Re: fit parameter errors

Very helpful documentation.
Thank you so much Eddy,
Guy.

On Sat, 1 Jul 2006, Edmond Offermann wrote:

> Hi Guy,
>
> No, those who claim that parameter correlations are not taken into
> account
> when taking the diagonal elements of the error matrix are wrong !!
>
> You can read up on it by checking the "Minuit" documentation, in
> particular
> section 7.3.1, page 41 "Error Matrix" amd further on .
>
> Google for "Minuit documentation" and you will find for instance :
>
> http://hep.fi.infn.it/minuit.pdf
>
> Eddy
>
>
> --- Guy Roche <roche_at_in2p3.fr> wrote:
>
> > Dear Rooters,
> > I am frequently asked about the fit parameters errors given in
> > the statistics/fit info box. People claim that the correlations
> > in between parameters are not included in the parametors errors.
> > Is it right?
> > From the screen output of the fit parameters, it is not clear to
> > me whether the diogonal elements of the error matrix are the only
> > ones taken into account (thus meaning no correlation taken into
> > account).
> > Well, I was just looking into the TMinuit class, source file
> > section, seems to be the case.
> > Thanks for your help,
> > Guy.
> >
> >
> >
>
>
Received on Sun Jul 02 2006 - 09:36:58 MEST