ALPS: An adaptive Lanczos-Pade spectral solution of mixed-potential integral equation

This paper presents the ALPS algorithm, a fast frequency sweep for solving Mixed-Potential Integral Equation (MPIE). By assuming a constant frequency parameter for the Green's functions, ALPS employs Lanczos-Pade approximatio n with selective orthogonalization (MPVL) to obtain an approximate spectra solution. Repeating MPVL at another frequency gives a second spectra soluti on. ALPS determines at what frequency the difference between two spectral s olutions is greatest and iteratively improves the spectral solution. (C) 19 99 Elsevier Science S.A. All rights reserved.