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TLinearFitter Class Reference

The Linear Fitter - For fitting functions that are LINEAR IN PARAMETERS.

The Linear Fitter

Linear fitter is used to fit a set of data points with a linear combination of specified functions. Note, that "linear" in the name stands only for the model dependency on parameters, the specified functions can be nonlinear. The general form of this kind of model is

y(x) = a[0] + a[1]*f[1](x)+...a[n]*f[n](x)

Functions f are fixed functions of x. For example, fitting with a polynomial is linear fitting in this sense.

Introduction

The fitting method

The fit is performed using the Normal Equations method with Cholesky decomposition.

Why should it be used?

The linear fitter is considerably faster than general non-linear fitters and doesn't require to set the initial values of parameters.

Using the fitter:

1.Adding the data points:

1.1 To store or not to store the input data?

1.2 The data can be added:

2.Setting the formula

2.1 The linear formula syntax:

-Additive parts are separated by 2 plus signes "++" –for example "1 ++ x" - for fitting a straight line -All standard functions, undrestood by TFormula, can be used as additive parts –TMath functions can be used too -Functions, used as additive parts, shouldn't have any parameters, even if those parameters are set. –for example, if normalizing a sum of a gaus(0, 1) and a gaus(0, 2), don't use the built-in "gaus" of TFormula, because it has parameters, take TMath::Gaus(x, 0, 1) instead. -Polynomials can be used like "pol3", .."polN" -If fitting a more than 3-dimensional formula, variables should be numbered as follows: – x[0], x[1], x[2]... For example, to fit "1 ++ x[0] ++ x[1] ++ x[2] ++ x[3]*x[3]"

2.2 Setting the formula:

2.2.1 If fitting a 1-2-3-dimensional formula, one can create a

TF123 based on a linear expression and pass this function to the fitter: –Example:

TF2 *f2 = new TF2("f2", "x ++ y ++ x*x*y*y", -2, 2, -2, 2);
lf->SetFormula(f2);

–The results of the fit are then stored in the function, just like when the TH1::Fit or TGraph::Fit is used –A linear function of this kind is by no means different from any other function, it can be drawn, evaluated, etc.

–For multidimensional fitting, TFormulas of the form: x[0]++...++x[n] can be used

2.2.2 There is no need to create the function if you don't want to,

the formula can be set by expression: –Example:

// 2 is the number of dimensions
lf->SetFormula("x ++ y ++ x*x*y*y");
2.2.3 The fastest functions to compute are polynomials and hyperplanes.

–Polynomials are set the usual way: "pol1", "pol2",... –Hyperplanes are set by expression "hyp3", "hyp4", ... —The "hypN" expressions only work when the linear fitter is used directly, not through TH1::Fit or TGraph::Fit. To fit a graph or a histogram with a hyperplane, define the function as "1++x++y". —A constant term is assumed for a hyperplane, when using the "hypN" expression, so "hyp3" is in fact fitting with "1++x++y++z" function. –Fitting hyperplanes is much faster than fitting other expressions so if performance is vital, calculate the function values beforehand and give them to the fitter as variables –Example: You want to fit "sin(x)|cos(2*x)" very fast. Calculate sin(x) and cos(2*x) beforehand and store them in array *data. Then: TLinearFitter *lf=new TLinearFitter(2, "hyp2"); lf->AssignData(npoint, 2, data, y);

2.3 Resetting the formula

2.3.1 If the input data is stored (or added via AssignData() function),

the fitting formula can be reset without re-adding all the points. –Example:

TLinearFitter *lf=new TLinearFitter("1++x++x*x");
lf->AssignData(n, 1, x, y, e);
lf->Eval()
//looking at the parameter significance, you see,
// that maybe the fit will improve, if you take out
// the constant term
lf->SetFormula("x++x*x");
lf->Eval();
...
2.3.2 If the input data is not stored, the fitter will have to be

cleared and the data will have to be added again to try a different formula.

3.Accessing the fit results

3.1 There are methods in the fitter to access all relevant information:

–GetParameters, GetCovarianceMatrix, etc –the t-values of parameters and their significance can be reached by GetParTValue() and GetParSignificance() methods

3.2 If fitting with a pre-defined TF123, the fit results are also

written into this function.

4.Robust fitting - Least Trimmed Squares regression (LTS)

Outliers are atypical(by definition), infrequant observations; data points which do not appear to follow the characteristic distribution of the rest of the data. These may reflect genuine properties of the underlying phenomenon(variable), or be due to measurement errors or anomalies which shouldn't be modelled. (StatSoft electronic textbook)

Even a single gross outlier can greatly influence the results of least- squares fitting procedure, and in this case use of robust(resistant) methods is recommended.

The method implemented here is based on the article and algorithm: "Computing LTS Regression for Large Data Sets" by P.J.Rousseeuw and Katrien Van Driessen The idea of the method is to find the fitting coefficients for a subset of h observations (out of n) with the smallest sum of squared residuals. The size of the subset h should lie between (npoints + nparameters +1)/2 and n, and represents the minimal number of good points in the dataset. The default value is set to (npoints + nparameters +1)/2, but of course if you are sure that the data contains less outliers it's better to change h according to your data.

To perform a robust fit, call EvalRobust() function instead of Eval() after adding the points and setting the fitting function. Note, that standard errors on parameters are not computed!

Definition at line 151 of file TLinearFitter.h.

Public Member Functions

 TLinearFitter ()
 default c-tor, input data is stored If you don't want to store the input data, run the function StoreData(kFALSE) after constructor More...
 
 TLinearFitter (Int_t ndim, const char *formula, Option_t *opt="D")
 First parameter stands for number of dimensions in the fitting formula Second parameter is the fitting formula: see class description for formula syntax Options: The option is to store or not to store the data If you don't want to store the data, choose "" for the option, or run StoreData(kFalse) member function after the constructor. More...
 
 TLinearFitter (Int_t ndim)
 The parameter stands for number of dimensions in the fitting formula The input data is stored. More...
 
 TLinearFitter (TFormula *function, Option_t *opt="D")
 This constructor uses a linear function. More...
 
 TLinearFitter (const TLinearFitter &tlf)
 Copy ctor. More...
 
virtual ~TLinearFitter ()
 Linear fitter cleanup. More...
 
virtual void Add (TLinearFitter *tlf)
 Add another linear fitter to this linear fitter. More...
 
virtual void AddPoint (Double_t *x, Double_t y, Double_t e=1)
 Adds 1 point to the fitter. More...
 
virtual void AddTempMatrices ()
 
virtual void AssignData (Int_t npoints, Int_t xncols, Double_t *x, Double_t *y, Double_t *e=0)
 This function is to use when you already have all the data in arrays and don't want to copy them into the fitter. More...
 
virtual void Chisquare ()
 Calculates the chisquare. More...
 
virtual Double_t Chisquare (Int_t, Double_t *) const
 
virtual void Clear (Option_t *option="")
 Clears everything. Used in TH1::Fit and TGraph::Fit(). More...
 
virtual void ClearPoints ()
 To be used when different sets of points are fitted with the same formula. More...
 
virtual Int_t Eval ()
 Perform the fit and evaluate the parameters Returns 0 if the fit is ok, 1 if there are errors. More...
 
virtual Int_t EvalRobust (Double_t h=-1)
 Finds the parameters of the fitted function in case data contains outliers. More...
 
virtual Int_t ExecuteCommand (const char *command, Double_t *args, Int_t nargs)
 To use in TGraph::Fit and TH1::Fit(). More...
 
virtual void FixParameter (Int_t ipar)
 Fixes paramter #ipar at its current value. More...
 
virtual void FixParameter (Int_t ipar, Double_t parvalue)
 Fixes parameter #ipar at value parvalue. More...
 
virtual void GetAtbVector (TVectorD &v)
 Get the Atb vector - a vector, used for internal computations. More...
 
virtual Double_t GetChisquare ()
 Get the Chisquare. More...
 
virtual void GetConfidenceIntervals (Int_t n, Int_t ndim, const Double_t *x, Double_t *ci, Double_t cl=0.95)
 Computes point-by-point confidence intervals for the fitted function Parameters: n - number of points ndim - dimensions of points x - points, at which to compute the intervals, for ndim > 1 should be in order: (x0,y0, x1, y1, ... More...
 
virtual void GetConfidenceIntervals (TObject *obj, Double_t cl=0.95)
 Computes confidence intervals at level cl. More...
 
virtual Double_t * GetCovarianceMatrix () const
 Returns covariance matrix. More...
 
virtual void GetCovarianceMatrix (TMatrixD &matr)
 Returns covariance matrix. More...
 
virtual Double_t GetCovarianceMatrixElement (Int_t i, Int_t j) const
 
virtual void GetDesignMatrix (TMatrixD &matr)
 Returns the internal design matrix. More...
 
virtual void GetErrors (TVectorD &vpar)
 Returns parameter errors. More...
 
virtual Int_t GetErrors (Int_t, Double_t &, Double_t &, Double_t &, Double_t &) const
 
virtual void GetFitSample (TBits &bits)
 For robust lts fitting, returns the sample, on which the best fit was based. More...
 
virtual Int_t GetNpoints ()
 
virtual Int_t GetNumberFreeParameters () const
 
virtual Int_t GetNumberTotalParameters () const
 
virtual Double_t GetParameter (Int_t ipar) const
 
virtual Int_t GetParameter (Int_t ipar, char *name, Double_t &value, Double_t &, Double_t &, Double_t &) const
 Returns the value and the name of the parameter #ipar NB: In the calling function the argument name must be set large enough. More...
 
virtual void GetParameters (TVectorD &vpar)
 Returns parameter values. More...
 
virtual Double_t GetParError (Int_t ipar) const
 Returns the error of parameter #ipar. More...
 
virtual const char * GetParName (Int_t ipar) const
 Returns name of parameter #ipar. More...
 
virtual Double_t GetParSignificance (Int_t ipar)
 Returns the significance of parameter #ipar. More...
 
virtual Double_t GetParTValue (Int_t ipar)
 Returns the t-value for parameter #ipar. More...
 
virtual Int_t GetStats (Double_t &, Double_t &, Double_t &, Int_t &, Int_t &) const
 
virtual Double_t GetSumLog (Int_t)
 
virtual Double_t GetY2 () const
 
virtual Bool_t IsFixed (Int_t ipar) const
 
virtual Int_t Merge (TCollection *list)
 Merge objects in list. More...
 
TLinearFitteroperator= (const TLinearFitter &tlf)
 Assignment operator. More...
 
virtual void PrintResults (Int_t level, Double_t amin=0) const
 Level = 3 (to be consistent with minuit) prints parameters and parameter errors. More...
 
virtual void ReleaseParameter (Int_t ipar)
 Releases parameter #ipar. More...
 
virtual void SetBasisFunctions (TObjArray *functions)
 set the basis functions in case the fitting function is not set directly The TLinearFitter will manage and delete the functions contained in the list More...
 
virtual void SetDim (Int_t n)
 set the number of dimensions More...
 
virtual void SetFitMethod (const char *)
 
virtual void SetFormula (const char *formula)
 Additive parts should be separated by "++". More...
 
virtual void SetFormula (TFormula *function)
 Set the fitting function. More...
 
virtual Int_t SetParameter (Int_t, const char *, Double_t, Double_t, Double_t, Double_t)
 
virtual void StoreData (Bool_t store)
 
virtual Bool_t UpdateMatrix ()
 Update the design matrix after the formula has been changed. More...
 

Private Member Functions

void AddToDesign (Double_t *x, Double_t y, Double_t e)
 Add a point to the AtA matrix and to the Atb vector. More...
 
void ComputeTValues ()
 Computes parameters' t-values and significance. More...
 
void CreateSubset (Int_t ntotal, Int_t h, Int_t *index)
 Creates a p-subset to start ntotal - total number of points from which the subset is chosen. More...
 
Double_t CStep (Int_t step, Int_t h, Double_t *residuals, Int_t *index, Int_t *subdat, Int_t start, Int_t end)
 The CStep procedure, as described in the article. More...
 
Int_t Graph2DLinearFitter (Double_t h)
 Minimisation function for a TGraph2D. More...
 
Int_t GraphLinearFitter (Double_t h)
 Used in TGraph::Fit(). More...
 
Int_t HistLinearFitter ()
 Minimization function for H1s using a Chisquare method. More...
 
Bool_t Linf ()
 
Int_t MultiGraphLinearFitter (Double_t h)
 Minimisation function for a TMultiGraph. More...
 
Int_t Partition (Int_t nmini, Int_t *indsubdat)
 divides the elements into approximately equal subgroups number of elements in each subgroup is stored in indsubdat number of subgroups is returned More...
 
void RDraw (Int_t *subdat, Int_t *indsubdat)
 Draws ngroup nonoverlapping subdatasets out of a dataset of size n such that the selected case numbers are uniformly distributed from 1 to n. More...
 

Private Attributes

TVectorD fAtb
 
TVectorD fAtbTemp
 
TVectorD fAtbTemp2
 temporary vector, used for num.stability More...
 
TVectorD fAtbTemp3
 
Double_t fChisquare
 
TMatrixDSym fDesign
 
TMatrixDSym fDesignTemp
 
TMatrixDSym fDesignTemp2
 temporary matrix, used for num.stability More...
 
TMatrixDSym fDesignTemp3
 
TVectorD fE
 
TBits fFitsample
 
Bool_t * fFixedParams
 
char * fFormula
 
Int_t fFormulaSize
 
TObjArray fFunctions
 map of basis functions and formula More...
 
Int_t fH
 
TFormula * fInputFunction
 
Bool_t fIsSet
 
Int_t fNdim
 
Int_t fNfixed
 
Int_t fNfunctions
 
Int_t fNpoints
 temporary More...
 
TVectorD fParams
 
TMatrixDSym fParCovar
 
TVectorD fParSign
 
Bool_t fRobust
 
Int_t fSpecial
 
Bool_t fStoreData
 
TVectorD fTValues
 
Double_t fVal [1000]
 
TMatrixD fX
 temporary variable used for num.stability More...
 
TVectorD fY
 
Double_t fY2
 
Double_t fY2Temp
 

Static Private Attributes

static std::map< TString, TFormula * > fgFormulaMap
 

#include <TLinearFitter.h>

Inheritance diagram for TLinearFitter:
[legend]

Constructor & Destructor Documentation

◆ TLinearFitter() [1/5]

TLinearFitter::TLinearFitter ( )

default c-tor, input data is stored If you don't want to store the input data, run the function StoreData(kFALSE) after constructor

Definition at line 223 of file TLinearFitter.cxx.

◆ TLinearFitter() [2/5]

TLinearFitter::TLinearFitter ( Int_t  ndim,
const char *  formula,
Option_t *  opt = "D" 
)

First parameter stands for number of dimensions in the fitting formula Second parameter is the fitting formula: see class description for formula syntax Options: The option is to store or not to store the data If you don't want to store the data, choose "" for the option, or run StoreData(kFalse) member function after the constructor.

Definition at line 294 of file TLinearFitter.cxx.

◆ TLinearFitter() [3/5]

TLinearFitter::TLinearFitter ( Int_t  ndim)

The parameter stands for number of dimensions in the fitting formula The input data is stored.

If you don't want to store the input data, run the function StoreData(kFALSE) after constructor

Definition at line 265 of file TLinearFitter.cxx.

◆ TLinearFitter() [4/5]

TLinearFitter::TLinearFitter ( TFormula *  function,
Option_t *  opt = "D" 
)

This constructor uses a linear function.

How to create it? TFormula now accepts formulas of the following kind: TFormula("f", "x++y++z++x*x") or TFormula("f", "x[0]++x[1]++x[2]*x[2]"); Other than the look, it's in no way different from the regular formula, it can be evaluated, drawn, etc. The option is to store or not to store the data If you don't want to store the data, choose "" for the option, or run StoreData(kFalse) member function after the constructor

Definition at line 327 of file TLinearFitter.cxx.

◆ TLinearFitter() [5/5]

TLinearFitter::TLinearFitter ( const TLinearFitter tlf)

Copy ctor.

Definition at line 360 of file TLinearFitter.cxx.

◆ ~TLinearFitter()

TLinearFitter::~TLinearFitter ( )
virtual

Linear fitter cleanup.

Definition at line 416 of file TLinearFitter.cxx.

Member Function Documentation

◆ Add()

void TLinearFitter::Add ( TLinearFitter tlf)
virtual

Add another linear fitter to this linear fitter.

Points and Design matrices are added, but the previos fitting results (if any) are deleted. Fitters must have same formulas (this is not checked). Fixed parameters are not changed

Definition at line 507 of file TLinearFitter.cxx.

◆ AddPoint()

void TLinearFitter::AddPoint ( Double_t *  x,
Double_t  y,
Double_t  e = 1 
)
virtual

Adds 1 point to the fitter.

First parameter stands for the coordinates of the point, where the function is measured Second parameter - the value being fitted Third parameter - weight(measurement error) of this point (=1 by default)

Definition at line 556 of file TLinearFitter.cxx.

◆ AddTempMatrices()

void TLinearFitter::AddTempMatrices ( )
virtual

Definition at line 718 of file TLinearFitter.cxx.

◆ AddToDesign()

void TLinearFitter::AddToDesign ( Double_t *  x,
Double_t  y,
Double_t  e 
)
private

Add a point to the AtA matrix and to the Atb vector.

Definition at line 632 of file TLinearFitter.cxx.

◆ AssignData()

void TLinearFitter::AssignData ( Int_t  npoints,
Int_t  xncols,
Double_t *  x,
Double_t *  y,
Double_t *  e = 0 
)
virtual

This function is to use when you already have all the data in arrays and don't want to copy them into the fitter.

In this function, the Use() method of TVectorD and TMatrixD is used, so no bytes are physically moved around. First parameter - number of points to fit Second parameter - number of variables in the model Third parameter - the variables of the model, stored in the following way: (x0(0), x1(0), x2(0), x3(0), x0(1), x1(1), x2(1), x3(1),...

Definition at line 594 of file TLinearFitter.cxx.

◆ Chisquare() [1/2]

void TLinearFitter::Chisquare ( )
virtual

Calculates the chisquare.

Definition at line 808 of file TLinearFitter.cxx.

◆ Chisquare() [2/2]

virtual Double_t TLinearFitter::Chisquare ( Int_t  ,
Double_t *   
) const
inlinevirtual

Definition at line 267 of file TLinearFitter.h.

◆ Clear()

void TLinearFitter::Clear ( Option_t *  option = "")
virtual

Clears everything. Used in TH1::Fit and TGraph::Fit().

Definition at line 742 of file TLinearFitter.cxx.

◆ ClearPoints()

void TLinearFitter::ClearPoints ( )
virtual

To be used when different sets of points are fitted with the same formula.

Definition at line 782 of file TLinearFitter.cxx.

◆ ComputeTValues()

void TLinearFitter::ComputeTValues ( )
private

Computes parameters' t-values and significance.

Definition at line 873 of file TLinearFitter.cxx.

◆ CreateSubset()

void TLinearFitter::CreateSubset ( Int_t  ntotal,
Int_t  h,
Int_t *  index 
)
private

Creates a p-subset to start ntotal - total number of points from which the subset is chosen.

Definition at line 2300 of file TLinearFitter.cxx.

◆ CStep()

Double_t TLinearFitter::CStep ( Int_t  step,
Int_t  h,
Double_t *  residuals,
Int_t *  index,
Int_t *  subdat,
Int_t  start,
Int_t  end 
)
private

The CStep procedure, as described in the article.

Definition at line 2363 of file TLinearFitter.cxx.

◆ Eval()

Int_t TLinearFitter::Eval ( )
virtual

Perform the fit and evaluate the parameters Returns 0 if the fit is ok, 1 if there are errors.

Definition at line 885 of file TLinearFitter.cxx.

◆ EvalRobust()

Int_t TLinearFitter::EvalRobust ( Double_t  h = -1)
virtual

Finds the parameters of the fitted function in case data contains outliers.

Parameter h stands for the minimal fraction of good points in the dataset (h < 1, i.e. for 70% of good points take h=0.7). The default value of h*Npoints is (Npoints + Nparameters+1)/2 If the user provides a value of h smaller than above, default is taken See class description for the algorithm details

Definition at line 2104 of file TLinearFitter.cxx.

◆ ExecuteCommand()

Int_t TLinearFitter::ExecuteCommand ( const char *  command,
Double_t *  args,
Int_t  nargs 
)
virtual

To use in TGraph::Fit and TH1::Fit().

Definition at line 1733 of file TLinearFitter.cxx.

◆ FixParameter() [1/2]

void TLinearFitter::FixParameter ( Int_t  ipar)
virtual

Fixes paramter #ipar at its current value.

Definition at line 1012 of file TLinearFitter.cxx.

◆ FixParameter() [2/2]

void TLinearFitter::FixParameter ( Int_t  ipar,
Double_t  parvalue 
)
virtual

Fixes parameter #ipar at value parvalue.

Definition at line 1035 of file TLinearFitter.cxx.

◆ GetAtbVector()

void TLinearFitter::GetAtbVector ( TVectorD v)
virtual

Get the Atb vector - a vector, used for internal computations.

Definition at line 1075 of file TLinearFitter.cxx.

◆ GetChisquare()

Double_t TLinearFitter::GetChisquare ( )
virtual

Get the Chisquare.

Definition at line 1085 of file TLinearFitter.cxx.

◆ GetConfidenceIntervals() [1/2]

void TLinearFitter::GetConfidenceIntervals ( Int_t  n,
Int_t  ndim,
const Double_t *  x,
Double_t *  ci,
Double_t  cl = 0.95 
)
virtual

Computes point-by-point confidence intervals for the fitted function Parameters: n - number of points ndim - dimensions of points x - points, at which to compute the intervals, for ndim > 1 should be in order: (x0,y0, x1, y1, ...

xn, yn) ci - computed intervals are returned in this array cl - confidence level, default=0.95

NOTE, that this method can only be used when the fitting function inherits from a TF1, so it's not possible when the fitting function was set as a string or as a pure TFormula

Definition at line 1108 of file TLinearFitter.cxx.

◆ GetConfidenceIntervals() [2/2]

void TLinearFitter::GetConfidenceIntervals ( TObject *  obj,
Double_t  cl = 0.95 
)
virtual

Computes confidence intervals at level cl.

Default is 0.95 The TObject parameter can be a TGraphErrors, a TGraph2DErrors or a TH123. For Graphs, confidence intervals are computed for each point, the value of the graph at that point is set to the function value at that point, and the graph y-errors (or z-errors) are set to the value of the confidence interval at that point For Histograms, confidence intervals are computed for each bin center The bin content of this bin is then set to the function value at the bin center, and the bin error is set to the confidence interval value. Allowed combinations: Fitted object Passed object TGraph TGraphErrors, TH1 TGraphErrors, AsymmErrors TGraphErrors, TH1 TH1 TGraphErrors, TH1 TGraph2D TGraph2DErrors, TH2 TGraph2DErrors TGraph2DErrors, TH2 TH2 TGraph2DErrors, TH2 TH3 TH3

Definition at line 1159 of file TLinearFitter.cxx.

◆ GetCovarianceMatrix() [1/2]

Double_t * TLinearFitter::GetCovarianceMatrix ( ) const
virtual

Returns covariance matrix.

Definition at line 1308 of file TLinearFitter.cxx.

◆ GetCovarianceMatrix() [2/2]

void TLinearFitter::GetCovarianceMatrix ( TMatrixD matr)
virtual

Returns covariance matrix.

Definition at line 1317 of file TLinearFitter.cxx.

◆ GetCovarianceMatrixElement()

virtual Double_t TLinearFitter::GetCovarianceMatrixElement ( Int_t  i,
Int_t  j 
) const
inlinevirtual

Definition at line 239 of file TLinearFitter.h.

◆ GetDesignMatrix()

void TLinearFitter::GetDesignMatrix ( TMatrixD matr)
virtual

Returns the internal design matrix.

Definition at line 1328 of file TLinearFitter.cxx.

◆ GetErrors() [1/2]

void TLinearFitter::GetErrors ( TVectorD vpar)
virtual

Returns parameter errors.

Definition at line 1339 of file TLinearFitter.cxx.

◆ GetErrors() [2/2]

virtual Int_t TLinearFitter::GetErrors ( Int_t  ,
Double_t &  ,
Double_t &  ,
Double_t &  ,
Double_t &   
) const
inlinevirtual

Definition at line 268 of file TLinearFitter.h.

◆ GetFitSample()

void TLinearFitter::GetFitSample ( TBits &  bits)
virtual

For robust lts fitting, returns the sample, on which the best fit was based.

Definition at line 1438 of file TLinearFitter.cxx.

◆ GetNpoints()

virtual Int_t TLinearFitter::GetNpoints ( )
inlinevirtual

Definition at line 244 of file TLinearFitter.h.

◆ GetNumberFreeParameters()

virtual Int_t TLinearFitter::GetNumberFreeParameters ( ) const
inlinevirtual

Definition at line 243 of file TLinearFitter.h.

◆ GetNumberTotalParameters()

virtual Int_t TLinearFitter::GetNumberTotalParameters ( ) const
inlinevirtual

Definition at line 242 of file TLinearFitter.h.

◆ GetParameter() [1/2]

virtual Double_t TLinearFitter::GetParameter ( Int_t  ipar) const
inlinevirtual

Definition at line 246 of file TLinearFitter.h.

◆ GetParameter() [2/2]

Int_t TLinearFitter::GetParameter ( Int_t  ipar,
char *  name,
Double_t &  value,
Double_t &  ,
Double_t &  ,
Double_t &   
) const
virtual

Returns the value and the name of the parameter #ipar NB: In the calling function the argument name must be set large enough.

Definition at line 1364 of file TLinearFitter.cxx.

◆ GetParameters()

void TLinearFitter::GetParameters ( TVectorD vpar)
virtual

Returns parameter values.

Definition at line 1352 of file TLinearFitter.cxx.

◆ GetParError()

Double_t TLinearFitter::GetParError ( Int_t  ipar) const
virtual

Returns the error of parameter #ipar.

Definition at line 1382 of file TLinearFitter.cxx.

◆ GetParName()

const char * TLinearFitter::GetParName ( Int_t  ipar) const
virtual

Returns name of parameter #ipar.

Definition at line 1396 of file TLinearFitter.cxx.

◆ GetParSignificance()

Double_t TLinearFitter::GetParSignificance ( Int_t  ipar)
virtual

Returns the significance of parameter #ipar.

Definition at line 1424 of file TLinearFitter.cxx.

◆ GetParTValue()

Double_t TLinearFitter::GetParTValue ( Int_t  ipar)
virtual

Returns the t-value for parameter #ipar.

Definition at line 1410 of file TLinearFitter.cxx.

◆ GetStats()

virtual Int_t TLinearFitter::GetStats ( Double_t &  ,
Double_t &  ,
Double_t &  ,
Int_t &  ,
Int_t &   
) const
inlinevirtual

Definition at line 270 of file TLinearFitter.h.

◆ GetSumLog()

virtual Double_t TLinearFitter::GetSumLog ( Int_t  )
inlinevirtual

Definition at line 271 of file TLinearFitter.h.

◆ GetY2()

virtual Double_t TLinearFitter::GetY2 ( ) const
inlinevirtual

Definition at line 253 of file TLinearFitter.h.

◆ Graph2DLinearFitter()

Int_t TLinearFitter::Graph2DLinearFitter ( Double_t  h)
private

Minimisation function for a TGraph2D.

Definition at line 1839 of file TLinearFitter.cxx.

◆ GraphLinearFitter()

Int_t TLinearFitter::GraphLinearFitter ( Double_t  h)
private

Used in TGraph::Fit().

Definition at line 1777 of file TLinearFitter.cxx.

◆ HistLinearFitter()

Int_t TLinearFitter::HistLinearFitter ( )
private

Minimization function for H1s using a Chisquare method.

Definition at line 1983 of file TLinearFitter.cxx.

◆ IsFixed()

virtual Bool_t TLinearFitter::IsFixed ( Int_t  ipar) const
inlinevirtual

Definition at line 254 of file TLinearFitter.h.

◆ Linf()

Bool_t TLinearFitter::Linf ( )
private

Definition at line 2524 of file TLinearFitter.cxx.

◆ Merge()

Int_t TLinearFitter::Merge ( TCollection *  list)
virtual

Merge objects in list.

Definition at line 1452 of file TLinearFitter.cxx.

◆ MultiGraphLinearFitter()

Int_t TLinearFitter::MultiGraphLinearFitter ( Double_t  h)
private

Minimisation function for a TMultiGraph.

Definition at line 1912 of file TLinearFitter.cxx.

◆ operator=()

TLinearFitter & TLinearFitter::operator= ( const TLinearFitter tlf)

Assignment operator.

Definition at line 436 of file TLinearFitter.cxx.

◆ Partition()

Int_t TLinearFitter::Partition ( Int_t  nmini,
Int_t *  indsubdat 
)
private

divides the elements into approximately equal subgroups number of elements in each subgroup is stored in indsubdat number of subgroups is returned

Definition at line 2563 of file TLinearFitter.cxx.

◆ PrintResults()

void TLinearFitter::PrintResults ( Int_t  level,
Double_t  amin = 0 
) const
virtual

Level = 3 (to be consistent with minuit) prints parameters and parameter errors.

Definition at line 1757 of file TLinearFitter.cxx.

◆ RDraw()

void TLinearFitter::RDraw ( Int_t *  subdat,
Int_t *  indsubdat 
)
private

Draws ngroup nonoverlapping subdatasets out of a dataset of size n such that the selected case numbers are uniformly distributed from 1 to n.

Definition at line 2615 of file TLinearFitter.cxx.

◆ ReleaseParameter()

void TLinearFitter::ReleaseParameter ( Int_t  ipar)
virtual

Releases parameter #ipar.

Definition at line 1057 of file TLinearFitter.cxx.

◆ SetBasisFunctions()

void TLinearFitter::SetBasisFunctions ( TObjArray *  functions)
virtual

set the basis functions in case the fitting function is not set directly The TLinearFitter will manage and delete the functions contained in the list

Definition at line 1471 of file TLinearFitter.cxx.

◆ SetDim()

void TLinearFitter::SetDim ( Int_t  n)
virtual

set the number of dimensions

Definition at line 1511 of file TLinearFitter.cxx.

◆ SetFitMethod()

virtual void TLinearFitter::SetFitMethod ( const char *  )
inlinevirtual

Definition at line 272 of file TLinearFitter.h.

◆ SetFormula() [1/2]

void TLinearFitter::SetFormula ( const char *  formula)
virtual

Additive parts should be separated by "++".

Examples (ai are parameters to fit): 1.fitting function: a0*x0 + a1*x1 + a2*x2 input formula "x[0]++x[1]++x[2]" 2.TMath functions can be used: fitting function: a0*TMath::Gaus(x, 0, 1) + a1*y input formula: "TMath::Gaus(x, 0, 1)++y" fills the array of functions

Definition at line 1532 of file TLinearFitter.cxx.

◆ SetFormula() [2/2]

void TLinearFitter::SetFormula ( TFormula *  function)
virtual

Set the fitting function.

Definition at line 1651 of file TLinearFitter.cxx.

◆ SetParameter()

virtual Int_t TLinearFitter::SetParameter ( Int_t  ,
const char *  ,
Double_t  ,
Double_t  ,
Double_t  ,
Double_t   
)
inlinevirtual

Definition at line 273 of file TLinearFitter.h.

◆ StoreData()

virtual void TLinearFitter::StoreData ( Bool_t  store)
inlinevirtual

Definition at line 262 of file TLinearFitter.h.

◆ UpdateMatrix()

Bool_t TLinearFitter::UpdateMatrix ( )
virtual

Update the design matrix after the formula has been changed.

Definition at line 1718 of file TLinearFitter.cxx.

Member Data Documentation

◆ fAtb

TVectorD TLinearFitter::fAtb
private

Definition at line 163 of file TLinearFitter.h.

◆ fAtbTemp

TVectorD TLinearFitter::fAtbTemp
private

Definition at line 164 of file TLinearFitter.h.

◆ fAtbTemp2

TVectorD TLinearFitter::fAtbTemp2
private

temporary vector, used for num.stability

Definition at line 165 of file TLinearFitter.h.

◆ fAtbTemp3

TVectorD TLinearFitter::fAtbTemp3
private

Definition at line 166 of file TLinearFitter.h.

◆ fChisquare

Double_t TLinearFitter::fChisquare
private

Definition at line 188 of file TLinearFitter.h.

◆ fDesign

TMatrixDSym TLinearFitter::fDesign
private

Definition at line 158 of file TLinearFitter.h.

◆ fDesignTemp

TMatrixDSym TLinearFitter::fDesignTemp
private

Definition at line 159 of file TLinearFitter.h.

◆ fDesignTemp2

TMatrixDSym TLinearFitter::fDesignTemp2
private

temporary matrix, used for num.stability

Definition at line 160 of file TLinearFitter.h.

◆ fDesignTemp3

TMatrixDSym TLinearFitter::fDesignTemp3
private

Definition at line 161 of file TLinearFitter.h.

◆ fE

TVectorD TLinearFitter::fE
private

Definition at line 174 of file TLinearFitter.h.

◆ fFitsample

TBits TLinearFitter::fFitsample
private

Definition at line 192 of file TLinearFitter.h.

◆ fFixedParams

Bool_t* TLinearFitter::fFixedParams
private

Definition at line 194 of file TLinearFitter.h.

◆ fFormula

char* TLinearFitter::fFormula
private

Definition at line 185 of file TLinearFitter.h.

◆ fFormulaSize

Int_t TLinearFitter::fFormulaSize
private

Definition at line 180 of file TLinearFitter.h.

◆ fFunctions

TObjArray TLinearFitter::fFunctions
private

map of basis functions and formula

Definition at line 169 of file TLinearFitter.h.

◆ fgFormulaMap

std::map< TString, TFormula * > TLinearFitter::fgFormulaMap
staticprivate

Definition at line 168 of file TLinearFitter.h.

◆ fH

Int_t TLinearFitter::fH
private

Definition at line 190 of file TLinearFitter.h.

◆ fInputFunction

TFormula* TLinearFitter::fInputFunction
private

Definition at line 175 of file TLinearFitter.h.

◆ fIsSet

Bool_t TLinearFitter::fIsSet
private

Definition at line 186 of file TLinearFitter.h.

◆ fNdim

Int_t TLinearFitter::fNdim
private

Definition at line 181 of file TLinearFitter.h.

◆ fNfixed

Int_t TLinearFitter::fNfixed
private

Definition at line 182 of file TLinearFitter.h.

◆ fNfunctions

Int_t TLinearFitter::fNfunctions
private

Definition at line 179 of file TLinearFitter.h.

◆ fNpoints

Int_t TLinearFitter::fNpoints
private

temporary

Definition at line 178 of file TLinearFitter.h.

◆ fParams

TVectorD TLinearFitter::fParams
private

Definition at line 154 of file TLinearFitter.h.

◆ fParCovar

TMatrixDSym TLinearFitter::fParCovar
private

Definition at line 155 of file TLinearFitter.h.

◆ fParSign

TVectorD TLinearFitter::fParSign
private

Definition at line 157 of file TLinearFitter.h.

◆ fRobust

Bool_t TLinearFitter::fRobust
private

Definition at line 191 of file TLinearFitter.h.

◆ fSpecial

Int_t TLinearFitter::fSpecial
private

Definition at line 183 of file TLinearFitter.h.

◆ fStoreData

Bool_t TLinearFitter::fStoreData
private

Definition at line 187 of file TLinearFitter.h.

◆ fTValues

TVectorD TLinearFitter::fTValues
private

Definition at line 156 of file TLinearFitter.h.

◆ fVal

Double_t TLinearFitter::fVal[1000]
private

Definition at line 176 of file TLinearFitter.h.

◆ fX

TMatrixD TLinearFitter::fX
private

temporary variable used for num.stability

Definition at line 173 of file TLinearFitter.h.

◆ fY

TVectorD TLinearFitter::fY
private

Definition at line 170 of file TLinearFitter.h.

◆ fY2

Double_t TLinearFitter::fY2
private

Definition at line 171 of file TLinearFitter.h.

◆ fY2Temp

Double_t TLinearFitter::fY2Temp
private

Definition at line 172 of file TLinearFitter.h.

Libraries for TLinearFitter:
[legend]

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