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Re: gaussfit question
- Subject: Re: gaussfit question
- From: davidf(at)dfanning.com (David Fanning)
- Date: Fri, 29 Oct 1999 09:19:03 -0600
- Newsgroups: comp.lang.idl-pvwave
- Organization: Fanning Software Consulting
- References: <firstname.lastname@example.org>
- Xref: news.doit.wisc.edu comp.lang.idl-pvwave:16991
Mirko (email@example.com) writes:
> I have a 2D dataset representing a surface (intensity plot of x-ray
> scattering data)
> and i like to fit these data with GAUSS2DFIT() function which does not work.
> So I tried to fit one line of the dataset wit GAUSSFIT which does not
> work either.
> This it is confusing to me because other math computer programs
> have no problem with this simple curve.
> Is there something I have to consider?
> IDL> y=[52.0,52.7,56.0,60.9,65.40,71.40, 75.20,
> 101.3,97.2,92.1,87.4,87.0,82.5,77.4,69.9,67.7, 62.1, 58.9, 53.4,53.8]
> IDL> x=findgen(37)
> IDL> yfit=gaussfit(x,y,a)
> % Compiled module: GAUSSFIT.
> % Compiled module: POLY_FIT.
> % Compiled module: CURVEFIT.
> % Program caused arithmetic error: Floating underflow
I don't see anything here to indicate that GAUSSFIT
didn't *work*. I see it produced a value very near
zero, which is hard to store on a computer, and so
produced a warning. (Which I very much wish RSI would
turn off. No other single thing causes so much
unnecessary anguish as this warning message!)
Why don't you continue on a bit and see if you
get the result you expect.
David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: firstname.lastname@example.org
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155