KVAlphaCalibration Class Reference

Detailed Description

Set up and run the calibration of siliciums.

This can be used either 'interactively' or in menu-driven mode. In both cases, in order to run a calirbation, the user must specify

• the histogram
• the energy and normalization factor of the peaks present in the histogram
• the parameter of the method that will initialise the position of the peaks

The role of this class is to search for a number of peaks given by the user in a histogram and to fit them in order to get several information about the response of the detectors. This class was made in order to calibrate silicium with alpha but it can be use for every detectors which response is a gaussian.

The way it has to be used

To set up the calibration class the user needs to give the number of peaks that has to be found in the constructor. If the user wants to fit several peaks with one program, it is recommended to set up only one KVAlphaCalibration class and to set the histograms in a loop, instead of using the constructor with a histogram.

Afterwards, the user needs to set the energy and the normalization factor of the peaks with the method SetPeak(). The method SetSigmaSpec needs to be used in order to set up the TSpectrum that will initialise the model, while SetSigmaFit will set the width for the model. The default value of ThresholdOfTSpectrum may be fine but if the TSpectrum find to many peaks it can be modified with SetThresholdOfTSpectrum. Finally the user just has to use the FitInit and FitSpectrum methods in order to get the results

It is possible for the user to draw the histogram, but he needs to create a canvas. The histogram will be drawn in it

Definition at line 71 of file KVAlphaCalibration.h.

#include <KVAlphaCalibration.h>

Public Member Functions
	KVAlphaCalibration (int NumberOfPeak_)
	KVAlphaCalibration (int NumberOfPeak_, TH1 *h)
	~KVAlphaCalibration ()
	Default destructor.
void	AddPeak (double Energy_, double Intensity_)
void	DrawResult (bool WhatToDraw=true)
void	FitAll (bool debug_=false)
	This function calls the FitInit and FitSpectrum function.
TGraph *	FitInit (bool debug_=false)
void	FitSpectrum (bool debug_=false)
double	GetGaussianFitParameter (int)
double	GetGaussianFitParError (int)
double	GetInitializationFitParameter (int)
void	Init (int)
void	PrintResult (void)
void	SetHisto (TH1 *h)
	Set the histogram that contains the data.
void	SetHistRange (double xmin, double xmax)
void	SetParameters (double SigmaOfTSpectrum_=1., double SigmaOfGaussian_=1., double ThresholdOfTSpectrum_=0.5, double IsOriginAtZero_=false)

Private Member Functions
double	FunctionToFit (double *x, double *par)
TF1	GetFunction (void)
void	HistoInit (TH1 *h)
void	SetFunction (std::string FunctionName="x*[0]")

Private Attributes
TGraph *	factorGraph
	Graph where the initial fit is done.
TF1 *	GaussianFit
	function that will fit the peaks
std::vector< double >	GaussianFitResults
	Array that contains results of the final fit.
std::vector< double >	GaussianFitResultsError
	Array that contains the error of the results of the final fit.
TH1 *	Histo
	histogram that contains the data to fit. Set by user
TF1 *	InitializationFit
	function that will do the initial fit
double	InitializationFitResults [2]
	Array that contain the results of the initialization fit.
std::vector< double >	InitializationPeak
std::vector< double >	IntensityOfPeak
	array of peaks amlitude. Set by user
bool	IsOriginAtZero
std::vector< double >	MeanOfPeak
	array peaks energy. Set by user
int	NumberOfPeak
	Number of Peak present in the histogram. Chose by user.
double	SigmaOfGaussian
	Width of the peak that the model will fit chosen by user. It is possible that it has to be different from SigmaSpec to get a better fit.
double	SigmaOfTSpectrum
	Width of the peaks that TSpectrum will search, chosen by user.
TSpectrum *	spec
	the method that will search for peaks
double	ThresholdOfTSpectrum
	Lowest peak that the TSpectrum has to search for. It is the ratio of the highest peak that the TSpectrum found. Chosen by user.

Constructor & Destructor Documentation

KVAlphaCalibration() [1/2]

KVAlphaCalibration::KVAlphaCalibration

(

int

NumberOfPeak_

)

Definition at line 15 of file KVAlphaCalibration.cpp.

KVAlphaCalibration() [2/2]

KVAlphaCalibration::KVAlphaCalibration	(	int	NumberOfPeak_,
		TH1 *	h
	)

Definition at line 26 of file KVAlphaCalibration.cpp.

~KVAlphaCalibration()

KVAlphaCalibration::~KVAlphaCalibration

(

)

Default destructor.

Definition at line 39 of file KVAlphaCalibration.cpp.

Member Function Documentation

AddPeak()

void KVAlphaCalibration::AddPeak	(	double	Energy_,
		double	Intensity_
	)

Set the energy and the normalization factor the peaks you want to fit. The normalization factor is only here to constrain the model

Definition at line 87 of file KVAlphaCalibration.cpp.

DrawResult()

void KVAlphaCalibration::DrawResult

(

bool

WhatToDraw = true

)

Definition at line 453 of file KVAlphaCalibration.cpp.

FitAll()

void KVAlphaCalibration::FitAll

(

bool

debug_ = false

)

This function calls the FitInit and FitSpectrum function.

Definition at line 254 of file KVAlphaCalibration.cpp.

FitInit()

TGraph * KVAlphaCalibration::FitInit

(

bool

debug_ = false

)

This method find the peaks with a TSpectrum and fit their position to initialize the model The boolean is false by default, but it is advised to set it true in order to check if the TSpectrum find the right peaks. If not, change the parameter SigmaOfTSpectrum and ThresholdOfTSpectrum

Definition at line 272 of file KVAlphaCalibration.cpp.

FitSpectrum()

void KVAlphaCalibration::FitSpectrum

(

bool

debug_ = false

)

This methods will use the model and fit the peaks in the histogram with a gaussian in order to get a very accurate calibration It also print the results at the end of the fit

Definition at line 338 of file KVAlphaCalibration.cpp.

FunctionToFit()

double KVAlphaCalibration::FunctionToFit ( double *  x, double *  par  )

private

Model called by the FitSpectrum method. Can not be called by the user It consist in a sum of gaussian. The number is the number of peak given by the user

Definition at line 421 of file KVAlphaCalibration.cpp.

GetFunction()

TF1 KVAlphaCalibration::GetFunction ( void  )

private

GetGaussianFitParameter()

double KVAlphaCalibration::GetGaussianFitParameter

(

int

j

)

Get the final parameter found by the model 0 for the slope 1 for the ordinate at the origin 2 for the width factor. This factor needs to be multiplied by the energy of one peak in order to get his width 3 - NumberOfPeak + 3 for the normalization factor

Definition at line 195 of file KVAlphaCalibration.cpp.

GetGaussianFitParError()

double KVAlphaCalibration::GetGaussianFitParError

(

int

j

)

Get the error of final parameter found by the model 0 for the error of the slope 1 for the error of the ordinate at the origin 2 for the error of the width factor. This factor needs to be multiplied by the energy of one peak in order to get his width 3 - NumberOfPeak + 3 for the error of the normalization factor

Definition at line 225 of file KVAlphaCalibration.cpp.

GetInitializationFitParameter()

double KVAlphaCalibration::GetInitializationFitParameter

(

int

j

)

Get the initialization parameter of the model. 0 for the slope 1 for the ordinate at the origin

Definition at line 168 of file KVAlphaCalibration.cpp.

HistoInit()

void KVAlphaCalibration::HistoInit ( TH1 *  h )

private

Definition at line 48 of file KVAlphaCalibration.cpp.

Init()

void KVAlphaCalibration::Init

(

int

NumberOfPeak_

)

Definition at line 63 of file KVAlphaCalibration.cpp.

PrintResult()

void KVAlphaCalibration::PrintResult

(

void

)

Definition at line 483 of file KVAlphaCalibration.cpp.

SetFunction()

void KVAlphaCalibration::SetFunction ( std::string  FunctionName = "x*[0]" )

private

SetHisto()

void KVAlphaCalibration::SetHisto

(

TH1 *

h

)

Set the histogram that contains the data.

Definition at line 108 of file KVAlphaCalibration.cpp.

SetHistRange()

void KVAlphaCalibration::SetHistRange	(	double	xmin,
		double	xmax
	)

Definition at line 120 of file KVAlphaCalibration.cpp.

SetParameters()

void KVAlphaCalibration::SetParameters	(	double	SigmaOfTSpectrum_ = 1.,
		double	SigmaOfGaussian_ = 1.,
		double	ThresholdOfTSpectrum_ = 0.5,
		double	IsOriginAtZero_ = false
	)

Definition at line 131 of file KVAlphaCalibration.cpp.

Member Data Documentation

factorGraph

TGraph* KVAlphaCalibration::factorGraph

private

Graph where the initial fit is done.

Definition at line 91 of file KVAlphaCalibration.h.

GaussianFit

TF1* KVAlphaCalibration::GaussianFit

private

function that will fit the peaks

Definition at line 90 of file KVAlphaCalibration.h.

GaussianFitResults

std::vector<double> KVAlphaCalibration::GaussianFitResults

private

Array that contains results of the final fit.

Definition at line 81 of file KVAlphaCalibration.h.

GaussianFitResultsError

std::vector<double> KVAlphaCalibration::GaussianFitResultsError

private

Array that contains the error of the results of the final fit.

Definition at line 82 of file KVAlphaCalibration.h.

Histo

TH1* KVAlphaCalibration::Histo

private

histogram that contains the data to fit. Set by user

Definition at line 88 of file KVAlphaCalibration.h.

InitializationFit

TF1* KVAlphaCalibration::InitializationFit

private

function that will do the initial fit

Definition at line 89 of file KVAlphaCalibration.h.

InitializationFitResults

double KVAlphaCalibration::InitializationFitResults[2]

private

Array that contain the results of the initialization fit.

Definition at line 80 of file KVAlphaCalibration.h.

InitializationPeak

std::vector<double> KVAlphaCalibration::InitializationPeak

private

Definition at line 84 of file KVAlphaCalibration.h.

IntensityOfPeak

std::vector<double> KVAlphaCalibration::IntensityOfPeak

private

array of peaks amlitude. Set by user

Definition at line 93 of file KVAlphaCalibration.h.

IsOriginAtZero

bool KVAlphaCalibration::IsOriginAtZero

private

Definition at line 77 of file KVAlphaCalibration.h.

MeanOfPeak

std::vector<double> KVAlphaCalibration::MeanOfPeak

private

array peaks energy. Set by user

Definition at line 92 of file KVAlphaCalibration.h.

NumberOfPeak

int KVAlphaCalibration::NumberOfPeak

private

Number of Peak present in the histogram. Chose by user.

Definition at line 78 of file KVAlphaCalibration.h.

SigmaOfGaussian

double KVAlphaCalibration::SigmaOfGaussian

private

Width of the peak that the model will fit chosen by user. It is possible that it has to be different from SigmaSpec to get a better fit.

Definition at line 75 of file KVAlphaCalibration.h.

SigmaOfTSpectrum

double KVAlphaCalibration::SigmaOfTSpectrum

private

Width of the peaks that TSpectrum will search, chosen by user.

Definition at line 74 of file KVAlphaCalibration.h.

spec

TSpectrum* KVAlphaCalibration::spec

private

the method that will search for peaks

Definition at line 79 of file KVAlphaCalibration.h.

ThresholdOfTSpectrum

double KVAlphaCalibration::ThresholdOfTSpectrum

private

Lowest peak that the TSpectrum has to search for. It is the ratio of the highest peak that the TSpectrum found. Chosen by user.

Definition at line 76 of file KVAlphaCalibration.h.