R package to run seasonal analyses in time series. For details see our book “Analysing Seasonal Health Data” (2010) https://www.springer.com/gp/book/9783642107474.
Useful functions are: * casecross for case-crossover
analysis * nscosinor to estimate non-stationary seasonal
patterns using the Kalman filter * nonlintest for a time
domain test of non-linearity