1
|
|
|
import random as rnd |
2
|
|
|
import copy |
3
|
|
|
from NiaPy.benchmarks.utility import Utility |
4
|
|
|
|
5
|
|
|
__all__ = ['GeneticAlgorithm'] |
6
|
|
|
|
7
|
|
|
|
8
|
|
View Code Duplication |
class Chromosome(object): |
|
|
|
|
9
|
|
|
def __init__(self, D, LB, UB): |
10
|
|
|
self.D = D |
11
|
|
|
self.LB = LB |
12
|
|
|
self.UB = UB |
13
|
|
|
|
14
|
|
|
self.Solution = [] |
15
|
|
|
self.Fitness = float('inf') |
16
|
|
|
self.generateSolution() |
17
|
|
|
|
18
|
|
|
def generateSolution(self): |
19
|
|
|
self.Solution = [self.LB + (self.UB - self.LB) * rnd.random() |
20
|
|
|
for _i in range(self.D)] |
21
|
|
|
|
22
|
|
|
def evaluate(self): |
23
|
|
|
self.Fitness = Chromosome.FuncEval(self.D, self.Solution) |
24
|
|
|
|
25
|
|
|
def repair(self): |
26
|
|
|
for i in range(self.D): |
27
|
|
|
if self.Solution[i] > self.UB: |
28
|
|
|
self.Solution[i] = self.UB |
29
|
|
|
if self.Solution[i] < self.LB: |
30
|
|
|
self.Solution[i] = self.LB |
31
|
|
|
|
32
|
|
|
def __eq__(self, other): |
33
|
|
|
return self.Solution == other.Solution and self.Fitness == other.Fitness |
34
|
|
|
|
35
|
|
|
def toString(self): |
36
|
|
|
print([i for i in self.Solution]) |
37
|
|
|
|
38
|
|
|
|
39
|
|
|
class GeneticAlgorithm(object): |
40
|
|
|
r"""Implementation of Genetic algorithm. |
41
|
|
|
|
42
|
|
|
**Algorithm:** Genetic algorithm |
43
|
|
|
|
44
|
|
|
**Date:** 2018 |
45
|
|
|
|
46
|
|
|
**Author:** Uros Mlakar |
47
|
|
|
|
48
|
|
|
**License:** MIT |
49
|
|
|
""" |
50
|
|
|
|
51
|
|
|
def __init__(self, D, NP, nFES, Ts, Mr, gamma, benchmark): |
52
|
|
|
r"""**__init__(self, D, NP, nFES, Ts, Mr, gamma, benchmark)**. |
53
|
|
|
|
54
|
|
|
Arguments: |
55
|
|
|
D {integer} -- dimension of problem |
56
|
|
|
|
57
|
|
|
NP {integer} -- population size |
58
|
|
|
|
59
|
|
|
nFES {integer} -- number of function evaluations |
60
|
|
|
|
61
|
|
|
Ts {decimal} -- tournament selection |
62
|
|
|
|
63
|
|
|
Mr {decimal} -- mutation rate |
64
|
|
|
|
65
|
|
|
gamma {decimal} -- minimum frequency |
66
|
|
|
|
67
|
|
|
benchmark {object} -- benchmark implementation object |
68
|
|
|
|
69
|
|
|
Raises: |
70
|
|
|
TypeError -- Raised when given benchmark function which does not exists. |
71
|
|
|
|
72
|
|
|
""" |
73
|
|
|
self.benchmark = Utility().get_benchmark(benchmark) |
74
|
|
|
self.NP = NP |
75
|
|
|
self.D = D |
76
|
|
|
self.Ts = Ts |
77
|
|
|
self.Mr = Mr |
78
|
|
|
self.gamma = gamma |
79
|
|
|
self.Lower = self.benchmark.Lower |
80
|
|
|
self.Upper = self.benchmark.Upper |
81
|
|
|
self.Population = [] |
82
|
|
|
self.nFES = nFES |
83
|
|
|
self.FEs = 0 |
84
|
|
|
self.Done = False |
85
|
|
|
Chromosome.FuncEval = staticmethod(self.benchmark.function()) |
86
|
|
|
|
87
|
|
|
self.Best = Chromosome(self.D, self.Lower, self.Upper) |
88
|
|
|
|
89
|
|
|
def checkForBest(self, pChromosome): |
90
|
|
|
if pChromosome.Fitness <= self.Best.Fitness: |
91
|
|
|
self.Best = copy.deepcopy(pChromosome) |
92
|
|
|
|
93
|
|
|
def TournamentSelection(self): |
94
|
|
|
indices = list(range(self.NP)) |
95
|
|
|
rnd.shuffle(indices) |
96
|
|
|
tPop = [] |
97
|
|
|
for i in range(self.Ts): |
98
|
|
|
tPop.append(self.Population[i]) |
99
|
|
|
tPop.sort(key=lambda x: x.Fitness) |
100
|
|
|
|
101
|
|
|
self.Population.remove(tPop[0]) |
102
|
|
|
self.Population.remove(tPop[1]) |
103
|
|
|
return tPop[0], tPop[1] |
104
|
|
|
|
105
|
|
|
def CrossOver(self, parent1, parent2): |
106
|
|
|
alpha = [-self.gamma + (1 + 2 * self.gamma) * rnd.random() |
107
|
|
|
for i in range(self.D)] |
108
|
|
|
child1 = Chromosome(self.D, self.Lower, self.Upper) |
109
|
|
|
child2 = Chromosome(self.D, self.Lower, self.Upper) |
110
|
|
|
child1.Solution = [alpha[i] * parent1.Solution[i] + |
111
|
|
|
(1 - alpha[i]) * parent2.Solution[i] for i in range(self.D)] |
112
|
|
|
child2.Solution = [alpha[i] * parent2.Solution[i] + |
113
|
|
|
(1 - alpha[i]) * parent1.Solution[i] for i in range(self.D)] |
114
|
|
|
return child1, child2 |
115
|
|
|
|
116
|
|
|
def Mutate(self, child): |
117
|
|
|
for i in range(self.D): |
118
|
|
|
if rnd.random() < self.Mr: |
119
|
|
|
sigma = 0.20 * float(child.UB - child.LB) |
120
|
|
|
child.Solution[i] = min( |
121
|
|
|
max(rnd.gauss(child.Solution[i], sigma), child.LB), child.UB) |
122
|
|
|
|
123
|
|
|
def init(self): |
124
|
|
|
for i in range(self.NP): |
125
|
|
|
self.Population.append(Chromosome(self.D, self.Lower, self.Upper)) |
126
|
|
|
self.Population[i].evaluate() |
127
|
|
|
self.checkForBest(self.Population[i]) |
128
|
|
|
|
129
|
|
|
def tryEval(self, c): |
130
|
|
|
if self.FEs < self.nFES: |
131
|
|
|
self.FEs += 1 |
132
|
|
|
c.evaluate() |
133
|
|
|
else: |
134
|
|
|
self.Done = True |
135
|
|
|
|
136
|
|
|
def run(self): |
137
|
|
|
self.init() |
138
|
|
|
self.FEs = self.NP |
139
|
|
|
while not self.Done: |
140
|
|
|
for _k in range(int(self.NP / 2)): |
141
|
|
|
parent1, parent2 = self.TournamentSelection() |
142
|
|
|
child1, child2 = self.CrossOver(parent1, parent2) |
143
|
|
|
|
144
|
|
|
self.Mutate(child1) |
145
|
|
|
self.Mutate(child2) |
146
|
|
|
|
147
|
|
|
child1.repair() |
148
|
|
|
child2.repair() |
149
|
|
|
|
150
|
|
|
self.tryEval(child1) |
151
|
|
|
self.tryEval(child2) |
152
|
|
|
|
153
|
|
|
tPop = [parent1, parent2, child1, child2] |
154
|
|
|
tPop.sort(key=lambda x: x.Fitness) |
155
|
|
|
self.Population.append(tPop[0]) |
156
|
|
|
self.Population.append(tPop[1]) |
157
|
|
|
|
158
|
|
|
for i in range(self.NP): |
159
|
|
|
self.checkForBest(self.Population[i]) |
160
|
|
|
return self.Best.Fitness |
161
|
|
|
|