periodic regression model

[MarcTC]

Does SAS have any statistical procedures for doing periodic regression?

An example:
http://www.cdc.gov/flu/weekly/weeklyarchives2010-2011/images/picurve22.gif

[Doc_Duke]

There are several tools to address cyclic variability. Try this Google search

cyclic variability regression site:sas.com

Doc Muhlbaier
Duke