Dear Experts,

I would like to Draw some efficiency plots. I try to different methods, I would have expected to get the same results, but seems not to be the case.

I have an histogram “h1” contains electrons passing some selection criteria. and another one “h4” which is the total truth electron events in my MC sample

1st method:

```
eff_l =new TH1F(*h1);
eff_l->Divide(h4);
```

2nd method:

```
eff_l =new TH1F(*h1);
eff_l->Scale(1/h4->Integral());
```

Can Anybody elaborate more ? and whether or not should give the same results ?

and which method I should use for my purpose ?

Thanks a lot,