Re: [ROOT] problem in TMath::BesselI

From: Rene Brun (Rene.Brun@cern.ch)
Date: Wed May 07 2003 - 18:07:19 MEST 

Hi Peter,

Thanks for reporting this oddity (mea culpa) introduced in the recent version.
Now fixed in CVS

Rene Brun

Peter Steinberg wrote:
> 
> hello -
> 
> in TMath::BesselI(Int_t n, Double_t x)
> 
> there is a line at the beginning of the function:
> 
> if (TMath::Abs(x) < kBigPositive) return 0;
> 
> this essentially renders the function useless for
> all practical applications, since in the n=0,1
> cases is simply uses TMath::BesselI0 and I1.
> 
> is this simply a bug?  can it be fixed?
> 
> thanks,
> peter
> 
> --
> Dr. Peter Steinberg
> 
> Fulbright Visting Professor
> Department of Physics, University of Cape Town, South Africa
> (currently on leave from Brookhaven National Laboratory, USA)
> 
> Office: +21 650 5091, Mobile: +83 426 9743 (+ = 011 27 from the US)
> Email: peter.steinberg@bnl.gov, Web: http://hep.phy.uct.ac.za/~steinber

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