There are three generic levels to include when building up an analysis that involves plotting: * HistogramManager * JetHists, ElectronHists, MuonHists, etc... * JetHistsAlgo, ElectronHistsAlgo, MuonHistsAlgo, etc...
In order: HistogramManager should rarely be changed. This manages the histograms for you in EventLoop algorithms by initializing histograms and adding it to the worker. JetHists, etc are plotting classes to pre-define the set of plots you want to use for a given set of objects -- as well as how to plot them. Finally, JetHistsAlgo, etc... are EventLoop algorithms that you would include in your jobs and run to actually apply those plots.
This is the base class from which all histogram management classes are made for Muons, Jets, Electrons, etcetera. It is meant to be flexible enough for someone to use it to create their own set of histograms to produce for an algorithm from scratch using the class.
In particular, the book() functions are overloaded for good reason - they all do the same thing except the number of arguments supplied tells us what kind of histogram you want to make: 1D, 2D, or 3D. All histograms take in a name and a title which get concatenated to provide the stored name of the histogram (name+title). If you wish to use TDirectoryFiles automagically, append a forward-slash to the end of the name, such as "AntiKt10/". The book() function will create the histogram, set up the title, the labels, append it to m_allHists, and returns a pointer to the newly created histogram. The last argument is sumw2 which tells the function whether to enable sumw2() for the histogram or not, this defaults to true. The order of the arguments are listed in the table.
HistogramManager
This is a class that predefines all the histograms, defines the execute function which fills in the histograms for you, given an object or a collection of objects, and handles a lot of other logic. This class extends HistogramManager.
JetHists MetHists MuonHists TrackHists VtxHists
This is an EL Algorithm that incorporates the correspondingly-named class.
JetHistsAlgo MetHistsAlgo MuonHistsAlgo TrackHistsAlgo