Computation of zeros of linear multivariable systems

Several algorithms have been proposed in the literature for the computation of the zeros of a linear system described by a state-space model 1x1 A,B,C,D}. In this report we discuss the numerical properties of a new algorithm and compare it with some earlier techniques of computing zeros. The new approach is shown to handle both nonsquare and/or degenerate systems without difficulties whereas earlier methods would either fail or would require special treatment for these cases. The method is also shown to be backward stable in a rigorous sense. Several numerical examples are given in order to compare speed and accuracy of the algorithm with its nearest