public member function
<random>
| (1) | explicit chi_squared_distribution ( result_type n = 1.0 ); |
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| (2) | explicit chi_squared_distribution ( const param_type& parm ); |
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Construct Chi-squared distribution
Constructs a chi_squared_distribution object, adopting the distribution parameters specified either by n or by object parm.
Parameters
- n
- Number of degrees of freedom, which specifies the number of independent variables simulated by the distribution.
This shall be a positive value (n>0).
result_type is a member type that represents the type of the random numbers generated on each call to operator(). It is defined as an alias of the first class template parameter (RealType).
- parm
- An object representing the distribution's parameters, obtained by a call to member function param.
param_type is a member type.
Example
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// chi_squared_distribution example
#include <iostream>
#include <chrono>
#include <random>
int main()
{
// construct a trivial random generator engine from a time-based seed:
unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
std::default_random_engine generator (seed);
std::chi_squared_distribution<double> distribution (4.0);
std::cout << "some chi-square-distributed(4.0) results:" << std::endl;
for (int i=0; i<5; ++i)
std::cout << distribution(generator) << std::endl;
return 0;
}
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Possible output:
some chi-squared-distributed(4.0) results:
5.69521
7.84941
3.86524
5.4442
5.38723
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