Re: [Help-gsl] subscribe

[Max Belushkin]

Ah, I see. Well, unless there's some clever way of numerically computing 
the gradient of that, I'd go with James' suggestion and use a simplex 
method...

address@hidden wrote:
> My model function is attached in a dvi file to this email. I am completely
> not sure what do you mean by (.... the actual function you're "fitting"
> doesn't matter, since chi squared is a sum over the whole range(s) of the
> squares of the function values minus the data bin (i.e. experimental
> data)....). Can you clarify,please?  Any library that I try to use
> invloves derivatives, abut I don't know the derivatives of my histogram
> par of the functiont?!
> Thank you for your response.
> Hassan
>
>
>
> >      I'm not sure I understand what you're trying to do 100%, but,
> > generally, for any regression, you choose a function to minimize - i.e.
> > chi squared. That takes some parameters over which you're minimizing,
> > and, if one is lucky, is continuous in those parameters - then you need
> > to take the derivatives in parameters, the actual function you're
> > "fitting" doesn't matter, since chi squared is a sum over the whole
> > range(s) of the squares of the function values minus the data bin (i.e.
> > experimental data). Well, I lost the experimental errors in there.
> >
> >    So, how are you composing your function to be minimized? Is it
> > somehow  discretized in terms of the parameters?
> >
> >    I think a bit more information on how you're trying to get to the end
> > result would be helpful.
> >
> > address@hidden wrote:
> > > Hello,
> > > I was looking for a non-linear fitting algorithm, and the manual only
> > > covers Algorithms with Derivatives, but unfortunatly this does not apply
> > > for code as I have a histogram convolved with a Gaussian as my fitting
> > > function. Is there any Algorithm without Derivatives that I may use in
> > > GSL, and if not what other software that maight be helpful, knowing that
> > > I
> > > only program in C. Thank you in advance for your response.
> > > Sincerely,
> > > Hassan
> > > ----------------------------------------------
> > > Hassan Saadaoui,
> > > PhD candidate,
> > > TRIUMF
> > > 4004 Wesbrook Mall
> > > Vancouver, B.C.
> > > Canada V6T 2A3
> > > 1-604-222-1047, ext. 6194
> > > ----------------------------------------------
> > >
> > >
> > >
> > > _______________________________________________
> > > Help-gsl mailing list
> > > address@hidden
> > > http://lists.gnu.org/mailman/listinfo/help-gsl
>
>
> Sincerely,
> Hassan
>
> ----------------------------------------------
> Hassan Saadaoui
> TRIUMF
> 4004 Wesbrook Mall
> Vancouver, B.C.
> Canada V6T 2A3
> 1-604-222-1047, ext. 6194
> ----------------------------------------------