detrend function

Detrend a Time Series

Returns a time series with the trend removed. The trend can be estimated using polynomial regression or using a lowess fit.

detrend(series, order = 1, lowess = FALSE, lowspan = 2/3)

Arguments

• series: The time series to be detrended.
• order: Order of the polynomial used to estimate the trend with a linear default (order=1) unless lowess is TRUE.
• lowess: If TRUE, lowess is used to find the trend. The default is FALSE.
• lowspan: The smoother span used for lowess.

Returns

The detrended series is returned.

References

You can find demonstrations of astsa capabilities at FUN WITH ASTSA.

The most recent version of the package can be found at https://github.com/nickpoison/astsa/.

In addition, the News and ChangeLog files are at https://github.com/nickpoison/astsa/blob/master/NEWS.md.

The webpages for the texts and some help on using R for time series analysis can be found at https://nickpoison.github.io/.

Author(s)

D.S. Stoffer

Examples

tsplot( cbind(salmon, detrend(salmon)), gg=TRUE, main='Norwegian Salmon USD/KG' )

See Also

trend