lonlinear fitting

[Francesco Potorti`]

I looked around  a found an answer to  my previous  request for help  about
nonlinear leat-sqares fitting.  I found  it on the  mathworks site.  If you
go   under the contrib/stats directory,  you'll   find a few programas that
answer the question.  I found the programs under  the leasqr directory most
useful they implement a Levenberg-Marquardt algorithm -- which is described
in Numerical Recipes  as the "standard" algorithm  for nonlinear LS fitting
-- together with output regarding confidence intervals and so on.  I hacked
it a little  to make it  work under Octave, and it  seems it behaves  well,
even if  I do not understand  everything about it.   The changes are really
small, but anyway I can send the hacked source to anyone needing it.

It is not clear to me if this could become  part of the Octave distribution
because of copyright restrictions or things like that.  If yes, I volunteer
to clean up the source.

-- 
Francesco Potorti` (researcher)        Voice:    +39-050-593 203 (op. 211)
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