RadialVectorField Class Reference

#include <RadialVectorField.hpp>

Inheritance diagram for RadialVectorField:

Public Member Functions
int	dimension () const override
double	exponent () const
double	unityRadius () const
Vec	vector (Position bfr) const override
virtual int	dimension () const =0
virtual Vec	vector (Position bfr) 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 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
	RadialVectorField ()
Protected Member Functions inherited from VectorField
	VectorField ()
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 = VectorField
using	ItemType = RadialVectorField

Private Attributes
double	_exponent
double	_unityRadius

Friends
class	ItemRegistry

Detailed Description

RadialVectorField represents a vector field with vectors pointing away from the origin and with a magnitude that varies with radial distance from the origin. The class has two configuration properties: the distance at which the vector magnitude becomes unity and a power law exponent. If the exponent is positive, the magnitude ramps up from zero at the origin to unity at the specified distance, and remains unity from there on. If the power law index is negative, the magnitude is unity from the origin to the specified distance, and then ramps down from there to zero at infinity.

Given the user-configurable unity radius $r_1\ge 0$ and power-law exponent $\alpha$, the magnitude $v(r)$ of the vectors as a function of radial distance $r$ is given by

$$r_1=0\vee \alpha =0v(r)=\{\begin{array}{ll}0& \mathrm{f}\mathrm{o}\mathrm{r}r=0\\ 1& \mathrm{f}\mathrm{o}\mathrm{r}r>0\end{array}$$

$$r_1>0\wedge \alpha >0v(r)=\{\begin{array}{ll}0& \mathrm{f}\mathrm{o}\mathrm{r}r=0\\ (r/r_1{)}^{\alpha }& \mathrm{f}\mathrm{o}\mathrm{r}0<r<r_1\\ 1& \mathrm{f}\mathrm{o}\mathrm{r}r\ge r_1\end{array}$$

$$r_1>0\wedge \alpha <0v(r)=\{\begin{array}{ll}0& \mathrm{f}\mathrm{o}\mathrm{r}r=0\\ 1& \mathrm{f}\mathrm{o}\mathrm{r}0<r<r_1\\ (r/r_1{)}^{\alpha }& \mathrm{f}\mathrm{o}\mathrm{r}r\ge r_1\end{array}$$

The first equation defines the vector field for the special values $r_1=0$ and/or $\alpha =0$ to consist solely of unit vectors except at the origin, where the direction of the vector is undefined. The default value of $r_1=0$ causes this behavior. If the unity radius is set to a value $r_1>0$, the default value of $\alpha =1$ specifies linear behavior: the vector magnitude scales linearly from zero at the origin to unity at $r=r_1$, and stays at unity for larger radii.

When an item of this type is used, the names provided by the conditional value expression "Dimension3" are inserted into the name sets used for evaluating Boolean expressions.

Constructor & Destructor Documentation

RadialVectorField()

RadialVectorField::RadialVectorField ( )

inlineprotected

Default constructor for concrete Item subclass RadialVectorField : "a vector field pointing away from the origin" .

Member Function Documentation

dimension()

int RadialVectorField::dimension ( ) const

overridevirtual

This function returns the dimension of the vector field, which is 3 for this class, indicating no symmetries (the vectors point in a different direction at each position).

Implements VectorField.

exponent()

RadialVectorField::exponent ( ) const

inline

This function returns the value of the discoverable double property exponent : "the power-law exponent governing the radial dependence of the magnitude" .

The default value for this property is given by the conditional value expression "1" .

unityRadius()

RadialVectorField::unityRadius ( ) const

inline

This function returns the value of the discoverable double property unityRadius : "the radius where the magnitude of the vectors is unity" .

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

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

The default value for this property is given by the conditional value expression "0" .

vector()

Vec RadialVectorField::vector ( Position  bfr ) const

overridevirtual

This function returns a vector pointing away from the origin at the given position $\mathbf{r}$ according to the definitions given in the class header.

Implements VectorField.

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

• RadialVectorField.hpp