C++

Reference

<random>

poisson_distribution

public member function
<random>

std::poisson_distribution::param

(1)
param_type param() const;
(2)
void param (const param_type& parm);
Distribution parameters
The first version (1) returns an object with the parameters currently associated with the distribution object.
The second version (2) associates the parameters in object parm to the distribution object.

A poisson_distribution is defined by a single parameter: its mean. An object of type param_type carries this information, but it is meant to be used only to construct or specify the parameters for a poisson_distribution object, not to inspect the individual parameter.

To inspect the individual parameter associated to the distribution object you can call geometric_distribution::mean.

Parameters

parm
An object representing the distribution's parameters, obtained by a call to member function param.
param_type is a member type.

Return value

An object representing the distribution's parameters.
param_type is a member type.

Example

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// poisson_distribution::param
#include <iostream>
#include <random>

int main()
{
  std::default_random_engine generator;
  std::poisson_distribution<int> d1(6.6);
  std::poisson_distribution<int> d2(d1.param());

  // print two independent values:
  std::cout << d1(generator) << std::endl;
  std::cout << d2(generator) << std::endl;

  return 0;
}

Possible output:
6
2


Complexity

No worse than the complexity of param_type's constructor.

See also

poisson_distribution::(constructor)
Construct Poisson distribution (public member function)
poisson_distribution::reset
Reset distribution (public member function)