# Proper calculation of the efficiency

1. Aug 10, 2017

### Silviu

1. The problem statement, all variables and given/known data
Hello! This is actually a computational-statistics problem in data analysis, and I got a bit stuck. I have several events from a Monte Carlo simulation from 2 particles collision and for each event I have the primary vertex and the tracks associated to it. I wrote an algorithm which, given the tracks (and their parameters) reconstructs the primary vertex (PV). I want to calculate the efficiency of the algorithm (so the number of reconstructed PV vs the number of actual PV) in bins of number of tracks. I attached a plot I obtained. The 3 colors represent the threshold for the energy of the tracks I used to reconstruct the primary vertex (the minimum energy needed by a track). My professor said that I should also think about the probability of getting a given number of tracks with a given energy. For example, we get to 90% with 5 tracks above 10 GeV but we need 20 above 3 GeV for the same efficiency. However, the probability of getting a vertex having 3 tracks with 3GeV associated with it is different than the probability of having a vertex with 20 tracks with 10GeV. So, should I take this into account and weight somehow my histogram using that information? And if so, how should I do it? I am not sure how to account for the probability of getting a certain number of tracks associated with a certain vertex. Thank you!

2. Relevant equations

3. The attempt at a solution

#### Attached Files:

• ###### plot.png
File size:
21.1 KB
Views:
18
2. Aug 15, 2017

### PF_Help_Bot

Thanks for the thread! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post? The more details the better.