Prepare shared library (TreeManager_C.so) as follows:
root -l
.L TreeManager.C++
Change the location of the file at the top of drawHistosFromEvent.C to: R__LOAD_LIBRARY(fromUmut/GluedCubes/Analysis/TreeManager_C.so);
Example of how to run:
root -l
.L drawHistosFromEvent.cpp
showHighLYEvent(3500)
The argument for the function is the cut you want to make on the light yield.
To show the total light yield distribution to determine a sensible value for this cut just run the totalLightYield() function.