C#遺傳演算法學習筆記

本文介紹C#遺傳演算法學習筆記，通過運行程式，你會發現通過不斷的進化，種群的總的適應環境的能力在逐步提高。

以下代碼實現了C#遺傳演算法一個簡單的花朵進化的類比過程。

花朵的種群數量是10，共進化了50代。通過運行程式，你會發現通過不斷的進化，種群的總的適應環境的能力在逐步提高（fitness的值下降）。

C#遺傳演算法實現代碼：

 

  
using System;  
  
using System.Collections.Generic;  
  
using System.Text;  
  
namespace GA  
  
{  
  
class Program  
  
{  
  
static void Main(string[] args)  
  
{  
  
World world = new World();  
  
world.Init();  
  
for (int i = 0; i  50; i++)  
  
{  
  
world.Evolve();  
  
Console.WriteLine(i);  
  
world.Show();  
  
}  
  
}  
  
}  
  
 
  
class World  
  
{  
  
int kMaxFlowers = 11;  
  
Random Rnd = new Random();  
  
public int[] temperature;  
  
public int[] water;  
  
public int[] sunlight;  
  
public int[] nutrient;  
  
public int[] beneficialInsect;  
  
public int[] harmfulInsect;  
  
public int currentTemperature;  
  
public int currentWater;  
  
public int currentSunlight;  
  
public int currentNutrient;  
  
public int currentBeneficialInsect;  
  
public int currentHarmfulInsect;  
  
public World()  
  
{  
  
temperature = new int[kMaxFlowers];  
  
water = new int[kMaxFlowers];  
  
sunlight = new int[kMaxFlowers];  
  
nutrient = new int[kMaxFlowers];  
  
beneficialInsect = new int[kMaxFlowers];  
  
harmfulInsect = new int[kMaxFlowers];  
  
}  
  
/**////  
  
/// 初始化第一代花朵的基因結構  
  
///  
  
public void Init()  
  
{  
  
for (int i = 1; i  kMaxFlowers; i++)  
  
{  
  
temperature[i] = Rnd.Next(1, 75);  
  
water[i] = Rnd.Next(1, 75);  
  
sunlight[i] = Rnd.Next(1, 75);  
  
nutrient[i] = Rnd.Next(1, 75);  
  
beneficialInsect[i] = Rnd.Next(1, 75);  
  
harmfulInsect[i] = Rnd.Next(1, 75);  
  
}  
  
currentTemperature = Rnd.Next(1, 75);  
  
currentWater = Rnd.Next(1, 75);  
  
currentSunlight = Rnd.Next(1, 75);  
  
currentNutrient = Rnd.Next(1, 75);  
  
currentBeneficialInsect = Rnd.Next(1, 75);  
  
currentHarmfulInsect = Rnd.Next(1, 75);  
  
}  
  
/**////  
  
/// 越大說明花朵的適應環境的能力差，小說明適應環境的能力強  
  
///  
  
///  name="flower"> 
  
///  
  
private int Fitness(int flower)  
  
{  
  
int theFitness = 0;  
  
theFitness = Math.Abs(temperature[flower] - currentTemperature);  
  
theFitnesstheFitness = theFitness + Math.Abs(water[flower] - currentWater);  
  
theFitnesstheFitness = theFitness + Math.Abs(sunlight[flower] -  
  
currentSunlight);  
  
theFitnesstheFitness = theFitness + Math.Abs(nutrient[flower] -  
  
currentNutrient);  
  
theFitnesstheFitness = theFitness + Math.Abs(beneficialInsect[flower] -  
  
currentBeneficialInsect);  
  
theFitnesstheFitness = theFitness + Math.Abs(harmfulInsect[flower] -  
  
currentHarmfulInsect);  
  
return (theFitness);  
  
}  
  
/**////  
  
/// 排除適應能力差的花朵，讓適應能力強的花朵雜交繁殖，產生下一代。同時有一定的機率變異。  
  
///  
  
public void Evolve()  
  
{  
  
int[] fitTemperature = new int[kMaxFlowers];  
  
int[] fitWater = new int[kMaxFlowers];  
  
int[] fitSunlight = new int[kMaxFlowers];  
  
int[] fitNutrient = new int[kMaxFlowers];  
  
int[] fitBeneficialInsect = new int[kMaxFlowers];  
  
int[] fitHarmfulInsect = new int[kMaxFlowers];  
  
int[] fitness = new int[kMaxFlowers];  
  
int i;  
  
int leastFit = 0;  
  
int leastFitIndex = 1;  
  
for (i = 1; i  kMaxFlowers; i++)  
  
if (Fitness(i) > leastFit)  
  
{  
  
leastFit = Fitness(i);  
  
leastFitIndex = i;  
  
}  
  
temperature[leastFitIndex] = temperature[Rnd.Next(1, 10)];  
  
water[leastFitIndex] = water[Rnd.Next(1, 10)];  
  
sunlight[leastFitIndex] = sunlight[Rnd.Next(1, 10)];  
  
nutrient[leastFitIndex] = nutrient[Rnd.Next(1, 10)];  
  
beneficialInsect[leastFitIndex] = beneficialInsect[Rnd.Next(1, 10)];  
  
harmfulInsect[leastFitIndex] = harmfulInsect[Rnd.Next(1, 10)];  
  
for (i = 1; i  kMaxFlowers; i++)  
  
{  
  
fitTemperature[i] = temperature[Rnd.Next(1, 10)];  
  
fitWater[i] = water[Rnd.Next(1, 10)];  
  
fitSunlight[i] = sunlight[Rnd.Next(1, 10)];  
  
fitNutrient[i] = nutrient[Rnd.Next(1, 10)];  
  
fitBeneficialInsect[i] = beneficialInsect[Rnd.Next(1, 10)];  
  
fitHarmfulInsect[i] = harmfulInsect[Rnd.Next(1, 10)];  
  
}  
  
for (i = 1; i  kMaxFlowers; i++)  
  
{  
  
temperature[i] = fitTemperature[i];  
  
water[i] = fitWater[i];  
  
sunlight[i] = fitSunlight[i];  
  
nutrient[i] = fitNutrient[i];  
  
beneficialInsect[i] = fitBeneficialInsect[i];  
  
harmfulInsect[i] = fitHarmfulInsect[i];  
  
}  
  
for (i = 1; i  kMaxFlowers; i++)  
  
{  
  
if (Rnd.Next(1, 100) == 1)  
  
temperature[i] = Rnd.Next(1, 75);  
  
if (Rnd.Next(1, 100) == 1)  
  
water[i] = Rnd.Next(1, 75);  
  
if (Rnd.Next(1, 100) == 1)  
  
sunlight[i] = Rnd.Next(1, 75);  
  
if (Rnd.Next(1, 100) == 1)  
  
nutrient[i] = Rnd.Next(1, 75);  
  
if (Rnd.Next(1, 100) == 1)  
  
beneficialInsect[i] = Rnd.Next(1, 75);  
  
if (Rnd.Next(1, 100) == 1)  
  
harmfulInsect[i] = Rnd.Next(1, 75);  
  
}  
  
}  
  
/**////  
  
/// 顯示種群中個體對環境的適應能力，還有所有個體對環境的適應能力之和。  
  
///  
  
public void Show()  
  
{  
  
int sum = 0;  
  
for (int i = 1; i  kMaxFlowers; i++)  
  
{  
  
int fitness = Fitness(i);  
  
sum += fitness;  
  
Console.WriteLine("No." + i + "'s fitness is " + fitness);  
  
}  
  
Console.WriteLine("fitness sum is " + sum);  
  
}  
  
}  
  
} 
 

轉載 吾搜 空間