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ns3::NormalRandomVariable Class Reference

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

#include <random-variable-stream.h> Inheritance diagram for ns3::NormalRandomVariable: Collaboration diagram for ns3::NormalRandomVariable:

## Public Member Functions

NormalRandomVariable ()
Creates a normal distribution RNG with the default values for the mean, variance, and bound. More...

double GetBound (void) const
Returns the bound on values that can be returned by this RNG stream. More...

uint32_t GetInteger (uint32_t mean, uint32_t variance, uint32_t bound)
Returns a random unsigned integer from a normal distribution with the specified mean, variance, and bound. More...

virtual uint32_t GetInteger (void)
Returns a random unsigned integer from a normal distribution with the current mean, variance, and bound. More...

double GetMean (void) const
Returns the mean value for the normal distribution returned by this RNG stream. More...

double GetValue (double mean, double variance, double bound=NormalRandomVariable::INFINITE_VALUE)
Returns a random double from a normal distribution with the specified mean, variance, and bound. More...

virtual double GetValue (void)
Returns a random double from a normal distribution with the current mean, variance, and bound. More...

double GetVariance (void) const
Returns the variance value for the normal distribution returned by this RNG stream. 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...

## Static Public Attributes

static const double INFINITE_VALUE = 1e307

## Private Attributes

double m_bound
The bound on values that can be returned by this RNG stream. More...

double m_mean
The mean value for the normal distribution returned by this RNG stream. More...

double m_next
The algorithm produces two values at a time. More...

bool m_nextValid
True if the next value is valid. More...

double m_variance
The variance value for the normal 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 normal (Gaussian) 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 normal distribution. It also supports the generation of single random numbers from various normal distributions.

The density probability function is defined over the interval ( , ) as: where and Since normal distributions can theoretically return unbounded values, it is sometimes useful to specify a fixed bound. The NormalRandomVariable is bounded symmetrically about the mean by this bound, i.e. its values are confined to the interval [ , ].

Here is an example of how to use this class:

double mean = 5.0;
double variance = 2.0;
Ptr<NormalRandomVariable> x = CreateObject<NormalRandomVariable> ();
x->SetAttribute ("Mean", DoubleValue (mean));
x->SetAttribute ("Variance", DoubleValue (variance));
// The expected value for the mean of the values returned by a
// normally distributed random variable is equal to mean.
double value = x->GetValue ();

### Config Paths

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

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

### Attributes

• Mean: The mean value for the normal distribution 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
• Variance: The variance value for the normal 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
• Bound: The 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: 1e+307
• 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 1054 of file random-variable-stream.h.

## Constructor & Destructor Documentation

 ns3::NormalRandomVariable::NormalRandomVariable ( )

Creates a normal distribution RNG with the default values for the mean, variance, and bound.

Definition at line 658 of file random-variable-stream.cc.

References NS_LOG_FUNCTION.

## Member Function Documentation

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

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

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

Definition at line 680 of file random-variable-stream.cc.

References m_bound, and NS_LOG_FUNCTION.

 uint32_t ns3::NormalRandomVariable::GetInteger ( uint32_t mean, uint32_t variance, uint32_t bound )

Returns a random unsigned integer from a normal distribution with the specified mean, variance, and bound.

Parameters
 mean Mean value for the normal distribution. variance Variance value for the normal distribution. bound 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 and are uniform variables over [0,1], then the values that would be returned normally, and , are calculated as follows: For the antithetic case, ) and ) are the distances that and would be from . The antithetic values returned, and , are calculated as follows: which now involves the distances and are from 1.

Definition at line 733 of file random-variable-stream.cc.

References GetValue(), and NS_LOG_FUNCTION. Here is the call graph for this function:

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

Returns a random unsigned integer from a normal distribution with the current mean, variance, and bound.

Returns
A random unsigned integer value.

Note that antithetic values are being generated if m_isAntithetic is equal to true. If and are uniform variables over [0,1], then the values that would be returned normally, and , are calculated as follows: For the antithetic case, ) and ) are the distances that and would be from . The antithetic values returned, and , are calculated as follows: which now involves the distances and are from 1.

Implements ns3::RandomVariableStream.

Definition at line 746 of file random-variable-stream.cc.

References GetValue(), m_bound, m_mean, m_variance, and NS_LOG_FUNCTION. Here is the call graph for this function:

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

Returns the mean value for the normal distribution returned by this RNG stream.

Returns
The mean value for the normal distribution returned by this RNG stream.

Definition at line 668 of file random-variable-stream.cc.

References m_mean, and NS_LOG_FUNCTION.

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

Definition at line 638 of file random-variable-stream.cc.

References INFINITE_VALUE, m_bound, m_mean, m_variance, and ns3::TypeId::SetParent(). Here is the call graph for this function:

 double ns3::NormalRandomVariable::GetValue ( double mean, double variance, double bound = NormalRandomVariable::INFINITE_VALUE )

Returns a random double from a normal distribution with the specified mean, variance, and bound.

Parameters
 mean Mean value for the normal distribution. variance Variance value for the normal distribution. bound 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 and are uniform variables over [0,1], then the values that would be returned normally, and , are calculated as follows: For the antithetic case, ) and ) are the distances that and would be from . The antithetic values returned, and , are calculated as follows: which now involves the distances and are from 1.

Definition at line 687 of file random-variable-stream.cc. Here is the call graph for this function: Here is the caller graph for this function:

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

Returns a random double from a normal distribution with the current mean, variance, and bound.

Returns
A floating point random value.

Note that antithetic values are being generated if m_isAntithetic is equal to true. If and are uniform variables over [0,1], then the values that would be returned normally, and , are calculated as follows: For the antithetic case, ) and ) are the distances that and would be from . The antithetic values returned, and , are calculated as follows: which now involves the distances and are from 1.

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 740 of file random-variable-stream.cc.

References m_bound, m_mean, m_variance, and NS_LOG_FUNCTION.

Referenced by GetInteger(). Here is the caller graph for this function:

 double ns3::NormalRandomVariable::GetVariance ( void ) const

Returns the variance value for the normal distribution returned by this RNG stream.

Returns
The variance value for the normal distribution returned by this RNG stream.

Definition at line 674 of file random-variable-stream.cc.

References m_variance, and NS_LOG_FUNCTION.

## Member Data Documentation

 const double ns3::NormalRandomVariable::INFINITE_VALUE = 1e307
static

Definition at line 1057 of file random-variable-stream.h.

Referenced by GetTypeId(), and ns3::GammaRandomVariable::GetValue().

 double ns3::NormalRandomVariable::m_bound
private

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

Definition at line 1244 of file random-variable-stream.h.

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

 double ns3::NormalRandomVariable::m_mean
private

The mean value for the normal distribution returned by this RNG stream.

Definition at line 1238 of file random-variable-stream.h.

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

 double ns3::NormalRandomVariable::m_next
private

The algorithm produces two values at a time.

Definition at line 1250 of file random-variable-stream.h.

Referenced by GetValue().

 bool ns3::NormalRandomVariable::m_nextValid
private

True if the next value is valid.

Definition at line 1247 of file random-variable-stream.h.

Referenced by GetValue().

 double ns3::NormalRandomVariable::m_variance
private

The variance value for the normal distribution returned by this RNG stream.

Definition at line 1241 of file random-variable-stream.h.

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

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