An algorithm for polynomial matrix factor extraction

algorithm is described for extracting a polynomial matrix factor featuring any subset of the zeros of a given nonsingular polynomial matrix. It is ass umed that the zeros to be extracted are given as input data. Complex or rep eated zeros are allowed. The algorithm is based on interpolation and relies upon numerically reliable subroutines only. It makes use of a procedure th at computes the generalized characteristic vectors of a polynomial matrix a t a given point. The extracted factor is provided in column- and row-reduce d Popov form. Applications of the algorithm include polynomial matrix inter polation, plus/minus factorization, column- and row-reduction, or computati on of the Smith form of a polynomial matrix. The numerical routines describ ed in this paper are implemented in the new release 2.0 of the Polynomial T oolbox for MATLAB.