methods to implement matrix operations.
This package includes 3 methods of triangularization of polynomial matrices:
Extended Euclidean algorithm which is most classical but numerically unstable;
Sylvester algorithm based on LQ decomposition;
Interpolation algorithm is based on LQ decomposition and Newton interpolation.
Both methods are described in
D. Henrion & M. Sebek, Reliable numerical methods for polynomial matrix triangularization,
IEEE Transactions on Automatic Control (Volume 44, Issue 3, Mar 1999, Pages 497-508)