Basic question about Statistics Box for TH2

ROOT
1

Greetings,

In the statistics box for a TH2, what exactly are the numbers in the 3x3 array? Something about underflow and overflow values, I imagine, but I can’t figure it out exactly.

I’m sorry for such a basic question, but I did look through the various doc and did not find a answer.

Pic p1 is a (un-zoomed) histogram, and shows the statistics values.
[attachment=2]p1.jpg[/attachment]

Pic p2 is after clicking the mouse once, approximately near the origin.
Why did the number 1083 show up in the stats box?
[attachment=1]p2.jpg[/attachment]

Pic p3 is zoomed in on both x and y. What does the -38 value in the stats box mean?
[attachment=0]p3.jpg[/attachment]

thanks,
buddy

p3.jpg952×380 52.8 KB


p2.jpg951×418 42.9 KB


p1.jpg995×429 46.5 KB

2

Hi,

[quote=“mrsoft99”]
In the statistics box for a TH2, what exactly are the numbers in the 3x3 array?[/quote]

these are underflow and overflow indeed. Imagine your distribution area is in central cell. So central cell shows number of entries you actually see. The one on the left (column 1, second line) - how many entries are in the exact the same Y range as your distribution you see and X range from -inf up to your Xmin. And so on. E.g., (column 3, third line) represents number of entries that are in the area: X: (Xmax; +inf), Y: (-inf,Ymin)