Calculates a multiple scattering correction Based on Muscat Fortran code provided by Spencer Howells. More...

#include <DiscusMultipleScatteringCorrection.h>

Inheritance diagram for Mantid::Algorithms::DiscusMultipleScatteringCorrection:

Public Types
using	ComponentWorkspaceMappings = boost::container::small_vector< ComponentWorkspaceMapping, 5 >

Public Types inherited from Mantid::API::Algorithm
using	WorkspaceVector = std::vector< std::shared_ptr< Workspace > >

Public Member Functions
const std::string	alias () const override
	function to return any aliases of the algorithm.

const std::string	category () const override
	Algorithm's category for identification.

bool	checkGroups () override
	Check the input workspace properties for groups.

const std::string	name () const override
	Algorithm's name.

const std::vector< std::string >	seeAlso () const override
	Function to return all of the seeAlso algorithms related to this algorithm.

const std::string	summary () const override
	Summary of algorithms purpose.

int	version () const override
	Algorithm's version.

Public Member Functions inherited from Mantid::API::Algorithm
	Algorithm ()
	Constructor.

	Algorithm (const Algorithm &)=delete

Algorithm &	operator= (const Algorithm &)=delete

	~Algorithm () override
	Virtual destructor.

void	initialize () override
	Initialization method invoked by the framework.

bool	execute () override final
	The actions to be performed by the algorithm on a dataset.

void	addTimer (const std::string &name, const Kernel::time_point_ns &begin, const Kernel::time_point_ns &end)

void	executeAsChildAlg () override
	Execute as a Child Algorithm.

std::map< std::string, std::string >	validateInputs () override
	Perform validation of ALL the input properties of the algorithm.

ExecutionState	executionState () const override
	Gets the current execution state.

ResultState	resultState () const override
	Gets the current result State.

bool	isInitialized () const override
	Has the Algorithm already been initialized.

bool	isExecuted () const override
	Has the Algorithm already been executed successfully.

bool	isRunning () const override
	True if the algorithm is running.

bool	isReadyForGarbageCollection () const override
	True if the algorithm is ready for garbage collection.

bool	isChild () const override
	To query whether algorithm is a child.

void	setChild (const bool isChild) override
	To set whether algorithm is a child.

void	enableHistoryRecordingForChild (const bool on) override
	Change the state of the history recording flag.

bool	isRecordingHistoryForChild ()

void	setAlwaysStoreInADS (const bool doStore) override
	Do we ALWAYS store in the AnalysisDataService? This is set to true for python algorithms' child algorithms.

bool	getAlwaysStoreInADS () const override
	Returns true if we always store in the AnalysisDataService.

void	setRethrows (const bool rethrow) override
	Set whether the algorithm will rethrow exceptions.

Poco::ActiveResult< bool >	executeAsync () override
	Asynchronous execution.

void	addObserver (const Poco::AbstractObserver &observer) const override
	Add an observer for a notification.

void	removeObserver (const Poco::AbstractObserver &observer) const override
	Remove an observer.

void	cancel () override
	Raises the cancel flag.

bool	getCancel () const
	Returns the cancellation state.

Kernel::Logger &	getLogger () const
	Returns a reference to the logger.

void	setLogging (const bool value) override
	Logging can be disabled by passing a value of false.

bool	isLogging () const override
	returns the status of logging, True = enabled

void	setLoggingOffset (const int value) override
	gets the logging priority offset

int	getLoggingOffset () const override
	returns the logging priority offset

void	setAlgStartupLogging (const bool enabled) override
	disable Logging of start and end messages

bool	getAlgStartupLogging () const override
	get the state of Logging of start and end messages

void	setChildStartProgress (const double startProgress) const override
	setting the child start progress

void	setChildEndProgress (const double endProgress) const override
	setting the child end progress

std::string	toString () const override
	Serialize an object to a string.

::Json::Value	toJson () const override
	Serialize an object to a json object.

virtual std::shared_ptr< Algorithm >	createChildAlgorithm (const std::string &name, const double startProgress=-1., const double endProgress=-1., const bool enableLogging=true, const int &version=-1)
	Create a Child Algorithm.

void	setupAsChildAlgorithm (const Algorithm_sptr &algorithm, const double startProgress=-1., const double endProgress=-1., const bool enableLogging=true)
	Setup algorithm as child algorithm.

void	trackAlgorithmHistory (std::shared_ptr< AlgorithmHistory > parentHist)
	set whether we wish to track the child algorithm's history and pass it the parent object to fill.

void	findWorkspaces (WorkspaceVector &workspaces, unsigned int direction, bool checkADS=false) const
	Populate lists of the workspace properties for a given direction (InOut workspaces are included in both input/output)

virtual bool	processGroups ()
	Process WorkspaceGroup inputs.

void	copyNonWorkspaceProperties (IAlgorithm *alg, int periodNum)
	Copy all the non-workspace properties from this to alg.

void	declareProperty (std::unique_ptr< Kernel::Property > p, const std::string &doc="") override
	Add a property to the list of managed properties.

void	declareOrReplaceProperty (std::unique_ptr< Kernel::Property > p, const std::string &doc="") override
	Add or replace property in the list of managed properties.

void	resetProperties () override
	Reset property values back to initial values (blank or default values)

void	setProperties (const std::string &propertiesJson, const std::unordered_set< std::string > &ignoreProperties=std::unordered_set< std::string >(), bool createMissing=false) override
	Set the ordered list of properties by one string of values, separated by semicolons.

void	setProperties (const ::Json::Value &jsonValue, const std::unordered_set< std::string > &ignoreProperties=std::unordered_set< std::string >(), bool createMissing=false) override
	Sets all the declared properties from a json object.

void	setPropertiesWithString (const std::string &propertiesString, const std::unordered_set< std::string > &ignoreProperties=std::unordered_set< std::string >()) override
	Sets all the declared properties from a string.

void	setPropertyValue (const std::string &name, const std::string &value) override
	Set the value of a property by string N.B.

void	setPropertyValueFromJson (const std::string &name, const Json::Value &value) override
	Set the value of a property by Json::Value object.

void	setPropertyOrdinal (const int &index, const std::string &value) override
	Set the value of a property by an index N.B.

virtual void	copyPropertiesFrom (const Algorithm &alg)
	Make m_properties point to the same PropertyManager as alg.m_properties.

bool	existsProperty (const std::string &name) const override
	Checks whether the named property is already in the list of managed property.

bool	validateProperties () const override
	Validates all the properties in the collection.

size_t	propertyCount () const override
	Count the number of properties under management.

std::string	getPropertyValue (const std::string &name) const override
	Get the value of a property as a string.

const std::vector< Kernel::Property * > &	getProperties () const override
	Get the list of managed properties.

std::vector< std::string >	getDeclaredPropertyNames () const noexcept override
	Return the list of declared property names.

TypedValue	getProperty (const std::string &name) const override
	Get the value of a property.

std::string	asString (bool withDefaultValues=false) const override
	Return the property manager serialized as a string.

::Json::Value	asJson (bool withDefaultValues=false) const override
	Return the property manager serialized as a json object.

bool	isDefault (const std::string &name) const

void	removeProperty (const std::string &name, const bool delproperty=true) override
	Removes the property from management.

std::unique_ptr< Kernel::Property >	takeProperty (const size_t index) override
	Removes the property from management and returns a pointer to it.

void	clear () override
	Clears all properties under management.

void	afterPropertySet (const std::string &) override
	Override this method to perform a custom action right after a property was set.

Kernel::Property *	getPointerToProperty (const std::string &name) const override
	Get a property by name.

Kernel::Property *	getPointerToPropertyOrdinal (const int &index) const override
	Get a property by an index.

virtual void	declareProperty (std::unique_ptr< Property > p, const std::string &doc="")=0
	Function to declare properties (i.e. store them)

template<typename T >
void	declareProperty (const std::string &name, T value, IValidator_sptr validator=std::make_shared< NullValidator >(), const std::string &doc="", const unsigned int direction=Direction::Input)
	Add a property of the template type to the list of managed properties.

template<typename T >
void	declareProperty (const std::string &name, T value, const std::string &doc, const unsigned int direction=Direction::Input)
	Add a property to the list of managed properties with no validator.

template<typename T >
void	declareProperty (const std::string &name, T value, const unsigned int direction)
	Add a property of the template type to the list of managed properties.

void	declareProperty (const std::string &name, const char *value, IValidator_sptr validator=std::make_shared< NullValidator >(), const std::string &doc=std::string(), const unsigned int direction=Direction::Input)
	Specialised version of declareProperty template method to prevent the creation of a PropertyWithValue of type const char* if an argument in quotes is passed (it will be converted to a string).

void	declareProperty (const std::string &name, const char *value, const std::string &doc, IValidator_sptr validator=std::make_shared< NullValidator >(), const unsigned int direction=Direction::Input)
	Specialised version of declareProperty template method to prevent the creation of a PropertyWithValue of type const char* if an argument in quotes is passed (it will be converted to a string).

void	declareProperty (const std::string &name, const char *value, const unsigned int direction)
	Add a property of string type to the list of managed properties.

const std::string	category () const override
	function to return a category of the algorithm.

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

const std::string	categorySeparator () const override
	Function to return the separator token for the category string.

const std::vector< std::string >	seeAlso () const override
	Function to return all of the seeAlso (these are not validated) algorithms related to this algorithm.A default implementation is provided.

const std::string	alias () const override
	function to return any aliases to the algorithm; A default implementation is provided

const std::string	aliasDeprecated () const override
	Expiration date (in ISO8601 format) for the algorithm aliases; default implementation for no expiration date.

const std::string	helpURL () const override
	function to return URL for algorithm documentation; A default implementation is provided.

template<typename T , typename = typename std::enable_if<std::is_convertible<T , MatrixWorkspace >::value>::type>
std::tuple< std::shared_ptr< T >, Indexing::SpectrumIndexSet >	getWorkspaceAndIndices (const std::string &name) const
	Mechanism for retriving the index property.

template<typename T1 , typename T2 , typename = typename std::enable_if<std::is_convertible<T1 , MatrixWorkspace >::value>::type, typename = typename std::enable_if<std::is_convertible<T2 , std::string >::value \|\| std::is_convertible<T2 , std::vector<int64_t> >::value>::type>
void	setWorkspaceInputProperties (const std::string &name, const std::shared_ptr< T1 > &wksp, IndexType type, const T2 &list)
	Mechanism for setting the index property with a workspace shared pointer.

template<typename T1 , typename T2 , typename = typename std::enable_if<std::is_convertible<T1 , MatrixWorkspace >::value>::type, typename = typename std::enable_if<std::is_convertible<T2 , std::string >::value \|\| std::is_convertible<T2 , std::vector<int64_t> >::value>::type>
void	setWorkspaceInputProperties (const std::string &name, const std::string &wsName, IndexType type, const T2 &list)
	Mechanism for setting the index property with a workspace shared pointer.

const std::string	workspaceMethodName () const override

const std::vector< std::string >	workspaceMethodOn () const override

const std::string	workspaceMethodInputProperty () const override

AlgorithmID	getAlgorithmID () const override
	Algorithm ID.

Algorithms As Methods
Public Member Functions inherited from Mantid::Kernel::IPropertyManager
void	declareProperty (const std::string &name, const char *value, const std::string &doc, IValidator_sptr validator=std::make_shared< NullValidator >(), const unsigned int direction=Direction::Input)
	Specialised version of declareProperty template method to prevent the creation of a PropertyWithValue of type const char* if an argument in quotes is passed (it will be converted to a string).

void	declareProperty (const std::string &name, const char *value, const unsigned int direction)
	Add a property of string type to the list of managed properties.

void	declareProperty (const std::string &name, const char *value, IValidator_sptr validator=std::make_shared< NullValidator >(), const std::string &doc=std::string(), const unsigned int direction=Direction::Input)
	Specialised version of declareProperty template method to prevent the creation of a PropertyWithValue of type const char* if an argument in quotes is passed (it will be converted to a string).

template<typename T >
void	declareProperty (const std::string &name, T value, const std::string &doc, const unsigned int direction=Direction::Input)
	Add a property to the list of managed properties with no validator.

template<typename T >
void	declareProperty (const std::string &name, T value, const unsigned int direction)
	Add a property of the template type to the list of managed properties.

template<typename T >
void	declareProperty (const std::string &name, T value, IValidator_sptr validator=std::make_shared< NullValidator >(), const std::string &doc="", const unsigned int direction=Direction::Input)
	Add a property of the template type to the list of managed properties.

virtual void	filterByProperty (Mantid::Kernel::LogFilter *, const std::vector< std::string > &)

std::vector< Property * >	getPropertiesInGroup (const std::string &group) const
	Get the list of managed properties in a given group.

IPropertyManager *	setProperty (const std::string &name, const char *value)
	Specialised version of setProperty template method to handle const char *.

IPropertyManager *	setProperty (const std::string &name, const std::string &value)
	Specialised version of setProperty template method to handle std::string.

template<typename T >
IPropertyManager *	setProperty (const std::string &name, const T &value)
	Templated method to set the value of a PropertyWithValue.

template<typename T >
IPropertyManager *	setProperty (const std::string &name, std::unique_ptr< T > value)
	Templated method to set the value of a PropertyWithValue from a std::unique_ptr.

void	setPropertyGroup (const std::string &name, const std::string &group)
	Set the group for a given property.

void	setPropertySettings (const std::string &name, std::unique_ptr< IPropertySettings > settings)

void	updatePropertyValues (const IPropertyManager &other)
	Update values of the existing properties.

virtual	~IPropertyManager ()=default

Protected Member Functions
const std::shared_ptr< Geometry::CSGObject >	createCollimatorHexahedronShape (const Kernel::V3D &samplePos, const Mantid::Geometry::DetectorInfo &detectorInfo, const size_t &histogramIndex)

virtual std::unique_ptr< InterpolationOption >	createInterpolateOption ()
	Factory method to return an instance of the required InterpolationOption class.

virtual std::shared_ptr< SparseWorkspace >	createSparseWorkspace (const API::MatrixWorkspace &modelWS, const size_t nXPoints, const size_t rows, const size_t columns)
	Factory method to return an instance of the required SparseInstrument class.

void	getXMinMax (const Mantid::API::MatrixWorkspace &ws, double &xmin, double &xmax) const
	This is a variation on the function MatrixWorkspace::getXMinMax with some additional logic eg if x values are all NaN values it raises an error.

void	integrateCumulative (const DiscusData1D &h, const double xmin, const double xmax, std::vector< double > &resultX, std::vector< double > &resultY, const bool returnCumulative)
	Integrate a distribution between the supplied xmin and xmax values using trapezoid rule without any extrapolation on either end of the distribution Return the integral for each x value between xmin and xmax.

API::MatrixWorkspace_sptr	integrateWS (const API::MatrixWorkspace_sptr &ws)
	Create new workspace with y equal to integral across the bins.

double	Interpolate2D (const ComponentWorkspaceMapping &SQWSMapping, double q, double w)
	Interpolate value on S(Q,w) surface given a Q and w.

double	interpolateFlat (const DiscusData1D &histToInterpolate, double x)
	Interpolate function using flat interpolation from previous point.

double	interpolateGaussian (const DiscusData1D &histToInterpolate, double x)
	Interpolate a value from a spectrum containing Gaussian peaks.

double	interpolateSquareRoot (const DiscusData1D &histToInterpolate, double x)
	Interpolate function of the form y = a * sqrt(x - b) ie inverse of a quadratic Used to lookup value in the cumulative probability distribution of Q S(Q) which for flat S(Q) will be a quadratic.

void	prepareSampleBeamGeometry (const API::MatrixWorkspace_sptr &inputWS)

std::tuple< double, int >	sampleQW (const std::shared_ptr< DiscusData2D > &CumulativeProb, double x)
	Use importance sampling to choose a Q and w value for the scatter.

void	updateTrackDirection (Geometry::Track &track, const double cosT, const double phi)
	Update the track's direction following a scatter event given theta and phi angles.

Protected Member Functions inherited from Mantid::API::Algorithm
virtual const std::string	workspaceMethodOnTypes () const
	Returns a semi-colon separated list of workspace types to attach this algorithm.

void	cacheWorkspaceProperties ()
	Go through the properties and cache the input/output workspace properties for later use.

void	cacheInputWorkspaceHistories ()
	Cache the histories of any input workspaces so they can be copied over after algorithm completion.

void	setExecutionState (const ExecutionState state)
	Sets the current execution state.

void	setResultState (const ResultState state)
	Sets the result execution state.

void	store ()
	Stores any output workspaces into the AnalysisDataService.

void	progress (double p, const std::string &msg="", double estimatedTime=0.0, int progressPrecision=0)
	Sends ProgressNotification.

void	interruption_point ()
	This is called during long-running operations, and check if the algorithm has requested that it be cancelled.

Poco::NotificationCenter &	notificationCenter () const
	Return a reference to the algorithm's notification dispatcher.

void	handleChildProgressNotification (const Poco::AutoPtr< ProgressNotification > &pNf)
	Observation slot for child algorithm progress notification messages, these are scaled and then signalled for this algorithm.

const Poco::AbstractObserver &	progressObserver () const
	Return a reference to the algorithm's object that is reporting progress.

bool	isWorkspaceProperty (const Kernel::Property *const prop) const
	checks the property is a workspace property

bool	trackingHistory ()
	get whether we are tracking the history for this algorithm,

virtual void	fillHistory ()
	Copy workspace history from input workspaces to output workspaces and record the history for ths algorithm.

void	fillHistory (const std::vector< Workspace_sptr > &outputWorkspaces)
	Copy workspace history from input workspaces to provided vector of output workspaces.

virtual void	setOtherProperties (IAlgorithm *alg, const std::string &propertyName, const std::string &propertyValue, int periodNum)
	Virtual method to set the non workspace properties for this algorithm.

template<typename T , const int AllowedIndexTypes = static_cast<int>(IndexType::WorkspaceIndex), typename... WSPropArgs, typename = typename std::enable_if<std::is_convertible<T , MatrixWorkspace >::value>::type>
void	declareWorkspaceInputProperties (const std::string &propertyName, const std::string &doc, WSPropArgs &&...wsPropArgs)
	Declare a property which defines the workspace and allowed index types, as well as a property for capturing the indices all at once.

Protected Member Functions inherited from Mantid::Kernel::IPropertyManager
template<typename T >
T	getValue (const std::string &name) const
	Templated method to get the value of a property.

template<>
MANTID_KERNEL_DLL PropertyManager_sptr	getValue (const std::string &name) const

template<>
MANTID_KERNEL_DLL PropertyManager_const_sptr	getValue (const std::string &name) const

Private Member Functions
void	addWorkspaceToDiscus2DData (const Geometry::IObject_const_sptr &shape, const std::string_view &matName, API::MatrixWorkspace_sptr ws)
	Function to convert between a Matrix workspace and the internal simplified 2D data structure.

void	calculateQSQIntegralAsFunctionOfK (ComponentWorkspaceMappings &matWSs, const std::vector< double > &specialKs)
	This is a generalised version of the normalisation done in the original Discus algorithm The original algorithm only considered two scatters so there was only ever one scatter with a free direction after scatter that got a contribution from the q_dir function.

void	convertToLogWorkspace (const std::shared_ptr< DiscusData2D > &SOfQ)

void	convertWsBothAxesToPoints (API::MatrixWorkspace_sptr &ws)
	Convert x axis of a workspace to points if it's bin edges.

void	correctForWorkspaceNameClash (std::string &wsName)
	Adjust workspace name in case of clash in the ADS.

void	createInvPOfQWorkspaces (ComponentWorkspaceMappings &matWSs, size_t nhists)

API::MatrixWorkspace_sptr	createOutputWorkspace (const API::MatrixWorkspace &inputWS) const

void	exec () override
	Execution code.

const ComponentWorkspaceMapping *	findMatchingComponent (const ComponentWorkspaceMappings &componentWorkspaces, const Geometry::IObject *shapeObjectWithScatter)
	Lookup a sample or sample environment component in the supplied list.

Geometry::Track	generateInitialTrack (Kernel::PseudoRandomNumberGenerator &rng)
	Generate an initial track starting at the source and entering the sample/sample environment at a random point on its front surface.

std::vector< std::tuple< double, int, double > >	generateInputKOutputWList (const double efixed, const std::vector< double > &xPoints)
	Generate a list of the k and w points where calculation results are required.

double	getDoubleParamFromIDF (std::string paramName)

double	getKf (const double deltaE, const double kinc)

std::tuple< double, double >	getKinematicRange (double kf, double ki)
	Get the range of q values accessible for a particular kinc and kf.

double	getQSQIntegral (const DiscusData1D &QSQScaleFactor, double k)
	This is a generalised version of the normalisation done in the original Discus algorithm The original algorithm only considered two scatters so there was only ever one scatter with a free direction after scatter that got a contribution from the q_dir function.

Kernel::V3D	getV3DParamFromIDF (std::string paramName)

void	inc_xyz (Geometry::Track &track, double vl)
	Update the x, y, z position of the neutron (or dV volume element to integrate over).

void	init () override
	Initialize the algorithm.

std::tuple< std::vector< double >, std::vector< double >, std::vector< double > >	integrateQSQ (const std::shared_ptr< DiscusData2D > &QSQ, double kinc, const bool returnCumulative)
	Integrate QSQ over Q and w over the kinematic range accessible for a given kinc.

void	interpolateFromSparse (API::MatrixWorkspace &targetWS, const SparseWorkspace &sparseWS, const Mantid::Algorithms::InterpolationOption &interpOpt)

void	loadCollimatorInfo ()

std::tuple< double, double >	new_vector (const Kernel::Material &material, double k, bool specialSingleScatterCalc)
	Calculate a total cross section using a k-specific scattering cross section Note - a separate tabulated scattering cross section is used elsewhere in the calculation.

void	prepareCumulativeProbForQ (double kinc, const ComponentWorkspaceMappings &PInvOfQs)
	Calculate a cumulative probability distribution for use in importance sampling.

void	prepareQSQ (double kinc)
	Prepare a profile of Q*S(Q) that will later be used to calculate a cumulative probability distribution for use in importance sampling.

void	prepareStructureFactors ()

bool	q_dir (Geometry::Track &track, const Geometry::IObject *shapePtr, const ComponentWorkspaceMappings &invPOfQs, double &k, const double scatteringXSection, Kernel::PseudoRandomNumberGenerator &rng, double &weight)
	Update track direction and weight as a result of a scatter.

const std::shared_ptr< Geometry::CSGObject >	readFromCollimatorCorridorCache (const std::size_t &histogramIndex)

std::tuple< double, double, int, double >	sampleQWUniform (const std::vector< double > &wValues, Kernel::PseudoRandomNumberGenerator &rng, const double kinc)
	Sample the q and w value for a scattering event without importance sampling.

std::tuple< bool, std::vector< double > >	scatter (const int nScatters, Kernel::PseudoRandomNumberGenerator &rng, const ComponentWorkspaceMappings &componentWorkspaces, const double kinc, const std::vector< double > &wValues, bool specialSingleScatterCalc, const Mantid::Geometry::DetectorInfo &detectorInfo, const size_t &histogramIndex)
	Simulates a single neutron path through the sample to a specific detector position containing the specified number of scattering events.

void	setWorkspaceName (const API::MatrixWorkspace_sptr &ws, std::string wsName)
	Set the name on a workspace, adjusting for potential clashes in the ADS.

std::tuple< std::vector< double >, std::vector< double > >	simulatePaths (const int nEvents, const int nScatters, Kernel::PseudoRandomNumberGenerator &rng, const ComponentWorkspaceMappings &componentWorkspaces, const double kinc, const std::vector< double > &wValues, bool specialSingleScatterCalc, const Mantid::Geometry::DetectorInfo &detectorInfo, const size_t &histogramIndex)
	Simulates a set of neutron paths through the sample to a specific detector position with each path containing the specified number of scattering events.

Geometry::Track	start_point (Kernel::PseudoRandomNumberGenerator &rng)
	Repeatedly attempt to generate an initial track starting at the source and entering the sample at a random point on its front surface.

const Geometry::IObject *	updateWeightAndPosition (Geometry::Track &track, double &weight, const double k, Kernel::PseudoRandomNumberGenerator &rng, bool specialSingleScatterCalc, const ComponentWorkspaceMappings &componentWorkspaces)
	update track start point and weight.

std::map< std::string, std::string >	validateInputs () override
	Validate the input properties.

void	writeToCollimatorCorridorCache (const std::size_t &histogramIndex, const std::shared_ptr< Geometry::CSGObject > &collimatorCorridorCsgObj)

Private Attributes
Geometry::BoundingBox	m_activeRegion

std::map< int, int >	m_attemptsToGenerateInitialTrack

std::unique_ptr< IBeamProfile >	m_beamProfile

long long	m_callsToInterceptSurface {0}

std::map< std::size_t, std::shared_ptr< Geometry::CSGObject > >	m_collimatorCorridorCache

std::unique_ptr< CollimatorInfo >	m_collimatorInfo

Kernel::DeltaEMode::Type	m_EMode {Kernel::DeltaEMode::Undefined}

const Geometry::SampleEnvironment *	m_env {nullptr}

long long	m_IkCalculations {0}

bool	m_importanceSampling {}

Mantid::Geometry::Instrument_const_sptr	m_instrument

int	m_maxScatterPtAttempts {}

std::shared_mutex	m_mutexCorridorCache

bool	m_NormalizeSQ {}

std::shared_ptr< const Geometry::ReferenceFrame >	m_refframe

Geometry::IObject_const_sptr	m_sampleShape

std::shared_ptr< const DiscusData1D >	m_sigmaSS

bool	m_simulateEnergiesIndependently {}

Kernel::V3D	m_sourcePos

ComponentWorkspaceMappings	m_SQWSs

Additional Inherited Members
Static Public Member Functions inherited from Mantid::API::Algorithm
static IAlgorithm_sptr	fromString (const std::string &input)
	De-serialize an object from a string.

static IAlgorithm_sptr	fromJson (const Json::Value &input)
	De-serialize an object from a Json.

static IAlgorithm_sptr	fromHistory (const AlgorithmHistory &history)
	Construct an object from a history entry.

Public Attributes inherited from Mantid::API::Algorithm
bool	calledByAlias = false
	Flag to indicate if the algorithm is called by its alias.

Static Protected Member Functions inherited from Mantid::API::Algorithm
template<typename NumT >
static bool	isEmpty (const NumT toCheck)
	checks that the value was not set by users, uses the value in empty double/int.

Protected Attributes inherited from Mantid::API::Algorithm
std::atomic< bool >	m_cancel
	Set to true to stop execution.

std::atomic< bool >	m_parallelException
	Set if an exception is thrown, and not caught, within a parallel region.

std::vector< IWorkspaceProperty * >	m_inputWorkspaceProps
	All the WorkspaceProperties that are Input or InOut. Set in execute()

std::shared_ptr< AlgorithmHistory >	m_history
	Pointer to the history for the algorithm being executed.

Kernel::Logger	m_log
	Logger for this algorithm.

Kernel::Logger &	g_log

std::shared_ptr< AlgorithmHistory >	m_parentHistory
	Pointer to the parent history object (if set)

std::vector< WorkspaceVector >	m_unrolledInputWorkspaces
	One vector of workspaces for each input workspace property.

size_t	m_groupSize
	Size of the group(s) being processed.

bool	m_usingBaseProcessGroups = false
	distinguish between base processGroups() and overriden/algorithm specific versions

Static Protected Attributes inherited from Mantid::API::Algorithm
static size_t	g_execCount = 0
	Counter to keep track of algorithm execution order.

Detailed Description

Calculates a multiple scattering correction Based on Muscat Fortran code provided by Spencer Howells.

Author: Danny Hindson

Date: 2020-11-10

Definition at line 88 of file DiscusMultipleScatteringCorrection.h.

Member Typedef Documentation

◆ ComponentWorkspaceMappings

using Mantid::Algorithms::DiscusMultipleScatteringCorrection::ComponentWorkspaceMappings = boost::container::small_vector<ComponentWorkspaceMapping, 5>

Definition at line 91 of file DiscusMultipleScatteringCorrection.h.

Member Function Documentation

◆ addWorkspaceToDiscus2DData()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::addWorkspaceToDiscus2DData	(	const Geometry::IObject_const_sptr &	shape,
		const std::string_view &	matName,
		API::MatrixWorkspace_sptr	SQWS
	)

private

Function to convert between a Matrix workspace and the internal simplified 2D data structure.

This decouples the internal calculation logic from the Mantid workspaces

Definition at line 425 of file DiscusMultipleScatteringCorrection.cpp.

References convertToLogWorkspace(), convertWsBothAxesToPoints(), Mantid::API::Algorithm::createChildAlgorithm(), Mantid::Algorithms::ComponentWorkspaceMapping::logSQ, and m_SQWSs.

Referenced by prepareStructureFactors().

◆ alias()

const std::string Mantid::Algorithms::DiscusMultipleScatteringCorrection::alias ( ) const

inlineoverridevirtual

function to return any aliases of the algorithm.

Implements Mantid::API::IAlgorithm.

Definition at line 105 of file DiscusMultipleScatteringCorrection.h.

◆ calculateQSQIntegralAsFunctionOfK()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::calculateQSQIntegralAsFunctionOfK	(	ComponentWorkspaceMappings &	matWSs,
		const std::vector< double > &	specialKs
	)

private

This is a generalised version of the normalisation done in the original Discus algorithm The original algorithm only considered two scatters so there was only ever one scatter with a free direction after scatter that got a contribution from the q_dir function.

This meant that the k value going into the scatter was always fixed and equal to the overall kinc The approach here will cope with multiple scatters by calculating a sumQSS at multiple kinc values. These will be interpolated as required later on

Parameters

matWSs	List of workspaces related to the structure factor for each sample/env component
specialKs	A list of special k values that the QSQ integral will be calculated for to reduce amount of interpolation required later on

Definition at line 994 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Kernel::DeltaEMode::Elastic, integrateCumulative(), integrateQSQ(), and m_EMode.

Referenced by exec().

◆ category()

const std::string Mantid::Algorithms::DiscusMultipleScatteringCorrection::category ( ) const

inlineoverridevirtual

Algorithm's category for identification.

Implements Mantid::API::IAlgorithm.

Definition at line 100 of file DiscusMultipleScatteringCorrection.h.

◆ checkGroups()

bool Mantid::Algorithms::DiscusMultipleScatteringCorrection::checkGroups ( )

inlineoverridevirtual

Check the input workspace properties for groups.

If there are more than one input workspace properties, then:

All inputs should be groups of the same size
- In this case, algorithms are processed in order
OR, only one input should be a group, the others being size of 1

If the property itself is a WorkspaceProperty<WorkspaceGroup> then this returns false

Returns true if processGroups() should be called. It also sets up some other members.

Override if it is needed to customize the group checking.

Exceptions

std::invalid_argument	if the groups sizes are incompatible.
std::invalid_argument	if a member is not found

This method (or an override) must NOT THROW any exception if there are no input workspace groups

Reimplemented from Mantid::API::Algorithm.

Definition at line 106 of file DiscusMultipleScatteringCorrection.h.

◆ convertToLogWorkspace()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::convertToLogWorkspace ( const std::shared_ptr< DiscusData2D > & SOfQ )

private

Definition at line 967 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Geometry::d.

Referenced by addWorkspaceToDiscus2DData().

◆ convertWsBothAxesToPoints()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::convertWsBothAxesToPoints ( API::MatrixWorkspace_sptr & ws )

private

Convert x axis of a workspace to points if it's bin edges.

If the spectrum axis is a numeric axis and also bin edges convert that to points as well

Parameters

ws	The workspace that will potentially be converted

Definition at line 462 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Kernel::VectorHelper::convertToBinCentre(), Mantid::API::Algorithm::createChildAlgorithm(), Mantid::API::NumericAxis::getValues(), Mantid::Kernel::SingletonHolder< T >::Instance(), and m_importanceSampling.

Referenced by addWorkspaceToDiscus2DData().

◆ correctForWorkspaceNameClash()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::correctForWorkspaceNameClash ( std::string & wsName )

private

Adjust workspace name in case of clash in the ADS.

Was mainly of value when member workspaces didn't have the group name as a prefix but have left this in place in case there is a clash for any reason

Parameters

wsName The name to set on the workspace

Definition at line 2128 of file DiscusMultipleScatteringCorrection.cpp.

References std::to_string().

Referenced by setWorkspaceName().

◆ createCollimatorHexahedronShape()

const std::shared_ptr< Geometry::CSGObject > Mantid::Algorithms::DiscusMultipleScatteringCorrection::createCollimatorHexahedronShape	(	const Kernel::V3D &	samplePos,
		const Mantid::Geometry::DetectorInfo &	detectorInfo,
		const size_t &	histogramIndex
	)

protected

Definition at line 1539 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Geometry::ShapeFactory::createShape(), Mantid::Geometry::detail::ShapeInfo::CUBOID, Mantid::Geometry::DetectorInfo::detector(), Mantid::Geometry::IDetector::getID(), Mantid::Geometry::DetectorInfo::indexOf(), m_collimatorInfo, Mantid::Kernel::normalize(), Mantid::Geometry::DetectorInfo::position(), readFromCollimatorCorridorCache(), Mantid::Geometry::IObjComponent::shape(), and writeToCollimatorCorridorCache().

◆ createInterpolateOption()

std::unique_ptr< InterpolationOption > Mantid::Algorithms::DiscusMultipleScatteringCorrection::createInterpolateOption ( )

protectedvirtual

Factory method to return an instance of the required InterpolationOption class.

Returns: a pointer to an InterpolationOption object

Definition at line 2092 of file DiscusMultipleScatteringCorrection.cpp.

◆ createInvPOfQWorkspaces()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::createInvPOfQWorkspaces	(	ComponentWorkspaceMappings &	matWSs,
		size_t	nhists
	)

private

Definition at line 2063 of file DiscusMultipleScatteringCorrection.cpp.

References value.

Referenced by exec().

◆ createOutputWorkspace()

MatrixWorkspace_sptr Mantid::Algorithms::DiscusMultipleScatteringCorrection::createOutputWorkspace ( const API::MatrixWorkspace & inputWS ) const

private

Definition at line 2077 of file DiscusMultipleScatteringCorrection.cpp.

Referenced by exec().

◆ createSparseWorkspace()

std::shared_ptr< SparseWorkspace > Mantid::Algorithms::DiscusMultipleScatteringCorrection::createSparseWorkspace	(	const API::MatrixWorkspace &	modelWS,
		const size_t	nXPoints,
		const size_t	rows,
		const size_t	columns
	)

protectedvirtual

Factory method to return an instance of the required SparseInstrument class.

Parameters

modelWS	The full workspace that the sparse one will be based on
nXPoints	The number of x points (k or w) to include in the histograms in the sparse workspace
rows	The number of rows of detectors to create
columns	The number of columns of detectors to create

Returns: a pointer to an SparseInstrument object

Definition at line 2057 of file DiscusMultipleScatteringCorrection.cpp.

Referenced by exec().

◆ exec()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::exec ( )

overrideprivatevirtual

Execution code.

Implements Mantid::API::Algorithm.

Definition at line 497 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Algorithms::InterpolationOption::applyInplace(), Mantid::Kernel::DeltaEMode::asString(), calculateQSQIntegralAsFunctionOfK(), Mantid::API::Algorithm::createChildAlgorithm(), createInvPOfQWorkspaces(), createOutputWorkspace(), createSparseWorkspace(), Mantid::API::ExperimentInfo::detectorInfo(), Mantid::Kernel::DeltaEMode::Direct, Mantid::Kernel::efixed, Mantid::Kernel::DeltaEMode::Elastic, Mantid::API::Algorithm::g_log, generateInputKOutputWList(), Mantid::API::Algorithm::getAlwaysStoreInADS(), Mantid::API::MatrixWorkspace::getNumberHistograms(), Mantid::API::Algorithm::getProperty(), Mantid::API::Algorithm::getPropertyValue(), Mantid::API::MatrixWorkspace::getSpectrum(), Mantid::API::ISpectrum::getSpectrumNo(), getXMinMax(), Mantid::Kernel::Logger::information(), integrateWS(), interpolateFromSparse(), Mantid::Kernel::Logger::is(), Mantid::API::Algorithm::isEmpty(), loadCollimatorInfo(), m_attemptsToGenerateInitialTrack, m_callsToInterceptSurface, m_EMode, m_IkCalculations, m_importanceSampling, m_maxScatterPtAttempts, m_NormalizeSQ, m_sigmaSS, m_simulateEnergiesIndependently, m_SQWSs, PARALLEL_CHECK_INTERRUPT_REGION, PARALLEL_END_INTERRUPT_REGION, PARALLEL_FOR_IF, PARALLEL_START_INTERRUPT_REGION, Mantid::API::MatrixWorkspace::points(), prepareCumulativeProbForQ(), prepareQSQ(), prepareSampleBeamGeometry(), prepareStructureFactors(), Mantid::Kernel::ProgressBase::report(), Mantid::Algorithms::InterpolationOption::set(), Mantid::Kernel::ProgressBase::setNotifyStep(), Mantid::Kernel::IPropertyManager::setProperty(), setWorkspaceName(), simulatePaths(), Mantid::API::ExperimentInfo::spectrumInfo(), Mantid::Kernel::threadSafe(), std::to_string(), and Mantid::Kernel::Logger::warning().

◆ findMatchingComponent()

const ComponentWorkspaceMapping * Mantid::Algorithms::DiscusMultipleScatteringCorrection::findMatchingComponent	(	const ComponentWorkspaceMappings &	componentWorkspaces,
		const Geometry::IObject *	shapeObjectWithScatter
	)

private

Lookup a sample or sample environment component in the supplied list.

Parameters

componentWorkspaces	The list of components, each with some associated workspaces
shapeObjectWithScatter	A pointer to the component shape that is to be looked up

Returns: an iterator to the found sample or sample environment component

Definition at line 2164 of file DiscusMultipleScatteringCorrection.cpp.

Referenced by q_dir(), and updateWeightAndPosition().

◆ generateInitialTrack()

Geometry::Track Mantid::Algorithms::DiscusMultipleScatteringCorrection::generateInitialTrack ( Kernel::PseudoRandomNumberGenerator & rng )

private

Generate an initial track starting at the source and entering the sample/sample environment at a random point on its front surface.

Parameters

rng	Random number generator

Returns: a track

Definition at line 2012 of file DiscusMultipleScatteringCorrection.cpp.

References m_activeRegion, m_beamProfile, m_refframe, and m_sourcePos.

Referenced by start_point().

◆ generateInputKOutputWList()

std::vector< std::tuple< double, int, double > > Mantid::Algorithms::DiscusMultipleScatteringCorrection::generateInputKOutputWList	(	const double	efixed,
		const std::vector< double > &	xPoints
	)

private

Generate a list of the k and w points where calculation results are required.

The w points are expressed as bin indices and values. The special bin index value -1 means calculate results for all w bins in the innermost calculation loop using a single set of simulated tracks

Parameters

efixed	The fixed energy (or zero if an elastic calculation)
xPoints	The x points either in momentum (elastic) or energy transfer (inelastic)

Definition at line 795 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Geometry::d, Mantid::Kernel::DeltaEMode::Direct, Mantid::Kernel::efixed, Mantid::Kernel::DeltaEMode::Elastic, index, Mantid::Kernel::DeltaEMode::Indirect, m_EMode, and m_simulateEnergiesIndependently.

Referenced by exec().

◆ getDoubleParamFromIDF()

double Mantid::Algorithms::DiscusMultipleScatteringCorrection::getDoubleParamFromIDF ( std::string paramName )

private

Definition at line 1689 of file DiscusMultipleScatteringCorrection.cpp.

References m_instrument.

Referenced by loadCollimatorInfo().

◆ getKf()

double Mantid::Algorithms::DiscusMultipleScatteringCorrection::getKf	(	const double	deltaE,
		const double	kinc
	)

private

Definition at line 1720 of file DiscusMultipleScatteringCorrection.cpp.

Referenced by integrateQSQ(), and q_dir().

◆ getKinematicRange()

std::tuple< double, double > Mantid::Algorithms::DiscusMultipleScatteringCorrection::getKinematicRange	(	double	kf,
		double	ki
	)

private

Get the range of q values accessible for a particular kinc and kf.

Since the kinc value is known during the simulation this is similar to direct geometry kinematics w | — |_/________Q | \ \ | \ \

Parameters

kf	The wavevector after the scatter event
ki	The wavevector before the scatter event

Returns: a tuple containing qmin and the qrange

Definition at line 1746 of file DiscusMultipleScatteringCorrection.cpp.

Referenced by integrateQSQ().

◆ getQSQIntegral()

double Mantid::Algorithms::DiscusMultipleScatteringCorrection::getQSQIntegral	(	const DiscusData1D &	QSQScaleFactor,
		double	k
	)

private

This is a generalised version of the normalisation done in the original Discus algorithm The original algorithm only considered two scatters so there was only ever one scatter with a free direction after scatter that got a contribution from the q_dir function.

This meant that the k value going into the scatter was always fixed and equal to the overall kinc The approach here will cope with multiple scatters by calculating a sumQSS at each required kinc values and cache the results

Definition at line 1802 of file DiscusMultipleScatteringCorrection.cpp.

References interpolateFlat().

Referenced by q_dir().

◆ getV3DParamFromIDF()

Kernel::V3D Mantid::Algorithms::DiscusMultipleScatteringCorrection::getV3DParamFromIDF ( std::string paramName )

private

Definition at line 1701 of file DiscusMultipleScatteringCorrection.cpp.

References m_instrument.

Referenced by loadCollimatorInfo().

◆ getXMinMax()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::getXMinMax	(	const Mantid::API::MatrixWorkspace &	ws,
		double &	xmin,
		double &	xmax
	)		const

protected

This is a variation on the function MatrixWorkspace::getXMinMax with some additional logic eg if x values are all NaN values it raises an error.

Parameters

ws	Workspace to scan for min and max x values
xmin	In/out parameter for min x value found
xmax	In/out parameter for max x value found

Definition at line 355 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::API::MatrixWorkspace::getNumberHistograms(), Mantid::API::MatrixWorkspace::points(), and Mantid::API::ExperimentInfo::spectrumInfo().

Referenced by exec().

◆ inc_xyz()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::inc_xyz	(	Geometry::Track &	track,
		double	vl
	)

private

Update the x, y, z position of the neutron (or dV volume element to integrate over).

Save new start point in to the track object supplied along

Parameters

track	A track defining the current trajectory
vl	A distance to move along the current trajectory

Definition at line 2036 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Geometry::Track::clearIntersectionResults(), Mantid::Geometry::Track::direction(), Mantid::Geometry::Track::front(), position, Mantid::Geometry::Track::reset(), Mantid::Geometry::x, Mantid::Geometry::y, and Mantid::Geometry::z.

Referenced by updateWeightAndPosition().

◆ init()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::init ( )

overrideprivatevirtual

Initialize the algorithm.

Implements Mantid::API::Algorithm.

Definition at line 107 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::EMPTY_INT(), Mantid::Kernel::Direction::Input, Mantid::API::PropertyMode::Optional, and Mantid::Kernel::Direction::Output.

◆ integrateCumulative()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::integrateCumulative	(	const DiscusData1D &	h,
		const double	xmin,
		const double	xmax,
		std::vector< double > &	resultX,
		std::vector< double > &	resultY,
		const bool	returnCumulative
	)

protected

Integrate a distribution between the supplied xmin and xmax values using trapezoid rule without any extrapolation on either end of the distribution Return the integral for each x value between xmin and xmax.

This is the main reason the Integration algorithm isn't used. The Integration algorithm also has some unexpected behaviour for points datasets Return two vectors rather than a histogram for performance reasons and to make transposing it easier

Parameters

h	Histogram object containing the distribution to integrate
xmin	The lower integration limit
xmax	The upper integration limit
resultX	The x values at which the integral has been calculated
resultY	the values of the integral at various x values up to xmax
returnCumulative	Flag to indicate whether the function should return the cumulative integral at each x value in the histogram or whether to just return the total integral (quicker)

Definition at line 1068 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::PhysicalConstants::h, std::to_string(), and Mantid::Geometry::x.

Referenced by calculateQSQIntegralAsFunctionOfK(), and integrateQSQ().

◆ integrateQSQ()

std::tuple< std::vector< double >, std::vector< double >, std::vector< double > > Mantid::Algorithms::DiscusMultipleScatteringCorrection::integrateQSQ	(	const std::shared_ptr< DiscusData2D > &	QSQ,
		double	kinc,
		const bool	returnCumulative
	)

private

Integrate QSQ over Q and w over the kinematic range accessible for a given kinc.

Parameters

kinc	The incident wavenumber
QSQ	A workspace containing Q.S(Q,w) with each spectra S(Q) at a particular w
returnCumulative	A flag indicating whether the function should return the cumulative integral at each q value or just the total (quicker)

Returns: a tuple containing a cumulative integral as a function of a pseudo variable based on the q values for each w concatenated into a single 1D sequence, the q values corresponding to each value of the pseudo variable, the w values corresponding to each value of the pseudo variable

Definition at line 884 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Kernel::VectorHelper::convertToBinBoundary(), Mantid::Geometry::d, getKf(), getKinematicRange(), integrateCumulative(), and m_IkCalculations.

Referenced by calculateQSQIntegralAsFunctionOfK(), and prepareCumulativeProbForQ().

◆ integrateWS()

API::MatrixWorkspace_sptr Mantid::Algorithms::DiscusMultipleScatteringCorrection::integrateWS ( const API::MatrixWorkspace_sptr & ws )

protected

Create new workspace with y equal to integral across the bins.

Parameters

ws	The workspace whose spectra need integrating

Returns: A workspace containing the integrals

Definition at line 1160 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::API::Algorithm::createChildAlgorithm().

Referenced by exec().

◆ Interpolate2D()

double Mantid::Algorithms::DiscusMultipleScatteringCorrection::Interpolate2D	(	const ComponentWorkspaceMapping &	SQWSMapping,
		double	q,
		double	w
	)

protected

Interpolate value on S(Q,w) surface given a Q and w.

For now there is no interpolation between w values so the nearest one is taken. Also S(Q,w) is assumed to be zero for w beyond the w limits of the supplied surface. S(Q,w) is assumed to equal the extreme value for q beyond the q limits

Parameters

SQWSMapping	A set of workspaces related to the structure factor to interpolate
q	The momentum transfer (q) value to interpolate at
w	The energy transfer (w) value to interpolate at

Returns: The interpolated S(Q,w) value

Definition at line 1315 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Kernel::VectorHelper::indexOfValueFromCentersNoThrow(), interpolateFlat(), interpolateGaussian(), Mantid::Algorithms::ComponentWorkspaceMapping::logSQ, m_importanceSampling, and Mantid::Algorithms::ComponentWorkspaceMapping::SQ.

◆ interpolateFlat()

double Mantid::Algorithms::DiscusMultipleScatteringCorrection::interpolateFlat	(	const DiscusData1D &	histToInterpolate,
		double	x
	)

protected

Interpolate function using flat interpolation from previous point.

Parameters

histToInterpolate	The histogram containing the data to interpolate
x	The x value to interpolate at

Returns: The interpolated value

Definition at line 1248 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Algorithms::DiscusData1D::X, Mantid::Geometry::x, and Mantid::Algorithms::DiscusData1D::Y.

Referenced by getQSQIntegral(), Interpolate2D(), new_vector(), and sampleQW().

◆ interpolateFromSparse()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::interpolateFromSparse	(	API::MatrixWorkspace &	targetWS,
		const SparseWorkspace &	sparseWS,
		const Mantid::Algorithms::InterpolationOption &	interpOpt
	)

private

Definition at line 2097 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Algorithms::InterpolationOption::applyInPlace(), Mantid::Algorithms::SparseWorkspace::bilinearInterpolateFromDetectorGrid(), Mantid::API::ExperimentInfo::getInstrument(), Mantid::API::MatrixWorkspace::histogram(), Mantid::API::MatrixWorkspace::mutableY(), PARALLEL_CHECK_INTERRUPT_REGION, PARALLEL_END_INTERRUPT_REGION, PARALLEL_FOR_IF, PARALLEL_START_INTERRUPT_REGION, Mantid::API::MatrixWorkspace::setHistogram(), Mantid::API::ExperimentInfo::spectrumInfo(), and Mantid::Kernel::threadSafe().

Referenced by exec().

◆ interpolateGaussian()

double Mantid::Algorithms::DiscusMultipleScatteringCorrection::interpolateGaussian	(	const DiscusData1D &	histToInterpolate,
		double	x
	)

protected

Interpolate a value from a spectrum containing Gaussian peaks.

The log of the spectrum has previously been taken so this method does a quadratic interpolation and returns e^y

Parameters

histToInterpolate	The histogram containing the data to interpolate
x	The x value to interpolate at

Returns: The exponential of the interpolated value

Definition at line 1271 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Algorithms::DiscusData1D::X, Mantid::Geometry::x, Mantid::Algorithms::DiscusData1D::Y, and Mantid::Geometry::y.

Referenced by Interpolate2D(), and q_dir().

◆ interpolateSquareRoot()

double Mantid::Algorithms::DiscusMultipleScatteringCorrection::interpolateSquareRoot	(	const DiscusData1D &	histToInterpolate,
		double	x
	)

protected

Interpolate function of the form y = a * sqrt(x - b) ie inverse of a quadratic Used to lookup value in the cumulative probability distribution of Q S(Q) which for flat S(Q) will be a quadratic.

Definition at line 1220 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Algorithms::DiscusData1D::X, Mantid::Geometry::x, and Mantid::Algorithms::DiscusData1D::Y.

Referenced by sampleQW().

◆ loadCollimatorInfo()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::loadCollimatorInfo ( )

private

Definition at line 1674 of file DiscusMultipleScatteringCorrection.cpp.

References getDoubleParamFromIDF(), Mantid::API::Algorithm::getProperty(), getV3DParamFromIDF(), m_collimatorCorridorCache, and m_collimatorInfo.

Referenced by exec().

◆ name()

const std::string Mantid::Algorithms::DiscusMultipleScatteringCorrection::name ( ) const

inlineoverridevirtual

Algorithm's name.

Implements Mantid::API::Algorithm.

Definition at line 93 of file DiscusMultipleScatteringCorrection.h.

◆ new_vector()

std::tuple< double, double > Mantid::Algorithms::DiscusMultipleScatteringCorrection::new_vector	(	const Kernel::Material &	material,
		double	k,
		bool	specialSingleScatterCalc
	)

private

Calculate a total cross section using a k-specific scattering cross section Note - a separate tabulated scattering cross section is used elsewhere in the calculation.

Parameters

material	The sample material
k	The wavenumber where the cross sections are required
specialSingleScatterCalc	Boolean indicating whether special single scatter calculation should be performed

Returns: A tuple containing the total cross section and the scattering cross section

Definition at line 1183 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Kernel::Material::absorbXSection(), interpolateFlat(), m_sigmaSS, and Mantid::Kernel::Material::totalScatterXSection().

Referenced by updateWeightAndPosition().

◆ prepareCumulativeProbForQ()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::prepareCumulativeProbForQ	(	double	kinc,
		const ComponentWorkspaceMappings &	materialWorkspaces
	)

private

Calculate a cumulative probability distribution for use in importance sampling.

The distribution is the inverse function P^-1(t4) where P(Q) = I(Q)/I(2k) and I(x) = integral of Q.S(Q)dQ between 0 and x

Parameters

kinc	The incident wavenumber
materialWorkspaces	List of workspaces for each material. Of particular interest here is the inverted cumulative probability distribution which is updated by this method

Definition at line 941 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Geometry::d, and integrateQSQ().

Referenced by exec().

◆ prepareQSQ()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::prepareQSQ ( double qmax )

private

Prepare a profile of Q*S(Q) that will later be used to calculate a cumulative probability distribution for use in importance sampling.

Parameters

qmax	The maxmimum q value required based on the data in the InputWorkspace

Definition at line 832 of file DiscusMultipleScatteringCorrection.cpp.

References m_SQWSs.

Referenced by exec().

◆ prepareSampleBeamGeometry()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::prepareSampleBeamGeometry ( const API::MatrixWorkspace_sptr & inputWS )

protected

Definition at line 2179 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Geometry::SampleEnvironment::boundingBox(), Mantid::Algorithms::BeamProfileFactory::createBeamProfile(), Mantid::Geometry::BoundingBox::grow(), m_activeRegion, m_beamProfile, m_env, m_instrument, m_refframe, m_sampleShape, and m_sourcePos.

Referenced by exec().

◆ prepareStructureFactors()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::prepareStructureFactors ( )

private

Definition at line 381 of file DiscusMultipleScatteringCorrection.cpp.

References addWorkspaceToDiscus2DData(), Mantid::API::Algorithm::g_log, Mantid::Geometry::SampleEnvironment::getComponent(), Mantid::Geometry::SampleEnvironment::getComponentPtr(), Mantid::Geometry::SampleEnvironment::getContainer(), Mantid::API::Algorithm::getProperty(), Mantid::Geometry::Container::getShapePtr(), Mantid::Kernel::Logger::information(), m_env, m_sampleShape, m_SQWSs, Mantid::Geometry::IObject::material(), Mantid::Geometry::Container::material(), Mantid::Kernel::Material::name(), and Mantid::Geometry::SampleEnvironment::nelements().

Referenced by exec().

◆ q_dir()

bool Mantid::Algorithms::DiscusMultipleScatteringCorrection::q_dir	(	Geometry::Track &	track,
		const Geometry::IObject *	shapePtr,
		const ComponentWorkspaceMappings &	componentWorkspaces,
		double &	k,
		const double	scatteringXSection,
		Kernel::PseudoRandomNumberGenerator &	rng,
		double &	weight
	)

private

Update track direction and weight as a result of a scatter.

Parameters

track	The track whose direction will be updated
shapePtr	A pointer to the shape in which the scatter is happening
componentWorkspaces	list of workspaces related to the structure factor for each sample/env component
k	The wavevector. Updated from the pre-scatter to post-scatter wavevector during the function
scatteringXSection	The scattering cross section of the material where the scatter happens
rng	Random number generator
weight	The current weight for this track. Updated to include this scatter during the function

Definition at line 1818 of file DiscusMultipleScatteringCorrection.cpp.

References findMatchingComponent(), getKf(), getQSQIntegral(), interpolateGaussian(), m_importanceSampling, Mantid::Kernel::PseudoRandomNumberGenerator::nextValue(), sampleQW(), sampleQWUniform(), and updateTrackDirection().

◆ readFromCollimatorCorridorCache()

const std::shared_ptr< Geometry::CSGObject > Mantid::Algorithms::DiscusMultipleScatteringCorrection::readFromCollimatorCorridorCache ( const std::size_t & histogramIndex )

private

Definition at line 1659 of file DiscusMultipleScatteringCorrection.cpp.

References m_collimatorCorridorCache, and m_mutexCorridorCache.

Referenced by createCollimatorHexahedronShape().

◆ sampleQW()

std::tuple< double, int > Mantid::Algorithms::DiscusMultipleScatteringCorrection::sampleQW	(	const std::shared_ptr< DiscusData2D > &	CumulativeProb,
		double	x
	)

protected

Use importance sampling to choose a Q and w value for the scatter.

Parameters

CumulativeProb	The inverse of the cumulative probability distribution. Both spectra have x set to 0-1. The first spectrum has y set to Q values and the second spectrum as y set to w index values
x	A randomly chosen value between 0 and 1

Returns: A tuple containing the sampled Q value and the index of the sampled w value in the S(Q,w) distribution

Definition at line 1210 of file DiscusMultipleScatteringCorrection.cpp.

References interpolateFlat(), interpolateSquareRoot(), and Mantid::Geometry::x.

Referenced by q_dir().

◆ sampleQWUniform()

std::tuple< double, double, int, double > Mantid::Algorithms::DiscusMultipleScatteringCorrection::sampleQWUniform	(	const std::vector< double > &	wValues,
		Kernel::PseudoRandomNumberGenerator &	rng,
		const double	kinc
	)

private

Sample the q and w value for a scattering event without importance sampling.

Parameters

wValues	The energy transfer values from the S(Q,w) workspace
rng	Random number generator
kinc	The wavevector before the scatter event

Returns: a tuple containing the sampled q, qrange, w and wrange values

Definition at line 1759 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Kernel::VectorHelper::convertToBinBoundary(), Mantid::Kernel::VectorHelper::indexOfValueFromCentersNoThrow(), and Mantid::Kernel::PseudoRandomNumberGenerator::nextValue().

Referenced by q_dir().

◆ scatter()

std::tuple< bool, std::vector< double > > Mantid::Algorithms::DiscusMultipleScatteringCorrection::scatter	(	const int	nScatters,
		Kernel::PseudoRandomNumberGenerator &	rng,
		const ComponentWorkspaceMappings &	componentWorkspaces,
		const double	kinc,
		const std::vector< double > &	wValues,
		bool	specialSingleScatterCalc,
		const Mantid::Geometry::DetectorInfo &	detectorInfo,
		const size_t &	histogramIndex
	)

private

Simulates a single neutron path through the sample to a specific detector position containing the specified number of scattering events.

Each path represents a group of neutrons and the proportion of neutrons making it to the destination without being scattered or absorbed is calculated as a weight using the cross section information from the sample material

Parameters

nScatters	The number of scattering events to simulate along each path
rng	Random number generator
componentWorkspaces	list of workspaces related to the structure factor for each sample/env component
kinc	The incident wavevector
wValues	A vector of overall energy transfers
specialSingleScatterCalc	Boolean indicating whether special single
detectorInfo	Obeject to get detector information
histogramIndex	Index of the current histogram being processed

Returns: A tuple containing a success/fail boolean and the calculated weights across the n-1 multiple scatters

Definition at line 1421 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Kernel::V3D::norm(), and Mantid::Kernel::V3D::normalize().

◆ seeAlso()

const std::vector< std::string > Mantid::Algorithms::DiscusMultipleScatteringCorrection::seeAlso ( ) const

inlineoverridevirtual

Function to return all of the seeAlso algorithms related to this algorithm.

Implements Mantid::API::IAlgorithm.

Definition at line 96 of file DiscusMultipleScatteringCorrection.h.

◆ setWorkspaceName()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::setWorkspaceName	(	const API::MatrixWorkspace_sptr &	ws,
		std::string	wsName
	)

private

Set the name on a workspace, adjusting for potential clashes in the ADS.

Used to set the names on the output workspace group members. N

Parameters

ws	The ws to set the name on
wsName	The name to set on the workspace

Definition at line 2152 of file DiscusMultipleScatteringCorrection.cpp.

References correctForWorkspaceNameClash().

Referenced by exec().

◆ simulatePaths()

std::tuple< std::vector< double >, std::vector< double > > Mantid::Algorithms::DiscusMultipleScatteringCorrection::simulatePaths	(	const int	nPaths,
		const int	nScatters,
		Kernel::PseudoRandomNumberGenerator &	rng,
		const ComponentWorkspaceMappings &	componentWorkspaces,
		const double	kinc,
		const std::vector< double > &	wValues,
		bool	specialSingleScatterCalc,
		const Mantid::Geometry::DetectorInfo &	detectorInfo,
		const size_t &	histogramIndex
	)

private

Simulates a set of neutron paths through the sample to a specific detector position with each path containing the specified number of scattering events.

Each path represents a group of neutrons and the proportion of neutrons making it to the destination without being scattered or absorbed is calculated as a weight using the cross section information from the sample material. The average weight across all the simulated paths is returned

Parameters

nPaths	The number of paths to simulate
nScatters	The number of scattering events to simulate along each path
rng	Random number generator
componentWorkspaces	list of workspaces related to the structure factor for each sample/env component
kinc	The incident wavevector
wValues	A vector of overall energy transfers
specialSingleScatterCalc	Boolean indicating whether special single
detectorInfo	Obeject to get detector information
histogramIndex	Index for the current histogram being processed

Returns: An average weight across all of the paths

Definition at line 1362 of file DiscusMultipleScatteringCorrection.cpp.

References count, and Mantid::Geometry::d.

Referenced by exec().

◆ start_point()

Geometry::Track Mantid::Algorithms::DiscusMultipleScatteringCorrection::start_point ( Kernel::PseudoRandomNumberGenerator & rng )

private

Repeatedly attempt to generate an initial track starting at the source and entering the sample at a random point on its front surface.

After each attempt check the track has at least one intercept with sample shape (sometimes for tracks very close to the surface this can sometimes be zero due to numerical precision)

Parameters

rng	Random number generator

Returns: a track intercepting the sample

Definition at line 1915 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::API::Algorithm::g_log, generateInitialTrack(), Mantid::Geometry::SampleEnvironment::interceptSurfaces(), Mantid::Kernel::Logger::is(), m_attemptsToGenerateInitialTrack, m_callsToInterceptSurface, m_env, m_maxScatterPtAttempts, m_sampleShape, Mantid::Geometry::SampleEnvironment::nelements(), and std::to_string().

◆ summary()

const std::string Mantid::Algorithms::DiscusMultipleScatteringCorrection::summary ( ) const

inlineoverridevirtual

Summary of algorithms purpose.

Implements Mantid::API::Algorithm.

Definition at line 102 of file DiscusMultipleScatteringCorrection.h.

◆ updateTrackDirection()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::updateTrackDirection	(	Geometry::Track &	track,
		const double	cosT,
		const double	phi
	)

protected

Update the track's direction following a scatter event given theta and phi angles.

Parameters

track	The track whose direction will be updated
cosT	Cos two theta. two theta is scattering angle
phi	Phi (radians) of after track. Measured in plane perpendicular to initial trajectory

Definition at line 1865 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Geometry::Track::direction(), Mantid::Geometry::Track::reset(), and Mantid::Geometry::Track::startPoint().

Referenced by q_dir().

◆ updateWeightAndPosition()

const Geometry::IObject * Mantid::Algorithms::DiscusMultipleScatteringCorrection::updateWeightAndPosition	(	Geometry::Track &	track,
		double &	weight,
		const double	k,
		Kernel::PseudoRandomNumberGenerator &	rng,
		bool	specialSingleScatterCalc,
		const ComponentWorkspaceMappings &	componentWorkspaces
	)

private

update track start point and weight.

The weight is based on a change of variables from length to t1 as described in Mancinelli paper

Parameters

track	A track defining the current trajectory
weight	The weight for the current path that is about to be updated
k	The wavevector of the track
rng	Random number generator
specialSingleScatterCalc	Boolean indicating whether special single scatter calculation should be performed
componentWorkspaces	list of workspaces related to the structure factor for each sample/env component

Returns: the shape object for the component where the scatter occurred

Definition at line 1949 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Geometry::Track::cbegin(), Mantid::Geometry::Track::cend(), Mantid::Geometry::Track::count(), findMatchingComponent(), Mantid::API::Algorithm::g_log, inc_xyz(), Mantid::Kernel::Logger::is(), new_vector(), and Mantid::Kernel::PseudoRandomNumberGenerator::nextValue().

◆ validateInputs()

std::map< std::string, std::string > Mantid::Algorithms::DiscusMultipleScatteringCorrection::validateInputs ( void )

overrideprivatevirtual

Validate the input properties.

Returns: a map where keys are property names and values the found issues

Implements Mantid::API::IAlgorithm.

Definition at line 199 of file DiscusMultipleScatteringCorrection.cpp.

References Mantid::Kernel::DeltaEMode::Elastic, Mantid::API::Algorithm::getProperty(), Mantid::API::Algorithm::getPropertyValue(), Mantid::API::NumericAxis::getValues(), Mantid::Kernel::DeltaEMode::Indirect, Mantid::API::Algorithm::isEmpty(), Mantid::Algorithms::InterpolationOption::set(), std::to_string(), Mantid::Kernel::EqualBinsChecker::validate(), Mantid::Algorithms::InterpolationOption::validateInputSize(), and Mantid::Geometry::y.

◆ version()

int Mantid::Algorithms::DiscusMultipleScatteringCorrection::version ( ) const

inlineoverridevirtual

Algorithm's version.

Implements Mantid::API::Algorithm.

Definition at line 95 of file DiscusMultipleScatteringCorrection.h.

◆ writeToCollimatorCorridorCache()

void Mantid::Algorithms::DiscusMultipleScatteringCorrection::writeToCollimatorCorridorCache	(	const std::size_t &	histogramIndex,
		const std::shared_ptr< Geometry::CSGObject > &	collimatorCorridorCsgObj
	)