[ROOT] drawing points in variable-binsize histo

From: Paul Balm (r45@nikhef.nl)
Date: Mon Mar 10 2003 - 18:47:07 MET


Hello,

I think I found a problem using the drawing options "P HIST SAME" on a
TH1F with variable binsize.

The problem is that if you first draw such a histogram, and on the next
line draw it again with "P HIST SAME", the markers are not in the center
of the bin, but they appear to be above the center of the previous bin.
See the upper left plot in this canvas:
http://www.nikhef.nl/~r45/root/march2003/result.ps
I also used a few other drawing options: "L P HIST SAME" and "L P SAME"-
these work. I think the point is, I have to redraw the line in order to
get the points right, but I don't want to do that. I'll explain why
below this message since it's not important to the problem.

The macro that generated these plots is in this directory as well:
http://www.nikhef.nl/~r45/root/march2003/draw_problem_w_points.C
And the rootfile containing the histogram that it draws:
http://www.nikhef.nl/~r45/root/march2003/histos_bjpsiks_p13_tracking_aa_hidca.root

Thanks,

Paul Balm

---
Why I don't want to redraw the line: The problem I have is that I want 
to draw two histograms in one plot with a fill area created by the draw 
option "LF2", but this fill area obscures the markers of the histogram. 
So, I want to redraw the plots with only the markers. I have to use 
"hist" because I don't want the errors, but if I use "hist" and I use 
the "L" option, I lose the nice filling generated by "LF2".
Now that I think about it, I suppose I could clone the histogram, set 
the fill style of the clone to hollow and draw it with "L P HIST SAME".



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