Dear TMVA experts,
when I try to inspect the output of my BDT training with the GUI, all the functionalities are working apart from “Input Variable Linear Correlation Coefficients” ; I get the following error message :
Did not find histogram CorrelationMatrixS in test.root
Did not find histogram CorrelationMatrixB in test.root
A similar issue was already mentionned in this topic . As suggested I tried the tutorial example (TMVAClassification.C), but the conclusion is the same.
Could you please tell me if I forgot to do something ? I’m using ROOT6.14, and a small example code is attached.
 Missing TMVA plots and histograms
test.cxx (2.1 KB)
May be @kialbert can help you .
I cannot reproduce your problem neither in the latest master, nor on version 6.14/04 on lxplus using the TMVAClassificaiton.C tutorial example.
If you could provide more information about your environment, maybe we can figure out what might cause the issue. E.g. what distribution of root are you using (downloaded binaries, compiled yourself, running directly from lxplus, running from lcg distribution…)
thank you for having a look. I am working locally, I downloaded the source code and compiled it following the “Quick Start” instructions. The version is :
Built for linuxx8664gcc | From tag v6-14-00
You’re right that the problem is on my end, since when I produce the file on lxplus, I am able to get the correlation plot when reading it locally. I guess there is a problem with
TMVA::Factory::WriteDataInformation() (I’m not sure at which point it is called), which is expected to create the correlation matrices…
If you have a suggestion I’m more than happy to try it, otherwise it’s not big a deal.
I think there was a bug in 6.14/00 that incorrectly handled the correlation matrix. Please try the latest patch release 6.14/04 !
Thank you very much, upgrading to the latest version indeed solved the problem.