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Class template binomial_distribution

boost::binomial_distribution

Synopsis

```// In header: <boost/random/binomial_distribution.hpp>

template<typename IntType = int, typename RealType = double>
class binomial_distribution {
public:
// types
typedef bernoulli_distribution< RealType >::input_type input_type;
typedef IntType                                        result_type;

// construct/copy/destruct
binomial_distribution(IntType = 1, const RealType & = RealType(0.5));

// public member functions
IntType t() const;
RealType p() const;
void reset();
template<typename Engine> result_type operator()(Engine &);

// friend functions
template<typename CharT, typename Traits>
friend std::basic_ostream< CharT, Traits > &
operator<<(std::basic_ostream< CharT, Traits > &,
const binomial_distribution &);
template<typename CharT, typename Traits>
friend std::basic_istream< CharT, Traits > &
operator>>(std::basic_istream< CharT, Traits > &, binomial_distribution &);
};```

Description

The binomial distribution is an integer valued distribution with two parameters, `t` and `p`. The values of the distribution are within the range [0,t].

The probability that the distribution produces a value k is .

`binomial_distribution` public construct/copy/destruct

1. `binomial_distribution(IntType t = 1, const RealType & p = RealType(0.5));`

Construct an `binomial_distribution` object. `t` and `p` are the parameters of the distribution.

Requires: t >=0 && 0 <= p <= 1

`binomial_distribution` public member functions

1. `IntType t() const;`

Returns: the `t` parameter of the distribution

2. `RealType p() const;`

Returns: the `p` parameter of the distribution

3. `void reset();`

Effects: Subsequent uses of the distribution do not depend on values produced by any engine prior to invoking reset.

4. `template<typename Engine> result_type operator()(Engine & eng);`

Returns: a random variate distributed according to the binomial distribution.

`binomial_distribution` friend functions

1. ```template<typename CharT, typename Traits>
friend std::basic_ostream< CharT, Traits > &
operator<<(std::basic_ostream< CharT, Traits > & os,
const binomial_distribution & bd);```

Writes the parameters of the distribution to a `std::ostream`.

2. ```template<typename CharT, typename Traits>
friend std::basic_istream< CharT, Traits > &
operator>>(std::basic_istream< CharT, Traits > & is,
binomial_distribution & bd);```

Reads the parameters of the distribution from a `std::istream`.