Prev: Struggling to resolve an important data problem in SAS....please help.
Next: How to get contional observation?
From: Ergin Erdem on 8 Aug 2010 23:37 Hi all, I am trying to run a ARMA+GARCH model for modeling the wind speed and my code is follows; - - -------------------------------------------------------------------------------------------------------------------------------------------------- proc model data = Erman; parms ar1 ar2 ma1 ma2 ma3 mu arch0 arch1 garch1; y = mu + ar1 * zlag1(y - mu) + ar2 * zlag2(y-mu)+ ma1 * zlag1(resid.y)+ ma2 * zlag2(resid.y) + ma3 * zlag3(resid.y); h.y = arch0 + arch1 * xlag(resid.y ** 2, mse.y) + garch1 * xlag(h.y, mse.y); spredict=pred.y; vsgarch=h.y; fit y / method = marquardt fiml out = forecast outresid; outvars vsgarch spredict; bounds arch0>=0; bounds garch1>=0; bounds arch1>=0; run; -------------------------------------------------------------------------------------------------------------------------------------------------------- I am able to print the h.y values. The question is how those values are calculated based on the available data? As far as I understand, the SAS runs a regression model to find the parameters for arch0, arch1, and garch1 based on h.y values, I am wondering how the h.y values are calculated for running those regression equation, if anybody can provide me an equation for calculating that value (h.y), it would be great. Thank you very much for your interest. Have a nice day. Regards ErgIn |