Forecasting Auto Sales
/*--------------------------------------------------------------
SAS Sample Library
Name: forex01.sas
Description: Example program from SAS/ETS User's Guide,
The FORECAST Procedure
Title: Forecasting Auto Sales
Product: SAS/ETS Software
Keys: time series forecasting
PROC: FORECAST
Notes:
--------------------------------------------------------------*/
title1 "Sales of Passenger Cars";
symbol1 i=spline v=dot;
axis2 label=(a=-90 r=90 "Vehicles and Parts" )
order=(6000 to 24000 by 3000);
title1 "Sales of Passenger Cars";
proc sgplot data=sashelp.usecon;
series x=date y=vehicles / markers;
xaxis values=('1jan80'd to '1jan92'd by year);
yaxis values=(6000 to 24000 by 3000);
format date year4.;
run;
proc forecast data=sashelp.usecon interval=month
method=winters seasons=month lead=12
out=out outfull outresid outest=est;
id date;
var vehicles;
where date >= '1jan80'd;
run;
title2 'The OUT= Data Set';
proc print data=out (obs=20) noobs;
run;
title2 'The OUTEST= Data Set: WINTERS Method';
proc print data=est;
run;
title1 "Sales of Passenger Cars";
title2 'Plot of Residuals';
proc sgplot data=out;
where _type_ = 'RESIDUAL';
needle x=date y=vehicles / markers markerattrs=(symbol=circlefilled);
xaxis values=('1jan80'd to '1jan92'd by year);
format date year4.;
run;
title1 "Sales of Passenger Cars";
title2 'Plot of Forecast from WINTERS Method';
proc sgplot data=out;
series x=date y=vehicles / group=_type_ lineattrs=(pattern=1);
where _type_ ^= 'RESIDUAL';
refline '15dec91'd / axis=x;
yaxis values=(9000 to 25000 by 1000);
xaxis values=('1jan90'd to '1jan93'd by qtr);
run;