R: Common exogenous regressors

common_xregs {fable} | R Documentation

## Common exogenous regressors

### Description

These special functions provide interfaces to more complicated functions within the model formulae interface.

### Usage

    common_xregs

### Specials

#### trend

The `trend` special includes common linear trend regressors in the model. It also supports piecewise linear trend via the `knots` argument.

    trend(knots = NULL, origin = NULL)

`knots` | A vector of times (same class as the data's time index) identifying the position of knots for a piecewise linear trend.
`origin` | An optional time value to act as the starting time for the trend.

#### season

The `season` special includes seasonal dummy variables in the model.

    season(period = NULL)

`period` | The periodic nature of the seasonality. This can be either a number indicating the number of observations in each seasonal period, or text to indicate the duration of the seasonal window (for example, annual seasonality would be "1 year").

#### fourier

The `fourier` special includes seasonal fourier terms in the model. The maximum order of the fourier terms must be specified using `K`.

    fourier(period = NULL, K, origin = NULL)

`period` | The periodic nature of the seasonality. This can be either a number indicating the number of observations in each seasonal period, or text to indicate the duration of the seasonal window (for example, annual seasonality would be "1 year").
`K` | The maximum order of the fourier terms.
`origin` | An optional time value to act as the starting time for the fourier series.

[Package fable version 0.3.0 Index]