#include <StMinuitVertexFinder.h>

Inheritance diagram for StMinuitVertexFinder:

Public Member Functions
	StMinuitVertexFinder (VertexFit_t fitMode=VertexFit_t::NoBeamline)

Int_t	fit (StEvent *)

void	printInfo (ostream &=cout) const

virtual void	InitRun (int run_number, const St_db_Maker *db_maker)

void	Clear ()

Int_t	NCtbMatches ()

void	CTBforSeed ()

void	NoCTBforSeed ()

void	setExternalSeed (const StThreeVectorD &)

void	setPrintLevel (Int_t=0)
	Use mMinuit print level.

Int_t	statusMin () const

void	DoUseITTF ()

void	DoNotUseITTF ()

void	useOldBEMCRank ()

void	lowerSplitVtxRank ()

void	setFlagBase ()

void	SetFitPointsCut (Int_t fitpoints)

void	SetMinimumTracks (Int_t n)

Public Member Functions inherited from StGenericVertexFinder
StPrimaryVertex *	getVertex (int idx) const

void	addVertex (const StPrimaryVertex &vtx)

int	size () const

void	UseVertexConstraint (const vertexSeed_st &beamline)

void	NoVertexConstraint ()

int	IsVertexConstraint () const

virtual void	UsePCT (bool usePCT=true)

virtual void	UseBTOF (bool useBTOF=true)

virtual void	UseCTB (bool useCTB=true)

virtual void	SetMode (Int_t mode=0)

virtual int	GetMode () const

void	SetDebugLevel (Int_t level)

virtual void	Init ()

virtual void	Finish ()

const std::vector < StPrimaryVertex > *	result ()

void	result (TClonesArray &stMuDstPrimaryVertices)

void	FillStEvent (StEvent *)

virtual void	SetVertexPosition (double x, double y, double z)

virtual void	SetVertexError (double x, double y, double z)

virtual int	IsFixed () const

virtual int	fit (const StMuDst &muDst)

Additional Inherited Members
Public Types inherited from StGenericVertexFinder
using	StDcaList = std::vector< const StDcaGeometry * >

using	VertexFit_t = star_vertex::VertexFit_t

using	SeedFinder_t = star_vertex::SeedFinder_t
	Options to select vertex seed finder.

Protected Member Functions inherited from StGenericVertexFinder
	StGenericVertexFinder ()
	Default initialization with unspecified seed finder and fitting mode.

	StGenericVertexFinder (SeedFinder_t seedFinder, VertexFit_t fitMode)

std::vector< double >	FindSeeds_TSpectrum ()

double	beamX (double z) const

double	beamY (double z) const

StThreeVectorD	CalcVertexSeed (const StDcaList &trackDcas)

double	CalcChi2Beamline (const StThreeVectorD &point)
	Caclulates chi2 for the beamline and a point. More...

double	CalcChi2DCAsBeamline (const StThreeVectorD &point)
	Caclulates total chi2 for the beamline and track DCAs stored in mDCAs and a point.

Static Protected Member Functions inherited from StGenericVertexFinder
static void	fcnCalcChi2DCAs (int &npar, double gin, double &f, double par, Int_t iflag)

static void	fcnCalcChi2DCAsBeamline1D (int &npar, double gin, double &f, double par, Int_t iflag)
	A static interface to CalcChi2DCAs(...) with x and y fixed by beamline equation.

static void	fcnCalcChi2DCAsBeamline (int &npar, double gin, double &f, double par, int iflag)
	A static interface to CalcChi2DCAsBeamline(...)

Protected Attributes inherited from StGenericVertexFinder
StPrimaryVertexOrder	mVertexOrderMethod

bool	mVertexConstrain

int	mMode

VertexFit_t	mVertexFitMode
	The type of vertex fit to use in derived concrete implementation.

SeedFinder_t	mSeedFinderType
	The type of vertex seed finder to use in derived concrete implementation.

int	mDebugLevel

bool	mUseBtof

bool	mUseCtb

vertexSeed_st	mBeamline

StDcaList	mDCAs

TMinuit *	mMinuit

Static Protected Attributes inherited from StGenericVertexFinder
static StGenericVertexFinder *	sSelf = nullptr
	By default point to invalid object. More...

Detailed Description

Author: Thomas Ullrich, Feb 2002

Modified for pp by David Hardtke, Summer 2002

StEvent based vertex fitter using a robust potential. The actual fit is performed by MINUIT (TMinuit). For documentation the following links and documents are very useful: http://wwwinfo.cern.ch/asdoc/minuit/minmain.html http://root.cern.ch/root/html/TMinuit.html http://www-glast.slac.stanford.edu/software/root/GRUG/docs/Feature/GRUGminuit.pdf

Modified for multiple veretx finding by Marco van Leeuwen April/May 2006

Vertexfinding process has been split into two stages: a seedfinding and a fitting stage. Multiple vertices can be found for each event and are sorted by 'ranking'. The highets ranked vertex is most likely the triggered vertex.

Vertex rank calculation is done in calculateRanks(). Three ranks are calculated, based on mean-dip, number of tracks crossing central membrane and number of tracks matched to BEMC. The ranks are normalised to have mean value close to 0 for triggered vertices and a sigma of about 1 (independent of multiplicity). Each individual rank is bounded to [-5,1]. For data analysis, a quality cut on the rank of the best vertex is recommended. This needs to be refined, but requiring rank > -3 seems to work OK.

for more info, see: http://www.star.bnl.gov/protected/highpt/mvl/multi_vertex/

Member Functions:

StMinuitVertexFinder::fit(StEvent* evt) Find and fit the vertex for given event.

StThreeVectorD StMinuitVertexFinder::result() Returns the found vertex.

Int_t StMinuitVertexFinder::status() The meaning of the return values of status() is as follows: -1 = not enough good tracks for fit in this case fit() returns false. All other values are related to the actual fit and reflect the status of the covariant matrix and thus the quality of the fit. (See also MNSTAT in Minuit documentation) 0 = not calculated at all 1 = diagonal approximation only 2 = full matrix, but forced positive-definite 3 = full accurate covariant matrix

void StMinuitVertexFinder::setExternalSeed(const StThreeVectorD& seed); If the seed is known, e.g. from pVPD, ZDC, or BBC, the estimated position can be passed to the fitter. In this case the fit performs faster, but not necessarily more accurate. The seed has to be provided for every fit (fit()). It will only be used for the next fit.

void StMinuitVertexFinder::setPrintLevel(Int_t level); Set Minuit print level: 0-3 0 means essentially no output 3 prints a lot, for debugging only 1 current default level

void StMinuitVertexFinder::printInfo([ostream& os]); Prints information of the last fit to output stream os. If no argument is given the info is printed to cout.

Example code:

StEvent *event = ...; StMinuitVertexFinder myfinder; StThreeVectorD myvertex; if (myfinder.fit(event)) { myvertex = myfinder.result(); myfinder.printInfo(); } else cout << "Error: vertex fit failed, no vertex." << endl;

PP vertex finding: For proton-proton (and presumable dAu) vertex finding, we only do a 1D fit and use the beamline constraint to get the x and y positions of the vertex.

Id:: StMinuitVertexFinder.h,v 1.30 2017/05/09 12:29:40 smirnovd Exp

Definition at line 104 of file StMinuitVertexFinder.h.

The documentation for this class was generated from the following files:

StGenericVertexMaker/Minuit/StMinuitVertexFinder.h
StGenericVertexMaker/Minuit/StMinuitVertexFinder.cxx

Public Member Functions

Additional Inherited Members

Detailed Description

Member Functions: