LMFit Class Reference

Parameter fit class. More...

#include <lmfit.h>

Inheritance diagram for LMFit:

Signals
void	updateMessage (const QString &message)
	Emitted when a message should be displayed.

Public Member Functions
	LMFit (const QList< const ArrayItem * > *aList, QList< FunItem * > *fList, const bool *bFit, double *par, QObject *parent=nullptr, const double *sigma=nullptr)
	Constructor.
	~LMFit ()
	Destructor.
bool	linFit (int n, int nPar, double par[], double resVector[], double fJac[], int iPvt[])
	Performs general linear least square parameter fit.
void	lmdif (int n, int nPar, double par[], double resVector[], double tol, int itMax, int *info, double fJac[], int iPvt[])
	Performs nonlinear Levenberg-Marquardt parameter fit.
void	setSigma (const double *sigma)
	Sets data error array.
void	setUserBreak (bool userBreak=true)
	Sets condition to stop calculations.
bool	userBreak () const
	Returns current break condition for calculations.

Static Public Member Functions
static double	enorm (int n, const double x[])
	Calculates the euclidean norm of x.
static double	igamc (double a, double x)
	Calculates complemented incomplete gamma integral.
static int	minv (double a[], double x[], int n)
	Finds the inverse of a square matrix.

Protected Member Functions
void	fcn (int n, int np, const double p[], double fvec[], int *iflag)
void	fdjac2 (int m, int n, double x[], const double fvec[], double fjac[], int ldfjac, int *iflag, double epsfcn, double wa[])
void	lmdif (int m, int np, double px[], double fvec[], double ftol, double ptol, double gtol, int maxfev, double epsfcn, double diag[], int mode, double factor, int nprint, int *info, int *nfev, double fjac[], int ldfjac, int ipvt[], double qtf[], double wa1[], double wa2[], double wa3[], double wa4[])

Protected Attributes
bool	m_userBreak
const bool *	m_bFit
double *	m_par
const double *	m_sigma
const QList< const ArrayItem * > *	m_aList
QList< FunItem * > *	m_fList

Detailed Description

Parameter fit class.

Provides methods for nonlinear Levenberg-Marquardt parameter fits and general linear least square parameter fits.

The functions lmdif, lmpar, fdjac2, qrsolv, qrfac, and enorm use code from the public domain Fortran version of Argonne National Laboratories MINPACK, C translation by Steve Moshier. Modifications by Werner Stille.

The functions minv, igamc, igam, simq, and mtransp are from the Cephes Math Library Release 2.7, Copyright by Stephen L. Moshier.

The function lgam (original name: gsl_sf_lngamma_impl, Author: G. Jungman) is from the GNU Scientific Library. Modifications by Werner Stille.

Constructor & Destructor Documentation

LMFit()

LMFit::LMFit	(	const QList< const ArrayItem * > *	aList,
		QList< FunItem * > *	fList,
		const bool *	bFit,
		double *	par,
		QObject *	parent = nullptr,
		const double *	sigma = nullptr )

Constructor.

Parameters

aList	list of array items.
fList	list of function items.
bFit	array containing true values for parameters to be fitted.
par	array of parameters.
sigma	array for data errors.
parent	pointer to parent widget.

Member Function Documentation

enorm()

static double LMFit::enorm ( int n, const double x[] )

static

Calculates the euclidean norm of x.

Parameters

n	length of x.
x	input array.

Returns

euclidean norm of x.

igamc()

static double LMFit::igamc ( double a, double x )

static

Calculates complemented incomplete gamma integral.

Parameters

a	argument of gamma function.
x	upper boundary of integral.

Returns

complemented incomplete gamma integral.

linFit()

bool LMFit::linFit	(	int	n,
		int	nPar,
		double	par[],
		double	resVector[],
		double	fJac[],
		int	iPvt[] )

Performs general linear least square parameter fit.

Parameters

n	number of data points.
nPar	number of parameters to be fitted.
par	array of parameters to be fitted.
resVector	array for weighted residuals.
fJac	array for calculating the Jacobian matrix.
iPvt	array defining a permutation matrix for calculating the Jacobian matrix.

Returns

true in case of termination by user.

lmdif()

void LMFit::lmdif	(	int	n,
		int	nPar,
		double	par[],
		double	resVector[],
		double	tol,
		int	itMax,
		int *	info,
		double	fJac[],
		int	iPvt[] )

Performs nonlinear Levenberg-Marquardt parameter fit.

Parameters

n	number of data points.
nPar	number of parameters to be fitted.
par	array of parameters to be fitted.
resVector	array for weighted residuals.
tol	tolerance value for stopping nonlinear fit iterations.
itMax	maximum number of nonlinear fit iterations.
info	error code.
fJac	array for calculating the Jacobian matrix.
iPvt	array defining a permutation matrix for calculating the Jacobian matrix.

minv()

static int LMFit::minv ( double a[], double x[], int n )

static

Finds the inverse of a square matrix.

Parameters

a	input matrix.
x	output matrix.
n	numbers of rows and columns of input matrix.

Returns

0 for success.

setSigma()

void LMFit::setSigma ( const double * sigma )

inline

Sets data error array.

Parameters

sigma

array for data errors.

setUserBreak()

void LMFit::setUserBreak ( bool userBreak = true )

inline

Sets condition to stop calculations.

Parameters

userBreak

true to break calculations.

updateMessage

void LMFit::updateMessage ( const QString & message )

signal

Emitted when a message should be displayed.

Parameters

message

message text

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

• lmfit.h