how to get the precise mean value of data in a bin ?

Hi rooters,

I am trying to get mean values of data in different bins but meet some problems.

Is there any function like TH1F::GetBinMean(ibin) ?

Learning from TH1::GetMean(), I find a way to do so, but as you can see, the result is wrong.

root [0] h=new TH1F("h","",2,0,2)
(class TH1F*)0x9cfdab8

root [1] h->Fill(0.25)
(Int_t)1

root [2] a=h->GetXaxis()
(const class TAxis*)0x9cfdaf8

root [3] a->SetRange(1,1)
root [4] Double_t stats[4]
root [5] h->GetStats(stats)
root [6] Double_t mean=stats[2]/stats[0]
root [7] mean


(Double_t)5.00000000000000000e-01

 I have been looking in the ROOT reference guide, and I noticed that the TH1 and its
inheritance do NOT record individual data values, NOR their sum in each bin when Fill()
is called. So it is impossible to get the true mean values in bins, right?

If so, is something going to be done for improvement? If no, how to get the precise mean values in bins?

Thanks a lot !

Ciao~
Xianguo

-- 
Take flight into the sky, beyond the moon, beyond my mind.

Xianguo LU
Physics Department, Peking University
Beijing, China
Tel: 0086-10-62753888(o)