Forecasting time series
forecast is a generic function for forecasting from time series or time series models.
The function invokes particular methods which depend on the class of the first argument.
forecast(object,...) ## S3 method for class 'ts': forecast(object, h, level=c(80,95), fan=FALSE, ...)
- a time series or time series model for which forecasts are required
- Number of periods for forecasting
- Confidence level for prediction intervals.
- If TRUE, level is set to seq(50,99,by=1). This is suitable for fan plots.
- Additional arguments affecting the forecasts produced.
forecast.tspasses these to
stlfdepending on the frequency of the time
- An object of class "
summaryis used to obtain and print a summary of the results, while the function
plotproduces a plot of the forecasts and prediction intervals.
The generic accessor functions
residualsextract various useful features of the value returned by
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
objectitself or the time series used to create the model stored as
residuals Residuals from the fitted model. That is x minus fitted values. fitted Fitted values (one-step forecasts)