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!=

operator<<operator>>

 

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).

std::chi_squared_distribution satisfies all requirements of RandomNumberDistribution

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, see RandomNumberDistribution.

Member functions

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

Non-member functions

operator==operator!=	compares two distribution objects (function)
operator<<operator>>	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.