# forecast.HoltWinters

##### Forecasting using Holt-Winters objects

Returns forecasts and other information for univariate Holt-Winters time series models.

- Keywords
- ts

##### Usage

```
# S3 method for HoltWinters
forecast(object, h = ifelse(frequency(object$x) > 1, 2 *
frequency(object$x), 10), level = c(80, 95), fan = FALSE, lambda = NULL,
biasadj = NULL, ...)
```

##### Arguments

- object
An object of class "

`HoltWinters`

". Usually the result of a call to`HoltWinters`

.- h
Number of periods for forecasting

- level
Confidence level for prediction intervals.

- fan
If TRUE, level is set to seq(51,99,by=3). This is suitable for fan plots.

- lambda
Box-Cox transformation parameter. Ignored if NULL. Otherwise, forecasts back-transformed via an inverse Box-Cox transformation.

- biasadj
Use adjusted back-transformed mean for Box-Cox transformations. If TRUE, point forecasts and fitted values are mean forecast. Otherwise, these points can be considered the median of the forecast densities.

- ...
Other arguments.

##### Details

This function calls `predict.HoltWinters`

and constructs
an object of class "`forecast`

" from the results.

It is included for completeness, but the `ets`

is recommended
for use instead of `HoltWinters`

.

##### Value

An object of class "`forecast`

".

The function `summary`

is used to obtain and print a summary of the
results, while the function `plot`

produces a plot of the forecasts and
prediction intervals.

The generic accessor functions `fitted.values`

and `residuals`

extract useful features of the value returned by
`forecast.HoltWinters`

.

An object of class `"forecast"`

is a list containing at least the
following elements:

A list containing information about the fitted model

The name of the forecasting method as a character string

Point forecasts as a time series

Lower limits for prediction intervals

Upper limits for prediction intervals

The confidence values associated with the prediction intervals

The original time series
(either `object`

itself or the time series used to create the model
stored as `object`

).

Residuals from the fitted model.

Fitted values (one-step forecasts)

##### See Also

##### Examples

```
# NOT RUN {
fit <- HoltWinters(WWWusage,gamma=FALSE)
plot(forecast(fit))
# }
```

*Documentation reproduced from package forecast, version 8.1, License: GPL (>= 3)*