Many chaotic time series are the observations of some continuous dynamical systems, especially differential dynamical systems. For a differential system, the phase space furnishes the observed value and its derivative to order m − 1, where m is the embedding dimension.-Many chaotic time series are the observations of some continuous dynamical systems, especially differential dynamical systems.　For a differential system, the phase space furnishes the observed value and its derivative to order m −　1, where m is the embedding dimension.