It seems that is a bug. We will fix it soon.
Caixia
[email protected]
On Wed, 4 Aug 2004 [email protected] wrote:
> Dev,
>
> I was able to replicate this error. When looking at the log, the problem appears to be the call to -fron_p.Calc-
>
> ---------------------------------------------------------------------------------------
> log: C:\Documents and Settings\scott.merryman\Desktop\foo.smcl
> log type: text
> opened on: 4 Aug 2004, 06:57:42
>
> . predict te,te
> ------------------------------------------------------- begin predict ---
> <snip>
>
> ---------------------------------------------------- begin fron_p.Calc ---
> <snip>
>
> - else if "`e(het)'" == "uv" {
> = else if "uv" == "uv" {
> - tempvar xb_v sigma_v sigma_u
> - qui _predict double `xb_u' if `cond', xb eq(lnsig2u)
> = qui _predict double if __000000, xb eq(lnsig2u)
> too many variables specified
> qui gen double `sigma_u' = exp(0.5*`xb_u')
> qui _predict double `xb_v' if `cond', xb eq(lnsig2v)
> qui gen double `sigma_v' = exp(0.5*`xb_v')
> }
> }
>
>
> What believe is the problem is that xb_u temporary variable is not declared before the -_predict double `xb_u' ...-
>
> I have added xb_u to the tempvar line in -fron_p- and now it seems to work fine:
>
> . clear
>
> . use http://www.stata-press.com/data/r8/greene9.dta
>
> . encode state, gen(state_id)
>
> . qui frontier lnv lnk lnl , vhet(capital) uhet(state_id )
>
> . predict te,te
>
>
> Of course, it is unwise to alter offical Stata programs; hopefully there will be an offical update to this soon.
>
> Hope this helps,
> Scott
>
> ----- Original Message -----
> From: Dev Vencappa <[email protected]>
> Date: Wednesday, August 4, 2004 6:28 am
> Subject: st: predicting technical efficiency after frontier command: error message
>
> > >>
> > >>
> > Stata users,
> >
> > I am running the following command.
> >
> >
> > reg lnrev lntoen lncap lntech lndebt
> > mat X=e(b)
> > local a=el(X,1,1)
> > local b=el(X,1,2)
> > local c=el(X,1,3)
> > local d=el(X,1,4)
> > frontier lnrev lntoen lncap lntech lndebt, diff uhet(lnass dumfra-
> > dumother,noconstant) vhet(lnass dumfra-dumother,noconstant) /*
> > */from(lntoen=`a' lncap=`b' lntech=`c' lndebt=`d')
> > predict CDrev1,te
> >
> > I am getting my parameter estimates and everything else fine,
> > except for the predict command which gives the following error
> > message.
> > " too many variables specified
> > r(103); "
> >
> > I am basically modelling heteroscedasticity in both the one-sided
> > and two-sided error component. In contrast, when I model
> > heteroscedasticity in either one of them, then the predict command
> > works fine. I have read the manual and it does not say anything
> > about possible problems with predict, te when heteroscedasticity
> > is modelled for both error components.
> > Any explanation why this is happening?
> >
> > Many thanks
> > Dev
> >
>
>
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
