Hello,

I create 2D histograms and then look at the statistic with

cout<GetEntries()<<" photons detected"<<endl;

cout<<"Mean x = "<ProjectionX()->GetMean()<<endl;

cout<<"Mean y = "<ProjectionY()->GetMean()<<endl;

cout<<"RMS x = "<ProjectionX()->GetRMS()<<endl;

cout<<"RMS y = "<ProjectionY()->GetRMS()<<endl;

The problem is that a typical output

1220 photons detected

Mean x = -0.0697131

Mean y = 0.0266393

RMS x = 1.79072

RMS y = 1.7959

is different from the label of that histogram in a rootfile, which state

Entries 1220

Mean x -0.07061

Mean y 0.02715

RMS x 1.791

RMS y 1.796

(see attachment)

The differences are tiny but still…

What is the problem?

Thanks

Philippe