Hi!

I have basic problems with operating on ntuple. All I can do is to read ntuple from loop made by MakeClass function. Now I’m suppposed to draw a histogram with bins whrere in the first one I have number of all events before preselction cuts, and next ones show number of events after each cut.

I wrote definotions for all of my cuts and then I have the part in my code form MakeClass:

```
if (fChain == 0) { cout << "fChain is null" << endl; return; }
Long64_t nentries = fChain->GetEntriesFast();
Long64_t nbytes = 0, nb = 0;
for (Long64_t jentry=0; jentry<nentries;jentry++) {
Long64_t ientry = LoadTree(jentry);
if (ientry < 0) break;
nb = fChain->GetEntry(jentry); nbytes += nb;
// if (Cut(ientry) < 0) continue;
```

And then I have the part that draw me a histogram for the leaf with all events:

```
h->Fill(NOMINAL_pileup_random_run_number);
}
int Events = h->GetEntries();
cout << Events << endl;
//etc...
```

However, I want to put all these entres to just one bin of histogram and then add bins with preselected events. I tried to use something like this:

```
if( !m_SR_passTrigger ) return false;
h->Fill(number of bin i guess, weight);
```

But all I get is empty histogram and the Events gives 0. And I have no more ideas on how aproach this problem. Thanks in andvace for any help!