Setting zero for bar graphs (log plots not looking right)

ROOT
1

I’m plotting a histrogram on a logy scale. It’s a bar graph, so the bars begin at “zero,” which is 1 on the log plot. How can I make them begin at logy=0… or at least something small enough that it looks like 0… instead of 1?

Thanks,
Jennifer

100MeV_6600_sei.gif963×675 25.7 KB

2

Set the histogram minimum to something small but positive. For instance 0.001.

3

Do I need to do this early? I tried adding it right before I plot it, but it didn’t work. Here’s the bit of code:

c1->cd(1);
promptScintEnergyHisto->SetXTitle(“MeV”);
promptScintEnergyHisto->SetFillColor(4);
promptScintEnergyHisto->SetMinimum(0.000001);
promptScintEnergyHisto->Draw(“bar”);
gPad->SetTicks();
gPad->SetLogy(1);

4

Can you send me your histogram ? I tried to reproduce this effect with the attached macro and I get the attched plot. Seems to me it looks fine.
log0.C (317 Bytes)

c1.gif696×472 7.22 KB

5

Thanks so much for your help! I’m not quite sure why it wasn’t working for me. I ended up taking off the “bar” option and it worked perfectly (the fill color makes it look like bars–I didn’t realize I didn’t have to specify).