Re: [ROOT] Fits in ROOT

From: Rene Brun (Rene.Brun@cern.ch)
Date: Tue Apr 11 2000 - 17:09:10 MEST


Hi Pascal,
This problem had already been reported by Marco van Leeuwen and fixed
in version 2.24/02. See release notes. (here is the extract)
- Many thanks to Marco van Leeuwen for reporting a problem with 
TGraph::Fit  when fitting with a polynomial. The problem has been fixed in
TGraph::LeastSquareFit. The last data point was ignored by this function 
computing the initial  value of parameters.

Rene Brun

On Tue, 11 Apr 2000, Pascal Perrodo wrote:

> 
> Hi rooters,
> 
> I have problem doing fits using Minuit in Root. You can find attached in
> this mail two examples where a simple polynomial is fitted to points into 
> a TGraphErrors plot.
> 
> The problem is that this fits don't converge all the time even with a low
> degree polynomials (degree 2).
> 
> Do you see any explanation ?
> 
> Thanks in advance.
> Cheers.
>                              Pascal Perrodo.
> 
> +-------------------------------------------------------------------------+
> | Tel : 04 50 09 16 32 (from France), 00 33 4 50 09 16 32 (from abroad)   | 
> | FAX : 04 50 27 94 95 (from France), 00 33 4 50 27 94 95 (from abroad)   |
> |						    		   	  |
> | LAPP, Chemin de Bellevue, BP 110, F-74941 Annecy-le-Vieux CEDEX         |
> +-------------------------------------------------------------------------+
> 



This archive was generated by hypermail 2b29 : Tue Jan 02 2001 - 11:50:23 MET