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std::bernoulli_distribution

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Pseudo-random number generation
Engines and engine adaptors
Generators
Distributions
Uniform distributions
Bernoulli distributions
bernoulli_distribution
(C++11)
Poisson distributions
Normal distributions
Sampling distributions
Seed Sequences
(C++11)
C library
 
 
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 == true 
1 − p if b == false

Contents

[edit] Member types

Member type Definition
result_type bool
param_type the type of the parameter set, unspecified

[edit] Member functions

constructs new distribution
(public member function) [edit]
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
returns the p distribution parameter (probability of generating true)
(public member function) [edit]
gets or sets the distribution parameter object
(public member function) [edit]
returns the minimum potentially generated value
(public member function) [edit]
returns the maximum potentially generated value
(public member function) [edit]

[edit] Non-member functions

compares two distribution objects
(function) [edit]
performs stream input and output on pseudo-random number distribution
(function template) [edit]

[edit] Example

#include <iostream>
#include <iomanip>
#include <string>
#include <map>
#include <random>
 
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)];
    }
    for(auto p : hist) {
        std::cout << std::boolalpha << std::setw(5) << p.first
                  << ' ' << std::string(p.second/500, '*') << '\n';
    }
}

Output:

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

[edit] External links

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