EEmcSectorFit Class Reference

Simultaneous fit of two smd planes to N gammas. More...

Inheritance diagram for EEmcSectorFit:

Public Member Functions
	EEmcSectorFit (Int_t maxGammas=10)
virtual	~EEmcSectorFit ()
	Destructor.
void	print () const
	print summary
void	SetHistograms (TH1F *u, TH1F *v)
	Set pointers to histograms which will be fit.
Double_t	FitFunc (Double_t x, Int_t plane) const
	Evaluate the N gamma fit for the specified plane.
virtual Int_t	Eval (Int_t np, Double_t *gr, Double_t &x2, Double_t *p, Int_t flg)
Double_t	Residual (Int_t x, Int_t plane) const
Double_t	Residual (Int_t x, Int_t plane, Int_t dx, Int_t side=0) const
Int_t	MaxStrip (Int_t plane) const
	Find maximum residual strip in specified plane. Returns strip index.
void	AddCandidate (Double_t yield, Double_t sigma, Double_t u, Double_t v)
	Add a candidate to the list of candidate gammas. More...
void	Draw (Option_t *opts)
	Draws the current fit. More...
void	InitParameters ()
	Initialize parameters.
void	TryPermutations ()
void	Clear (Option_t *opts="")
	Clear the array of photon candidates.
Int_t	numberOfCandidates ()
	Returns the number of gamma candidates.
void	GetCandidate (Int_t i, Double_t &nmips, Double_t &width, Double_t &u, Double_t &v)
	Returns the parameters of the fit to the ith gamma candidate.
void	GetLastCandidate (Double_t &nmips, Double_t &width, Double_t &u, Double_t &v)
	Returns the parameters of the last candidate found.
TH1F *	histo (Int_t plane)
	Return the histogram for the specified plane.
Double_t	chi2 () const
	Return the chisquared of the fit.
Int_t	ndf () const
	Return the number of degrees of freedom.
void	AddFits (TH1F *u, TH1F *v)
	Adds TF1 to histogram. More...

Public Attributes
Bool_t	doPermutations
	Flag to determine if we test all permutations or not.

Protected Member Functions
	ClassDef (EEmcSectorFit, 1)
	MAkes class available to root.

Protected Attributes
TH1F *	mSMD [2]
	The histograms we fit.
std::vector< Double_t >	yield
	Yield of N gammas.
std::vector< Double_t >	sigma
	Width of N gammas.
std::vector< Double_t >	umean
	Mean U position of N gammas.
std::vector< Double_t >	vmean
	Mean V position of N gammas.
Double_t	mChi2
	Chi^2 of the fit.
Int_t	mNDF
	Degrees o' freedom.

Detailed Description

Simultaneous fit of two smd planes to N gammas.

This class implements a TMinuit-based fitting algorithm which performs a simultaneous fit of N gamma candidates in 2 SMD planes.

Author

Jason C. Webb

Date:

2010/08/26 22:49:26

Revision:

1.5

Definition at line 7 of file EEmcSectorFit.h.

Constructor & Destructor Documentation

EEmcSectorFit::EEmcSectorFit

(

Int_t

maxGammas = 10

)

Constructor

Parameters

maxGammas,:

Maximum number of gammas which we will attempt to fit.

Definition at line 31 of file EEmcSectorFit.cxx.

References doPermutations, mChi2, mNDF, and mSMD.

Member Function Documentation

void EEmcSectorFit::AddCandidate	(	Double_t	yield,
		Double_t	sigma,
		Double_t	u,
		Double_t	v
	)

Add a candidate to the list of candidate gammas.

initialize parameters

Definition at line 177 of file EEmcSectorFit.cxx.

References InitParameters(), mSMD, sigma, umean, vmean, and yield.

void EEmcSectorFit::AddFits	(	TH1F *	u,
		TH1F *	v
	)

Adds TF1 to histogram.

add fits to histograms

Definition at line 370 of file EEmcSectorFit.cxx.

References sigma, umean, vmean, and yield.

void EEmcSectorFit::Draw

(

Option_t *

opts

)

Draws the current fit.

add fits to histograms

Definition at line 209 of file EEmcSectorFit.cxx.

References mSMD, sigma, umean, vmean, and yield.

Int_t EEmcSectorFit::Eval ( Int_t  np, Double_t *  gr, Double_t &  x2, Double_t *  p, Int_t  flg  )

virtual

Overrides TMinuit's chi^2 function

Parameters

np	= number of parameters
gr	= array of derivitavies of chi^2 function
x2	= the chi^2 value computed
p	= array of parameters
flg	= flag (not used)

Definition at line 65 of file EEmcSectorFit.cxx.

References FitFunc(), histo(), mChi2, mNDF, mSMD, sigma, umean, vmean, and yield.

Double_t EEmcSectorFit::Residual	(	Int_t	x,
		Int_t	plane
	)		const

Returns the residual (data - fit) for the specified strip index.

Parameters

x,:	strip index, [0,288)
plane,:	smd plane, 0=u, 1=v

Definition at line 118 of file EEmcSectorFit.cxx.

References FitFunc(), histo(), mSMD, umean, vmean, and yield.

Referenced by StEEmcPointFitMaker::FitSector(), MaxStrip(), and Residual().

Double_t EEmcSectorFit::Residual	(	Int_t	x,
		Int_t	plane,
		Int_t	dx,
		Int_t	side = 0
	)		const

Returns the residual (data - fit) for the specified strip index, summed over +/- dx strips.

Parameters

x,:	strip index, [0,288)
plane,:	smd plane, 0=u, 1=v
dx,:	number of strips on either side to sum over
side,:	0=both, 1=left, 2=right

Definition at line 132 of file EEmcSectorFit.cxx.

References Residual().

void EEmcSectorFit::TryPermutations

(

)

Once the driving routine believes that all gammas have been found, we try all permutations of u,v pairs to find the true best fit.

Vectors of our fit parameters

Vector of resulting chi^2

Permute on old_vmean

Initialze params for this permutaion

Fix the widths

Now fit relative to this permutation

Save parameters and record chi2

restore to original yield, sigma, umean

find minimum chi^2, restore and fit

Refit to ensure minimum chi^2 is loaded into the fitter

Free the widths

Definition at line 282 of file EEmcSectorFit.cxx.

References doPermutations, InitParameters(), mChi2, sigma, umean, vmean, and yield.

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

• StEEmcPool/StEEmcPointMaker/EEmcSectorFit.h
• StEEmcPool/StEEmcPointMaker/EEmcSectorFit.cxx