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Topic: Start Curve Fitting Tool GUI with initial guesses and bounds already entered
Replies: 3   Last Post: Jun 26, 2012 11:47 AM

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Frank

Posts: 115
Registered: 12/27/07
Re: Start Curve Fitting Tool GUI with initial guesses and bounds already entered
Posted: Jun 25, 2012 4:24 PM
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"Eli" wrote in message <jsaalj$cb2$1@newscl01ah.mathworks.com>...
> I'm still interested in getting help for this. I have tried but can't get this to work.
>
> If you could offer some help or re-direct me to another sub-forum/newsgroup that would be really helpful.


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It might be easier if, instead of the GUI, you used programmatic curve-fitting such as 'lsqnonlin', 'lsqcurvefit' or one of the others that allow parameter bounds. (Unless I overlooked something in the documentation, 'NonLinearModel.fit' and 'nlinfit' don't allow parameter bounds.)

The problem I (and perhaps others) have in responding to your question is that you stated:

'QUESTION:
Is there some way that I can specify the custom fitting equation, initial guesses, lower and upper bounds from the command line similar to how I specified the exclusion range?'

and then:

'NOTE: I do not want to perform command line curve fitting.'

So I'm not sure what you actually want to do. Programmatic curve-fitting (from a script, not the command line) is easy enough and will do what you want, even if it's not quite as straightforward as using the GUI. I've only done programatic curve-fitting and haven't had any problems with it.

Your use of 'Inf' and '-Inf' in your bounds also makes me a bit queasy. Why not '1E+100' and '-1E+100' or some such instead? It would achieve the same essential effect and wouldn't produce an unbounded or undefined result if your objective function wandered off into the wilderness.



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