Re: st: Nonlinear constraints in -ml- programming

[Gordon Hughes <G.A.Hughes@ed.ac.uk>]

As you have stated the problem, you should rewrite the model so that 
it specified in terms of the parameters: beta, gamma, eta_j and 
lambda where lambda is the constant ratio of delta_j/eta_j and then 
use -nl- for non-linear least squares.  It is always best to 
substitute out constraints if you can do that.

However, I suspect that you might have something else in mind.  Do 
you really want to test whether the ratios delta_j/eta_j are constant 
over j?  In that case, your question is not really about constraints 
but about testing a set of non-linear hypotheses and you need to 
consider -testnl- or other test procedures.

Gordon Hughes
g.a.hughes@ed.ac.uk
 

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