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st: Maximum likelihood convergence

Subject   st: Maximum likelihood convergence
Date   Fri, 07 May 2004 10:48:36 -0700

Hi all, 

I am running a maximum likelihood program (method lf) and I
am having
problems achieving convergence. The model passes all the
tests of ml check
but then when I use ml max (or ml max, difficult) it stops
and gives the
following message "could not calculate numerical derivatives
missing values
encountered". In my program when I use generate I specify
double as recommended by Gould and Sribney, but that isn't
solving the problem. 

I have tried changing ltol and tol but that doesn't help. I
have also
specified the initial values but that doesn't work either. 

Any advice will be highly appreciated. 

Thanks in advance

Alejandro Lopez-Feldman
Ph.D. Candidate
Agricultural and Resource Economics
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