The aim of this work is to supply the necessary tools for an optimal c
hoice of initial values of the Taylor-integrator parameters, step size
, and order. The optimization in the first step is fundamental to the
future evolution of both the global error and the complexity of the al
gorithm. The local error in the Taylor approximation is controlled by
two methods for obtaining an accurate analytic expression for the loca
l error as a function of step size and order. (C) 1998 American Instit
ute of Physics.