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ns3::ZetaRandomVariable Class Reference

The zeta distribution Random Number Generator (RNG) that allows stream numbers to be set deterministically. More...

#include "random-variable-stream.h"

+ Inheritance diagram for ns3::ZetaRandomVariable:

Public Member Functions

 ZetaRandomVariable ()
 Creates a zeta distribution RNG with the default value for alpha. More...
 
double GetAlpha (void) const
 Returns the alpha value for the zeta distribution returned by this RNG stream. More...
 
uint32_t GetInteger (uint32_t alpha)
 Returns a random unsigned integer from a zeta distribution with the specified alpha. More...
 
virtual uint32_t GetInteger (void)
 Returns a random unsigned integer from a zeta distribution with the current alpha. More...
 
double GetValue (double alpha)
 Returns a random double from a zeta distribution with the specified alpha. More...
 
virtual double GetValue (void)
 Returns a random double from a zeta distribution with the current alpha. More...
 
- Public Member Functions inherited from ns3::RandomVariableStream
 RandomVariableStream ()
 Default constructor. More...
 
virtual ~RandomVariableStream ()
 Destructor. More...
 
int64_t GetStream (void) const
 Returns the stream number for the RngStream. More...
 
bool IsAntithetic (void) const
 Check if antithetic values will be generated. More...
 
void SetAntithetic (bool isAntithetic)
 Specify whether antithetic values should be generated. More...
 
void SetStream (int64_t stream)
 Specifies the stream number for the RngStream. More...
 
- Public Member Functions inherited from ns3::Object
 Object ()
 Constructor. More...
 
virtual ~Object ()
 Destructor. More...
 
void AggregateObject (Ptr< Object > other)
 Aggregate two Objects together. More...
 
void Dispose (void)
 Dispose of this Object. More...
 
AggregateIterator GetAggregateIterator (void) const
 Get an iterator to the Objects aggregated to this one. More...
 
virtual TypeId GetInstanceTypeId (void) const
 Get the most derived TypeId for this Object. More...
 
template<typename T >
Ptr< T > GetObject (void) const
 Get a pointer to the requested aggregated Object. More...
 
template<typename T >
Ptr< T > GetObject (TypeId tid) const
 Get a pointer to the requested aggregated Object by TypeId. More...
 
void Initialize (void)
 Invoke DoInitialize on all Objects aggregated to this one. More...
 
bool IsInitialized (void) const
 Check if the object has been initialized. More...
 
- Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
 SimpleRefCount ()
 Default constructor. More...
 
 SimpleRefCount (const SimpleRefCount &o)
 Copy constructor. More...
 
uint32_t GetReferenceCount (void) const
 Get the reference count of the object. More...
 
SimpleRefCountoperator= (const SimpleRefCount &o)
 Assignment operator. More...
 
void Ref (void) const
 Increment the reference count. More...
 
void Unref (void) const
 Decrement the reference count. More...
 
- Public Member Functions inherited from ns3::ObjectBase
virtual ~ObjectBase ()
 Virtual destructor. More...
 
void GetAttribute (std::string name, AttributeValue &value) const
 Get the value of an attribute, raising fatal errors if unsuccessful. More...
 
bool GetAttributeFailSafe (std::string name, AttributeValue &value) const
 Get the value of an attribute without raising erros. More...
 
void SetAttribute (std::string name, const AttributeValue &value)
 Set a single attribute, raising fatal errors if unsuccessful. More...
 
bool SetAttributeFailSafe (std::string name, const AttributeValue &value)
 Set a single attribute without raising errors. More...
 
bool TraceConnect (std::string name, std::string context, const CallbackBase &cb)
 Connect a TraceSource to a Callback with a context. More...
 
bool TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
 Connect a TraceSource to a Callback without a context. More...
 
bool TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
 Disconnect from a TraceSource a Callback previously connected with a context. More...
 
bool TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
 Disconnect from a TraceSource a Callback previously connected without a context. More...
 

Static Public Member Functions

static TypeId GetTypeId (void)
 Register this type. More...
 
- Static Public Member Functions inherited from ns3::RandomVariableStream
static TypeId GetTypeId (void)
 Register this type. More...
 
- Static Public Member Functions inherited from ns3::Object
static TypeId GetTypeId (void)
 Register this type. More...
 
- Static Public Member Functions inherited from ns3::ObjectBase
static TypeId GetTypeId (void)
 Get the type ID. More...
 

Private Attributes

double m_alpha
 The alpha value for the zeta distribution returned by this RNG stream. More...
 
double m_b
 Just for calculus simplifications. More...
 

Additional Inherited Members

- Protected Member Functions inherited from ns3::RandomVariableStream
RngStreamPeek (void) const
 Get the pointer to the underlying RngStream. More...
 
- Protected Member Functions inherited from ns3::Object
 Object (const Object &o)
 Copy an Object. More...
 
virtual void DoDispose (void)
 Destructor implementation. More...
 
virtual void DoInitialize (void)
 Initialize() implementation. More...
 
virtual void NotifyNewAggregate (void)
 Notify all Objects aggregated to this one of a new Object being aggregated. More...
 
- Protected Member Functions inherited from ns3::ObjectBase
void ConstructSelf (const AttributeConstructionList &attributes)
 Complete construction of ObjectBase; invoked by derived classes. More...
 
virtual void NotifyConstructionCompleted (void)
 Notifier called once the ObjectBase is fully constructed. More...
 

Detailed Description

The zeta distribution Random Number Generator (RNG) that allows stream numbers to be set deterministically.


This class supports the creation of objects that return random numbers from a fixed zeta distribution. It also supports the generation of single random numbers from various zeta distributions.

The Zeta distribution is closely related to Zipf distribution when N goes to infinity.

Zeta distribution has one parameter, alpha, $ \alpha > 1 $ (real). Probability Mass Function is $ f(k; \alpha) = k^{-\alpha}/\zeta(\alpha) $ where $ \zeta(\alpha) $ is the Riemann zeta function ( $ \sum_{n=1}^\infty n^{-\alpha} ) $

Here is an example of how to use this class:

double alpha = 2.0;
Ptr<ZetaRandomVariable> x = CreateObject<ZetaRandomVariable> ();
x->SetAttribute ("Alpha", DoubleValue (alpha));
// The expected value for the mean of the values returned by a
// zetaly distributed random variable is equal to
//
// zeta(alpha - 1)
// E[value] = --------------- for alpha > 2 ,
// zeta(alpha)
//
// where zeta(alpha) is the Riemann zeta function.
//
// There are no simple analytic forms for the Riemann zeta
// function, which is the reason the known mean of the values
// cannot be calculated in this example.
//
double value = x->GetValue ();

Config Paths

ns3::ZetaRandomVariable is accessible through the following paths with Config::Set and Config::Connect:

Attributes

Attributes defined in parent class ns3::RandomVariableStream

No TraceSources are defined for this type.
Size of this type is 72 bytes (on a 64-bit architecture).

Definition at line 2240 of file random-variable-stream.h.

Constructor & Destructor Documentation

◆ ZetaRandomVariable()

ns3::ZetaRandomVariable::ZetaRandomVariable ( )

Creates a zeta distribution RNG with the default value for alpha.

Definition at line 1392 of file random-variable-stream.cc.

References NS_LOG_FUNCTION.

Member Function Documentation

◆ GetAlpha()

double ns3::ZetaRandomVariable::GetAlpha ( void  ) const

Returns the alpha value for the zeta distribution returned by this RNG stream.

Returns
The alpha value for the zeta distribution returned by this RNG stream.

Definition at line 1399 of file random-variable-stream.cc.

References m_alpha, and NS_LOG_FUNCTION.

◆ GetInteger() [1/2]

uint32_t ns3::ZetaRandomVariable::GetInteger ( uint32_t  alpha)

Returns a random unsigned integer from a zeta distribution with the specified alpha.

Parameters
[in]alphaAlpha value for the zeta distribution.
Returns
A random unsigned integer value.

Note that antithetic values are being generated if m_isAntithetic is equal to true. If $u$ is a uniform variable over [0,1] and $x$ is a value that would be returned normally, then $(1 - u$) is the distance that $u$ would be from $1$. The value returned in the antithetic case, $x'$, uses (1-u), which is the distance $u$ is from the 1.

Definition at line 1441 of file random-variable-stream.cc.

References sample-rng-plot::alpha, GetValue(), and NS_LOG_FUNCTION.

◆ GetInteger() [2/2]

uint32_t ns3::ZetaRandomVariable::GetInteger ( void  )
virtual

Returns a random unsigned integer from a zeta distribution with the current alpha.

Returns
A random unsigned integer value.

Note that antithetic values are being generated if m_isAntithetic is equal to true. If $u$ is a uniform variable over [0,1] and $x$ is a value that would be returned normally, then $(1 - u$) is the distance that $u$ would be from $1$. The value returned in the antithetic case, $x'$, uses (1-u), which is the distance $u$ is from the 1.

Implements ns3::RandomVariableStream.

Definition at line 1454 of file random-variable-stream.cc.

References GetValue(), m_alpha, and NS_LOG_FUNCTION.

◆ GetTypeId()

TypeId ns3::ZetaRandomVariable::GetTypeId ( void  )
static

Register this type.

Returns
The object TypeId.

Definition at line 1379 of file random-variable-stream.cc.

References m_alpha, ns3::MakeDoubleAccessor(), and ns3::TypeId::SetParent().

◆ GetValue() [1/2]

double ns3::ZetaRandomVariable::GetValue ( double  alpha)

Returns a random double from a zeta distribution with the specified alpha.

Parameters
[in]alphaAlpha value for the zeta distribution.
Returns
A floating point random value.

Note that antithetic values are being generated if m_isAntithetic is equal to true. If $u$ is a uniform variable over [0,1] and $x$ is a value that would be returned normally, then $(1 - u$) is the distance that $u$ would be from $1$. The value returned in the antithetic case, $x'$, uses (1-u), which is the distance $u$ is from the 1.

Definition at line 1406 of file random-variable-stream.cc.

References sample-rng-plot::alpha, m_b, and NS_LOG_FUNCTION.

◆ GetValue() [2/2]

double ns3::ZetaRandomVariable::GetValue ( void  )
virtual

Returns a random double from a zeta distribution with the current alpha.

Returns
A floating point random value.

Note that antithetic values are being generated if m_isAntithetic is equal to true. If $u$ is a uniform variable over [0,1] and $x$ is a value that would be returned normally, then $(1 - u$) is the distance that $u$ would be from $1$. The value returned in the antithetic case, $x'$, uses (1-u), which is the distance $u$ is from the 1.

Note that we have to re-implement this method here because the method is overloaded above for the two-argument variant and the c++ name resolution rules don't work well with overloads split between parent and child classes.

Implements ns3::RandomVariableStream.

Definition at line 1448 of file random-variable-stream.cc.

References m_alpha, and NS_LOG_FUNCTION.

Referenced by GetInteger().

Member Data Documentation

◆ m_alpha

double ns3::ZetaRandomVariable::m_alpha
private

The alpha value for the zeta distribution returned by this RNG stream.

Definition at line 2322 of file random-variable-stream.h.

Referenced by GetAlpha(), GetInteger(), GetTypeId(), and GetValue().

◆ m_b

double ns3::ZetaRandomVariable::m_b
private

Just for calculus simplifications.

Definition at line 2325 of file random-variable-stream.h.

Referenced by GetValue().


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