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std::bernoulli_distribution

From cppreference.com
< cpp‎ | numeric‎ | random
 
 
 
 
std::bernoulli_distribution
 
Defined in header <random>
class bernoulli_distribution;
(since C++11)

Produces random boolean values, according to the discrete probability function. The probability of true is

P(b|p) =

p, if b is true
1 − p, if b is false

std::bernoulli_distribution satisfies RandomNumberDistribution.

Contents

[edit] Member types

Member type Definition
result_type (C++11) bool
param_type (C++11) the type of the parameter set, see RandomNumberDistribution.

[edit] Member functions

constructs new distribution
(public member function) [edit]
(C++11)
resets the internal state of the distribution
(public member function) [edit]
Generation
generates the next random number in the distribution
(public member function) [edit]
Characteristics
(C++11)
returns the p distribution parameter (probability of generating true)
(public member function) [edit]
(C++11)
gets or sets the distribution parameter object
(public member function) [edit]
(C++11)
returns the minimum potentially generated value
(public member function) [edit]
(C++11)
returns the maximum potentially generated value
(public member function) [edit]

[edit] Non-member functions

(C++11)(C++11)(removed in C++20)
compares two distribution objects
(function) [edit]
performs stream input and output on pseudo-random number distribution
(function template) [edit]

[edit] Example

#include <iomanip>
#include <iostream>
#include <map>
#include <random>
#include <string>
 
int main()
{
    std::random_device rd;
    std::mt19937 gen(rd());
    // give "true" 1/4 of the time
    // give "false" 3/4 of the time
    std::bernoulli_distribution d(0.25);
 
    std::map<bool, int> hist;
    for (int n = 0; n < 10000; ++n)
        ++hist[d(gen)];
 
    std::cout << std::boolalpha;
    for (auto const& [key, value] : hist)
        std::cout << std::setw(5) << key << ' '
                  << std::string(value / 500, '*') << '\n';
}

Possible output:

false ***************
 true ****

[edit] External links

Weisstein, Eric W. "Bernoulli Distribution." From MathWorld — A Wolfram Web Resource.