Error bars in macro

ROOT
1

Hi,

I ma trying to draw a variable from the same file and tree but with different cuts of other variable in order to study the systematic uncertainty in the shape of the distribution. i have plotted all the histograms on top of each others plus the plot of the variable without any cut. i did a small macro to do this but i couldn’t draw the error bars. i am attaching the plot i produced and the macro when i added the option “E SAME” and the error bars reached the lower edge which i think it is correct.

thanks,

Mai

16%20AM
Screen Shot 2019-08-16 at 7.51.16 AM.png1390×950 27.1 KB
hstack_slicesf51_dEdX.C (3.4 KB)

_ROOT Version: 5.34/38
Platform: Not Provided
Compiler: Not Provided

2

At least, right after you create histograms:

h1->Sumw2(kTRUE);
h2->Sumw2(kTRUE);
h3->Sumw2(kTRUE);
h4->Sumw2(kTRUE);
h5->Sumw2(kTRUE);
h6->Sumw2(kTRUE);
3

18%20PM
Screen Shot 2019-08-16 at 5.28.18 PM.png1324×928 6.13 KB
55%20PM
Screen Shot 2019-08-16 at 5.27.55 PM.png1296×914 7.57 KB

Hello,

Thanks, now it is getting better … but when i removed the Y log scale it becomes better , is that mean that this behavior (to reach the x axis ) is related to the log scale???

thanks,

Mai

4

Your Y axis has negative minium, and log of something negative
is undefined.
May be try to set the minimum of the histogram to something positive.