The Zipf distribution Random Number Generator (RNG) that allows stream numbers to be set deterministically. More...
#include <random-variable-stream.h>
Public Member Functions | |
ZipfRandomVariable () | |
Creates a Zipf distribution RNG with the default values for n and alpha. More... | |
double | GetAlpha (void) const |
Returns the alpha value for the Zipf distribution returned by this RNG stream. More... | |
uint32_t | GetInteger (uint32_t n, uint32_t alpha) |
Returns a random unsigned integer from a Zipf distribution with the specified n and alpha. More... | |
virtual uint32_t | GetInteger (void) |
Returns a random unsigned integer from a Zipf distribution with the current n and alpha. More... | |
uint32_t | GetN (void) const |
Returns the n value for the Zipf distribution returned by this RNG stream. More... | |
double | GetValue (uint32_t n, double alpha) |
Returns a random double from a Zipf distribution with the specified n and alpha. More... | |
virtual double | GetValue (void) |
Returns a random double from a Zipf distribution with the current n and alpha. More... | |
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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... | |
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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... | |
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SimpleRefCount () | |
Constructor. More... | |
SimpleRefCount (const SimpleRefCount &o) | |
Copy constructor. More... | |
uint32_t | GetReferenceCount (void) const |
Get the reference count of the object. More... | |
SimpleRefCount & | operator= (const SimpleRefCount &o) |
Assignment. More... | |
void | Ref (void) const |
Increment the reference count. More... | |
void | Unref (void) const |
Decrement the reference count. More... | |
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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) |
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static TypeId | GetTypeId (void) |
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static TypeId | GetTypeId (void) |
Register this type. More... | |
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static void | Cleanup (void) |
Noop. More... | |
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static TypeId | GetTypeId (void) |
Get the type ID. More... | |
Private Attributes | |
double | m_alpha |
The alpha value for the Zipf distribution returned by this RNG stream. More... | |
double | m_c |
The normalization constant. More... | |
uint32_t | m_n |
The n value for the Zipf distribution returned by this RNG stream. More... | |
Additional Inherited Members | |
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RngStream * | Peek (void) const |
Returns a pointer to the underlying RNG stream. More... | |
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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... | |
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void | ConstructSelf (const AttributeConstructionList &attributes) |
virtual void | NotifyConstructionCompleted (void) |
This method is invoked once all member attributes have been initialized. More... | |
The Zipf 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 Zipf distribution. It also supports the generation of single random numbers from various Zipf distributions.
The Zipf's law states that given some corpus of natural language utterances, the frequency of any word is inversely proportional to its rank in the frequency table.
Zipf's distribution has two parameters, alpha and N, where: (real) and
(integer). Probability Mass Function is
where
Here is an example of how to use this class:
ns3::ZipfRandomVariable is accessible through the following paths with Config::Set and Config::Connect:
No TraceSources are defined for this type.
Definition at line 2075 of file random-variable-stream.h.
ns3::ZipfRandomVariable::ZipfRandomVariable | ( | ) |
Creates a Zipf distribution RNG with the default values for n and alpha.
Definition at line 1275 of file random-variable-stream.cc.
References NS_LOG_FUNCTION.
double ns3::ZipfRandomVariable::GetAlpha | ( | void | ) | const |
Returns the alpha value for the Zipf distribution returned by this RNG stream.
Definition at line 1288 of file random-variable-stream.cc.
References m_alpha, and NS_LOG_FUNCTION.
uint32_t ns3::ZipfRandomVariable::GetInteger | ( | uint32_t | n, |
uint32_t | alpha | ||
) |
Returns a random unsigned integer from a Zipf distribution with the specified n and alpha.
n | N value for the Zipf distribution. |
alpha | Alpha value for the Zipf distribution. |
Note that antithetic values are being generated if m_isAntithetic is equal to true. If is a uniform variable over [0,1] and
is a value that would be returned normally, then
) is the distance that
would be from
. The value returned in the antithetic case,
, uses (1-u), which is the distance
is from the 1.
Definition at line 1327 of file random-variable-stream.cc.
References GetValue(), and NS_LOG_FUNCTION.
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virtual |
Returns a random unsigned integer from a Zipf distribution with the current n and alpha.
Note that antithetic values are being generated if m_isAntithetic is equal to true. If is a uniform variable over [0,1] and
is a value that would be returned normally, then
) is the distance that
would be from
. The value returned in the antithetic case,
, uses (1-u), which is the distance
is from the 1.
Implements ns3::RandomVariableStream.
Definition at line 1340 of file random-variable-stream.cc.
References GetValue(), m_alpha, m_n, and NS_LOG_FUNCTION.
uint32_t ns3::ZipfRandomVariable::GetN | ( | void | ) | const |
Returns the n value for the Zipf distribution returned by this RNG stream.
Definition at line 1282 of file random-variable-stream.cc.
References m_n, and NS_LOG_FUNCTION.
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static |
Definition at line 1259 of file random-variable-stream.cc.
References m_alpha, m_n, and ns3::TypeId::SetParent().
double ns3::ZipfRandomVariable::GetValue | ( | uint32_t | n, |
double | alpha | ||
) |
Returns a random double from a Zipf distribution with the specified n and alpha.
n | N value for the Zipf distribution. |
alpha | Alpha value for the Zipf distribution. |
Note that antithetic values are being generated if m_isAntithetic is equal to true. If is a uniform variable over [0,1] and
is a value that would be returned normally, then
) is the distance that
would be from
. The value returned in the antithetic case,
, uses (1-u), which is the distance
is from the 1.
Definition at line 1295 of file random-variable-stream.cc.
References ns3::RandomVariableStream::IsAntithetic(), m_alpha, m_c, m_n, NS_LOG_FUNCTION, ns3::RandomVariableStream::Peek(), and ns3::RngStream::RandU01().
Referenced by RandomVariableStreamZipfTestCase::DoRun(), and RandomVariableStreamZipfAntitheticTestCase::DoRun().
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virtual |
Returns a random double from a Zipf distribution with the current n and alpha.
Note that antithetic values are being generated if m_isAntithetic is equal to true. If is a uniform variable over [0,1] and
is a value that would be returned normally, then
) is the distance that
would be from
. The value returned in the antithetic case,
, uses (1-u), which is the distance
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 1334 of file random-variable-stream.cc.
References m_alpha, m_n, and NS_LOG_FUNCTION.
Referenced by GetInteger().
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private |
The alpha value for the Zipf distribution returned by this RNG stream.
Definition at line 2164 of file random-variable-stream.h.
Referenced by GetAlpha(), GetInteger(), GetTypeId(), and GetValue().
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private |
The normalization constant.
Definition at line 2167 of file random-variable-stream.h.
Referenced by GetValue().
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private |
The n value for the Zipf distribution returned by this RNG stream.
Definition at line 2161 of file random-variable-stream.h.
Referenced by GetInteger(), GetN(), GetTypeId(), and GetValue().