Histograms¶
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.
HistogramManager¶
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.
-
class
HistogramManager
¶ This is used by any class extending to pre-define a set of histograms to book by default.
Note
The expectation is that the user does not directly use this class but rather inherits from it.
We expect the user to create a new group of histograms, such as for jets:
class JetHists : public HistogramManager { public: JetHists(std::string name, std::string detailStr); virtual ~JetHists() ; bool m_debug; StatusCode initialize(); StatusCode execute( const xAOD::JetContainer jets, float eventWeight, int pvLoc = -1); StatusCode execute( const xAOD::Jet jet, float eventWeight, int pvLoc = -1 ); using HistogramManager::book; // make other overloaded version of book() to show up in subclass using HistogramManager::execute; // overload };
The above example is taken from our implementation in
JetHists
.Subclassed by MetHists
Public Types
-
typedef std::unordered_map<std::string, TH1 *>
HistMap_t
¶ Typedef for convenience.
Public Functions
-
HistogramManager
(std::string name, std::string detailStr)¶ Initialization.
- Parameters
name
: The top-level path in which all histograms are stored under (think ofTDirectory
)detailStr
: Specify the various details of which to plot. For example, jets might want"kinematic substructure"
.
-
~HistogramManager
()¶ Destructor, allows the user to delete histograms that are not being recorded.
-
virtual StatusCode
initialize
()¶ Initialize and book all histograms.
Note
This should call the overloaded functions
HistogramManager::book()
to create the histograms so that the user can call hists->record(wk()) to record all histograms to the EventLoop worker.Example implementation:
StatusCode JetHists::initialize() { m_jetPt = book(m_name, "jetPt", "jet p_{T} [GeV]", 120, 0, 3000.); return StatusCode::SUCCESS; }
-
virtual StatusCode
execute
()¶ Execute by filling in the histograms.
Example implementation:
StatusCode JetHists::execute( const xAOD::JetContainer jets, float eventWeight ){ for(const auto& jet: jets) m_jetPt->Fill( jet->pt()/1.e3, eventWeight ); return StatusCode::SUCCESS; }
-
virtual StatusCode
finalize
()¶ Finalize anything that needs to be finalized.
Warning
This should rarely be used. There is not a good use case for this functionality but it needs to exist in the off-chance that a user comes along and needs it for their histogram class.
-
TH1F *
book
(std::string name, std::string title, std::string xlabel, int xbins, double xlow, double xhigh)¶ record a histogram and call various functions
- Note
This is an overloaded function. It will build the right histogram given the correct number of input arguments.
- Parameters
name
: name of histogram, access it in ROOT file likeh_jetPt->Draw()
title
: usually pointless,put a description of the histogram in herexlabel
: label to put on the x-axisxbins
: number of xbins to usexlow
: lower bound on xbinsxhigh
: upper bound on xbinsxbinsArr
: variable xbins, test math \((x_1,y_1)\) and \((x_2,y_2)\)ylabel
: label to put on the y-axisylow
: lower bound on ybinsyhigh
: upper bound on ybinsybinsArr
: variable ybinszlabel
: label to put on the z-axixzlow
: lower bound on zbinszhigh
: upper bound on zbinszbinsArr
: variable zbins
-
TH2F *
book
(std::string name, std::string title, std::string xlabel, int xbins, double xlow, double xhigh, std::string xyabel, int ybins, double ylow, double yhigh)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
TH3F *
book
(std::string name, std::string title, std::string xlabel, int xbins, double xlow, double xhigh, std::string ylabel, int ybins, double ylow, double yhigh, std::string zlabel, int zbins, double zlow, double zhigh)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
TH1F *
book
(std::string name, std::string title, std::string xlabel, int xbins, const Double_t *xbinsArr)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
TH2F *
book
(std::string name, std::string title, std::string xlabel, int xbins, const Double_t *xbinsArr, std::string ylabel, int ybins, double ylow, double yhigh)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
TH2F *
book
(std::string name, std::string title, std::string xyabel, int xbins, double xlow, double xhigh, std::string ylabel, int ybins, const Double_t *ybinsArr)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
TH2F *
book
(std::string name, std::string title, std::string xyabel, int xbins, const Double_t *xbinsArr, std::string ylabel, int ybins, const Double_t *ybinsArr)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
TH3F *
book
(std::string name, std::string title, std::string xlabel, int xbins, const Double_t *xbinsArr, std::string ylabel, int ybins, const Double_t *ybinsArr, std::string zlabel, int zbins, const Double_t *zbinsArr)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
TProfile *
book
(std::string name, std::string title, std::string xlabel, int xbins, double xlow, double xhigh, std::string ylabel, double ylow, double yhigh, std::string option = "")¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
void
record
(EL::IWorker *wk)¶ record all histograms from HistogramManager::m_allHists to the worker
-
MsgStream &
msg
() const¶ the standard message stream for this algorithm
-
MsgStream &
msg
(int level) const¶ allow ANA_MSG_XXXX macros to be used within algorithms for a given level
-
TH1 *
findHist
(const std::string &histName)¶ Return the pointer to the histogram.
-
void
fillHist
(const std::string &histName, double value)¶ Fill a histogram by name. Can be overloaded with weight.
- Parameters
histName
: The name of the histogram to be filledvalue
: The value to fill the histogram with
-
void
fillHist
(const std::string &histName, double value, double weight)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
void
fillHist
(const std::string &histName, double valueX, double valueY, double weight)¶
Protected Attributes
-
std::string
m_name
¶ generically the main name assigned to all histograms
-
std::string
m_detailStr
¶ a detail level in the form of a string
-
std::vector<TH1 *>
m_allHists
¶ a container holding all generated histograms
-
MsgStream
m_msg
¶ hold the MsgStream object
Private Functions
-
void
Sumw2
(TH1 *hist, bool flag = true)¶ Turn on Sumw2 for the histogram.
- Parameters
hist
: The histogram to modifyflag
: Pass in whether to turn on Sumw2 or not
-
void
record
(TH1 *hist)¶ Push the new histogram to HistogramManager::m_allHists and add its name to HistogramManager::m_histMap.
-
void
SetLabel
(TH1 *hist, std::string xlabel)¶ Set the labels on a histogram.
- Parameters
hist
: The histogram to set the labels onxlabel
: The xlabel to setylabel
: The ylabel to setzlabel
: The zlabel to set
-
void
SetLabel
(TH1 *hist, std::string xlabel, std::string ylabel)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
void
SetLabel
(TH1 *hist, std::string xlabel, std::string ylabel, std::string zlabel)¶ This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
-
typedef std::unordered_map<std::string, TH1 *>
Classes¶
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.
Algorithms¶
This is an EL Algorithm that incorporates the correspondingly-named class.