Fit the contributions use template histograms to a target histogram. More...

#include "NAGASH/TemplateFitter.h"

Inheritance diagram for NAGASH::TemplateFitter:

Classes
class	TemplateFitterFCN

Public Member Functions
	TemplateFitter (std::shared_ptr< MSGTool > MSG)

void	Clear ()
	Clear this tool.

void	Fit ()
	Run the fit.

double	GetChi2 ()
	Get the fit \(\chi^2\).

double	GetSF (uint64_t i)
	Get the scale factors for ith template.

double	GetSFError (uint64_t i)
	Get the uncertainty of the scale factors for ith template.

void	SetFitRange (int min, int max)
	Set the fit range.

void	SetRelation (std::function< double(const std::vector< double > &, const std::vector< double > &)>, std::function< double(const std::vector< double > &, const std::vector< double > &, const std::vector< double > &)>)
	Set the relation between the target histogram and the template histograms. if not called, the default relation is: \( t=\sum s_i \cdot h_i\), here \( t\) is the target histogram, \( s_i\) is the scale factor and \( h_i\) is the corresponding template histogram.

void	SetTarget (TH1D *h)
	Set the target histogram.

void	SetTemplate (TH1D *h, double SF, double min, double max)
	Set the template histogram.

void	SetTemplate (TH1D *h, double SF=1, bool fix=false)
	Set the template histogram.

Private Member Functions
bool	Check ()

Private Attributes
double	chi2 = 0

std::function< double(const std::vector< double > &, const std::vector< double > &)>	contentfunction

std::function< double(const std::vector< double > &, const std::vector< double > &, const std::vector< double > &)>	errorfunction

int	FitRangeMax = 0

int	FitRangeMin = 0

TH1D *	ht = nullptr

std::vector< bool >	isfixed

std::vector< double >	sf

std::vector< double >	sferr

std::vector< double >	sfmax

std::vector< double >	sfmin

std::vector< TH1D * >	vh

Additional Inherited Members
Protected Member Functions inherited from NAGASH::Tool
	Tool ()=delete

	Tool (const Tool &tool)=delete

	Tool (std::shared_ptr< MSGTool > MSG)
	Constructor.

	Tool (Tool &&tool)=delete

virtual	~Tool ()=default

std::shared_ptr< MSGTool >	MSGUser ()
	return the MSGTool inside.

Tool &	operator= (const Tool &tool)=delete

Tool &	operator= (Tool &&tool)=delete

Detailed Description

Fit the contributions use template histograms to a target histogram.

For example, if you know the target distribution is composed of two sub distributions like:

\[ f(x) = \alpha\cdot\frac{\exp\left(-(x-1)^2/2\right)}{\sqrt{2\pi}}+\beta\cdot\frac{2\exp\left(-2(x-2)^2\right)}{{\sqrt{2\pi}}} \]

Of course \(\alpha = 1-\beta\), but in real world we are more interested in the ratio \(\alpha/\beta\). And now you have a histogram filled with distribution \((x)\), then you can get \(\alpha/\beta\) using this tool like:

// Demonstration of using NAGASH::TemplatFitter
#include "NAGASH.h"
 
using namespace NAGASH;
 
int main()
{
    // prepare for target histogram and sub histograms
    TRandom3 myrnd;
    TH1D *htarget = new TH1D("htarget", "htarget", 50, -3, 5);
    TH1D *hsub1 = new TH1D("hsub1", "hsub1", 50, -3, 5);
    TH1D *hsub2 = new TH1D("hsub2", "hsub2", 50, -3, 5);
 
    for (int i = 0; i < 1e6; i++)
    {
        hsub1->Fill(myrnd.Gaus(1, 1));
        hsub2->Fill(myrnd.Gaus(2, 0.5));
 
        // the contribution is 2:1
        htarget->Fill(myrnd.Gaus(1, 1));
        if (i % 2 == 0)
            htarget->Fill(myrnd.Gaus(2, 0.5));
    }
 
    // start fitting
    TemplateFitter fitter(std::make_shared<MSGTool>());
    fitter.SetTarget(htarget);
    fitter.SetTemplate(hsub1);
    fitter.SetTemplate(hsub2);
    fitter.Fit();
    std::cout << "The ratio is : " << fitter.GetSF(0) / fitter.GetSF(1) << std::endl;
    std::cout << "Fit chi2 is " << fitter.GetChi2() << std::endl;
}

The output will be like:

The ratio is : 2.01191

Fit chi2 is 39.7431

NAGASH::TemplateFitter::Fit

void Fit()

Run the fit.

Definition TemplateFitter.cxx:258

NAGASH::TemplateFitter::chi2

double chi2

Definition TemplateFitter.h:67

Definition at line 24 of file TemplateFitter.h.

Constructor & Destructor Documentation

◆ TemplateFitter()

NAGASH::TemplateFitter::TemplateFitter ( std::shared_ptr< MSGTool > MSG )

inline

Definition at line 27 of file TemplateFitter.h.

Member Function Documentation

◆ Check()

bool TemplateFitter::Check ( )

private

Definition at line 230 of file TemplateFitter.cxx.

◆ Clear()

void TemplateFitter::Clear ( )

Clear this tool.

Definition at line 122 of file TemplateFitter.cxx.

◆ Fit()

void TemplateFitter::Fit ( )

Run the fit.

Definition at line 258 of file TemplateFitter.cxx.

◆ GetChi2()

double TemplateFitter::GetChi2 ( )

Get the fit \(\chi^2\).

Definition at line 339 of file TemplateFitter.cxx.

◆ GetSF()

double TemplateFitter::GetSF ( uint64_t i )

Get the scale factors for ith template.

Parameters

i	template index

Definition at line 306 of file TemplateFitter.cxx.

◆ GetSFError()

double TemplateFitter::GetSFError ( uint64_t i )

Get the uncertainty of the scale factors for ith template.

Parameters

i	template index

Definition at line 323 of file TemplateFitter.cxx.

◆ SetFitRange()

void TemplateFitter::SetFitRange	(	int	min,
		int	max
	)

Set the fit range.

Parameters

min	minimum bin index.
max	maximum bin index.

Definition at line 215 of file TemplateFitter.cxx.

◆ SetRelation()

void TemplateFitter::SetRelation	(	std::function< double(const std::vector< double > &, const std::vector< double > &)>	cf,
		std::function< double(const std::vector< double > &, const std::vector< double > &, const std::vector< double > &)>	ef
	)

Set the relation between the target histogram and the template histograms. if not called, the default relation is: \( t=\sum s_i \cdot h_i\), here \( t\) is the target histogram, \( s_i\) is the scale factor and \( h_i\) is the corresponding template histogram.

Parameters

cf	the function to calculate the content, first argument is the vector of the scale factors, second argument is the vector of the contents of template histograms.
ef	the function to calculate the error, first argument is the vector of the scale factors, second argument is the vector of the contents of template histograms, third argument is the vector of the errors of template histograms.

Definition at line 205 of file TemplateFitter.cxx.

◆ SetTarget()

void TemplateFitter::SetTarget ( TH1D * h )

Set the target histogram.

Definition at line 133 of file TemplateFitter.cxx.

◆ SetTemplate() [1/2]

void TemplateFitter::SetTemplate	(	TH1D *	h,
		double	SF,
		double	SFMIN,
		double	SFMAX
	)

Set the template histogram.

Parameters

h	template histogram.
SF	initial value of the scale factor.
SFMIN	minimum value of the scale factor during the fit.
SFMAX	maximum value of the scale factor during the fit.

Definition at line 175 of file TemplateFitter.cxx.

◆ SetTemplate() [2/2]

void TemplateFitter::SetTemplate	(	TH1D *	h,
		double	SF = `1`,
		bool	fix = `false`
	)

Set the template histogram.

Parameters

h	template histogram.
SF	initial value of the scale factor.
fix	whether to fix the scale factor during the fit.

Definition at line 152 of file TemplateFitter.cxx.

Member Data Documentation

◆ chi2

double NAGASH::TemplateFitter::chi2 = 0

private

Definition at line 67 of file TemplateFitter.h.

◆ contentfunction

std::function<double(const std::vector<double> &, const std::vector<double> &)> NAGASH::TemplateFitter::contentfunction

private

Definition at line 71 of file TemplateFitter.h.

◆ errorfunction

std::function<double(const std::vector<double> &, const std::vector<double> &, const std::vector<double> &)> NAGASH::TemplateFitter::errorfunction

private

Definition at line 72 of file TemplateFitter.h.

◆ FitRangeMax

int NAGASH::TemplateFitter::FitRangeMax = 0

private

Definition at line 69 of file TemplateFitter.h.

◆ FitRangeMin

int NAGASH::TemplateFitter::FitRangeMin = 0

private

Definition at line 68 of file TemplateFitter.h.

◆ ht

TH1D* NAGASH::TemplateFitter::ht = nullptr

private

Definition at line 74 of file TemplateFitter.h.

◆ isfixed

std::vector<bool> NAGASH::TemplateFitter::isfixed

private

Definition at line 66 of file TemplateFitter.h.

◆ sf

std::vector<double> NAGASH::TemplateFitter::sf

private

Definition at line 62 of file TemplateFitter.h.

◆ sferr

std::vector<double> NAGASH::TemplateFitter::sferr

private

Definition at line 65 of file TemplateFitter.h.

◆ sfmax

std::vector<double> NAGASH::TemplateFitter::sfmax

private

Definition at line 64 of file TemplateFitter.h.

◆ sfmin

std::vector<double> NAGASH::TemplateFitter::sfmin

private

Definition at line 63 of file TemplateFitter.h.

◆ vh

std::vector<TH1D *> NAGASH::TemplateFitter::vh

private

Definition at line 75 of file TemplateFitter.h.

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

include/NAGASH/TemplateFitter.h
src/TemplateFitter.cxx

Classes

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ TemplateFitter()

Member Function Documentation

◆ Check()

◆ Clear()

◆ Fit()

◆ GetChi2()

◆ GetSF()

◆ GetSFError()

◆ SetFitRange()

◆ SetRelation()

◆ SetTarget()

◆ SetTemplate() [1/2]

◆ SetTemplate() [2/2]

Member Data Documentation

◆ chi2

◆ contentfunction

◆ errorfunction

◆ FitRangeMax

◆ FitRangeMin

◆ ht

◆ isfixed

◆ sf

◆ sferr

◆ sfmax

◆ sfmin

◆ vh