Error en TMVA Cut Method

TMVA
1

Hello everyone,

I have an error using the Cuts method in the TMVA package and I have no clue of the reason of why or how I could solve it. Can anyone help me?

I use the following method:
Use[“Cuts”] = 1;

with seven variables and the following configuration:

if (Use[“Cuts”])
factory->BookMethod( TMVA::Types::kCuts, “Cuts”, “!H:V:FitMethod=MC:EffSel:SampleSize=2000:VarProp=FSmart” );

and the error I get everytime is this one:

— Cuts : Begin training
— Interval : maximum lower than minimum
***> abort program execution

I have tried to set the CutMinRange (and Max) for each variable but it didn’t solve anything.

Any ideas?

Thank you in advance!

Damián

2

Hi again,

I really need help with this error, so any suggestion would be very much appreciated.

Thanks,

Damián

3

Hello Damian,

sorry for the very lat reply - I’m still not used to the ROOT talk, we mainly use the sourceforge mailing list
for all TMVA related questions. There at least i get a notification (mail) once there’s a question!

But now to your problem. Well, you have 7 variables, imagine how LARGE your possible space of cut values is an you used the MC method (which is just random trial of different cuts) with a tiny number of 2000 ties. Guess, you simply didn’t get any cuts that made any reasonalb sense in this small sample ! For any more in depth debugging I’d certainly need more (e.g. a log output, TMVA version etc.)

Now from the little output log you provided, it might however be another problem all together…

— Interval : maximum lower than minimum

did you look at how the variable distributions look like ? Do they make sense ?? I would almost guess
that one variable is ‘empty’ as the algorithm doesn’t seem to be able to find min/max such that it could
determine the range in which to perform the cut search.

Now, if you really run into trouble, wouldn’t it make sense first to try with 1,2,3 … variables to found out when it fails ? You’d learn much more than just trying one configuration.

And apart from that: try with FitMethod=GA (as recommended in the TMVA Users guide) …
(although that will of course not solve the 'interval min/max problem)

cheers,

Helge

Cheers,

Helge