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A Discrete-Event Network Simulator
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API |
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A Discrete-Event Network Simulator
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API |
The Weibull distribution Random Number Generator (RNG) which allows stream numbers to be set deterministically. More...
#include "random-variable-stream.h"
Inheritance diagram for ns3::WeibullRandomVariable: Collaboration diagram for ns3::WeibullRandomVariable:Public Member Functions | |
| WeibullRandomVariable () | |
| Creates a Weibull distribution RNG with the default values for the scale, shape, and upper bound. | |
| double | GetBound () const |
| Returns the upper bound on values that can be returned by this RNG stream. | |
| virtual uint32_t | GetInteger () |
| Get the next random value drawn from the distribution. | |
| uint32_t | GetInteger (uint32_t scale, uint32_t shape, uint32_t bound) |
| Get the next random value drawn from the distribution. | |
| double | GetMean () const |
| Returns the mean value for the Weibull distribution returned by this RNG stream. | |
| double | GetScale () const |
| Returns the scale parameter for the Weibull distribution returned by this RNG stream. | |
| double | GetShape () const |
| Returns the shape parameter for the Weibull distribution returned by this RNG stream. | |
| double | GetValue () override |
| Get the next random value drawn from the distribution. | |
| double | GetValue (double scale, double shape, double bound) |
| Get the next random value drawn from the distribution. | |
| Public Member Functions inherited from ns3::RandomVariableStream | |
| RandomVariableStream () | |
| Default constructor. | |
| RandomVariableStream (const RandomVariableStream &)=delete | |
| ~RandomVariableStream () override | |
| Destructor. | |
| int64_t | GetStream () const |
| Returns the stream number for the RngStream. | |
| bool | IsAntithetic () const |
| Check if antithetic values will be generated. | |
| RandomVariableStream & | operator= (const RandomVariableStream &)=delete |
| void | SetAntithetic (bool isAntithetic) |
| Specify whether antithetic values should be generated. | |
| void | SetStream (int64_t stream) |
| Specifies the stream number for the RngStream. | |
| Public Member Functions inherited from ns3::Object | |
| Object () | |
| Constructor. | |
| ~Object () override | |
| Destructor. | |
| void | AggregateObject (Ptr< Object > other) |
| Aggregate two Objects together. | |
| void | Dispose () |
| Dispose of this Object. | |
| AggregateIterator | GetAggregateIterator () const |
| Get an iterator to the Objects aggregated to this one. | |
| TypeId | GetInstanceTypeId () const final |
| Get the most derived TypeId for this Object. | |
| template<typename T> | |
| Ptr< T > | GetObject () const |
| Get a pointer to the requested aggregated Object. | |
| template<> | |
| Ptr< Object > | GetObject () const |
| Specialization of () for objects of type ns3::Object. | |
| template<typename T> | |
| Ptr< T > | GetObject (TypeId tid) const |
| Get a pointer to the requested aggregated Object by TypeId. | |
| template<> | |
| Ptr< Object > | GetObject (TypeId tid) const |
| Specialization of (TypeId tid) for objects of type ns3::Object. | |
| void | Initialize () |
| Invoke DoInitialize on all Objects aggregated to this one. | |
| bool | IsInitialized () const |
| Check if the object has been initialized. | |
| void | UnidirectionalAggregateObject (Ptr< Object > other) |
| Aggregate an Object to another Object. | |
| Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter > | |
| SimpleRefCount () | |
| Default constructor. | |
| SimpleRefCount (const SimpleRefCount &o) | |
| Copy constructor. | |
| uint32_t | GetReferenceCount () const |
| Get the reference count of the object. | |
| SimpleRefCount & | operator= (const SimpleRefCount &o) |
| Assignment operator. | |
| void | Ref () const |
| Increment the reference count. | |
| void | Unref () const |
| Decrement the reference count. | |
| Public Member Functions inherited from ns3::ObjectBase | |
| virtual | ~ObjectBase () |
| Virtual destructor. | |
| void | GetAttribute (std::string name, AttributeValue &value, bool permissive=false) const |
| Get the value of an attribute, raising fatal errors if unsuccessful. | |
| bool | GetAttributeFailSafe (std::string name, AttributeValue &value) const |
| Get the value of an attribute without raising errors. | |
| void | SetAttribute (std::string name, const AttributeValue &value) |
| Set a single attribute, raising fatal errors if unsuccessful. | |
| bool | SetAttributeFailSafe (std::string name, const AttributeValue &value) |
| Set a single attribute without raising errors. | |
| bool | TraceConnect (std::string name, std::string context, const CallbackBase &cb) |
| Connect a TraceSource to a Callback with a context. | |
| bool | TraceConnectWithoutContext (std::string name, const CallbackBase &cb) |
| Connect a TraceSource to a Callback without a context. | |
| bool | TraceDisconnect (std::string name, std::string context, const CallbackBase &cb) |
| Disconnect from a TraceSource a Callback previously connected with a context. | |
| bool | TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb) |
| Disconnect from a TraceSource a Callback previously connected without a context. | |
Static Public Member Functions | |
| static double | GetMean (double scale, double shape) |
| Returns the mean value for the Weibull distribution returned by this RNG stream. | |
| static TypeId | GetTypeId () |
| Register this type. | |
| Static Public Member Functions inherited from ns3::RandomVariableStream | |
| static TypeId | GetTypeId () |
| Register this type. | |
| Static Public Member Functions inherited from ns3::Object | |
| static TypeId | GetTypeId () |
| Register this type. | |
| Static Public Member Functions inherited from ns3::ObjectBase | |
| static TypeId | GetTypeId () |
| Get the type ID. | |
Private Attributes | |
| double | m_bound |
| The upper bound on values that can be returned by this RNG stream. | |
| double | m_scale |
| The scale parameter for the Weibull distribution returned by this RNG stream. | |
| double | m_shape |
| The shape parameter for the Weibull distribution returned by this RNG stream. | |
Additional Inherited Members | |
| Protected Member Functions inherited from ns3::RandomVariableStream | |
| RngStream * | Peek () const |
| Get the pointer to the underlying RngStream. | |
| Protected Member Functions inherited from ns3::Object | |
| Object (const Object &o) | |
| Copy an Object. | |
| virtual void | DoDispose () |
| Destructor implementation. | |
| virtual void | DoInitialize () |
| Initialize() implementation. | |
| virtual void | NotifyNewAggregate () |
| Notify all Objects aggregated to this one of a new Object being aggregated. | |
| Protected Member Functions inherited from ns3::ObjectBase | |
| void | ConstructSelf (const AttributeConstructionList &attributes) |
| Complete construction of ObjectBase; invoked by derived classes. | |
| virtual void | NotifyConstructionCompleted () |
| Notifier called once the ObjectBase is fully constructed. | |
| Related Symbols inherited from ns3::ObjectBase | |
| static TypeId | GetObjectIid () |
| Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly. | |
The Weibull distribution Random Number Generator (RNG) which allows stream numbers to be set deterministically.
This class supports the creation of objects that return random numbers from a fixed Weibull distribution. It also supports the generation of single random numbers from various Weibull distributions.
The probability density function is:
![\[ P(x; \lambda, k) dx = \frac{k}{\lambda} \\
\left(\frac{x}{\lambda}\right)^{k-1} \\
e^{-\left(\frac{x}{\lambda}\right)^k} dx, \\
\quad x \in [0, +\infty)
\]](../../form_37_dark.png)
where 
Shape parameter and 
Scale parameter.
The mean 
Scale and Shape parameters by the following relation:
![\[ \mu = \lambda\Gamma\left(1+\frac{1}{k}\right)
\]](../../form_40_dark.png)
where 
The variance of the distribution is
![\[ \sigma^2 = \lambda^2 \left[ \Gamma\left(1 + \frac{2}{k}\right) - \\
\left( \Gamma\left(1 + \frac{1}{k}\right)\right)^2
\right]
\]](../../form_42_dark.png)
For 
![\[ \sigma^2 \approx \frac{\pi^2}{6 k^2} + \mathcal{O}(k^{-3})
\]](../../form_45_dark.png)
The Weibull RNG value 
![\[ x = \lambda {(-\log(u))}^{\frac{1}{k}}
\]](../../form_46_dark.png)
where 
Since Weibull distributions can theoretically return unbounded values, it is sometimes useful to specify a fixed upper limit. The bounded version is defined over the interval ![$ x \in [0, b] $](../../form_47_dark.png)
Here is an example of how to use this class:
If an instance of this RNG is configured to return antithetic values, the actual value returned, 
![\[ x' = \lambda {(-\log(1 - u))}^{\frac{1}{k}} ,
\]](../../form_48_dark.png)
which now involves the log of the distance
ns3::WeibullRandomVariable is accessible through the following paths with Config::Set and Config::Connect:
No TraceSources are defined for this type
Group: Core
Size of this type is 104 bytes (on a 64-bit architecture).
Definition at line 828 of file random-variable-stream.h.
| ns3::WeibullRandomVariable::WeibullRandomVariable | ( | ) |
Creates a Weibull distribution RNG with the default values for the scale, shape, and upper bound.
Definition at line 572 of file random-variable-stream.cc.
References NS_LOG_FUNCTION.
Referenced by GetTypeId().
Here is the caller graph for this function:| double ns3::WeibullRandomVariable::GetBound | ( | ) | const |
Returns the upper bound on values that can be returned by this RNG stream.
Definition at line 592 of file random-variable-stream.cc.
References m_bound.
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virtual |
Get the next random value drawn from the distribution.
Reimplemented from ns3::RandomVariableStream.
Definition at line 145 of file random-variable-stream.cc.
Get the next random value drawn from the distribution.
| [in] | scale | Scale parameter for the Weibull distribution. |
| [in] | shape | Shape parameter for the Weibull distribution. |
| [in] | bound | Upper bound on values returned. |
Definition at line 638 of file random-variable-stream.cc.
References ns3::RandomVariableStream::GetStream(), GetValue(), and NS_LOG_DEBUG.
Here is the call graph for this function:| double ns3::WeibullRandomVariable::GetMean | ( | ) | const |
Returns the mean value for the Weibull distribution returned by this RNG stream.
Definition at line 605 of file random-variable-stream.cc.
References GetMean(), m_scale, m_shape, and NS_LOG_FUNCTION.
Referenced by GetMean().
Here is the call graph for this function: Here is the caller graph for this function:Returns the mean value for the Weibull distribution returned by this RNG stream.
| [in] | scale | Scale parameter for the Weibull distribution. |
| [in] | shape | Shape parameter for the Weibull distribution. |
Definition at line 598 of file random-variable-stream.cc.
References NS_LOG_FUNCTION.
| double ns3::WeibullRandomVariable::GetScale | ( | ) | const |
Returns the scale parameter for the Weibull distribution returned by this RNG stream.
Definition at line 580 of file random-variable-stream.cc.
References m_scale.
| double ns3::WeibullRandomVariable::GetShape | ( | ) | const |
Returns the shape parameter for the Weibull distribution returned by this RNG stream.
Definition at line 586 of file random-variable-stream.cc.
References m_shape.
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static |
Register this type.
Definition at line 545 of file random-variable-stream.cc.
References ns3::RandomVariableStream::RandomVariableStream(), WeibullRandomVariable(), m_bound, m_scale, m_shape, ns3::MakeDoubleAccessor(), ns3::MakeDoubleChecker(), and ns3::TypeId::SetParent().
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overridevirtual |
Get the next random value drawn from the distribution.
Implements ns3::RandomVariableStream.
Definition at line 647 of file random-variable-stream.cc.
References GetValue(), m_bound, m_scale, m_shape, and NS_LOG_FUNCTION.
Referenced by GetInteger(), and GetValue().
Here is the call graph for this function: Here is the caller graph for this function:Get the next random value drawn from the distribution.
| [in] | scale | Scale parameter for the Weibull distribution. |
| [in] | shape | Shape parameter for the Weibull distribution. |
| [in] | bound | Upper bound on values returned. |
Definition at line 612 of file random-variable-stream.cc.
References ns3::RandomVariableStream::GetStream(), ns3::RandomVariableStream::IsAntithetic(), NS_LOG_DEBUG, ns3::RandomVariableStream::Peek(), and ns3::RngStream::RandU01().
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private |
The upper bound on values that can be returned by this RNG stream.
Definition at line 897 of file random-variable-stream.h.
Referenced by GetBound(), GetTypeId(), and GetValue().
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private |
The scale parameter for the Weibull distribution returned by this RNG stream.
Definition at line 891 of file random-variable-stream.h.
Referenced by GetMean(), GetScale(), GetTypeId(), and GetValue().
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private |
The shape parameter for the Weibull distribution returned by this RNG stream.
Definition at line 894 of file random-variable-stream.h.
Referenced by GetMean(), GetShape(), GetTypeId(), and GetValue().
1.13.2