Forecasts for intermittent demand using Croston's method
Returns forecasts and other information for Croston's forecasts applied to y.
croston(y, h=10, alpha=0.1, x=y)
- a numeric vector or time series
- Number of periods for forecasting.
- Value of alpha. Default value is 0.1.
- Deprecated. Included for backwards compatibility.
Based on Croston's (1972) method for intermittent demand
forecasting, also described in Shenstone and Hyndman (2005).
Croston's method involves using simple exponential smoothing (SES) on
the non-zero elements of the time series and a separate application
of SES to the times between non-zero elements of the time series. The
smoothing parameters of the two applications of SES are assumed to be
equal and are denoted by
Note that prediction intervals are not computed as Croston's method has no underlying stochastic model. The separate forecasts for the non-zero demands, and for the times between non-zero demands do have prediction intervals based on ETS(A,N,N) models.
An object of class
"forecast"is a list containing at least the following elements: is a list containing at least the following elements:The function
summaryis used to obtain and print a summary of the results, while the function
plotproduces a plot of the forecasts.The generic accessor functions
residualsextract useful features of the value returned by
crostonand associated functions.
Croston, J. (1972) "Forecasting and stock control for intermittent demands", Operational Research Quarterly, 23(3), 289-303.
Shenstone, L., and Hyndman, R.J. (2005) "Stochastic models underlying Croston's method for intermittent demand forecasting". Journal of Forecasting, 24, 389-402.
fcast <- croston(y) plot(fcast)