std::bernoulli_distribution (3) - Linux Manuals

std::bernoulli_distribution: std::bernoulli_distribution

NAME

std::bernoulli_distribution - std::bernoulli_distribution

Synopsis

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

Member types

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

Member functions

              constructs new distribution
constructor (public member function)
              resets the internal state of the distribution
reset (public member function)

Generation

              generates the next random number in the distribution
operator() (public member function)

Characteristics

              returns the p distribution parameter (probability of generating true)
p (public member function)
              gets or sets the distribution parameter object
param (public member function)
              returns the minimum potentially generated value
min (public member function)
              returns the maximum potentially generated value
max (public member function)

Non-member functions

           compares two distribution objects
operator== (function)
operator!=
           performs stream input and output on pseudo-random number distribution
operator<< (function template)
operator>>

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 ****

External links

Weisstein,_Eric_W._"Bernoulli_Distribution." From MathWorld--A Wolfram Web Resource.