C++

Reference

<random>

exponential_distribution

public member function
<random>

std::exponential_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.

An exponential_distribution is defined by a single parameter: lambda (λ), which can be interpreted as the mean frequence of occurrences. 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 exponential_distribution object, not to inspect the individual parameters.

To inspect the individual parameter associated to the distribution object you can use: exponential_distribution::lambda.

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

int main()
{
  std::default_random_engine generator;
  std::exponential_distribution<double> d1(0.8);
  std::exponential_distribution<double> d2(d1.param());

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

  return 0;
}

Possible output:
2.53558
0.974334


Complexity

No worse than the complexity of param_type's constructor.

See also

exponential_distribution::(constructor)
Construct exponential distribution (public member function)
exponential_distribution::reset
Reset distribution (public member function)