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std::bernoulli_distribution

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Revision as of 21:12, 2 November 2012 by P12bot (Talk | contribs)

 
 
 
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

Member types

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

Member functions

Template:cpp/numeric/random/distribution/dcl list constructorTemplate:cpp/numeric/random/distribution/dcl list resetTemplate:cpp/numeric/random/distribution/dcl list operator()Template:cpp/numeric/random/bernoulli distribution/dcl list pTemplate:cpp/numeric/random/distribution/dcl list paramTemplate:cpp/numeric/random/distribution/dcl list minTemplate:cpp/numeric/random/distribution/dcl list max
Generation
Characteristics

Non-member functions

Template:cpp/numeric/random/distribution/dcl list operator cmpTemplate:cpp/numeric/random/distribution/dcl list operator ltltgtgt

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 ****

External links

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