Hi all

I am a beginner with TMVA and probably this is a naive question. I am reading the manual about BDT and I don’t get very clear what is the meaning of the nCuts parameter

Here is what I understand:

Samples are sets of events; each event contains a set of variables and each variable a defined value.

In theory, BDT training scans over all the variables and their values to find the variable and splitting/cut value that produce the best separation. In practice, “the cut values are optimized by scanning over the variable range with a granularity that is set via the option nCuts. The default value of nCuts=20 proved to be a good compromise between computing time and step size”.

Let’s say, the variable is the number of particles in the final state N_i. for 100 events the range of values for N_i is 1<N_i<100; nCuts=20 split this range in 20 and makes 20 scans!

is that statement true? and if so, which one of the 5 values in the chosen subrange is the splitting value?

if the statements is not true then what is the correct meaning of nCuts?

thanks in advance for the help

Jose