gum::Dirichlet Class Reference

A class for sampling w.r.t. More...

#include <agrum/tools/core/math/Dirichlet.h>

Public Member Functions
template<class URNG >
INLINE Dirichlet::result_type	operator() (URNG &generator, const Dirichlet::param_type &parm)
Constructors / Destructors
	Dirichlet (const param_type &params, unsigned int seed=GUM_RANDOMSEED)
	Default constructor. More...
	Dirichlet (const Dirichlet &from)
	Copy constructor. More...
	Dirichlet (Dirichlet &&from)
	Move constructor. More...
	~Dirichlet ()
	Class destructor. More...
Operators
Dirichlet &	operator= (const Dirichlet &from)
	Copy operator. More...
Dirichlet &	operator= (Dirichlet &&from)
	Move operator. More...
result_type	operator() ()
	Returns a sample from the Dirichlet distribution. More...
result_type	operator() (const param_type &p)
	Returns a sample from the Dirichlet distribution. More...
template<class URNG >
result_type	operator() (URNG &generator, const param_type &p)
	Returns a sample from the Dirichlet distribution. More...
Accessors / Modifiers
const param_type &	param () const noexcept
	Returns the parameters of the distribution. More...
void	param (const param_type &p)
	Sets the parameters of the distribution. More...
float	min () const noexcept
	Returns the greatest lower bound of the range of values returned by gum::Dirichlet::operator()(). More...
float	max () const noexcept
	Returns the lowest higher bound of the range of values returned by gum::Dirichlet::operator()(). More...

Public Types
using	param_type = std::vector< float >
	The parameter type. More...
using	result_type = std::vector< float >
	The type for the samples generated. More...

Detailed Description

A class for sampling w.r.t.

Dirichlet distributions.

Definition at line 49 of file Dirichlet.h.

Member Typedef Documentation

param_type

using gum::Dirichlet::param_type = std::vector< float >

The parameter type.

Definition at line 52 of file Dirichlet.h.

result_type

using gum::Dirichlet::result_type = std::vector< float >

The type for the samples generated.

Definition at line 55 of file Dirichlet.h.

Constructor & Destructor Documentation

Dirichlet() [1/3]

INLINE gum::Dirichlet::Dirichlet	(	const param_type &	params,
		unsigned int	seed = GUM_RANDOMSEED
	)

Default constructor.

Parameters

params	The distribution parameters.
seed	The distribution seed.

Definition at line 31 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                                         :
      _generator_(gum::getRandomGenerator(seed)), _params_(params) {
    GUM_CONSTRUCTOR(Dirichlet);
  }

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Dirichlet() [2/3]

INLINE gum::Dirichlet::Dirichlet

(

const Dirichlet &

from

)

Copy constructor.

Parameters

from	The distribution to copy.

Definition at line 37 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                   :
      _generator_(from._generator_), _gamma_(from._gamma_), _params_(from._params_) {
    GUM_CONS_CPY(Dirichlet);
  }

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Dirichlet() [3/3]

INLINE gum::Dirichlet::Dirichlet

(

Dirichlet &&

from

)

Move constructor.

Parameters

from	The distribution to move.

Definition at line 43 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                              :
      _generator_(std::move(from._generator_)), _gamma_(std::move(from._gamma_)),
      _params_(std::move(from._params_)) {
    GUM_CONS_MOV(Dirichlet);
  }

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~Dirichlet()

INLINE gum::Dirichlet::~Dirichlet

(

)

Class destructor.

Definition at line 50 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

                               {
    GUM_DESTRUCTOR(Dirichlet);
    ;
  }

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Member Function Documentation

max()

INLINE float gum::Dirichlet::max ( ) const

noexcept

Returns the lowest higher bound of the range of values returned by gum::Dirichlet::operator()().

Returns

Returns the lowest higher bound of the range of values returned by gum::Dirichlet::operator()().

Definition at line 121 of file Dirichlet_inl.h.

{ return 1.0f; }

min()

INLINE float gum::Dirichlet::min ( ) const

noexcept

Returns the greatest lower bound of the range of values returned by gum::Dirichlet::operator()().

Returns

Returns the greatest lower bound of the range of values returned by gum::Dirichlet::operator()().

Definition at line 118 of file Dirichlet_inl.h.

{ return 0.0f; }

operator()() [1/4]

template<class URNG >

INLINE Dirichlet::result_type gum::Dirichlet::operator()	(	URNG &	generator,
		const Dirichlet::param_type &	parm
	)

Definition at line 33 of file Dirichlet_tpl.h.

References gum::Set< Key, Alloc >::emplace().

                                                                                       {
    Size        size = Size(parm.size());
    result_type res(size);
    float       sum = 0.0f;
    while (sum == 0.0f) {
      for (Idx i = 0; i < size; ++i) {
        _gamma_.param(std::gamma_distribution< float >::param_type(parm[i], 1));
        res[i] = _gamma_(generator);
        sum += res[i];
      }
    }
    for (Idx i = 0; i < size; ++i) {
      res[i] /= sum;
    }
    return res;
  }

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operator()() [2/4]

INLINE Dirichlet::result_type gum::Dirichlet::operator()

(

)

Returns a sample from the Dirichlet distribution.

Returns

Returns a sample from the Dirichlet distribution.

Definition at line 76 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                    {
    Size        size = Size(_params_.size());
    result_type res(size);
    float       sum = 0.0f;
    while (sum == 0.0f) {
      for (Idx i = 0; i < size; ++i) {
        _gamma_.param(std::gamma_distribution< float >::param_type(_params_[i], 1));
        res[i] = _gamma_(_generator_);
        sum += res[i];
      }
    }
    for (Idx i = 0; i < size; ++i) {
      res[i] /= sum;
    }
    return res;
  }

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operator()() [3/4]

INLINE Dirichlet::result_type gum::Dirichlet::operator()

(

const param_type &

p

)

Returns a sample from the Dirichlet distribution.

Parameters

p	An object representing the distribution's parameters, obtained by a call to gum::Dirichlet::param(const param_type&).

Definition at line 94 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                                                   {
    Size        size = Size(parm.size());
    result_type res(size);
    float       sum = 0.0f;
    while (sum == 0.0f) {
      for (Idx i = 0; i < size; ++i) {
        _gamma_.param(std::gamma_distribution< float >::param_type(parm[i], 1));
        res[i] = _gamma_(_generator_);
        sum += res[i];
      }
    }
    for (Idx i = 0; i < size; ++i) {
      res[i] /= sum;
    }
    return res;
  }

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operator()() [4/4]

template<class URNG >

result_type gum::Dirichlet::operator()	(	URNG &	generator,
		const param_type &	p
	)

Returns a sample from the Dirichlet distribution.

Parameters

generator	A uniform random number generator object, used as the source of randomness. URNG shall be a uniform random number generator type, such as one of the standard generator classes.
p	An object representing the distribution's parameters, obtained by a call to gum::Dirichlet::param(const param_type&).

operator=() [1/2]

INLINE Dirichlet & gum::Dirichlet::operator=

(

const Dirichlet &

from

)

Copy operator.

Parameters

from	The distribution to copy.

Returns

Returns this gum::Dirichlet distribution.

Definition at line 56 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                              {
    if (&from != this) {
      _generator_ = from._generator_;
      _gamma_     = from._gamma_;
      _params_    = from._params_;
    }
    return *this;
  }

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operator=() [2/2]

INLINE Dirichlet & gum::Dirichlet::operator=

(

Dirichlet &&

from

)

Move operator.

Parameters

from	The distribution to move.

Returns

Returns this gum::Dirichlet distribution.

Definition at line 66 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                         {
    if (&from != this) {
      _generator_ = std::move(from._generator_);
      _gamma_     = std::move(from._gamma_);
      _params_    = std::move(from._params_);
    }
    return *this;
  }

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param() [1/2]

INLINE const Dirichlet::param_type & gum::Dirichlet::param ( ) const

noexcept

Returns the parameters of the distribution.

Returns

Returns the parameters of the distribution.

Definition at line 112 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

{ return _params_; }

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param() [2/2]

INLINE void gum::Dirichlet::param

(

const param_type &

p

)

Sets the parameters of the distribution.

Parameters

p	An object representing the distribution's parameters, obtained by a call to member function param.

Definition at line 115 of file Dirichlet_inl.h.

References gum::Set< Key, Alloc >::emplace().

{ _params_ = parm; }

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Member Data Documentation

_gamma_

std::gamma_distribution< float > gum::Dirichlet::_gamma_

private

The gamma distribution used to compute the Dirichlet unnormalized samples.

Definition at line 174 of file Dirichlet.h.

_generator_

std::default_random_engine gum::Dirichlet::_generator_

private

The random engine used by the unform random distribution.

Definition at line 170 of file Dirichlet.h.

_params_

param_type gum::Dirichlet::_params_

private

The parameters of the distribution.

Definition at line 177 of file Dirichlet.h.

---

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

• agrum/tools/core/math/Dirichlet.h
• agrum/tools/core/math/Dirichlet_inl.h
• agrum/tools/core/math/Dirichlet_tpl.h