An exponential_distribution random number distribution produces random numbers x > 0 distributed according to the probability density function p(x | λ) = λ e-λ x .
template<class RealType = double> class exponential_distribution{ public: // types typedef RealType result_type; typedef unspecified param_type; // constructors and reset functions explicit exponential_distribution(RealType lambda = 1.0); explicit exponential_distribution(const param_type& parm); void reset(); // generating functions template<class URNG> result_type operator()(URNG& g); template<class URNG> result_type operator()(URNG& g, const param_type& parm); // property functions RealType lambda() const; param_type param() const; void param(const param_type& parm); result_type min() const; result_type max() const; };
Requires: 0 < lambda .
Effects: Constructs a exponential_distribution object; lambda corresponds to the parameter of the distribution.
Returns: The value of the lambda parameter with which the object was constructed.