摘要：AbstractIterative Rational Krylov Algorithm (irka) of Gugercin et al. [2008] is an effective tool for optimal H2rational approximation. Beattie and Gugercin [2012] has recently developed a new formulation of irka that only uses transfer function evaluations, without requiring any particular realization; thus extending irka to H2approximation of irrational, infinitedimensional dynamical systems. The main computational cost of this new framework is the need for repeated transfer function evaluations. In this paper, based on the reproducing kernel formulation of the underlying Hilbert space, we introduce a quadrature-based formulation of irka where a number of transfer function evaluation are computed only at the beginning (the offline phase) and the irka steps (the online phase) never revisit the original transfer function performing all the computations in the reduced order dimension.
