A class to handle the normalization of Monte Carlo. More...

#include <MCWeighter.h>

Classes
struct	ProcessValidator
	Helper to keep track of events with invalid process id. More...
struct	SumwMapKey
Public Types
enum	SumwMethod { Sumw_NT = 0, Sumw_MAP }
enum	XsecMethod { Xsec_NT = 0, Xsec_ST }
enum	WeightSys { Sys_NOM = 0, Sys_XSEC_UP, Sys_XSEC_DN, Sys_PILEUP_UP, Sys_PILEUP_DN, Sys_N }
typedef std::map< SumwMapKey, float >	SumwMap
Public Member Functions
	MCWeighter (TTree *tree, std::string xsecDir="$ROOTCOREDIR/data/SUSYTools/mc12_8TeV/")
void	buildSumwMap (TTree *tree)
	Build a map of MCID -> sumw.
void	clearAndRebuildSumwMap (TTree *tree)
void	dumpSumwMap () const
void	dumpXsecCache () const
void	dumpXsecDb () const
void	setUseProcSumw (bool useProcSumw=true)
	Specify methods to retrieve sumw and xsec.
void	setSumwMethod (SumwMethod opt=Sumw_MAP)
void	setXsecMethod (XsecMethod opt=Xsec_ST)
float	getMCWeight (const Susy::Event *evt, const float lumi=LUMI_A_A3, WeightSys sys=Sys_NOM)
	MC Weight includes generator, xsec, lumi, and pileup weights.
bool	sumwmapHasKey (SumwMapKey k)
float	getSumw (const Susy::Event *evt)
SUSY::CrossSectionDB::Process	getCrossSection (const Susy::Event *evt)
	Get cross section for this event.
float	getXsecTimesEff (const Susy::Event *evt, WeightSys sys=Sys_NOM)
float	getPileupWeight (const Susy::Event *evt, WeightSys sys=Sys_NOM)
	Get the pileup weight.
MCWeighter &	setLabelBinCounter (const std::string &v)
	specify the bin used to compute sumw
size_t	parseAdditionalXsecFile (const std::string &filename, bool verbose)
	read additional files containing more cross section values
size_t	parseAdditionalXsecDirectory (const std::string &dir, bool verbose)
	same as parseAdditionalXsecFile, but get any *.txt in a given directory
MCWeighter &	setAllowInvalid (bool v)
	toggle m_allowInvalid option
MCWeighter &	setVerbose (bool v)
	toggle m_verbose
Static Public Member Functions
static std::string	defaultLabelBinCounter (const unsigned int &dsid, bool verbose)
	counter used to compute the normalization
static void	checkHistoHasBin (const TH1F &histo, const std::string &binLabel)
	print a warning if the histo doesn't have a bin with the given label
static std::string	defaultXsecDir ()
	default directory from which we read the xsec files for SUSY::CrossSectionDB
static std::vector< std::string >	xsecFilesForSimplifiedModels ()
	a list of the xsec files containing known simplified models
static std::vector< int >	dsidsForKnownSimpliedModelSamples (bool verbose)
	a list of known SM dsids from xsecFilesForSimplifiedModels()
static bool	isFormattedAsSusyCrossSection (std::string filename, bool verbose)
	determine whether a given file is formatted following the CrossSectionDB format
static std::vector< int >	readDsidsFromSusyCrossSectionFile (std::string filename, bool verbose)
	given a text file containing cross sections for CrossSectionDB, return the dsids
static bool	readDsidsFromSusyCrossSectionLine (const std::string &line, int &dsid, bool verbose)
	given a line from a xsec file, parse the dsid; return false if cannot parse
static bool	isSimplifiedModel (const unsigned int &dsid, bool verbose)
	guess from dsid whether this sample is a simplified model one
static const Susy::Event &	readFirstEvent (TTree *tree)
	read the first event from the tree (often used to retrieve sample parameters)
static int	extractProcessFromCutflowHistoname (const std::string &histoName, const std::string &prefix)
	extract 'XYZ' from 'prefixXYZ'
Public Attributes
float	total_sumw
	Get sumw for this event.

Detailed Description

A class to handle the normalization of Monte Carlo.

A MC sample is normalized with the factor $\sigma * lumi / \sum w$ This factor multiplies the generator event weight and all the other factors (pileup, lepton efficiency, trigger scale factors etc.) Some samples can include multiple processes. This class holds a map of the $\sum w$ values for each process. The $\sum w$ is computed from the cutflow histograms that are stored with the susyNt tree.

The user can specify the bin whose contents are used to compute w; otherwise defaultLabelBinCounter() will be used.

Two types of histograms are considered:

for samples that contain only one process (most of them) `genCutFlow`
for samples that contain multiple processes (mostly slepton samples) `procCutFlowXYZ`, where `XYZ` is the process number

Todo:: drop all the obsolete functionalities. Right now we support only the sumwmap method with the sumw retrieved from the histogram.

Member Function Documentation

void MCWeighter::buildSumwMap ( TTree * tree )

Build a map of MCID -> sumw.

This method will loop over the input files associated with the TChain. The MCID in the first entry of the tree will be used, so one CANNOT use this if multiple datasets are combined into one SusyNt tree file! The generator weighted cutflow histograms will then be used to calculate the total sumw for each MCID. Each dataset used here must be complete, they CANNOT be spread out across multiple jobs. However, one can have more than one (complete) dataset in the chain, which is why we use the map.

std::string MCWeighter::defaultLabelBinCounter	(	const unsigned int &	dsid,
		bool	verbose
	)		`[static]`

counter used to compute the normalization

Unless the user has specified a value with setLabelBinCounter(), use "Initial" for all samples, and "SusyProp Veto" for SUSY simplified models.

bool MCWeighter::isFormattedAsSusyCrossSection	(	std::string	filename,
		bool	verbose
	)		`[static]`

determine whether a given file is formatted following the CrossSectionDB format

The format is essentially 6 words:

id name(or final_state) xsect kfactor efficiency rel.uncertainty

Empty lines and comments ('#') are skipped. For more details, see SUSYTools/SUSYCrossSection.h

bool MCWeighter::isSimplifiedModel	(	const unsigned int &	dsid,
		bool	verbose
	)		`[static]`

guess from dsid whether this sample is a simplified model one

This guess is based on whether the dsid is in a list of known dsids from the xsec files in 'SUSYTools/data'.

size_t MCWeighter::parseAdditionalXsecFile	(	const std::string &	filename,
		bool	verbose
	)

Classes

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Member Function Documentation