Could someone help me understand the codes?

Newbie
1

Here are the codes:

TCanvas *c=new TCanvas(c,name,600,600);
TH2F *histo2=new TH2F(histo2,name,20,0,20,20,0,20);
TF2 *dist=new TF2(dist,[0]+[1]*x+[2]*y,0,20,0,20);
dist->SetParameters(1,0,0);
histo2->FillRandom(dist,40000);
histo2->SetMinimum(0);
histo2->Draw(LEGO2);

the output was saved as an image attached. How can I understand the value of each bar? why the mean x is almost 10?

Screenshot from 2024-10-25 10-38-01
Screenshot from 2024-10-25 10-38-01974×881 28.3 KB

Thanks for your help.

ROOT Version: 6.32
_Platform: Ubuntu
_Compiler:_g++

W

2

Hi,
TH2F is a histogram the mean x it is an mean value of value x in the histogram.
I suppose that you expected to get ~110, but this is not a mean x but an average number of entries per bin - something what is on Z axis.