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ns3::ParetoRandomVariable Class Reference

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

#include <random-variable-stream.h>

+ Inheritance diagram for ns3::ParetoRandomVariable:
+ Collaboration diagram for ns3::ParetoRandomVariable:

Public Member Functions

 ParetoRandomVariable ()
 Creates a Pareto distribution RNG with the default values for the mean, the shape, and upper bound. More...
 
double GetBound (void) const
 Returns the upper bound on values that can be returned by this RNG stream. More...
 
uint32_t GetInteger (uint32_t mean, uint32_t shape, uint32_t bound)
 Returns a random unsigned integer from a Pareto distribution with the specified mean, shape, and upper bound. More...
 
virtual uint32_t GetInteger (void)
 Returns a random unsigned integer from a Pareto distribution with the current mean, shape, and upper bound. More...
 
double GetMean (void) const
 Returns the mean parameter for the Pareto distribution returned by this RNG stream. More...
 
double GetShape (void) const
 Returns the shape parameter for the Pareto distribution returned by this RNG stream. More...
 
double GetValue (double mean, double shape, double bound)
 Returns a random double from a Pareto distribution with the specified mean, shape, and upper bound. More...
 
virtual double GetValue (void)
 Returns a random double from a Pareto distribution with the current mean, shape, and upper bound. More...
 
- Public Member Functions inherited from ns3::RandomVariableStream
 RandomVariableStream ()
 
virtual ~RandomVariableStream ()
 
int64_t GetStream (void) const
 Returns the stream number for this RNG stream. More...
 
bool IsAntithetic (void) const
 Returns true if antithetic values should be generated. More...
 
void SetAntithetic (bool isAntithetic)
 Specifies whether antithetic values should be generated. More...
 
void SetStream (int64_t stream)
 Specifies the stream number for this RNG stream. More...
 
- Public Member Functions inherited from ns3::Object
 Object ()
 
virtual ~Object ()
 
void AggregateObject (Ptr< Object > other)
 
void Dispose (void)
 Run the DoDispose methods of this object and all the objects aggregated to it. More...
 
AggregateIterator GetAggregateIterator (void) const
 
virtual TypeId GetInstanceTypeId (void) const
 
template<typename T >
Ptr< T > GetObject (void) const
 
template<typename T >
Ptr< T > GetObject (TypeId tid) const
 
void Initialize (void)
 This method calls the virtual DoInitialize method on all the objects aggregated to this object. More...
 
- Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
 SimpleRefCount ()
 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. 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
 
bool GetAttributeFailSafe (std::string name, AttributeValue &attribute) const
 
void SetAttribute (std::string name, const AttributeValue &value)
 
bool SetAttributeFailSafe (std::string name, const AttributeValue &value)
 
bool TraceConnect (std::string name, std::string context, const CallbackBase &cb)
 
bool TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
 
bool TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
 
bool TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
 

Static Public Member Functions

static TypeId GetTypeId (void)
 
- Static Public Member Functions inherited from ns3::RandomVariableStream
static TypeId GetTypeId (void)
 
- Static Public Member Functions inherited from ns3::Object
static TypeId GetTypeId (void)
 Register this type. More...
 
- Static Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
static void Cleanup (void)
 Noop. More...
 
- Static Public Member Functions inherited from ns3::ObjectBase
static TypeId GetTypeId (void)
 Get the type ID. More...
 

Private Attributes

double m_bound
 The upper bound on values that can be returned by this RNG stream. More...
 
double m_mean
 The mean parameter for the Pareto distribution returned by this RNG stream. More...
 
double m_shape
 The shape parameter for the Pareto distribution returned by this RNG stream. More...
 

Additional Inherited Members

- Protected Member Functions inherited from ns3::RandomVariableStream
RngStreamPeek (void) const
 Returns a pointer to the underlying RNG stream. More...
 
- Protected Member Functions inherited from ns3::Object
 Object (const Object &o)
 
virtual void DoDispose (void)
 This method is called by Object::Dispose or by the object's destructor, whichever comes first. More...
 
virtual void DoInitialize (void)
 This method is called only once by Object::Initialize. More...
 
virtual void NotifyNewAggregate (void)
 This method is invoked whenever two sets of objects are aggregated together. More...
 
- Protected Member Functions inherited from ns3::ObjectBase
void ConstructSelf (const AttributeConstructionList &attributes)
 
virtual void NotifyConstructionCompleted (void)
 This method is invoked once all member attributes have been initialized. More...
 

Detailed Description

The Pareto 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 Pareto distribution. It also supports the generation of single random numbers from various Pareto distributions.

The probability density function of a Pareto variable is defined over the range [ $x_m$, $+\infty$) as: $ k \frac{x_m^k}{x^{k+1}}$ where $x_m > 0$ is called the scale parameter and $ k > 0$ is called the pareto index or shape.

The parameter $ x_m $ can be infered from the mean and the parameter $ k $ with the equation $ x_m = mean \frac{k-1}{k}, k > 1$.

Since Pareto distributions can theoretically return unbounded values, it is sometimes useful to specify a fixed upper limit. Note however when the upper limit is specified, the true mean of the distribution is slightly smaller than the mean value specified.

Here is an example of how to use this class:

double mean = 5.0;
double shape = 2.0;
Ptr<ParetoRandomVariable> x = CreateObject<ParetoRandomVariable> ();
x->SetAttribute ("Mean", DoubleValue (mean));
x->SetAttribute ("Shape", DoubleValue (shape));
// The expected value for the mean of the values returned by a
// Pareto distributed random variable is
//
// shape * scale
// E[value] = --------------- ,
// shape - 1
//
// where
//
// scale = mean * (shape - 1.0) / shape .
//
double value = x->GetValue ();

Config Paths

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

  • /ChannelList/[i]/$ns3::WifiChannel/$ns3::YansWifiChannel/PropagationDelayModel/$ns3::RandomPropagationDelayModel/Variable/$ns3::ParetoRandomVariable
  • /ChannelList/[i]/$ns3::WifiChannel/$ns3::YansWifiChannel/PropagationLossModel/$ns3::RandomPropagationLossModel/Variable/$ns3::ParetoRandomVariable
  • /ChannelList/[i]/$ns3::YansWifiChannel/PropagationDelayModel/$ns3::RandomPropagationDelayModel/Variable/$ns3::ParetoRandomVariable
  • /ChannelList/[i]/$ns3::YansWifiChannel/PropagationLossModel/$ns3::RandomPropagationLossModel/Variable/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::ArpL3Protocol/RequestJitter/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::Icmpv6L4Protocol/SolicitationJitter/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::GaussMarkovMobilityModel/MeanDirection/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::GaussMarkovMobilityModel/MeanPitch/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::GaussMarkovMobilityModel/MeanVelocity/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomDirection2dMobilityModel/Pause/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomDirection2dMobilityModel/Speed/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWalk2dMobilityModel/Direction/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWalk2dMobilityModel/Speed/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/Pause/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/PositionAllocator/$ns3::RandomBoxPositionAllocator/X/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/PositionAllocator/$ns3::RandomBoxPositionAllocator/Y/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/PositionAllocator/$ns3::RandomBoxPositionAllocator/Z/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/PositionAllocator/$ns3::RandomDiscPositionAllocator/Rho/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/PositionAllocator/$ns3::RandomDiscPositionAllocator/Theta/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/PositionAllocator/$ns3::RandomRectanglePositionAllocator/X/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/PositionAllocator/$ns3::RandomRectanglePositionAllocator/Y/$ns3::ParetoRandomVariable
  • /NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWaypointMobilityModel/Speed/$ns3::ParetoRandomVariable
  • /NodeList/[i]/ApplicationList/[i]/$ns3::OnOffApplication/OffTime/$ns3::ParetoRandomVariable
  • /NodeList/[i]/ApplicationList/[i]/$ns3::OnOffApplication/OnTime/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::CsmaNetDevice/ReceiveErrorModel/$ns3::BurstErrorModel/BurstSize/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::CsmaNetDevice/ReceiveErrorModel/$ns3::BurstErrorModel/BurstStart/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::CsmaNetDevice/ReceiveErrorModel/$ns3::RateErrorModel/RanVar/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::PointToPointNetDevice/ReceiveErrorModel/$ns3::BurstErrorModel/BurstSize/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::PointToPointNetDevice/ReceiveErrorModel/$ns3::BurstErrorModel/BurstStart/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::PointToPointNetDevice/ReceiveErrorModel/$ns3::RateErrorModel/RanVar/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::SimpleNetDevice/ReceiveErrorModel/$ns3::BurstErrorModel/BurstSize/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::SimpleNetDevice/ReceiveErrorModel/$ns3::BurstErrorModel/BurstStart/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::SimpleNetDevice/ReceiveErrorModel/$ns3::RateErrorModel/RanVar/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::WifiNetDevice/Channel/$ns3::YansWifiChannel/PropagationDelayModel/$ns3::RandomPropagationDelayModel/Variable/$ns3::ParetoRandomVariable
  • /NodeList/[i]/DeviceList/[i]/$ns3::WifiNetDevice/Channel/$ns3::YansWifiChannel/PropagationLossModel/$ns3::RandomPropagationLossModel/Variable/$ns3::ParetoRandomVariable

Attributes

  • Mean: The mean parameter for the Pareto distribution returned by this RNG stream.
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 1
    • Flags: construct write read
  • Shape: The shape parameter for the Pareto distribution returned by this RNG stream.
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 2
    • Flags: construct write read
  • Bound: The upper bound on the values returned by this RNG stream.
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 0
    • Flags: construct write read

Attributes defined in parent class ns3::RandomVariableStream

  • Stream: The stream number for this RNG stream. -1 means "allocate a stream automatically". Note that if -1 is set, Get will return -1 so that it is not possible to know which value was automatically allocated.
    • Set with class: ns3::IntegerValue
    • Underlying type: int64_t -9223372036854775808:9223372036854775807
    • Initial value: -1
    • Flags: construct write read
  • Antithetic: Set this RNG stream to generate antithetic values
    • Set with class: BooleanValue
    • Underlying type: bool
    • Initial value: false
    • Flags: construct write read

No TraceSources are defined for this type.

Definition at line 650 of file random-variable-stream.h.

Constructor & Destructor Documentation

ns3::ParetoRandomVariable::ParetoRandomVariable ( )

Creates a Pareto distribution RNG with the default values for the mean, the shape, and upper bound.

Definition at line 460 of file random-variable-stream.cc.

References NS_LOG_FUNCTION.

Member Function Documentation

double ns3::ParetoRandomVariable::GetBound ( void  ) const

Returns the upper bound on values that can be returned by this RNG stream.

Returns
The upper bound on values that can be returned by this RNG stream.

Definition at line 480 of file random-variable-stream.cc.

References m_bound, and NS_LOG_FUNCTION.

uint32_t ns3::ParetoRandomVariable::GetInteger ( uint32_t  mean,
uint32_t  shape,
uint32_t  bound 
)

Returns a random unsigned integer from a Pareto distribution with the specified mean, shape, and upper bound.

Parameters
meanMean parameter for the Pareto distribution.
shapeShape parameter for the Pareto distribution.
boundUpper bound on values returned.
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

\[ x = \frac{scale}{u^{\frac{1}{shape}}} \]

is a value that would be returned normally, where

\[ scale = mean * (shape - 1.0) / shape . \]

Then $(1 - u$) is the distance that $u$ would be from $1$. The value returned in the antithetic case, $x'$, is calculated as

\[ x' = \frac{scale}{{(1 - u)}^{\frac{1}{shape}}} , \]

which now involves the distance $u$ is from 1 in the denonator.

Definition at line 513 of file random-variable-stream.cc.

References GetValue(), and NS_LOG_FUNCTION.

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

Returns a random unsigned integer from a Pareto distribution with the current mean, shape, and upper bound.

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

\[ x = \frac{scale}{u^{\frac{1}{shape}}} \]

is a value that would be returned normally, where

\[ scale = mean * (shape - 1.0) / shape . \]

Then $(1 - u$) is the distance that $u$ would be from $1$. The value returned in the antithetic case, $x'$, is calculated as

\[ x' = \frac{scale}{{(1 - u)}^{\frac{1}{shape}}} , \]

which now involves the distance $u$ is from 1 in the denonator.

Implements ns3::RandomVariableStream.

Definition at line 526 of file random-variable-stream.cc.

References GetValue(), m_bound, m_mean, m_shape, and NS_LOG_FUNCTION.

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double ns3::ParetoRandomVariable::GetMean ( void  ) const

Returns the mean parameter for the Pareto distribution returned by this RNG stream.

Returns
The mean parameter for the Pareto distribution returned by this RNG stream.

Definition at line 468 of file random-variable-stream.cc.

References m_mean, and NS_LOG_FUNCTION.

double ns3::ParetoRandomVariable::GetShape ( void  ) const

Returns the shape parameter for the Pareto distribution returned by this RNG stream.

Returns
The shape parameter for the Pareto distribution returned by this RNG stream.

Definition at line 474 of file random-variable-stream.cc.

References m_shape, and NS_LOG_FUNCTION.

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

Definition at line 440 of file random-variable-stream.cc.

References m_bound, m_mean, m_shape, and ns3::TypeId::SetParent().

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double ns3::ParetoRandomVariable::GetValue ( double  mean,
double  shape,
double  bound 
)

Returns a random double from a Pareto distribution with the specified mean, shape, and upper bound.

Parameters
meanMean parameter for the Pareto distribution.
shapeShape parameter for the Pareto distribution.
boundUpper bound on values returned.
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

\[ x = \frac{scale}{u^{\frac{1}{shape}}} \]

is a value that would be returned normally, where

\[ scale = mean * (shape - 1.0) / shape . \]

Then $(1 - u$) is the distance that $u$ would be from $1$. The value returned in the antithetic case, $x'$, is calculated as

\[ x' = \frac{scale}{{(1 - u)}^{\frac{1}{shape}}} , \]

which now involves the distance $u$ is from 1 in the denonator.

Definition at line 487 of file random-variable-stream.cc.

References ns3::RandomVariableStream::IsAntithetic(), NS_LOG_FUNCTION, ns3::RandomVariableStream::Peek(), and ns3::RngStream::RandU01().

Referenced by RandomVariableStreamParetoTestCase::ChiSquaredTest(), RandomVariableStreamParetoAntitheticTestCase::ChiSquaredTest(), RandomVariableStreamParetoTestCase::DoRun(), and RandomVariableStreamParetoAntitheticTestCase::DoRun().

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

Returns a random double from a Pareto distribution with the current mean, shape, and upper bound.

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

\[ x = \frac{scale}{u^{\frac{1}{shape}}} \]

is a value that would be returned normally, where

\[ scale = mean * (shape - 1.0) / shape . \]

Then $(1 - u$) is the distance that $u$ would be from $1$. The value returned in the antithetic case, $x'$, is calculated as

\[ x' = \frac{scale}{{(1 - u)}^{\frac{1}{shape}}} , \]

which now involves the distance $u$ is from 1 in the denonator.

Note that we have to re-implement this method here because the method is overloaded above for the three-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 520 of file random-variable-stream.cc.

References m_bound, m_mean, m_shape, and NS_LOG_FUNCTION.

Referenced by GetInteger().

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Member Data Documentation

double ns3::ParetoRandomVariable::m_bound
private

The upper bound on values that can be returned by this RNG stream.

Definition at line 818 of file random-variable-stream.h.

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

double ns3::ParetoRandomVariable::m_mean
private

The mean parameter for the Pareto distribution returned by this RNG stream.

Definition at line 812 of file random-variable-stream.h.

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

double ns3::ParetoRandomVariable::m_shape
private

The shape parameter for the Pareto distribution returned by this RNG stream.

Definition at line 815 of file random-variable-stream.h.

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


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