  A general stability analysis is presented for the determination of the
transition from incoherent to coherent behavior in an ensemble of globally
coupled, heterogeneous, continuous-time dynamical systems. The formalism allows
for the simultaneous presence of ensemble members exhibiting chaotic and
periodic behavior, and, in a special case, yields the Kuramoto model for
globally coupled periodic oscillators described by a phase. Numerical
experiments using different types of ensembles of Lorenz equations with a
distribution of parameters are presented.
