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Re: NonlinearRegression

• To: mathgroup at smc.vnet.net
• Subject: [mg25104] Re: NonlinearRegression
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Sun, 10 Sep 2000 03:14:28 -0400 (EDT)
• Organization: Universitaet Leipzig
• References: <8p9kit$1rm@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

no, because NonlinearRegression[] use *unconstrained* nonlinear
optimization methods. Giving a range for x would turn the
problem into a constrained optimization problem and
Mathematica has no solver for it :-)

Regards
  Jens

David Pires wrote:
> 
> I want to fit my data with a function such as:
> f(x)=Sqrt(a-b*x), where a and b are the parameters I want to adjust and x
> is the variable. The problem is that there is only a given range of x for
> that f(x) has real values. When I use the NonlinearRegression (or
> NonlinearFit) command, Mathematica gives error messages and aborts the
> fitting process.
> 
> I'd like to know if someone knows how to set the range of x when using
> that command.
> Thanks.