Hello,
I have a file which contains a TH2F histogram. I can verify this by f.ls(). I can also verify the histogram content by GetMaximum(), GetBinContent() etc.
But when I draw the histogram totalions->Draw() I get only the axis on the screen and no content. I have tried different options on the Draw() command (col,colz) but nothing changes.
Is there any parameter I should modify?
Thank you in advance,
Makis
ps. the file is attached.
histos.root (20.7 KB)
Have you changed the number of entries by hand ? it is equal to 0 …
root [4] totalions->GetEntries()
(const Double_t)0.00000000000000000e+00
No I haven’t.
The histogram is a 2d variable bin histogram in both axis. The histogram is filled with a AddBinContent function.
Why don’t you use Fill() ?
Because I want each event to go to more than one bin. The code looks like
Int_t nbins=200;
Double_t x[200];
for (Int_t i=0; i<nbins; i++){
x[i]=50*pow((1.005/0.995),i);
}
TH2F *totalions = new TH2F("totalions","number of ions per magnetic rigidity",700,50,400,700,50,400);
totalions->SetBins(nbins-1,x,nbins-1,x);
and for the filling of the histogram inside a duoble for loop over i,j glbin=totalions->GetBin(i,j);
totalions->AddBinContent(glbin);
If it is important I will try to produce a running example.
So you do not care about the number of entries.
In that case simply do:
totalions->SetEntries(1);And it will work.
It really does!
Thank you very much,
Makis