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Re: nonlinear fit with weights
- From: Brian Gough <bjg at network-theory dot co dot uk>
- To: M Atakan Gurkan <ato at northwestern dot edu>
- Cc: GSL Discussion List <gsl-discuss at sources dot redhat dot com>
- Date: Wed, 12 Nov 2003 13:38:08 +0000
- Subject: Re: nonlinear fit with weights
- References: <20031111154745.A28663@chinook.phys.northwestern.edu>
M Atakan Gurkan writes:
> I am trying to use the nonlinear multifit functions in GSL with a
> weight. Different points in my data set has different error bars
> and I would like to use this information while making the fit. I
> basically copied and modified the example from the manual, then I
> set values of sigma[] to reflect my error bars. However the only
> effect of changing sigma was to change the error estimates in the
> fit, it did not change the fit itself. I think I am doing
> something completely wrong. I read the manual, but could not find
> anything that looks helpful. Is it possible at all to use different
> weights for different data points (as in, e.g., xmgrace)? And if
> so, how?
The gsl_multifit_fdf routines have been tested against the NIST
standard reference datasets, which use variable weights (see
multifit/test*.c for examples). So I think that GSL itself is ok.
--
Brian Gough