SourceSystem Class Reference

#include <SourceSystem.hpp>

Inheritance diagram for SourceSystem:

Public Member Functions
int	dimension () const
void	installLaunchCallBack (ProbePhotonPacketInterface *callback)
void	launch (PhotonPacket *pp, size_t historyIndex) const
double	luminosity () const
double	maxWavelength () const
double	minWavelength () const
int	numSources () const
void	prepareForLaunch (size_t numPackets)
double	sourceBias () const
const vector< Source * > &	sources () const
const vector< double > &	wavelengths () const
Public Member Functions inherited from SimulationItem
template<class T >
T *	find (bool setup=true) const
template<class T >
T *	interface (int levels=-999999, bool setup=true) const
virtual string	itemName () const
void	setup ()
string	typeAndName () const
Public Member Functions inherited from Item
	Item (const Item &)=delete
virtual	~Item ()
void	addChild (Item *child)
const vector< Item * > &	children () const
virtual void	clearItemListProperty (const PropertyDef *property)
void	destroyChild (Item *child)
virtual bool	getBoolProperty (const PropertyDef *property) const
virtual vector< double >	getDoubleListProperty (const PropertyDef *property) const
virtual double	getDoubleProperty (const PropertyDef *property) const
virtual string	getEnumProperty (const PropertyDef *property) const
virtual int	getIntProperty (const PropertyDef *property) const
virtual vector< Item * >	getItemListProperty (const PropertyDef *property) const
virtual Item *	getItemProperty (const PropertyDef *property) const
virtual string	getStringProperty (const PropertyDef *property) const
int	getUtilityProperty (string name) const
virtual void	insertIntoItemListProperty (const PropertyDef *property, int index, Item *item)
Item &	operator= (const Item &)=delete
Item *	parent () const
virtual void	removeFromItemListProperty (const PropertyDef *property, int index)
virtual void	setBoolProperty (const PropertyDef *property, bool value)
virtual void	setDoubleListProperty (const PropertyDef *property, vector< double > value)
virtual void	setDoubleProperty (const PropertyDef *property, double value)
virtual void	setEnumProperty (const PropertyDef *property, string value)
virtual void	setIntProperty (const PropertyDef *property, int value)
virtual void	setItemProperty (const PropertyDef *property, Item *item)
virtual void	setStringProperty (const PropertyDef *property, string value)
void	setUtilityProperty (string name, int value)
virtual string	type () const

Protected Member Functions
	SourceSystem ()
void	setupSelfAfter () override
Protected Member Functions inherited from SimulationItem
	SimulationItem ()
virtual bool	offersInterface (const std::type_info &interfaceTypeInfo) const
virtual void	setupSelfAfter ()
virtual void	setupSelfBefore ()
Protected Member Functions inherited from Item
	Item ()

Private Types
using	BaseType = SimulationItem
using	ItemType = SourceSystem

Private Attributes
vector< ProbePhotonPacketInterface * >	_callbackv
vector< size_t >	_Iv
double	_L
double	_Lpp
Array	_Lv
double	_maxWavelength
double	_minWavelength
double	_sourceBias
vector< Source * >	_sources
vector< double >	_wavelengths
Array	_Wv

Friends
class	ItemRegistry

Detailed Description

An instance of the SourceSystem class represents a complete primary source system, which is the superposition of one or more sources. Each source provides a complete description of its radiation, including the spatial and spectral distribution and characteristics such as anisotropy and polarization.

One key task of the SourceSystem object is to distribute photon packet launches across the sources. In principle, this should/could be achieved by randomly selecting a source for each launch through sampling from an appropriate probability distribution. However, for some sources, a deterministic approach allows significant performance optimizations. Because the number of photon packets should be and usually is (much) larger than the number of (sub)sources, a deterministic approach can be considered to be equivalent to the randomized procedure.

The idea is to iterate through the sources and launch consecutive photon packets from each. A source consisting of many subsources (such as particles or cells) can then use a similar approach, iterating over these components. The implementation can now construct and cache relevant data structures (such as a cumulative spectral distribution) for each subsource, and release the information as soon as the iteration moves on to the next subsource. Because photon packets can (and often are) launched in parallel, these data structures must be allocated in thread-local storage, but that is only a minor complication.

For each primary emission segment (i.e. a sequence of photon packet launches) in the simulation, the MonteCarloSimulation object uses the following procedure. It first determines the number of photon packets to be launched from the simulation configuration. This number $N$ is passed to the SourceSystem::prepareForLaunch() function in serial mode. Subsequently, the MonteCarloSimulation object launches $N$ photon packets in (potentially) parallel mode, labeling each of the packets with a history index in the range $0,...,N-1$. While parallel execution threads are working on photon packets in various chunks of this range, each thread handles photon packets with consecutive history indices within a given chunk.

To achieve the goals described above, the SourceSystem::prepareForLaunch() function maps consecutive history index ranges to each of the sources being held. This mapping is also passed on to each source, so that it can (but doesn't have to) implement a similar approach for its subsources. The number of photon packets allocated to each source is determined as follows:

$$N_s=[(1-\xi )\frac{w_s{L}_s}{\sum w_s{L}_s}+\xi \frac{w_s}{\sum w_s}]N$$

where $N$ is the total number of photon packets to be launched, $N_s$ is the number of photon packets to be launched by source $s$, $L_s$ is the bolometric luminosity of source $s$, $w_s$ is the sourceWeight property value for source $s$, $\xi$ is the sourceBias property value of the source system, and the sums range over all sources in the source system.

Constructor & Destructor Documentation

SourceSystem()

SourceSystem::SourceSystem ( )

inlineprotected

Default constructor for concrete Item subclass SourceSystem : "a primary source system" .

Member Function Documentation

dimension()

int SourceSystem::dimension

(

)

const

This function returns the dimension of the source system, which depends on the (lack of) symmetry in the geometries of its components. A value of 1 means spherical symmetry, 2 means axial symmetry and 3 means none of these symmetries. The source with the least symmetry (i.e. the highest dimension) determines the result for the whole system.

installLaunchCallBack()

void SourceSystem::installLaunchCallBack

(

ProbePhotonPacketInterface *

callback

)

This function installs the specified interface as photon packet launch call-back. The function probePhotonPacket() provided by the interface will be called for each photon packet that is ready to be launched.

launch()

void SourceSystem::launch	(	PhotonPacket *	pp,
		size_t	historyIndex
	)		const

This function causes the photon packet pp to be launched from one of the sources in the source system using the given history index. The photon packet's contents is fully (re-)initialized so that it is ready to start its lifecycle.

luminosity()

double SourceSystem::luminosity

(

)

const

This function returns the bolometric luminosity $L$ of the source system across its spatial and spectral domain, which is the sum of the luminosities of the sources in the system.

maxWavelength()

SourceSystem::maxWavelength ( ) const

inline

This function returns the value of the discoverable double property maxWavelength : "the longest wavelength of photon packets launched from primary sources" .

This property represents a physical quantity of type "wavelength" .

The minimum value for this property is "1 pm" .

The maximum value for this property is "1 m" .

The default value for this property is given by the conditional value expression "100 micron" .

This property is relevant only if the Boolean expression "Panchromatic" evaluates to true after replacing the names by true or false depending on their presence.

minWavelength()

SourceSystem::minWavelength ( ) const

inline

This function returns the value of the discoverable double property minWavelength : "the shortest wavelength of photon packets launched from primary sources" .

This property represents a physical quantity of type "wavelength" .

The minimum value for this property is "1 pm" .

The maximum value for this property is "1 m" .

The default value for this property is given by the conditional value expression "0.09 micron" .

This property is relevant only if the Boolean expression "Panchromatic" evaluates to true after replacing the names by true or false depending on their presence.

numSources()

int SourceSystem::numSources

(

)

const

This function returns the number of sources in the source system.

prepareForLaunch()

void SourceSystem::prepareForLaunch

(

size_t

numPackets

)

This function prepares the mapping of history indices to sources; see the description in the class header for more information.

setupSelfAfter()

void SourceSystem::setupSelfAfter ( )

overrideprotectedvirtual

This function obtains the bolometric luminosity of each source for later use.

Reimplemented from SimulationItem.

sourceBias()

SourceSystem::sourceBias ( ) const

inline

This function returns the value of the discoverable double property sourceBias : "the fraction of photon packets distributed uniformly across primary sources" .

The minimum value for this property is "[0" .

The maximum value for this property is "1]" .

The default value for this property is given by the conditional value expression "0.5" .

This property is displayed only if the Boolean expression "Level3" evaluates to true after replacing the names by true or false depending on their presence.

sources()

SourceSystem::sources ( ) const

inline

This function returns the value of the discoverable item list property sources : "the primary sources" .

The default value for this property is given by the conditional value expression "GeometricSource" .

This property is required only if the Boolean expression "false" evaluates to true after replacing the names by true or false depending on their presence.

wavelengths()

SourceSystem::wavelengths ( ) const

inline

This function returns the value of the discoverable double list property wavelengths : "the discrete wavelengths of photon packets launched from primary sources" .

This property represents a physical quantity of type "wavelength" .

The minimum value for this property is "1 pm" .

The maximum value for this property is "1 m" .

The default value for this property is given by the conditional value expression "0.55 micron" .

This property is relevant only if the Boolean expression "Oligochromatic" evaluates to true after replacing the names by true or false depending on their presence.

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

• SourceSystem.hpp