1. A method for simulating behavior of a microelectronic circuit, comprising the steps of: storing a representation of said microelectronic circuit in a computer; transforming the stored representation of said microelectronic circuit into an equivalent DC circuit containing resistive and capacitive elements; converting said equivalent DC circuit for said microelectronic circuit into a directed graph having a spanning tree; traversing said spanning tree of said directed graph to obtain unshifted moments of said microelectronic circuit including resistive and capacitive elements; shifting said unshifted moments to obtain shifted moments; determining poles of said microelectronic circuit from said shifted moments; determining residues from said unshifted moments and the poles; and producing a time domain simulation of the behavior of said microelectronic circuit from the poles and residues.