Implements an analytical approximation to the Voigt function. More...

#include <Voigt.h>

Inheritance diagram for Mantid::CurveFitting::Functions::Voigt:

Private Member Functions
void	calculateFunctionAndDerivative (const double xValues, const size_t nData, double functionValues, API::Jacobian *derivatives) const
	Calculate both function & derivative together. More...

double	centre () const override
	Return value of centre of peak. More...

void	declareParameters () override
	Declare parameters. More...

void	functionDerivLocal (API::Jacobian out, const double xValues, const size_t nData) override
	Derivatives of function with respect to active parameters. More...

void	functionLocal (double out, const double xValues, const size_t nData) const override
	Fill out with function values at given x points. More...

double	fwhm () const override
	Return value of FWHM of peak. More...

double	height () const override
	Return value of height of peak. More...

double	intensity () const override
	Returns the integral intensity of the peak. More...

std::string	name () const override
	Return a string identifier for the function. More...

void	setCentre (const double value) override
	Set the centre of the peak. More...

void	setFwhm (const double value) override
	Set the FWHM of the peak. More...

void	setHeight (const double value) override
	Set the height of the peak. More...

void	setIntensity (const double value) override
	Sets the integral intensity of the peak. More...

Additional Inherited Members
Public Types inherited from Mantid::API::IFunction
enum	ParameterStatus { Active , Fixed , FixedByDefault , Tied }
	Describe parameter status in relation to fitting: Active: Fit varies such parameter directly. More...

enum class	StepSizeMethod { DEFAULT , SQRT_EPSILON }
	Describes the method in which the step size will be calculated: DEFAULT: Uses the traditional Mantid method of calculating the step size. More...

Public Member Functions inherited from Mantid::API::IPeakFunction
virtual void	fixIntensity (bool isDefault=false)
	Fix a parameter or set up a tie such that value returned by intensity() is constant during fitting. More...

void	function (const FunctionDomain &domain, FunctionValues &values) const override
	Evaluates the function for all arguments in the domain. More...

void	function1D (double out, const double xValues, const size_t nData) const override
	General implementation of the method for all peaks. More...

void	functionDeriv1D (Jacobian out, const double xValues, const size_t nData) override
	General implementation of the method for all peaks. More...

virtual void	functionDerivLocal (Jacobian jacobian, const double xValues, const size_t nData)
	Derivative evaluation method. Default is to calculate numerically. More...

virtual void	functionLocal (double out, const double xValues, const size_t nData) const =0
	Function evaluation method to be implemented in the inherited classes. More...

virtual double	fwhm () const =0
	Returns the peak FWHM. More...

std::string	getCentreParameterName () const
	Get name of parameter that is associated to centre. More...

virtual std::pair< double, double >	getDomainInterval (double level=DEFAULT_SEARCH_LEVEL) const
	Get the interval on which the peak has all its values above a certain level. More...

virtual std::string	getWidthParameterName () const
	Get the name of the parameter that is changed when the fwhm is changed. More...

virtual double	intensity () const
	Returns the integral intensity of the peak. More...

virtual double	intensityError () const
	Error in the integrated intensity of the peak due to uncertainties in the values of the fit parameters. More...

	IPeakFunction ()
	Constructor. More...

virtual void	setFwhm (const double w)=0
	Sets the parameters such that FWHM = w. More...

virtual void	setIntensity (const double newIntensity)
	Sets the integral intensity of the peak. More...

void	setParameter (const std::string &name, const double &value, bool explicitlySet=true) override
	Override parent so that we may bust the cache when a parameter is set. More...

void	setParameter (size_t, const double &value, bool explicitlySet=true) override
	Override parent so that we may bust the cache when a parameter is set. More...

virtual void	unfixIntensity ()
	Free the intensity parameter. More...

Public Member Functions inherited from Mantid::API::IFunctionWithLocation
virtual double	centre () const =0
	Returns the centre of the function, which may be something as simple as the centre of the fitting range in the case of a background function or peak shape function this return value reflects the centre of the peak. More...

virtual void	fixCentre (bool isDefault=false)
	Fix a parameter or set up a tie such that value returned by centre() is constant during fitting. More...

virtual double	height () const =0
	Returns the height of the function. More...

virtual void	setCentre (const double c)=0
	Sets the parameters such that centre == c. More...

virtual void	setHeight (const double h)=0
	Sets the parameters such that height == h. More...

virtual void	unfixCentre ()
	Free the centre parameter. More...

	~IFunctionWithLocation () override=default
	Virtual destructor (avoids warnings about non-trivial move assignment in virtually inheriting classes) More...

Public Member Functions inherited from Mantid::API::ParamFunction
IFunction_sptr	getContainingFunction (const ParameterReference &ref) const
	Get the containing function. More...

IFunction_sptr	getContainingFunction (IFunction_sptr fun)
	Get the containing function. More...

double	getError (const std::string &name) const override
	Get the fitting error for a parameter by name. More...

double	getError (size_t i) const override
	Get the fitting error for a parameter. More...

double	getParameter (const std::string &name) const override
	Get parameter by name. More...

double	getParameter (size_t i) const override
	Get i-th parameter. More...

size_t	getParameterIndex (const ParameterReference &ref) const override
	Return parameter index from a parameter reference. More...

bool	hasParameter (const std::string &name) const override
	Check if function has a parameter with this name. More...

bool	isExplicitlySet (size_t i) const override
	Checks if a parameter has been set explicitly. More...

size_t	nParams () const override
	Total number of parameters. More...

std::string	parameterDescription (size_t i) const override
	Returns the description of parameter i. More...

size_t	parameterIndex (const std::string &name) const override
	Returns the index of parameter name. More...

std::string	parameterName (size_t i) const override
	Returns the name of parameter i. More...

	ParamFunction ()
	Default constructor. More...

void	setError (const std::string &name, double err) override
	Set the fitting error for a parameter by name. More...

void	setError (size_t i, double err) override
	Set the fitting error for a parameter. More...

void	setParameter (const std::string &name, const double &value, bool explicitlySet=true) override
	Set parameter by name. More...

void	setParameter (size_t, const double &value, bool explicitlySet=true) override
	Set i-th parameter. More...

void	setParameterDescription (const std::string &name, const std::string &description) override
	Set description of parameter by name. More...

void	setParameterDescription (size_t, const std::string &description) override
	Set i-th parameter description. More...

Public Member Functions inherited from Mantid::API::IFunction
std::string	asString () const
	Writes itself into a string. More...

bool	cancellationRequestReceived () const
	Returns true if a progress reporter is set & evalaution has been requested to stop. More...

virtual const std::vector< std::string >	categories () const
	Function to return all of the categories that contain this algorithm. More...

virtual const std::string	category () const
	The categories the Fit function belong to. More...

virtual const std::string	categorySeparator () const
	Function to return the sperator token for the category string. More...

virtual std::shared_ptr< IFunction >	clone () const
	Virtual copy constructor. More...

virtual int64_t	estimateNoProgressCalls () const
	Returns an estimate of the number of progress reports a single evaluation of the function will have. More...

virtual void	function (const FunctionDomain &domain, FunctionValues &values) const =0
	Evaluates the function for all arguments in the domain. More...

virtual void	functionDeriv (const FunctionDomain &domain, Jacobian &jacobian)
	Derivatives of function with respect to active parameters. More...

	IFunction ()
	Constructor. More...

	IFunction (const IFunction &)=delete
	No copying. More...

virtual void	initialize ()
	Iinialize the function. More...

virtual void	iterationFinished ()
	Called at the end of an iteration. More...

virtual void	iterationStarting ()
	Called at the start of each iteration. More...

virtual std::string	name () const =0
	Returns the function's name. More...

IFunction &	operator= (const IFunction &)=delete
	No copying. More...

virtual void	registerFunctionUsage (bool internal)
	Registers the usage of the algorithm with the UsageService. More...

void	reportProgress (const std::string &msg="") const
	Reports progress with an optional message. More...

virtual void	setMatrixWorkspace (std::shared_ptr< const API::MatrixWorkspace > workspace, size_t wi, double startX, double endX)
	Set matrix workspace. More...

void	setProgressReporter (std::shared_ptr< Kernel::ProgressBase > reporter)
	Attach a progress reporter. More...

virtual void	setWorkspace (std::shared_ptr< const Workspace > ws)
	Set the workspace. More...

virtual	~IFunction ()
	Virtual destructor. More...

bool	isFixed (size_t i) const
	Check if a parameter i is fixed. More...

bool	isFixedByDefault (size_t i) const
	Check if a parameter i is fixed by default (not by user). More...

void	fix (size_t i, bool isDefault=false)
	Removes a parameter i from the list of active. More...

void	unfix (size_t i)
	Restores a declared parameter i to the active status. More...

void	fixParameter (const std::string &name, bool isDefault=false)
	Fix a parameter. More...

void	unfixParameter (const std::string &name)
	Free a parameter. More...

void	fixAll (bool isDefault=false)
	Fix all parameters. More...

void	unfixAll ()
	Free all parameters. More...

void	unfixAllDefault ()
	Free all parameters fixed by default. More...

void	fixAllActive (bool isDefault=false)
	Fix all active parameters. More...

std::vector< std::string >	getParameterNames () const
	Return a vector with all parameter names. More...

virtual double	activeParameter (size_t i) const
	Value of i-th active parameter. More...

virtual void	setActiveParameter (size_t i, double value)
	Set new value of i-th active parameter. More...

virtual std::string	nameOfActive (size_t i) const
	Returns the name of active parameter i. More...

virtual std::string	descriptionOfActive (size_t i) const
	Returns the name of active parameter i. More...

bool	isActive (size_t i) const
	Check if an active parameter i is actually active. More...

virtual void	tie (const std::string &parName, const std::string &expr, bool isDefault=false)
	Tie a parameter to other parameters (or a constant) More...

virtual void	addTies (const std::string &ties, bool isDefault=false)
	Add several ties. More...

virtual void	applyTies ()
	Apply the ties. More...

virtual void	removeTie (const std::string &parName)
	Removes the tie off a parameter. More...

virtual void	clearTies ()
	Remove all ties. More...

virtual bool	removeTie (size_t i)
	Removes i-th parameter's tie. More...

virtual ParameterTie *	getTie (size_t i) const
	Get the tie of i-th parameter. More...

virtual bool	ignoreTie (const ParameterTie &) const
	Ignore a tie. More...

void	sortTies ()
	Put all ties in order in which they will be applied correctly. More...

std::string	writeTies () const
	Write a parameter tie to a string. More...

virtual void	addConstraints (const std::string &str, bool isDefault=false)
	Add a list of conatraints from a string. More...

virtual void	addConstraint (std::unique_ptr< IConstraint > ic)
	Add a constraint to function. More...

virtual IConstraint *	getConstraint (size_t i) const
	Get constraint of i-th parameter. More...

virtual void	removeConstraint (const std::string &parName)
	Remove a constraint. More...

virtual void	setConstraintPenaltyFactor (const std::string &parName, const double &c)
	Set a constraint penalty. More...

std::string	writeConstraints () const
	Write a parameter constraint to a string. More...

virtual void	clearConstraints ()
	Remove all constraints. More...

virtual size_t	nAttributes () const
	Returns the number of attributes associated with the function. More...

virtual std::vector< std::string >	getAttributeNames () const
	Returns a list of attribute names. More...

virtual std::string	attributeName (size_t index) const
	Get name of ith attribute. More...

virtual Attribute	getAttribute (const std::string &name) const
	Return a value of attribute attName. More...

virtual void	setAttribute (const std::string &name, const Attribute &)
	Set a value to attribute attName. More...

virtual bool	hasAttribute (const std::string &name) const
	Check if attribute attName exists. More...

template<typename T >
void	setAttributeValue (const std::string &attName, const T &value)
	Set an attribute value. More...

void	setAttributeValue (const std::string &attName, const char *value)
	Overload for const char* values. More...

void	setAttributeValue (const std::string &attName, const std::string &value)
	Set string attribute by value. More...

virtual std::shared_ptr< IFunction >	getFunction (size_t i) const
	Returns the pointer to i-th child function. More...

virtual std::size_t	nFunctions () const
	Number of child functions. More...

virtual void	setUpForFit ()
	Set up the function for a fit. More...

virtual size_t	getValuesSize (const FunctionDomain &domain) const
	Get number of values for a given domain. More...

virtual size_t	getNumberDomains () const
	Get number of domains required by this function. More...

virtual std::vector< std::shared_ptr< IFunction > >	createEquivalentFunctions () const
	Split this function (if needed) into a list of independent functions. More...

void	calNumericalDeriv (const FunctionDomain &domain, Jacobian &jacobian)
	Calculate numerical derivatives. More...

double	calculateStepSize (const double parameterValue) const
	Calculate step size for the given parameter value. More...

void	setCovarianceMatrix (const std::shared_ptr< Kernel::Matrix< double > > &covar)
	Set the covariance matrix. More...

std::shared_ptr< const Kernel::Matrix< double > >	getCovarianceMatrix () const
	Get the covariance matrix. More...

void	setReducedChiSquared (double chi2)
	Set the reduced chi^2. More...

double	getReducedChiSquared () const
	Get the reduced chi^2. More...

void	setParallel (bool on)
	Set the parallel hint. More...

bool	isParallel () const
	Get the parallel hint. More...

void	setHandler (std::unique_ptr< FunctionHandler > handler)
	Set a function handler. More...

FunctionHandler *	getHandler () const
	Return the handler. More...

virtual void	setStepSizeMethod (const StepSizeMethod method)
	Sets the StepSizeMethod to use when calculation the step size. More...

Public Member Functions inherited from Mantid::API::IFunction1D
virtual void	derivative (const FunctionDomain &domain, FunctionValues &values, const size_t order=1) const

virtual void	derivative1D (double out, const double xValues, const size_t nData, const size_t order) const
	Function to calculate the derivatives of the data set. More...

void	function (const FunctionDomain &domain, FunctionValues &values) const override
	Evaluates the function for all arguments in the domain. More...

virtual void	function1D (double out, const double xValues, const size_t nData) const =0
	Function you want to fit to. More...

void	functionDeriv (const FunctionDomain &domain, Jacobian &jacobian) override
	Derivatives of function with respect to active parameters. More...

virtual void	functionDeriv1D (Jacobian jacobian, const double xValues, const size_t nData)
	Derivatives of function with respect to active parameters. More...

Protected Types inherited from Mantid::API::IFunction1D
template<typename FunctionType >
using	Function1DMethod = void(FunctionType::)(double , const double *, const size_t) const

Protected Member Functions inherited from Mantid::API::IPeakFunction
virtual IntegrationResultCache	integrate () const

Protected Member Functions inherited from Mantid::API::ParamFunction
void	clearAllParameters ()
	Nonvirtual member which removes all declared parameters. More...

void	declareParameter (const std::string &name, double initValue=0, const std::string &description="") override
	Declare a new parameter. More...

virtual double *	getParameterAddress (size_t i)
	Get the address of the parameter. For use in UserFunction with mu::Parser. More...

ParameterStatus	getParameterStatus (size_t i) const override
	Get status of parameter. More...

void	setParameterStatus (size_t i, ParameterStatus status) override
	Change status of parameter. More...

Protected Member Functions inherited from Mantid::API::IFunction
virtual void	init ()
	Function initialization. Declare function parameters in this method. More...

double	convertValue (double value, Kernel::Unit_sptr &outUnit, const std::shared_ptr< const MatrixWorkspace > &ws, size_t wsIndex) const
	Convert a value from one unit (inUnit) to unit defined in workspace (ws) More...

void	convertValue (std::vector< double > &values, Kernel::Unit_sptr &outUnit, const std::shared_ptr< const MatrixWorkspace > &ws, size_t wsIndex) const
	Convert values from unit defined in workspace (ws) to outUnit. More...

virtual void	declareAttributes ()
	Override to declare function attributes. More...

void	declareAttribute (const std::string &name, const API::IFunction::Attribute &defaultValue)
	Declare a single attribute. More...

void	declareAttribute (const std::string &name, const API::IFunction::Attribute &defaultValue, const Kernel::IValidator &validator)
	Declare a single attribute with validator. More...

void	checkAttributeName (const std::string &name)
	Check Attribute to declare does not already exist. More...

void	storeAttributeValue (const std::string &name, const API::IFunction::Attribute &value)
	Store an attribute's value. More...

void	storeReadOnlyAttribute (const std::string &name, const API::IFunction::Attribute &value) const
	A read-only ("mutable") attribute can be stored in a const method. More...

virtual void	addTie (std::unique_ptr< ParameterTie > tie)
	Add a new tie. Derived classes must provide storage for ties. More...

bool	hasOrderedTies () const

void	applyOrderedTies ()

virtual std::string	writeToString (const std::string &parentLocalAttributesStr="") const
	Writes itself into a string. More...

Protected Member Functions inherited from Mantid::API::IFunction1D
template<typename EvaluationMethod >
void	calcNumericalDerivative1D (Jacobian jacobian, EvaluationMethod func1D, const double xValues, const size_t nData)
	Calculate a numerical derivative for the 1D data. More...

virtual void	histogram1D (double out, double left, const double right, const size_t nBins) const
	Calculate histogram data for the given bin boundaries. More...

virtual void	histogramDerivative1D (Jacobian jacobian, double left, const double right, const size_t nBins) const
	Derivatives of the histogram1D with respect to active parameters. More...

Protected Attributes inherited from Mantid::API::IFunction
bool	m_isParallel
	Flag to hint that the function is being used in parallel computations. More...

std::unique_ptr< FunctionHandler >	m_handler
	Pointer to a function handler. More...

std::shared_ptr< Kernel::ProgressBase >	m_progReporter
	Pointer to the progress handler. More...

Static Protected Attributes inherited from Mantid::API::IFunction1D
static Kernel::Logger	g_log
	Logger instance. More...

Detailed Description

Implements an analytical approximation to the Voigt function.

See http://www.citeulike.org/user/dbomse/article/9553243 for approximation used

Definition at line 21 of file Voigt.h.

Member Function Documentation

◆ calculateFunctionAndDerivative()

void Mantid::CurveFitting::Functions::Voigt::calculateFunctionAndDerivative	(	const double *	xValues,
		const size_t	nData,
		double *	functionValues,
		API::Jacobian *	derivatives
	)		const

private

Calculate both function & derivative together.

Calculates both function & derivative together.

Parameters

xValues	:: The X values
nData	:: The number of X values to evaluate
functionValues	:: Calculated y values
derivatives	:: The Jacobian matrix containing the partial derivatives for each x value (allowed null)

Definition at line 81 of file Voigt.cpp.

References Mantid::API::ParamFunction::getParameter(), Mantid::API::Jacobian::set(), Mantid::Geometry::X, and Mantid::Geometry::Y.

Referenced by functionDerivLocal(), and functionLocal().

◆ centre()

double Mantid::CurveFitting::Functions::Voigt::centre ( ) const

overrideprivatevirtual

Return value of centre of peak.

Returns the value of the "LorentzPos" parameter.

Returns: value of centre of peak

Implements Mantid::API::IFunctionWithLocation.

Definition at line 124 of file Voigt.cpp.

References Mantid::API::ParamFunction::getParameter().

◆ declareParameters()

void Mantid::CurveFitting::Functions::Voigt::declareParameters ( )

overrideprivatevirtual

Declare parameters.

Declare the active parameters for the function.

Reimplemented from Mantid::API::IFunction.

Definition at line 45 of file Voigt.cpp.

References Mantid::API::ParamFunction::declareParameter().

◆ functionDerivLocal()

void Mantid::CurveFitting::Functions::Voigt::functionDerivLocal	(	API::Jacobian *	out,
		const double *	xValues,
		const size_t	nData
	)

overrideprivatevirtual

Derivatives of function with respect to active parameters.

Parameters

out	:: The Jacobian matrix containing the partial derivatives for each x value
xValues	:: The X values
nData	:: The number of X values to evaluate

Reimplemented from Mantid::API::IPeakFunction.

Definition at line 69 of file Voigt.cpp.

References calculateFunctionAndDerivative().

◆ functionLocal()

void Mantid::CurveFitting::Functions::Voigt::functionLocal	(	double *	out,
		const double *	xValues,
		const size_t	nData
	)		const

overrideprivatevirtual

Fill out with function values at given x points.

Calculate Voigt function for each x value.

Parameters

out	:: The values of the function at each x point
xValues	:: The X values
nData	:: The number of X values to evaluate

Implements Mantid::API::IPeakFunction.

Definition at line 58 of file Voigt.cpp.

References calculateFunctionAndDerivative().

Referenced by height().

◆ fwhm()

double Mantid::CurveFitting::Functions::Voigt::fwhm ( ) const

overrideprivatevirtual

Return value of FWHM of peak.

Gives the FWHM of the peak.

This is estimated as 0.5*(LorentzFWHM + GaussianFWHM)

Returns: value of FWHM of peak

Implements Mantid::API::IPeakFunction.

Definition at line 145 of file Voigt.cpp.

References Mantid::API::ParamFunction::getParameter().

◆ height()

double Mantid::CurveFitting::Functions::Voigt::height ( ) const

overrideprivatevirtual

Return value of height of peak.

Return the value of the "LorentzAmp" parameter.

Returns: value of height of peak

Implements Mantid::API::IFunctionWithLocation.

Definition at line 130 of file Voigt.cpp.

References functionLocal(), and Mantid::API::ParamFunction::getParameter().

Referenced by setHeight().

◆ intensity()

double Mantid::CurveFitting::Functions::Voigt::intensity ( ) const

overrideprivatevirtual

Returns the integral intensity of the peak.

Reimplemented from Mantid::API::IPeakFunction.

Definition at line 197 of file Voigt.cpp.

References Mantid::API::ParamFunction::getParameter().

◆ name()

std::string Mantid::CurveFitting::Functions::Voigt::name ( ) const

inlineoverrideprivatevirtual

Return a string identifier for the function.

Implements Mantid::API::IFunction.

Definition at line 24 of file Voigt.h.

◆ setCentre()

void Mantid::CurveFitting::Functions::Voigt::setCentre ( const double value )

overrideprivatevirtual

Set the centre of the peak.

Set the centre of the peak, the LorentzPos parameter.

Parameters

value :: The new value for the centre of the peak

Implements Mantid::API::IFunctionWithLocation.

Definition at line 151 of file Voigt.cpp.

References Mantid::API::IPeakFunction::setParameter(), and value.

◆ setFwhm()

void Mantid::CurveFitting::Functions::Voigt::setFwhm ( const double value )

overrideprivatevirtual

Set the FWHM of the peak.

Parameters

value :: The new value for the FWHM of the peak

Implements Mantid::API::IPeakFunction.

Definition at line 180 of file Voigt.cpp.

References Mantid::API::ParamFunction::getParameter(), Mantid::API::IPeakFunction::setParameter(), and value.

◆ setHeight()

void Mantid::CurveFitting::Functions::Voigt::setHeight ( const double value )

overrideprivatevirtual

Set the height of the peak.

Sets LorentzAmp parameter to 1.5*value

Parameters

value :: The new value for the centre of the peak

Implements Mantid::API::IFunctionWithLocation.

Definition at line 157 of file Voigt.cpp.

References Mantid::API::ParamFunction::getParameter(), height(), Mantid::API::IPeakFunction::setParameter(), and value.

◆ setIntensity()

void Mantid::CurveFitting::Functions::Voigt::setIntensity ( const double value )

overrideprivatevirtual

Sets the integral intensity of the peak.

Parameters

value :: The new value for the intensity.

Reimplemented from Mantid::API::IPeakFunction.

Definition at line 208 of file Voigt.cpp.

References Mantid::API::ParamFunction::getParameter(), Mantid::API::IPeakFunction::setParameter(), and value.

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

Framework/CurveFitting/inc/MantidCurveFitting/Functions/Voigt.h
Framework/CurveFitting/src/Functions/Voigt.cpp

Private Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ calculateFunctionAndDerivative()

◆ centre()

◆ declareParameters()

◆ functionDerivLocal()

◆ functionLocal()

◆ fwhm()

◆ height()

◆ intensity()

◆ name()

◆ setCentre()

◆ setFwhm()

◆ setHeight()

◆ setIntensity()