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boost::random::piecewise_linear_distribution
// In header: <boost/random/piecewise_linear_distribution.hpp> template<typename RealType = double> class piecewise_linear_distribution { public: // types typedef std::size_t input_type; typedef RealType result_type; // member classes/structs/unions class param_type { public: // types typedef piecewise_linear_distribution distribution_type; // construct/copy/destruct param_type(); template<typename IntervalIter, typename WeightIter> param_type(IntervalIter, IntervalIter, WeightIter); template<typename T, typename F> param_type(const std::initializer_list< T > &, F); template<typename IntervalRange, typename WeightRange> param_type(const IntervalRange &, const WeightRange &); template<typename F> param_type(std::size_t, RealType, RealType, F); // friend functions template<typename CharT, typename Traits> friend std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > &, const param_type &); template<typename CharT, typename Traits> friend std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > &, const param_type &); friend bool operator==(const param_type &, const param_type &); friend bool operator!=(const param_type &, const param_type &); // public member functions std::vector< RealType > intervals() const; std::vector< RealType > densities() const; }; // construct/copy/destruct piecewise_linear_distribution(); template<typename IntervalIter, typename WeightIter> piecewise_linear_distribution(IntervalIter, IntervalIter, WeightIter); template<typename T, typename F> piecewise_linear_distribution(std::initializer_list< T >, F); template<typename IntervalsRange, typename WeightsRange> piecewise_linear_distribution(const IntervalsRange &, const WeightsRange &); template<typename F> piecewise_linear_distribution(std::size_t, RealType, RealType, F); explicit piecewise_linear_distribution(const param_type &); // public member functions template<typename URNG> RealType operator()(URNG &) const; template<typename URNG> RealType operator()(URNG &, const param_type &) const; result_type min() const; result_type max() const; std::vector< RealType > densities() const; std::vector< RealType > intervals() const; param_type param() const; void param(const param_type &); void reset(); // friend functions template<typename CharT, typename Traits> friend std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > &, const piecewise_linear_distribution &); template<typename CharT, typename Traits> friend std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > &, const piecewise_linear_distribution &); friend bool operator==(const piecewise_linear_distribution &, const piecewise_linear_distribution &); friend bool operator!=(const piecewise_linear_distribution &, const piecewise_linear_distribution &); };
The class piecewise_linear_distribution
models a random distribution .
piecewise_linear_distribution
public
construct/copy/destructpiecewise_linear_distribution();
Creates a new
that produces values uniformly distributed in the range [0, 1). piecewise_linear_distribution
template<typename IntervalIter, typename WeightIter> piecewise_linear_distribution(IntervalIter first_interval, IntervalIter last_interval, WeightIter first_weight);
Constructs a piecewise_linear_distribution
from two iterator ranges containing the interval boundaries and the weights at the boundaries. If there are fewer than two boundaries, then this is equivalent to the default constructor and creates a distribution that produces values uniformly distributed in the range [0, 1).
The values of the interval boundaries must be strictly increasing, and the number of weights must be equal to the number of interval boundaries. If there are extra weights, they are ignored.
For example,
double intervals[] = { 0.0, 1.0, 2.0 }; double weights[] = { 0.0, 1.0, 0.0 }; piecewise_constant_distribution<> dist( &intervals[0], &intervals[0] + 3, &weights[0]);
produces a triangle distribution.
template<typename T, typename F> piecewise_linear_distribution(std::initializer_list< T > il, F f);
Constructs a piecewise_linear_distribution
from an initializer_list containing the interval boundaries and a unary function specifying the weights. Each weight is determined by calling the function at the corresponding interval boundary.
If the initializer_list contains fewer than two elements, this is equivalent to the default constructor and the distribution will produce values uniformly distributed in the range [0, 1).
template<typename IntervalsRange, typename WeightsRange> piecewise_linear_distribution(const IntervalsRange & intervals_arg, const WeightsRange & weights_arg);
Constructs a piecewise_linear_distribution
from Boost.Range ranges holding the interval boundaries and the weights. If there are fewer than two interval boundaries, this is equivalent to the default constructor and the distribution will produce values uniformly distributed in the range [0, 1). The number of weights must be equal to the number of interval boundaries.
template<typename F> piecewise_linear_distribution(std::size_t nw, RealType xmin, RealType xmax, F f);
Constructs a piecewise_linear_distribution
that approximates a function. The range of the distribution is [xmin, xmax). This range is divided into nw equally sized intervals and the weights are found by calling the unary function f on the interval boundaries.
explicit piecewise_linear_distribution(const param_type & param);
Constructs a piecewise_linear_distribution
from its parameters.
piecewise_linear_distribution
public member functionstemplate<typename URNG> RealType operator()(URNG & urng) const;
Returns a value distributed according to the parameters of the piecewise_linear_distribution
.
template<typename URNG> RealType operator()(URNG & urng, const param_type & param) const;
Returns a value distributed according to the parameters specified by param.
result_type min() const;
Returns the smallest value that the distribution can produce.
result_type max() const;
Returns the largest value that the distribution can produce.
std::vector< RealType > densities() const;
Returns a vector containing the probability densities at the interval boundaries.
std::vector< RealType > intervals() const;
Returns a vector containing the interval boundaries.
param_type param() const;
Returns the parameters of the distribution.
void param(const param_type & param);
Sets the parameters of the distribution.
void reset();
Effects: Subsequent uses of the distribution do not depend on values produced by any engine prior to invoking reset.
piecewise_linear_distribution
friend functionstemplate<typename CharT, typename Traits> friend std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > & os, const piecewise_linear_distribution & pld);
Writes a distribution to a std::ostream
.
template<typename CharT, typename Traits> friend std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > & is, const piecewise_linear_distribution & pld);
Reads a distribution from a std::istream
friend bool operator==(const piecewise_linear_distribution & lhs, const piecewise_linear_distribution & rhs);
Returns true if the two distributions will return the same sequence of values, when passed equal generators.
friend bool operator!=(const piecewise_linear_distribution & lhs, const piecewise_linear_distribution & rhs);
Returns true if the two distributions may return different sequences of values, when passed equal generators.