SetMarkerStyle(20) Draw("p") problem

ROOT
1

Hi,
I’m trying to draw a histogram with symbols. I’ve done this for years, but I can’t get the attached code to work. When I use the Draw(“p”) option, I get no symbols, but rather a line drawn between the histogram bins.
Thanks
Ken
sorted.ps (16.5 KB)
sorted_pic1.C (423 Bytes)

2

For your first call use option “ap” instead of "p"
Option “a” computes the range and draw the axis.

Rene

3

Hi Rene,
the “ap” option did not change the line problem. But I played around with it some more and found that symbols will draw if I lower the number of bins in the histogram. If I use too many bins, the symbols seem to get drawn as points with a line between them. See attached.
btw, thanks for all the help
sorted_pic1.C (614 Bytes)
sorted.ps (14.6 KB)

4

When drawing a histogram with more bins than the number of pixels on your screen, ROOT switches automatically in low/fast resolution mode.
Why do you use histograms with so many bins where only a tiny fraction is filled? You should use a TGraph instead.

Rene

5

OK, thanks Rene, mystery solved. You are correct, I am being lazy and using a histogram to plot points. Never hit this limit before.
Thanks
Ken