全体的な改修

iga.php

@@ -0,0 +1,107 @@
+<?php
+
+class Iga
+{
+  private $poplation = [];        # 集団
+  private $poplation_num;         # 集団の個体数
+  private $mutation_probability;  # 突然変異確率
+
+  public function __construct(int $population_num, float $mutation_probability)
+  {
+    if ($population_num < 2 || $mutation_probability > 1.0) {
+      throw new UnexpectedValueException();
+    }
+    $this->population_num = $population_num;
+    $this->mutation_probability = $mutation_probability;
+  }
+
+  public function get_population()
+  {
+    return $this->poplation;
+  }
+
+  public function set_population(array $population)
+  {
+    if (count($population) != $this->poplation_num) {
+      throw new LengthException();
+    }
+    foreach ($population as $individual) {
+      if ($individual instanceof Individual) {
+        throw new UnexpectedValueException();
+      }
+    }
+    $this->population = $population;
+  }
+
+  # 初期集団生成
+  public function init_population(int $chrom_num)
+  {
+    $chrom = [];
+    for ($i = 0; $i < $chrom_num; $i++) {
+      $chrom[$i] = $i == 0 ? rand(0, 7) : rand(0, 255);
+    }
+    for ($i = 0; $i < $this->poplation_num; $i++) {
+      $this->poplation[$i] = new Individual($chrom, 0);
+    }
+  }
+
+  # 評価値設定
+  public function set_evaluations(array $evaluations)
+  {
+    foreach ($evaluations as $index => $evaluation) {
+      $this->poplation[$index]->evaluation;
+    }
+  }
+
+  # 次世代生成
+  public function generate_next_population()
+  {
+    $evaluation_sum = 0;
+    $next_population = [];
+
+    foreach ($this->population as $individual) {
+      $evaluation_sum += $individual->evaluation;
+    }
+    for ($i = 0; $i < $this->population_num; $i++) {
+      $parent1 = new Individual();
+      $parent2 = new Individual();
+      $child = new Individual();
+      # ルーレット選択(親1)
+      $roulette_target_num = rand(0, $evaluation_sum);
+      $roulette_current_num = 0;
+      foreach ($this->population as $individual) {
+        $roulette_current_num += $individual->evaluation;
+        if ($roulette_current_num >= $roulette_target_num) {
+          for ($j = 0; $j < 13; $j++) {
+            $parent1->chrom[$j] = $individual->chrom[$j];
+          }
+          break;
+        }
+      }
+      # ルーレット選択(親2)
+      $roulette_target_num = rand(0, $evaluation_sum);
+      $roulette_current_num = 0;
+      foreach ($this->population as $individual) {
+        $roulette_current_num += $individual->evaluation;
+        if ($roulette_current_num >= $roulette_target_num) {
+          for ($j = 0; $j < 13; $j++) {
+            $parent2->chrom[$j] = $individual->chrom[$j];
+          }
+          break;
+        }
+      }
+      # 一様交叉
+      for ($j = 0; $j < 13; $j++) {
+        $child->chrom[$j] = rand(0, 1) == 0 ? $parent1->chrom[$j] : $parent2->chrom[$j];
+      }
+      # 突然変異
+      for ($j = 0; $j < 13; $j++) {
+        if (rand(0, 100) < $this->mutation_probability * 100) {
+          $child->chrom[$j] = $j == 0 ? rand(0, 7) : rand(0, 255);
+        }
+      }
+      array_push($next_population, $child);
+    }
+    $this->population = $next_population;
+  }
+}