说明：  Cosinor analysis uses the least squares method to fit a sine wave to a time series. Cosinor analysis is often used in the analysis of biologic time series that demonstrate predictible rhythms. This method can be used with an unequally spaced time series. Follows cosinor analysis of a time series as outlined by Nelson et al. Methods for Cosinor-Rhythmometry Chronobiologica. 1979. Please consult reference.