Re: [ROOT] FixParameter ??

From: Rene Brun (Rene.Brun@cern.ch)
Date: Fri Jul 26 2002 - 23:24:30 MEST


Hi Ahmet,

See this short example. For more details, see doc
of TH1::Fit

{
   TF1 *f1 = new TF1("f1","gaus+pol1(3)",-3,3);
   f1->SetParameters(100,0,1,60,-8);
   TH1F *h = new TH1F("h","h",100,-3,3);
   h->FillRandom("f1",10000);

   f1->SetParLimits(2,1,1);
   h->Fit("f1","b");
}

Rene Brun


On Wed, 24 Jul 2002, Ahmet Sedat Ayan wrote:

> 
> Dear Rooters,
> I am trying to do a linear background + gaussian fit to my data and when
> force a fixed width (sigma) to the gaussian function 
> 
> with Fiffunction->FixParameter(par,value)
> 
> I am still getting the Sigma calculated NOT the value  I want that I want
> the fit function to use. 
> 
> Could anyone comment on that please? 
> 
> thanx a lot and cheers
> ahmet.
> 
> ***************
> 
> Ahmet Sedat Ayan		
> 
> Physics & Astronomy Dept.
> Van Allen Hall    
> University of Iowa
> Iowa City, IA, 52242
>   
> Voice      : (++ 1 319) 335-1941 (W) (GMT-6)      
> Occupation : Ph.D Candidate (But still dreamer!)	
> e-mail     : ayan@cms.physics.uiowa.edu
> web        : http://jazz.physics.uiowa.edu/~ayan
> 
> 



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