std::chi_squared_distribution

 

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std::chi_squared_distribution

Member functions

chi_squared_distribution::chi_squared_distribution

chi_squared_distribution::reset

Generation

chi_squared_distribution::operator()

Characteristics

chi_squared_distribution::n

chi_squared_distribution::param

chi_squared_distribution::min

chi_squared_distribution::max

Non-member functions

operator==operator!= (C++11)(C++11)(until C++20)

operator<<operator>> (C++11)(C++11)

 

Defined in header <random>
template< class RealType = double > class chi_squared_distribution;		(since C++11)

The chi_squared_distribution produces random numbers x>0 according to the Chi-squared distribution:

f(x;n) =

x(n/2)-1 e-x/2

Γ(n/2) 2n/2

Γ is the Gamma function (See also std::tgamma) and n are the degrees of freedom (default 1).

Template parameters

RealType

-

The result type generated by the generator. The effect is undefined if this is not one of float, double, or long double.

Member types

Member type	Definition
result_type	RealType
param_type	the type of the parameter set, unspecified

Member functions

(constructor) (C++11)	constructs new distribution (public member function)
reset (C++11)	resets the internal state of the distribution (public member function)
Generation
operator() (C++11)	generates the next random number in the distribution (public member function)
Characteristics
n (C++11)	returns the degrees of freedom (\(\small n\)n) distribution parameter (public member function)
param (C++11)	gets or sets the distribution parameter object (public member function)
min (C++11)	returns the minimum potentially generated value (public member function)
max (C++11)	returns the maximum potentially generated value (public member function)

Non-member functions

operator==operator!= (C++11)(C++11)(removed in C++20)	compares two distribution objects (function)
operator<<operator>> (C++11)	performs stream input and output on pseudo-random number distribution (function template)

External links

• Weisstein, Eric W. "Chi-Squared Distribution." From MathWorld--A Wolfram Web Resource.
• Chi-squared distribution. From Wikipedia.