Re: TGraph fitting bug

From: Rene Brun (Rene.Brun@cern.ch)
Date: Fri Oct 16 1998 - 19:26:34 MEST


Pavol Strizenec wrote:
> 
>   Dear Rooters,
> 
>   I would like to report small bug in fitting the graph.
> If one have the constant in the graph, and try to fit with first
> order polynomial, result is floating point exception.
> Let's try the following macro:
> 
> {
> gROOT->Reset();
> 
> Float_t a[5]={1,2,3,4,5};
> Float_t b[5]={0.5,0.5,0.5,0.5,0.5};
> 
> TGraph *test = new TGraph(5,a,b);
> 
> test->Fit("pol1");
> }
> 
> with other functions (e.g. gauss) all works normaly. The same is true
> for constant histogram.
> 
>  I am working with Root v. 2.00/12, on Alpha/Unix with DEC/CXX compiler.
> 

Thanks for reporting this simple case. Now fixed in my dev version.

Rene Brun



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