Coprime factorisation and gap metric for nonlinear systems

Abstract

Several graph and gap metrics are defined using normalized coprime factorisations for nonlinear signal operators. Their relation to the gap metrics of a Georgiou and Smith type are discussed. It is proved that the topological structures of the two classes of metrics are equivalent. Formulas for a /spl rho/-gap metric and a nonlinear generalization of the Georgiou-type gap metric are shown to be equal.