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PowerLawGrainSizeDistribution Class Reference

#include <PowerLawGrainSizeDistribution.hpp>

Inheritance diagram for PowerLawGrainSizeDistribution:
Inheritance graph
[legend]

Public Member Functions

 PowerLawGrainSizeDistribution (SimulationItem *parent, double minSize, double maxSize, double exponent)
 
double dnda (double a) const override
 
double exponent () const
 
- Public Member Functions inherited from RangeGrainSizeDistribution
double amax () const override
 
double amin () const override
 
double maxSize () const
 
double minSize () const
 
virtual double amax () const =0
 
virtual double amin () const =0
 
virtual double dnda (double a) 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

 PowerLawGrainSizeDistribution ()
 
- Protected Member Functions inherited from RangeGrainSizeDistribution
 RangeGrainSizeDistribution ()
 
 RangeGrainSizeDistribution (double minSize, double maxSize)
 
void setupSelfBefore () override
 
- Protected Member Functions inherited from GrainSizeDistribution
 GrainSizeDistribution ()
 
- 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 = RangeGrainSizeDistribution
 
using ItemType = PowerLawGrainSizeDistribution
 

Private Attributes

double _exponent
 

Friends

class ItemRegistry
 

Detailed Description

PowerLawGrainSizeDistribution is a GrainSizeDistribution subclass that represents a dust grain size distribution of the form

\[ \frac{\text{d}n_\text{D}}{\text{d}a} \propto a^{-\gamma} \qquad \text{for}\quad a_\text{min} \leq a \leq a_\text{max}, \]

where the exponent \(\gamma>0\) can be configured as an attribute of this class, and the size range can be configured in the RangeGrainSizeDistribution base class.

In fact, the function is guaranteed to exactly return the value of \(a^{-\gamma}\), without any multiplication factor, so that the size distribution can be normalized (externally) by specifying a proportionality factor with the appropriate units. For example, to obtain a size distribution function specifying the amount of dust per hydrogen atom as a function of grain size, one would (externally) add a factor \(C\), as in

\[ \frac{\text{d}n_\text{D}}{\text{d}a} / n_\text{H}= C\, a^{-\gamma} \qquad \text{for}\quad a_\text{min} \leq a \leq a_\text{max}, \]

where \(C\) has units of \(\text{m}^{\gamma-1}\).

Constructor & Destructor Documentation

◆ PowerLawGrainSizeDistribution() [1/2]

PowerLawGrainSizeDistribution::PowerLawGrainSizeDistribution ( )
inlineprotected

Default constructor for concrete Item subclass PowerLawGrainSizeDistribution : "a power-law dust grain size distribution" .

◆ PowerLawGrainSizeDistribution() [2/2]

PowerLawGrainSizeDistribution::PowerLawGrainSizeDistribution ( SimulationItem parent,
double  minSize,
double  maxSize,
double  exponent 
)
explicit

This constructor can be invoked by classes that wish to hard-code the creation of a new grain size distribution object of this type (as opposed to creation through the ski file). Before the constructor returns, the newly created object is hooked up as a child to the specified parent in the simulation hierarchy (so it will automatically be deleted), its properties have been initialized to the specified values, and its setup() function has been called.

Member Function Documentation

◆ dnda()

double PowerLawGrainSizeDistribution::dnda ( double  a) const
overridevirtual

This function returns the value of \(a^{-\gamma}\).

Implements GrainSizeDistribution.

◆ exponent()

PowerLawGrainSizeDistribution::exponent ( ) const
inline

This function returns the value of the discoverable double property exponent : "the (absolute value of the) exponent in the power-law distribution function" .

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

The maximum value for this property is "10]" .

The default value for this property is given by the conditional value expression "3.5" .


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