public member function
<random>

std::negative_binomial_distribution::(ctor)

(1)
explicit negative_binomial_distribution ( result_type k = 1, double p = 0.5 );
(2)
explicit negative_binomial_distribution ( const param_type& parm );
Construct negative binomial distribution
Constructs a negative_binomial_distribution object, adopting the distribution parameters specified either by k and p or by object parm.

Parameters

k
Parameter k of the negative binomial distribution.
This represents the number of unsuccessful trials that stops the count of successful Bernoulli-distributed experiments each generated value is said to simulate.
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 (IntType).
p
Probability of success.
This represents the probability of success on each of the independent Bernoulli-distributed experiments each generated value is said to simulate.
This shall be a value between 0.0 and 1.0 (both included).
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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// negative_binomial_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::negative_binomial_distribution<int> distribution (5,0.5);

  std::cout << "some negative binomial results (k=5,p=0.5): ";
  for (int i=0; i<10; ++i)
    std::cout << distribution(generator) << " ";

  std::cout << std::endl;

  return 0;
}

Possible output:
some negative binomial results (k=5,p=0.5): 1 1 6 4 4 5 2 9 2 4 


Complexity

Constant.

See also