Trouble with displaying scatter plots

Newbie
1

Dear ROOTers,
I am having difficulty displaying a scatter plot for my analysis. I have attached a couple of canvases, one displaying the default scatter and the other displaying the same scatter plot with the “box” option. The x axis values have a cut at 25, so no events should be observed below that ( as displayed by the box plot), but the normal scatter plot shows that there are. If I zoom into the X axis (say from 0 to 20) they disappear! If I choose to create a profile along X, there are no bins below 25, as expected… Moreover, when I try to save the normal scatter plot into PDF, the resulting file is ~15MB and is almost completely covered in black. Does anyone know what is causing this? I am using version “6.12/06”.
Thank you,
Vangelis
Box_scatter.root (98.2 KB)
Normal_scatter.root (98.2 KB)file_with_histo.root (93.2 KB)

2

instead of canvases, can you provide the histogram in a ROOT file ?

3

Thank you for your reply, I attached the file I took the histogram from.

4

I see. Your histogram has negative bins and the SCAT option cannot not dealing with them properly (it draws the random markers in bins according the absolute value of the contain). The option is not ideal for histo with negative bins. I would recommend BOX or COL1 … also the LEGO option in 3D.

5

if you do not care about the negative bins you can set the minimum value to 0:

root [2] a_scatter_plot_1->GetMinimum()
(double) -1.1883184
root [3]  a_scatter_plot_1->SetMinimum(0.)
root [4] a_scatter_plot_1->Draw()
6

Thank you very much for your reply!