Removes seasonal components from a time series. It uses autocorrelation to identify the periods of dominant seasonal components, then subtracts the seasonal average from each point to yield a series of the seasonal residuals. Because of the autocorrelation step it is recommended that the series be de-trended first using "/TimeSeries/LinearDetrend" as a linear trend may result in undesirable autocorrelation artifacts. For instance, it has been observed in test cases that removing seasonality from series with a noticeable linear trend and non-zero mean yields a series in which almost all entries are zero, except for points at the beginning and end.

There are two options, "givenPeriod" and "topNPeriods". Calling [[series],k,"givenPeriod"] subtracts from each point it's period length k seasonal average, removing a seasonal trend with period k. [[series],k,"topNPeriods"] removes the top k strongest seasonal trends as identified by autocorrelation. Calling the algorithm with just the series means the default option, e.g. removing only the strongest seasonal pattern, will be used.