The VAR statement specifies the variables in the input data set
to model and forecast.
The VAR statement also specifies differencing of the input variables.
The VAR statement is required.
- VAR variable (difference, difference, ... ) ... ;
Differencing is specified by following the variable name
with a list of difference periods separated by commas.
See the section "Stationarity and Differencing" for more
information on differencing of input variables.
The order in which variables are listed in the VAR statement
controls the order in which variables are included in the state vector.
Usually, potential inputs should be listed before potential outputs.
For example, assuming the input data are monthly,
the following VAR statement specifies modeling and forecasting
of the one period and seasonal second difference of X and Y:
var x(1,12) y(1,12);
In this example, the vector time series analyzed is
where B represents the back shift operator,
and and represent
the means of the differenced series.
If the NOCENTER option is specified the mean differences are not subtracted.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.