distribution/golombek_rapp.cpp - TerrainGen coverage

distribution/golombek_rapp.cpp

Line	Branch	Exec	Source
1			#include "terraingen/distribution/golombek_rapp.h"
2
3			#include "terraingen/util/checks.h"
4			#include "terraingen/util/special_functions.h"
5
6			#include <cmath>
7			#include <numbers>
8			#include <stdexcept>
9
10			namespace terraingen {
11
12		96475	GolombekRappSfd::GolombekRappSfd(double coverage, double qa, double qb, DiameterRange range)
13		96475	: SizeFrequencyDistribution(SfdKind::Density, range), coverage_(coverage) {
14	4/4 ✓ Branch 0 taken 96474 times. ✓ Branch 1 taken 1 time. ✓ Branch 2 taken 1 time. ✓ Branch 3 taken 96473 times.	96475	if (!(coverage_ > 0.0 && coverage_ < 1.0)) {
15	1/1 ✓ Branch 2 taken 2 times.	2	throw std::invalid_argument("Boulder coverage k must be between 0 and 1");
16			}
17	5/6 ✓ Branch 1 taken 96471 times. ✓ Branch 2 taken 2 times. ✗ Branch 4 not taken. ✓ Branch 5 taken 96471 times. ✓ Branch 6 taken 2 times. ✓ Branch 7 taken 96471 times.	96473	if (!(IsNonNegative(qa) && IsNonNegative(qb))) {
18	1/1 ✓ Branch 2 taken 2 times.	2	throw std::invalid_argument("Golombek-Rapp qa and qb must be finite and not negative");
19			}
20		96471	q_ = qa + qb / coverage_;
21	2/2 ✓ Branch 0 taken 1 time. ✓ Branch 1 taken 96470 times.	96471	if (!(q_ > 0.0)) {
22	1/1 ✓ Branch 2 taken 1 time.	1	throw std::invalid_argument("Golombek-Rapp q must be positive");
23			}
24		96475	}
25
26		5649	double GolombekRappSfd::FractionalArea(double diameter) const {
27		5649	return coverage_ * std::exp(-q_ * diameter);
28			}
29
30		3915944	double GolombekRappSfd::CumulativeAt(double diameter) const {
31		3915944	return 4.0 * coverage_ * q_ / std::numbers::pi * ExponentialIntegral(2, q_ * diameter) /
32		3915944	diameter;
33			}
34
35		5044257	double GolombekRappSfd::IncrementalAt(double diameter) const {
36		5044257	return coverage_ * q_ * std::exp(-q_ * diameter) /
37		5044257	(std::numbers::pi * diameter * diameter / 4.0);
38			}
39
40			} // namespace terraingen
41