1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
use crate::{
algorithm::EvaluatedPopulation,
genetic::{AsScalar, Fitness, Genotype, Parents},
operator::{GeneticOperator, SelectionOp, SingleObjective},
random::{random_probability, Rng, WeightedDistribution},
};
#[allow(missing_copy_implementations)]
#[derive(Clone, Debug, PartialEq)]
pub struct RouletteWheelSelector {
selection_ratio: f64,
num_individuals_per_parents: usize,
}
impl RouletteWheelSelector {
pub fn new(selection_ratio: f64, num_individuals_per_parents: usize) -> Self {
RouletteWheelSelector {
selection_ratio,
num_individuals_per_parents,
}
}
pub fn selection_ratio(&self) -> f64 {
self.selection_ratio
}
pub fn set_selection_ratio(&mut self, value: f64) {
self.selection_ratio = value;
}
pub fn num_individuals_per_parents(&self) -> usize {
self.num_individuals_per_parents
}
pub fn set_num_individuals_per_parents(&mut self, value: usize) {
self.num_individuals_per_parents = value;
}
}
impl SingleObjective for RouletteWheelSelector {}
impl GeneticOperator for RouletteWheelSelector {
fn name() -> String {
"Roulette-Wheel-Selection".to_string()
}
}
impl<G, F> SelectionOp<G, F> for RouletteWheelSelector
where
G: Genotype,
F: Fitness + AsScalar,
{
fn select_from<R>(&self, evaluated: &EvaluatedPopulation<G, F>, rng: &mut R) -> Vec<Parents<G>>
where
R: Rng + Sized,
{
let individuals = evaluated.individuals();
let num_parents_to_select =
(individuals.len() as f64 * self.selection_ratio + 0.5).floor() as usize;
let mut parents = Vec::with_capacity(num_parents_to_select);
let weighted_distribution =
WeightedDistribution::from_scalar_values(evaluated.fitness_values());
for _ in 0..num_parents_to_select {
let mut tuple = Vec::with_capacity(self.num_individuals_per_parents);
for _ in 0..self.num_individuals_per_parents {
let random = random_probability(rng) * weighted_distribution.sum();
let selected = weighted_distribution.select(random);
tuple.push(individuals[selected].clone());
}
parents.push(tuple);
}
parents
}
}
#[allow(missing_copy_implementations)]
#[derive(Clone, Debug, PartialEq)]
pub struct UniversalSamplingSelector {
selection_ratio: f64,
num_individuals_per_parents: usize,
}
impl UniversalSamplingSelector {
pub fn new(selection_ratio: f64, num_individuals_per_parents: usize) -> Self {
UniversalSamplingSelector {
selection_ratio,
num_individuals_per_parents,
}
}
pub fn selection_ratio(&self) -> f64 {
self.selection_ratio
}
pub fn set_selection_ratio(&mut self, value: f64) {
self.selection_ratio = value;
}
pub fn num_individuals_per_parents(&self) -> usize {
self.num_individuals_per_parents
}
pub fn set_num_individuals_per_parents(&mut self, value: usize) {
self.num_individuals_per_parents = value;
}
}
impl SingleObjective for UniversalSamplingSelector {}
impl GeneticOperator for UniversalSamplingSelector {
fn name() -> String {
"Stochastic-Universal-Sampling-Selection".to_string()
}
}
impl<G, F> SelectionOp<G, F> for UniversalSamplingSelector
where
G: Genotype,
F: Fitness + AsScalar,
{
fn select_from<R>(&self, evaluated: &EvaluatedPopulation<G, F>, rng: &mut R) -> Vec<Parents<G>>
where
R: Rng + Sized,
{
let individuals = evaluated.individuals();
let num_parents_to_select =
(individuals.len() as f64 * self.selection_ratio + 0.5).floor() as usize;
let mut parents = Vec::with_capacity(num_parents_to_select);
let weighted_distribution =
WeightedDistribution::from_scalar_values(evaluated.fitness_values());
let distance = weighted_distribution.sum()
/ (num_parents_to_select * self.num_individuals_per_parents) as f64;
let mut pointer = random_probability(rng) * weighted_distribution.sum();
for _ in 0..num_parents_to_select {
let mut tuple = Vec::with_capacity(self.num_individuals_per_parents);
for _ in 0..self.num_individuals_per_parents {
let selected = weighted_distribution.select(pointer);
tuple.push(individuals[selected].clone());
pointer += distance;
}
parents.push(tuple);
}
parents
}
}