std::bernoulli_distribution

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C library
 
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 == true 
1 − p if b == false

std::bernoulli_distribution satisfies RandomNumberDistribution

Contents

[edit] Member types

Member type Definition
result_type bool
param_type the type of the parameter set, see RandomNumberDistribution.

[edit] Member functions

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

[edit] Non-member functions

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

[edit] Example

Run this code
#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';
    }
}

Possible output: 

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

[edit] External links

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

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