st: Calling -ml- program with more than one equation!

[Peter Grand <grand@ihs.ac.at>]

Dear Statauser!

Maybe that is a dumb question. I have written a conditional logit ml program, which works fine when I call it as follows:

ml model d0 myclog (Eq1: vote_choice_eu=u_pr_eu pid, nocons) ;

However, if I call it with 

ml model d0 myclog (Eq1: vote_choice_eu=u_pr_eu pid, nocons) ();

I get the error message:

`could not calculate numerical derivatives -- discontinuous region with missing values encountered'

Does anyone know what happens if I call a d0 program with extra parenthesis, but do not add a second equation with mleval?

Thank you very much for your help!

Best,

Peter Grand

****************************************************************
program myclog ;
args todo b lnf ;
tempvar denom p xb ;
local by $MY_panel ;
mleval `xb' = `b', eq(1) ;
qui { ;
egen double `denom' = sum(exp(`xb')), by(`by') ;
gen double `p' = exp(`xb')/`denom' ;
mlsum `lnf' = $ML_y1*ln(`p') if $ML_y1==1 ;
if (`todo'==0 | `lnf'>=.) exit ;
} ;
end ;
****************************************************************

Peter Grand
grand(at)ihs.ac.at
Institute for Advanced Studies
Stumpergasse 56
1060 Vienna

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/