57 lines
1.6 KiB
C++
57 lines
1.6 KiB
C++
/* @file Uniform.hpp */
|
|
|
|
#pragma once
|
|
|
|
#include "Distribution.hpp"
|
|
|
|
namespace xo {
|
|
namespace distribution {
|
|
/* uniform distribution on an interval */
|
|
class Uniform : public Distribution<double> {
|
|
public:
|
|
Uniform(double lo, double hi) : lo_(lo), hi_(hi) {}
|
|
|
|
static ref::rp<Uniform> unit() { return new Uniform(0.0, 1.0); }
|
|
|
|
static double density_impl(double lo, double hi, double x) {
|
|
if (x <= lo)
|
|
return 0.0;
|
|
if (x >= hi)
|
|
return 0.0;
|
|
|
|
return 1.0 / (hi - lo);
|
|
} /*density_impl*/
|
|
|
|
static double distr_impl(double lo, double hi, double x) {
|
|
if (x <= lo)
|
|
return 0.0;
|
|
if (x >= hi)
|
|
return 1.0;
|
|
|
|
return (x - lo) / (hi - lo);
|
|
} /*distr_impl*/
|
|
|
|
double lo() const { return lo_; }
|
|
double hi() const { return hi_; }
|
|
|
|
double density(double x) const {
|
|
return density_impl(this->lo_, this->hi_, x);
|
|
} /*density*/
|
|
|
|
double distribution(double x) const {
|
|
return distr_impl(this->lo_, this->hi_, x);
|
|
} /*distribution*/
|
|
|
|
// ----- inherited from Distribution<double> -----
|
|
|
|
virtual double cdf(double const & x) const override {
|
|
return this->distribution(x);
|
|
} /*cdf*/
|
|
|
|
private:
|
|
/* Invariant: .lo < .hi */
|
|
double lo_ = 0.0;
|
|
double hi_ = 1.0;
|
|
}; /*Uniform*/
|
|
} /*namespace distribution*/
|
|
} /*namespace xo*/
|