title: Efficient formulation of the stochastic simulation algorithm for chemically reacting systems.
abstract: In this paper we examine the different formulations of Gillespie's stochastic simulation algorithm (SSA) [D. Gillespie, J. Phys. Chem. 81, 2340 (1977)] with respect to computational efficiency, and propose an optimization to improve the efficiency of the direct method. Based on careful timing studies and an analysis of the time-consuming operations, we conclude that for most practical problems the optimized direct method is the most efficient formulation of SSA. This is in contrast to the widely held belief that Gibson and Bruck's next reaction method [M. Gibson and J. Bruck, J. Phys. Chem. A 104, 1876 (2000)] is the best way to implement the SSA for large systems. Our analysis explains the source of the discrepancy.
authors.affiliation: Department of Computer Science, University of California Santa Barbara, Santa Barbara, California 93106, USA. yao@cs.ucsb.edu
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Linda
authors.initials: L
authors.lastname: Petzold