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

## 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. If

`lambda="auto"`

, then a transformation is automatically selected using`BoxCox.lambda`

. The transformation is ignored if NULL. Otherwise, data transformed before model is estimated.- biasadj
Use adjusted back-transformed mean for Box-Cox transformations. If transformed data is used to produce forecasts and fitted values, a regular back transformation will result in median forecasts. If biasadj is TRUE, an adjustment will be made to produce mean forecasts and fitted values.

- ...
Other arguments.

## 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:

- model
A list containing information about the fitted model

- method
The name of the forecasting method as a character string

- mean
Point forecasts as a time series

- lower
Lower limits for prediction intervals

- upper
Upper limits for prediction intervals

- level
The confidence values associated with the prediction intervals

- x
The original time series (either

`object`

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

).- residuals
Residuals from the fitted model.

- fitted
Fitted values (one-step forecasts)

## 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`

.

## Examples

```
fit <- HoltWinters(WWWusage,gamma=FALSE)
plot(forecast(fit))
```