Classes
class	LinearFunction
	A linear function. More...

Typedefs
using	FunctionMapType = std::map< std::string, std::pair< size_t, Function > >

Enumerations
enum	Function { None , Gaussian , Lorentzian , BackToBackExponential }

Functions
void MANTID_CURVEFITTING_DLL	estimate (API::IFunction &function, const API::FunctionDomain1D &domain, const API::FunctionValues &values)
	ParameterEstimator estimates parameter values of some fitting functions from fitting data. More...

void	extractValues (const API::FunctionDomain1D &domain, const API::FunctionValues &values, std::vector< double > &x, std::vector< double > &y)
	Extract values from domain and values objects to vectors. More...

const FunctionMapType &	getFunctionMapType ()
	Returns a reference to the static functionMapType. More...

double	getPeakCentre (double centre, const SimpleChebfun &der1)
	Improve an estimate of a peak centre. More...

std::pair< double, double >	getPeakHWHM (double centre, double height, const SimpleChebfun &fun)
	Get displacements from peak centre where peak reaches half the maximum. More...

std::pair< double, double >	getPeakLeftRightExtent (double centre, const SimpleChebfun &der2)
	Get the peak's extent on either side of the centre. More...

std::pair< double, double >	getPeakLeftRightWidth (double centre, const SimpleChebfun &der2, size_t n=1)
	Get a measure of peak's width. More...

double	getPeakWidth (double centre, const SimpleChebfun &der2)
	Estimate a peak width from a second derivative of the data. More...

void	initFunctionLookup (FunctionMapType &functionMapType)
	Initializes a FunctionMapType object. More...

bool	needSettingInitialValues (const API::IFunction &function)
	Test if initial values need to be set before fitting. More...

void	setBackToBackExponential (API::IFunction &function, const SimpleChebfun &fun, const SimpleChebfun &der1, const SimpleChebfun &der2)
	Set initial values to a BackToBackExponential. More...

void	setValues (API::IFunction &function, const SimpleChebfun &fun, const SimpleChebfun &der1, const SimpleChebfun &der2)
	Set initial values to a function if it needs to. More...

Function	whichFunction (const API::IFunction &function)
	Return a function code for a function if it needs setting values or None otherwise. More...

Variables
Kernel::Logger	g_log ("ParameterEstimator")
	The logger. More...

Typedef Documentation

◆ FunctionMapType

using Mantid::CurveFitting::ParameterEstimator::FunctionMapType = typedef std::map<std::string, std::pair<size_t, Function> >

Definition at line 32 of file ParameterEstimator.cpp.

Enumeration Type Documentation

◆ Function

enum Mantid::CurveFitting::ParameterEstimator::Function

Enumerator
None
Gaussian
Lorentzian
BackToBackExponential

Definition at line 31 of file ParameterEstimator.cpp.

Function Documentation

◆ estimate()

void Mantid::CurveFitting::ParameterEstimator::estimate	(	API::IFunction &	function,
		const API::FunctionDomain1D &	domain,
		const API::FunctionValues &	values
	)

ParameterEstimator estimates parameter values of some fitting functions from fitting data.

Parameters

function	:: A function to estimate parameters for.
domain	:: A domain with fitting data arguments.
values	:: A FunctionValues object with the fitting data.

Definition at line 391 of file ParameterEstimator.cpp.

References Mantid::CurveFitting::Functions::SimpleChebfun::derivative(), extractValues(), needSettingInitialValues(), setValues(), Mantid::Geometry::x, and Mantid::Geometry::y.

Referenced by Mantid::CurveFitting::IMWDomainCreator::setInitialValues(), and Mantid::CurveFitting::TableWorkspaceDomainCreator::setInitialValues().

◆ extractValues()

void Mantid::CurveFitting::ParameterEstimator::extractValues	(	const API::FunctionDomain1D &	domain,
		const API::FunctionValues &	values,
		std::vector< double > &	x,
		std::vector< double > &	y
	)

Extract values from domain and values objects to vectors.

Parameters

domain	:: A domain with fitting data arguments.
values	:: A FunctionValues object with the fitting data.
x	:: A vector to store the domain values
y	:: A vector to store the fitting data values.

Definition at line 91 of file ParameterEstimator.cpp.

References Mantid::API::FunctionValues::getFitData(), Mantid::API::FunctionDomain1D::getPointerAt(), n, Mantid::API::FunctionDomain1D::size(), Mantid::Geometry::x, and Mantid::Geometry::y.

Referenced by estimate().

◆ getFunctionMapType()

const FunctionMapType & Mantid::CurveFitting::ParameterEstimator::getFunctionMapType ( )

Returns a reference to the static functionMapType.

Returns: :: a const reference to the functionMapType

Definition at line 48 of file ParameterEstimator.cpp.

References initFunctionLookup().

Referenced by whichFunction().

◆ getPeakCentre()

double Mantid::CurveFitting::ParameterEstimator::getPeakCentre	(	double	centre,
		const SimpleChebfun &	der1
	)

Improve an estimate of a peak centre.

Parameters

centre	:: A rough estimate of the centre.
der1	:: A first derivative of a function.

Returns: :: Improved estimate for the centre.

Definition at line 216 of file ParameterEstimator.cpp.

References fabs, n, Mantid::CurveFitting::Functions::SimpleChebfun::roughRoots(), and Mantid::CurveFitting::Functions::SimpleChebfun::width().

Referenced by setBackToBackExponential().

◆ getPeakHWHM()

std::pair< double, double > Mantid::CurveFitting::ParameterEstimator::getPeakHWHM	(	double	centre,
		double	height,
		const SimpleChebfun &	fun
	)

Get displacements from peak centre where peak reaches half the maximum.

Parameters

centre	:: Peak centre.
height	:: Peak height above background. height == fun(centre) - background.
fun	:: A function which is expected to be a peak on a background.

Returns: :: The left and right displacements from peak centre.

Definition at line 176 of file ParameterEstimator.cpp.

References Mantid::CurveFitting::Functions::SimpleChebfun::endX(), height, left, right, Mantid::CurveFitting::Functions::SimpleChebfun::roughRoots(), and Mantid::CurveFitting::Functions::SimpleChebfun::startX().

Referenced by setBackToBackExponential().

◆ getPeakLeftRightExtent()

std::pair< double, double > Mantid::CurveFitting::ParameterEstimator::getPeakLeftRightExtent	(	double	centre,
		const SimpleChebfun &	der2
	)

Get the peak's extent on either side of the centre.

Parameters

centre	:: An approximate peak centre.
der2	:: A second derivative of a function.

Returns: :: The left and right boundaries.

Definition at line 165 of file ParameterEstimator.cpp.

References getPeakLeftRightWidth().

Referenced by setBackToBackExponential().

◆ getPeakLeftRightWidth()

std::pair< double, double > Mantid::CurveFitting::ParameterEstimator::getPeakLeftRightWidth	(	double	centre,
		const SimpleChebfun &	der2,
		size_t	n = `1`
	)

Get a measure of peak's width.

It finds approximate zeros of the second derivative of a function. Zeros nearest to the centre are interpreted as the peak's inflection points. The next zero is interpreted as peak boundary.

Parameters

centre	:: Approximate peak centre.
der2	:: A second derivative of a peak. It is expected to have a minimum at centre.
n	:: An order of the zeros to look for. If n == 1 it's the inflection points, if n == 2 it's the boundary.

Returns: :: A pair of zero points on either side of the centre.

Definition at line 134 of file ParameterEstimator.cpp.

References left, n, right, Mantid::CurveFitting::Functions::SimpleChebfun::roughRoots(), and Mantid::CurveFitting::Functions::SimpleChebfun::xPoints().

Referenced by getPeakLeftRightExtent(), and getPeakWidth().

◆ getPeakWidth()

double Mantid::CurveFitting::ParameterEstimator::getPeakWidth	(	double	centre,
		const SimpleChebfun &	der2
	)

Estimate a peak width from a second derivative of the data.

Parameters

centre	:: Approximate peak centre.
der2	:: An approximation to the second derivative.

Definition at line 206 of file ParameterEstimator.cpp.

References fabs, and getPeakLeftRightWidth().

Referenced by setBackToBackExponential(), and setValues().

◆ initFunctionLookup()

void Mantid::CurveFitting::ParameterEstimator::initFunctionLookup ( FunctionMapType & functionMapType )

Initializes a FunctionMapType object.

Parameters

functionMapType :: the function map to initialize

Definition at line 38 of file ParameterEstimator.cpp.

Referenced by getFunctionMapType().

◆ needSettingInitialValues()

bool Mantid::CurveFitting::ParameterEstimator::needSettingInitialValues ( const API::IFunction & function )

Test if initial values need to be set before fitting.

Parameters

function :: A fitting function to test.

Definition at line 73 of file ParameterEstimator.cpp.

References needSettingInitialValues(), None, and whichFunction().

Referenced by estimate(), and needSettingInitialValues().

◆ setBackToBackExponential()

void Mantid::CurveFitting::ParameterEstimator::setBackToBackExponential	(	API::IFunction &	function,
		const SimpleChebfun &	fun,
		const SimpleChebfun &	der1,
		const SimpleChebfun &	der2
	)

Set initial values to a BackToBackExponential.

Parameters

function	:: A fitting BackToBackExponential function.
fun	:: A smooth approximation of the fitting data.
der1	:: The first derivative of the fitting data.
der2	:: The second derivative of the fitting data.

Definition at line 252 of file ParameterEstimator.cpp.

References Mantid::Kernel::Logger::debug(), Mantid::CurveFitting::Functions::SimpleChebfun::derivative(), Mantid::API::IFunction::fix(), Mantid::API::g_log, Mantid::API::IFunction::getParameter(), getPeakCentre(), getPeakHWHM(), getPeakLeftRightExtent(), getPeakWidth(), height, Mantid::CurveFitting::Functions::SimpleChebfun::order(), Mantid::API::IFunction::setParameter(), and sigma.

Referenced by setValues().

◆ setValues()

void Mantid::CurveFitting::ParameterEstimator::setValues	(	API::IFunction &	function,
		const SimpleChebfun &	fun,
		const SimpleChebfun &	der1,
		const SimpleChebfun &	der2
	)

Set initial values to a function if it needs to.

Parameters

function	:: A fitting function.
fun	:: A smooth approximation of the fitting data.
der1	:: The first derivative of the fitting data.
der2	:: The second derivative of the fitting data.

Definition at line 356 of file ParameterEstimator.cpp.

References Mantid::API::IFunction::getParameter(), getPeakWidth(), setBackToBackExponential(), Mantid::API::IFunction::setParameter(), setValues(), and whichFunction().

Referenced by estimate(), and setValues().

◆ whichFunction()

Function Mantid::CurveFitting::ParameterEstimator::whichFunction ( const API::IFunction & function )

Return a function code for a function if it needs setting values or None otherwise.

Definition at line 60 of file ParameterEstimator.cpp.

References getFunctionMapType(), index, Mantid::API::IFunction::isExplicitlySet(), Mantid::API::IFunction::name(), and None.

Referenced by needSettingInitialValues(), and setValues().

Variable Documentation

◆ g_log

Kernel::Logger Mantid::CurveFitting::ParameterEstimator::g_log("ParameterEstimator") ( "ParameterEstimator" )

The logger.

Classes

Typedefs

Enumerations

Functions

Variables

Typedef Documentation

◆ FunctionMapType

Enumeration Type Documentation

◆ Function

Function Documentation

◆ estimate()

◆ extractValues()

◆ getFunctionMapType()

◆ getPeakCentre()

◆ getPeakHWHM()

◆ getPeakLeftRightExtent()

◆ getPeakLeftRightWidth()

◆ getPeakWidth()

◆ initFunctionLookup()

◆ needSettingInitialValues()

◆ setBackToBackExponential()

◆ setValues()

◆ whichFunction()

Variable Documentation

◆ g_log