Calculation of transmission zeros using QZ techniques

The computation of various "system zeros" is investigated through application of QZ-type algorithms for the nonsymmetric generalized eigenvalue problem. Such algorithms use unitary similarities to efficiently reduce the problem to one where the zeros may be determined in a useful, accurate, and dependable manner. Recent reliable and sophisticated analysis and software (specifically, EISPACK) developed by numerical linear algebra specialists is used. EISPACK, moreover, is widely available and can be applied directly to the transmission zero problem. Examples and timing estimates are given and the associated generalized eigenvecter problem is noted with its application to the computation of supremal (A,B)-invariant and controllability subspaces.