Empty graph with draw option "F"

[diboye]

Dear All sorry if this is trivial,
Does someone know why I have an empty graph if I use option F for drawing ?
Thanks in advance.
PS: the code can be run just by doing: root -l Efficiency.C
Cheers,
Diallo
AtlasStyle.h (388 Bytes)
Efficiency.C (11.1 KB)

---

_ROOT Version: 6.12/06

---

[Wile_E_Coyote]

Try: gr_eff_Prim_Vert_4e->Draw("ALF");

[diboye]

Hi,
Thanks for replying, gr_eff_Prim_Vert_4e->Draw(“ALF”); doesn’t work neither, it just draws a line where I want to have a filled area.
Does it work for you ?
Cheers,
Diallo.

[Wile_E_Coyote]

All your points have the same “y coordinate” so you get a straight line (i.e. the area is “empty”).

[diboye]

Hi,
I am not sure that’s related to the fact that the points are equals, for instance if I draw this:

gr_eff_trigger_4e->Draw("ALF");

(by using the same option) I don’t have a straight line anymore but the area under the line is still empty.
Cheers,
Diallo.

[Wile_E_Coyote]

You misunderstand the meaning of the “F” option. Try another graph which has different “x” and “y” points’ coordinates.

[diboye]

Hi,
I tried another graph in my previous message.
I used to use draw option “F” with histograms and it always works, or maybe I am mistaken but this example is what I am expected to have.

Cheers,
Diallo.

[diboye]

I think you are right about the meaning of option “F”, it doesn’t work as in histogram, for instance for different x, and y and by changed the color (this is what I missed in the message where I changed graph, otherwise it will be white by default and then invisible) it works but differently as I expected in the plot I attached.
So I still don’t know then how to reproduce this kind of plot I attached ?
Cheers,
Diallo.

[Wile_E_Coyote]

You must make sure that the first and the last points of your graphs have y = 0 (if necessary, add two such points, the first one with x = xmin and the last one with x = xmax).

[diboye]

Hi,
Thanks very much, that works
Cheers,
Diallo