Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: boundary constraints within nl


From   Marc Keuschnigg <Marc.Keuschnigg@soziologie.uni-muenchen.de>
To   statalist@hsphsun2.harvard.edu
Subject   st: boundary constraints within nl
Date   Fri, 06 Jun 2008 19:22:53 +0200

Hey,

I am estimating non linear least squares models (nl) using equations like: nl (y = ({a}+{b}* x) * (1-x)).
My question is, how do I impose parameter restrictions like a >=0 and b >=0?
I could log-transform the parameters, but I don't know how to do it technically within the nl command.

Thanks for helping,
Marc



*
* 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/




© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index