On the choice of an optimal interpolation point in Krylov-based order reduction

In this paper, the well-known problem of finding a suitable interpolation point in order reduction via moment matching by Krylov subspaces is investigated. By using the equivalence property of moment matching and Laguerre-based order reduction, the problem is reformulated as finding the best choice for the free parameter ¿ in the Laguerre basis. Minimizing appropriate cost functions with very few iterations is the key point toward finding this best interpolation point.