[rand.dist.norm] (original) (raw)

26 Numerics library [numerics]

26.6 Random number generation [rand]

26.6.8 Random number distribution class templates [rand.dist]

26.6.8.5 Normal distributions [rand.dist.norm]

26.6.8.5.1 Class template normal_­distribution [rand.dist.norm.normal]

A normal_­distribution random number distribution produces random numbers xdistributed according to the probability density function

The distribution parameters μ and σare also known as this distribution's meanand standard deviation.

template class normal_distribution { public:

using result_type = RealType;
using param_type  = unspecified;


normal_distribution() : normal_distribution(0.0) {}
explicit normal_distribution(RealType mean, RealType stddev = 1.0);
explicit normal_distribution(const param_type& parm);
void reset();


template<class URBG>
  result_type operator()(URBG& g);
template<class URBG>
  result_type operator()(URBG& g, const param_type& parm);


RealType mean() const;
RealType stddev() const;
param_type param() const;
void param(const param_type& parm);
result_type min() const;
result_type max() const;

};

explicit normal_distribution(RealType mean, RealType stddev = 1.0);

Remarks: mean and stddevcorrespond to the respective parameters of the distribution.

Returns:The value of the mean parameter with which the object was constructed.

Returns:The value of the stddev parameter with which the object was constructed.

26.6.8.5.2 Class template lognormal_­distribution [rand.dist.norm.lognormal]

A lognormal_­distribution random number distribution produces random numbers distributed according to the probability density function

template class lognormal_distribution { public:

using result_type = RealType;
using param_type  = unspecified;


lognormal_distribution() : lognormal_distribution(0.0) {}
explicit lognormal_distribution(RealType m, RealType s = 1.0);
explicit lognormal_distribution(const param_type& parm);
void reset();


template<class URBG>
  result_type operator()(URBG& g);
template<class URBG>
  result_type operator()(URBG& g, const param_type& parm);


RealType m() const;
RealType s() const;
param_type param() const;
void param(const param_type& parm);
result_type min() const;
result_type max() const;

};

explicit lognormal_distribution(RealType m, RealType s = 1.0);

Remarks: m and scorrespond to the respective parameters of the distribution.

Returns:The value of the m parameter with which the object was constructed.

Returns:The value of the s parameter with which the object was constructed.

26.6.8.5.3 Class template chi_­squared_­distribution [rand.dist.norm.chisq]

A chi_­squared_­distribution random number distribution produces random numbers distributed according to the probability density function

template class chi_squared_distribution { public:

using result_type = RealType;
using param_type  = unspecified;


chi_squared_distribution() : chi_squared_distribution(1.0) {}
explicit chi_squared_distribution(RealType n);
explicit chi_squared_distribution(const param_type& parm);
void reset();


template<class URBG>
  result_type operator()(URBG& g);
template<class URBG>
  result_type operator()(URBG& g, const param_type& parm);


RealType n() const;
param_type param() const;
void param(const param_type& parm);
result_type min() const;
result_type max() const;

};

explicit chi_squared_distribution(RealType n);

Remarks: n corresponds to the parameter of the distribution.

Returns:The value of the n parameter with which the object was constructed.

26.6.8.5.4 Class template cauchy_­distribution [rand.dist.norm.cauchy]

A cauchy_­distribution random number distribution produces random numbers xdistributed according to the probability density function

template class cauchy_distribution { public:

using result_type = RealType;
using param_type  = unspecified;


cauchy_distribution() : cauchy_distribution(0.0) {}
explicit cauchy_distribution(RealType a, RealType b = 1.0);
explicit cauchy_distribution(const param_type& parm);
void reset();


template<class URBG>
  result_type operator()(URBG& g);
template<class URBG>
  result_type operator()(URBG& g, const param_type& parm);


RealType a() const;
RealType b() const;
param_type param() const;
void param(const param_type& parm);
result_type min() const;
result_type max() const;

};

explicit cauchy_distribution(RealType a, RealType b = 1.0);

Remarks: a and bcorrespond to the respective parameters of the distribution.

Returns:The value of the a parameter with which the object was constructed.

Returns:The value of the b parameter with which the object was constructed.

26.6.8.5.5 Class template fisher_­f_­distribution [rand.dist.norm.f]

A fisher_­f_­distribution random number distribution produces random numbers distributed according to the probability density function

template class fisher_f_distribution { public:

using result_type = RealType;
using param_type  = unspecified;


fisher_f_distribution() : fisher_f_distribution(1.0) {}
explicit fisher_f_distribution(RealType m, RealType n = 1.0);
explicit fisher_f_distribution(const param_type& parm);
void reset();


template<class URBG>
  result_type operator()(URBG& g);
template<class URBG>
  result_type operator()(URBG& g, const param_type& parm);


RealType m() const;
RealType n() const;
param_type param() const;
void param(const param_type& parm);
result_type min() const;
result_type max() const;

};

explicit fisher_f_distribution(RealType m, RealType n = 1);

Remarks: m and ncorrespond to the respective parameters of the distribution.

Returns:The value of the m parameter with which the object was constructed.

Returns:The value of the n parameter with which the object was constructed.

26.6.8.5.6 Class template student_­t_­distribution [rand.dist.norm.t]

A student_­t_­distribution random number distribution produces random numbers xdistributed according to the probability density function

template class student_t_distribution { public:

using result_type = RealType;
using param_type  = unspecified;


student_t_distribution() : student_t_distribution(1.0) {}
explicit student_t_distribution(RealType n);
explicit student_t_distribution(const param_type& parm);
void reset();


template<class URBG>
  result_type operator()(URBG& g);
template<class URBG>
  result_type operator()(URBG& g, const param_type& parm);


RealType n() const;
param_type param() const;
void param(const param_type& parm);
result_type min() const;
result_type max() const;

};

explicit student_t_distribution(RealType n);

Remarks: n corresponds to the parameter of the distribution.

Returns:The value of the n parameter with which the object was constructed.