加法虫的源代码

author: 辉格

找了一下，源代码还在，我用Delphi5写的，因为用了几个第三方库和我自己的库，现在没法编译，不过真有兴趣的话，很容易照着用其他语言改写一下，很小，也就1000多行代码。

我把“个体”类（TIndividual）的发育、表达、遭遇等方法都声明为抽象或虚拟方法，对价值函数的调用也是通过指针进行，所以，你只要从TIndividual派生一个子类（比如我的虫子的声明：TEvJumble = class(TEvIndividual)），并给它一个价值函数，再配置一下进化环境文件，即可开始孵育你自己的虫子了，呵呵。

下面是最核心的一段代码，实现了“种群”类的“世代交替”：

procedure TEvPopulus.Digenesize;

var

i, j, n, nPopu, nBorn, nDead: Integer;

fFav, fAch, fRep, fSur, fElm, fAge, fFert, fR: Double;

P, F: TEvIndividual;

lBabies: TEvIndividuals;

L: TStringList;

FF: TIniFile;

begin

FF := TIniFile.Create(FileName);

fFav := Individuals[0].Favorable;

Individuals.SortByFavorable;

fAch := Individuals[0].Favorable;

if fAch > fFav * 1.01 then

FF.WriteString(‘Specimens’, IntToStrN(LineageNo, 6),

Individuals[0].Genes[0].AsHex + ‘,’

+ FormatFloat(‘0.000000′, fAch));

nPopu := Individuals.Count;

fFav := 0;

i := 0;

while (i < nPopu) and (Individuals[i].Experience > 0) do

begin

fFav := fFav + Individuals[i].Favorable;

Inc(i);

end;

if i > 0 then fFav := fFav / i;

fElm := Max(0.0, (0.00001 + nPopu – Population) / (nPopu * 1.0));

fFert := Fertility * Min(3, Population / nPopu);

lBabies := TEvIndividuals.Create(False);

L := TStringList.Create;

L.Sorted := True;

L.Duplicates := dupIgnore;

fAch := 0; fAge := 0;

nDead := 0;

i := 0;

while i < Individuals.Count do

begin

P := Individuals[i];

L.Add(P.Genes[0].AsHex);

fAch := fAch + P.Favorable;

fAge := fAge + P.Experience;

if fFav > 0 then

begin

fRep := Power(P.Favorable / fFav, EOR);

fSur := Power(P.Favorable / fFav, EOS);

end else

begin

fRep := 1;

fSur := 1;

end;

P.Reproductivity := fRep;

P.Survivability  := fSur;

fRep := fFert * fRep;

n := Trunc(fRep);

fR := Random;

if fR <= fRep – n then

Inc(n);

for j := 0 to n – 1 do

begin

fR := Random;

F := IndividualClass.Create;

F.Inherit(P, fR <= MutateRate);

F.Develop;

lBabies.Add(F);

end;

fR := Random;

if fR * fSur <= fElm then

begin

Individuals.Delete(i);

Inc(nDead);

end else

Inc(i);

end;

nBorn := lBabies.Count;

for i := 0 to nBorn – 1 do

Individuals.Add(lBabies[i]);

lBabies.Free;

fAge := fAge / nPopu;

Achievement := fAch / nPopu;

Variety := L.Count / nPopu;

FF.WriteString(‘Progress’, IntToStrN(LineageNo, 6),

FormatFloat(‘0.000000′, Achievement) + ‘,’

+ FormatFloat(‘0.000000′, Individuals[0].Favorable) + ‘,’

+ FormatFloat(‘0.0000′, Variety) + ‘,’

+ IntToStrN(nBorn, 6) + ‘,’

+ IntToStrN(nDead, 6) + ‘,’

+ FormatFloat(‘#0.0′, fAge));

FF.Free;

LineageNo := LineageNo + 1;

L.Free;

end;