Doubt about the number o bins in SetLineAttributes

ROOT
1

Hi,

I’m new in ROOT.
I notice something “weird” in the graphics.
I right click on a graphic and then click in the option ‘SetLineAttributes’, so I go to tab ‘Binning’. In ‘Rebin’ option when a change the numbers of bins, the ‘y’ axis values change, why?

For example, when a change the number of bins from 100 to 200, the maximum point in the ‘y’ axis drops by half (i.e., from 450 to 230).

In my understanding, the ‘y’ axis values could not be changed, because when I change the numbers of bins, I’m only changing the number of divisions in ‘x’ axis, right?

Can anyone help me to understand what is happening?

Thank you!

2

Each bin is like a container with e.g. 10 balls. If you divide 1 container in 2 subcontainers, then there are just 5 balls in each subcontainer. Note that in a histogram you are “counting” events on the bins (containers) of the horizontal axis. It is not an x-y graph where you can add interpolating points in the middle of two points!

Anyway, you can always rescale later your histogram with the Scale(2) function.

3

Hi,
Thank you for your reply!