1
|
|
|
<?php |
2
|
|
|
|
3
|
|
|
declare(strict_types=1); |
4
|
|
|
|
5
|
|
|
namespace Phpml\Clustering\KMeans; |
6
|
|
|
|
7
|
|
|
use InvalidArgumentException; |
8
|
|
|
use LogicException; |
9
|
|
|
use Phpml\Clustering\KMeans; |
10
|
|
|
use SplObjectStorage; |
11
|
|
|
|
12
|
|
|
class Space extends SplObjectStorage |
13
|
|
|
{ |
14
|
|
|
/** |
15
|
|
|
* @var int |
16
|
|
|
*/ |
17
|
|
|
protected $dimension; |
18
|
|
|
|
19
|
|
|
public function __construct(int $dimension) |
20
|
|
|
{ |
21
|
|
|
if ($dimension < 1) { |
22
|
|
|
throw new LogicException('a space dimension cannot be null or negative'); |
23
|
|
|
} |
24
|
|
|
|
25
|
|
|
$this->dimension = $dimension; |
26
|
|
|
} |
27
|
|
|
|
28
|
|
|
public function toArray(): array |
29
|
|
|
{ |
30
|
|
|
$points = []; |
31
|
|
|
|
32
|
|
|
/** @var Point $point */ |
33
|
|
|
foreach ($this as $point) { |
34
|
|
|
$points[] = $point->toArray(); |
35
|
|
|
} |
36
|
|
|
|
37
|
|
|
return ['points' => $points]; |
38
|
|
|
} |
39
|
|
|
|
40
|
|
|
/** |
41
|
|
|
* @param mixed $label |
42
|
|
|
*/ |
43
|
|
|
public function newPoint(array $coordinates, $label = null): Point |
44
|
|
|
{ |
45
|
|
|
if (count($coordinates) !== $this->dimension) { |
46
|
|
|
throw new LogicException('('.implode(',', $coordinates).') is not a point of this space'); |
47
|
|
|
} |
48
|
|
|
|
49
|
|
|
return new Point($coordinates, $label); |
50
|
|
|
} |
51
|
|
|
|
52
|
|
|
/** |
53
|
|
|
* @param mixed $label |
54
|
|
|
* @param mixed $data |
55
|
|
|
*/ |
56
|
|
|
public function addPoint(array $coordinates, $label = null, $data = null): void |
57
|
|
|
{ |
58
|
|
|
$this->attach($this->newPoint($coordinates, $label), $data); |
59
|
|
|
} |
60
|
|
|
|
61
|
|
|
/** |
62
|
|
|
* @param object $point |
63
|
|
|
* @param mixed $data |
64
|
|
|
*/ |
65
|
|
|
public function attach($point, $data = null): void |
66
|
|
|
{ |
67
|
|
|
if (!$point instanceof Point) { |
68
|
|
|
throw new InvalidArgumentException('can only attach points to spaces'); |
69
|
|
|
} |
70
|
|
|
|
71
|
|
|
parent::attach($point, $data); |
72
|
|
|
} |
73
|
|
|
|
74
|
|
|
public function getDimension(): int |
75
|
|
|
{ |
76
|
|
|
return $this->dimension; |
77
|
|
|
} |
78
|
|
|
|
79
|
|
|
/** |
80
|
|
|
* @return array|bool |
81
|
|
|
*/ |
82
|
|
|
public function getBoundaries() |
83
|
|
|
{ |
84
|
|
|
if (count($this) === 0) { |
85
|
|
|
return false; |
86
|
|
|
} |
87
|
|
|
|
88
|
|
|
$min = $this->newPoint(array_fill(0, $this->dimension, null)); |
89
|
|
|
$max = $this->newPoint(array_fill(0, $this->dimension, null)); |
90
|
|
|
|
91
|
|
|
/** @var Point $point */ |
92
|
|
|
foreach ($this as $point) { |
93
|
|
|
for ($n = 0; $n < $this->dimension; ++$n) { |
94
|
|
|
if ($min[$n] === null || $min[$n] > $point[$n]) { |
95
|
|
|
$min[$n] = $point[$n]; |
96
|
|
|
} |
97
|
|
|
|
98
|
|
|
if ($max[$n] === null || $max[$n] < $point[$n]) { |
99
|
|
|
$max[$n] = $point[$n]; |
100
|
|
|
} |
101
|
|
|
} |
102
|
|
|
} |
103
|
|
|
|
104
|
|
|
return [$min, $max]; |
105
|
|
|
} |
106
|
|
|
|
107
|
|
|
public function getRandomPoint(Point $min, Point $max): Point |
108
|
|
|
{ |
109
|
|
|
$point = $this->newPoint(array_fill(0, $this->dimension, null)); |
110
|
|
|
|
111
|
|
|
for ($n = 0; $n < $this->dimension; ++$n) { |
112
|
|
|
$point[$n] = random_int($min[$n], $max[$n]); |
113
|
|
|
} |
114
|
|
|
|
115
|
|
|
return $point; |
116
|
|
|
} |
117
|
|
|
|
118
|
|
|
/** |
119
|
|
|
* @return Cluster[] |
120
|
|
|
*/ |
121
|
|
|
public function cluster(int $clustersNumber, int $initMethod = KMeans::INIT_RANDOM): array |
122
|
|
|
{ |
123
|
|
|
$clusters = $this->initializeClusters($clustersNumber, $initMethod); |
124
|
|
|
|
125
|
|
|
do { |
126
|
|
|
} while (!$this->iterate($clusters)); |
127
|
|
|
|
128
|
|
|
return $clusters; |
129
|
|
|
} |
130
|
|
|
|
131
|
|
|
/** |
132
|
|
|
* @return Cluster[] |
133
|
|
|
*/ |
134
|
|
|
protected function initializeClusters(int $clustersNumber, int $initMethod): array |
135
|
|
|
{ |
136
|
|
|
switch ($initMethod) { |
137
|
|
|
case KMeans::INIT_RANDOM: |
138
|
|
|
$clusters = $this->initializeRandomClusters($clustersNumber); |
139
|
|
|
|
140
|
|
|
break; |
141
|
|
|
|
142
|
|
|
case KMeans::INIT_KMEANS_PLUS_PLUS: |
143
|
|
|
$clusters = $this->initializeKMPPClusters($clustersNumber); |
144
|
|
|
|
145
|
|
|
break; |
146
|
|
|
|
147
|
|
|
default: |
148
|
|
|
return []; |
149
|
|
|
} |
150
|
|
|
|
151
|
|
|
$clusters[0]->attachAll($this); |
152
|
|
|
|
153
|
|
|
return $clusters; |
154
|
|
|
} |
155
|
|
|
|
156
|
|
|
/** |
157
|
|
|
* @param Cluster[] $clusters |
158
|
|
|
*/ |
159
|
|
|
protected function iterate(array $clusters): bool |
160
|
|
|
{ |
161
|
|
|
$convergence = true; |
162
|
|
|
|
163
|
|
|
$attach = new SplObjectStorage(); |
164
|
|
|
$detach = new SplObjectStorage(); |
165
|
|
|
|
166
|
|
|
foreach ($clusters as $cluster) { |
167
|
|
|
foreach ($cluster as $point) { |
168
|
|
|
$closest = $point->getClosest($clusters); |
169
|
|
|
|
170
|
|
|
if ($closest === null) { |
171
|
|
|
continue; |
172
|
|
|
} |
173
|
|
|
|
174
|
|
|
if ($closest !== $cluster) { |
175
|
|
|
$attach[$closest] ?? $attach[$closest] = new SplObjectStorage(); |
176
|
|
|
$detach[$cluster] ?? $detach[$cluster] = new SplObjectStorage(); |
177
|
|
|
|
178
|
|
|
$attach[$closest]->attach($point); |
179
|
|
|
$detach[$cluster]->attach($point); |
180
|
|
|
|
181
|
|
|
$convergence = false; |
182
|
|
|
} |
183
|
|
|
} |
184
|
|
|
} |
185
|
|
|
|
186
|
|
|
/** @var Cluster $cluster */ |
187
|
|
|
foreach ($attach as $cluster) { |
188
|
|
|
$cluster->attachAll($attach[$cluster]); |
189
|
|
|
} |
190
|
|
|
|
191
|
|
|
/** @var Cluster $cluster */ |
192
|
|
|
foreach ($detach as $cluster) { |
193
|
|
|
$cluster->detachAll($detach[$cluster]); |
194
|
|
|
} |
195
|
|
|
|
196
|
|
|
foreach ($clusters as $cluster) { |
197
|
|
|
$cluster->updateCentroid(); |
198
|
|
|
} |
199
|
|
|
|
200
|
|
|
return $convergence; |
201
|
|
|
} |
202
|
|
|
|
203
|
|
|
/** |
204
|
|
|
* @return Cluster[] |
205
|
|
|
*/ |
206
|
|
|
protected function initializeKMPPClusters(int $clustersNumber): array |
207
|
|
|
{ |
208
|
|
|
$clusters = []; |
209
|
|
|
$this->rewind(); |
210
|
|
|
|
211
|
|
|
/** @var Point $current */ |
212
|
|
|
$current = $this->current(); |
213
|
|
|
|
214
|
|
|
$clusters[] = new Cluster($this, $current->getCoordinates()); |
215
|
|
|
|
216
|
|
|
$distances = new SplObjectStorage(); |
217
|
|
|
|
218
|
|
|
for ($i = 1; $i < $clustersNumber; ++$i) { |
219
|
|
|
$sum = 0; |
220
|
|
|
/** @var Point $point */ |
221
|
|
|
foreach ($this as $point) { |
222
|
|
|
$closest = $point->getClosest($clusters); |
223
|
|
|
if ($closest === null) { |
224
|
|
|
continue; |
225
|
|
|
} |
226
|
|
|
|
227
|
|
|
$distance = $point->getDistanceWith($closest); |
228
|
|
|
$sum += $distances[$point] = $distance; |
229
|
|
|
} |
230
|
|
|
|
231
|
|
|
$sum = random_int(0, (int) $sum); |
232
|
|
|
/** @var Point $point */ |
233
|
|
|
foreach ($this as $point) { |
234
|
|
|
$sum -= $distances[$point]; |
235
|
|
|
|
236
|
|
|
if ($sum > 0) { |
237
|
|
|
continue; |
238
|
|
|
} |
239
|
|
|
|
240
|
|
|
$clusters[] = new Cluster($this, $point->getCoordinates()); |
241
|
|
|
|
242
|
|
|
break; |
243
|
|
|
} |
244
|
|
|
} |
245
|
|
|
|
246
|
|
|
return $clusters; |
247
|
|
|
} |
248
|
|
|
|
249
|
|
|
/** |
250
|
|
|
* @return Cluster[] |
251
|
|
|
*/ |
252
|
|
|
private function initializeRandomClusters(int $clustersNumber): array |
253
|
|
|
{ |
254
|
|
|
$clusters = []; |
255
|
|
|
[$min, $max] = $this->getBoundaries(); |
256
|
|
|
|
257
|
|
|
for ($n = 0; $n < $clustersNumber; ++$n) { |
258
|
|
|
$clusters[] = new Cluster($this, $this->getRandomPoint($min, $max)->getCoordinates()); |
259
|
|
|
} |
260
|
|
|
|
261
|
|
|
return $clusters; |
262
|
|
|
} |
263
|
|
|
} |
264
|
|
|
|