[ROOT] Bug in likelihood fitting?

From: Burt Holzman (bholzm1@uic.edu)
Date: Fri Apr 28 2000 - 19:49:00 MEST


Greetings Rootmeisters,

It seems that log-likelihood fitting is integerizing bin
contents before fitting.  Is this intended behavior?  

The following code snippet demonstrates the problem:
if the histogram is scaled by a factor of 10, the fit is
done correctly; otherwise, it fails to converge in MIGRAD.
This is ROOT 2.23/12.

{
TH1F* hist = new TH1F("hist", "hist", 5, 0, 5);
 TF1* func = new TF1("func", "[0] + [1]*x", 0,5);

hist->Fill(.5,.1); hist->Fill(1.5,.2); hist->Fill(2.5,.3);
hist->Fill(3.5,.4); hist->Fill(4.5,.5);

// hist->Scale(10.);
hist->Fit("func", "VL");
}



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