forecast (version 7.1)

naive: Naive forecasts

Description

naive() returns forecasts and prediction intervals for an ARIMA(0,1,0) random walk model applied to x. snaive() returns forecasts and prediction intervals from an ARIMA(0,0,0)(0,1,0)m model where m is the seasonal period.

Usage

naive(x, h=10, level=c(80,95), fan=FALSE, lambda=NULL)
snaive(x, h=2*frequency(x), level=c(80,95), fan=FALSE, lambda=NULL)

Arguments

x

a numeric vector or time series

h

Number of periods for forecasting

level

Confidence levels 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.

Value

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 naive or snaive.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. That is x minus fitted values.

fitted

Fitted values (one-step forecasts)

Details

These functions are simply convenient wrappers to Arima with the appropriate arguments to return naive and seasonal naive forecasts.

See Also

Arima, rwf

Examples

plot(naive(gold,h=50),include=200)
plot(snaive(wineind))