The SKIRT project
advanced radiative transfer for astrophysics
RedistributeGeometryDecorator Class Referenceabstract

#include <RedistributeGeometryDecorator.hpp>

Inheritance diagram for RedistributeGeometryDecorator:

Public Member Functions

double density (Position bfr) const override
Position generatePosition () const override
Geometrygeometry () const
double SigmaX () const override
double SigmaY () const override
double SigmaZ () const override
Public Member Functions inherited from Geometry
virtual int dimension () const =0
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 ItemgetItemProperty (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)
Itemoperator= (const Item &)=delete
Itemparent () 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

 RedistributeGeometryDecorator ()
virtual double maxWeight () const =0
void setupSelfAfter () override
virtual double weight (Position bfr) const =0
Protected Member Functions inherited from Geometry
 Geometry ()
Randomrandom () const
void setupSelfBefore () override
Protected Member Functions inherited from SimulationItem
 SimulationItem ()
virtual bool offersInterface (const std::type_info &interfaceTypeInfo) const
Protected Member Functions inherited from Item
 Item ()

Private Types

using BaseType
using ItemType

Private Attributes

Geometry_geometry
double _maxWeight
double _norm

Friends

class ItemRegistry

Detailed Description

The abstract RedistributeGeometryDecorator class implements a decorator that adjusts another geometry by multiplying the density with some abstract weight function

\[ \rho'({\bf{r}}) = n \rho({\bf{r}}) w({\bf{r}}). \]

Each RedistributeGeometryDecorator subclass must implement the virtual functions dimension(), weight() and maxWeight(). The decorator renormalizes the distribution by using the importance sampling method from the original distribution. The random positions are generated using the rejection method with the reference distribution the original density. The current implementation does not properly adjust the surface densities along the coordinate axes.

This item type is displayed only if the Boolean expression "Level2" evaluates to true after replacing the names by true or false depending on their presence.

Constructor & Destructor Documentation

◆ RedistributeGeometryDecorator()

RedistributeGeometryDecorator::RedistributeGeometryDecorator ( )
inlineprotected

Default constructor for abstract Item subclass RedistributeGeometryDecorator: "a decorator that redistributes another geometry".

Member Function Documentation

◆ density()

double RedistributeGeometryDecorator::density ( Position bfr) const
overridevirtual

This function returns the normalized density \(n\rho({\bf{r}})w({\bf{r}})\) at the position \({\bf{r}}\).

Implements Geometry.

◆ generatePosition()

Position RedistributeGeometryDecorator::generatePosition ( ) const
overridevirtual

This function generates a random position from the geometry using the rejection method. It draws a random point from the probability density \(\rho({\bf{r}})\), this point is accepted if \(t=\xi \frac{\max_{\bf{r}}{(w({\bf{r}}))}}{w({\bf{r}})}\le 1.\)

Implements Geometry.

◆ geometry()

Geometry * RedistributeGeometryDecorator::geometry ( ) const
inline

This function returns the value of the discoverable item property geometry: "the geometry for which the density will be redistributed".

◆ maxWeight()

virtual double RedistributeGeometryDecorator::maxWeight ( ) const
protectedpure virtual

This pure virtual function, to be implemented by a subclass, gives the maximum value of the weight function. This value is used in the rejection method.

Implemented in AxPowerLawRedistributeGeometryDecorator, and SphePowerLawRedistributeGeometryDecorator.

◆ setupSelfAfter()

void RedistributeGeometryDecorator::setupSelfAfter ( )
overrideprotectedvirtual

This function calculates the norm using the importance sampling method from the original distribution. It also calculates the factor \(\frac{c}{n}\) for the rejection method, which is just the maxWeight().

Reimplemented from SimulationItem.

◆ SigmaX()

double RedistributeGeometryDecorator::SigmaX ( ) const
overridevirtual

This function returns the X-axis surface density, i.e. the integration of the density along the entire X-axis,

\[ \Sigma_X = \int_{-\infty}^\infty \rho(x,0,0)\,{\text{d}}x. \]

For a general geometry this decorator will not have an analytical solution for this integral. We use the X-axis surface density of the original distribution.

Implements Geometry.

◆ SigmaY()

double RedistributeGeometryDecorator::SigmaY ( ) const
overridevirtual

This function returns the Y-axis surface density, i.e. the integration of the density along the entire Y-axis,

\[ \Sigma_Y = \int_{-\infty}^\infty \rho(y,0,0)\,{\text{d}}y. \]

For a general geometry this decorator will not have an analytical solution for this integral. We use the Y-axis surface density of the original distribution.

Implements Geometry.

◆ SigmaZ()

double RedistributeGeometryDecorator::SigmaZ ( ) const
overridevirtual

This function returns the Z-axis surface density, i.e. the integration of the density along the entire Z-axis,

\[ \Sigma_Z = \int_{-\infty}^\infty \rho(Z,0,0)\,{\text{d}}z. \]

For a general geometry this decorator will not have an analytical solution for this integral. We use the Z-axis surface density of the original distribution.

Implements Geometry.

◆ weight()

virtual double RedistributeGeometryDecorator::weight ( Position bfr) const
protectedpure virtual

This pure virtual function, to be implemented by a subclass, gives the weight function's value at a given position. This function does not need to be normalized.

Implemented in AxPowerLawRedistributeGeometryDecorator, and SphePowerLawRedistributeGeometryDecorator.


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