In this paper, we outline a method for symplectic integration of three
degree-of-freedom Hamiltonian systems. We start by representing the H
amiltonian system as a symplectic map. This map (in general) has an in
finite Taylor series. In practice, we can compute only a finite number
of terms in this series. This gives rise to a truncated map approxima
tion of the original map. This truncated map is however not symplectic
and can lead to wrong stability results when iterated. In this paper,
following a generalization of the approach pioneered by Irwin (SSC Re
port No. 228, 1989), we factorize the map as a product of special maps
called ''jolt maps'' in such a manner that symplecticity is maintaine
d. (C) 1996 American Institute of Physics.