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TRSGABits.CrossOver(TRSGABits,TRSGABits,Integer) Method

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Modifies the bits of the current object by mixing the bits of the two Source bits, or Parents. The method uses the CrossBit crossover point to copy bits from Source1 from the first bit to the crossover bit and then copy bits from Source2 from the crossover bit to the last bit. Thus, the current bits object becomes the child of the two parent bits.

Namespace: RSGeneticAlgorithm

expandingSyntax

Delphi

public
  function CrossOver( Source1, Source2: TRSGABits; CrossBit: Integer ): TRSGABits; overload;
 

Parameters

Source1

Type: TRSGABits

Source2

Type: TRSGABits

CrossBit

Type: Integer

Return Value

Type: TRSGABits

expandingExamples

The following example randomly mixes the chromosome bits of two parents into a child chromosome (all represented by TRSGABits in the TRSGAIndividual). It first selects the crossover bit using a CrossOver method and then mixes the bits:

Delphi

procedure TRSCustomGeneticAlgorithm.Crossover(const Parent1, Parent2, Child1,
   Child2: TRSGAIndividual);
 var
    CrossBit: Integer;
 begin
      if Random >= CrossoverProbability then Exit;
      case CrossoverMethod of
           cmGeneBoundary:
             if (CrossoverMethod = cmGeneBoundary) and (Genes.Count > 1) then
                CrossBit := Genes[Random(Genes.Count-1)+1].Offset
             else // cmBit
                  CrossBit := Random(Child1.Bits.Size);
           cmByteBoundary:
             if GeneSize < 16 then // need at least 2 bytes
                CrossBit := Random(Child1.Bits.Size)
             else
                 CrossBit := (Random(Child1.Bits.Size div 8)+1)*8;
           cmWordBoundary:
             if GeneSize < 32 then // need at least 2 words
                CrossBit := Random(Child1.Bits.Size)
             else
                 CrossBit := (Random(Child1.Bits.Size div 16)+1)*16;
           cmLongwordBoundary:
             if GeneSize < 64 then // need at least 2 long words
                CrossBit := Random(Child1.Bits.Size)
             else
                 CrossBit := (Random(Child1.Bits.Size div 32)+1)*32;
      else
          // cmBitBoundary:
          CrossBit := Random(Child1.Bits.Size);
      end;
      Child1.Bits.CrossOver(Parent1.Bits, Parent2.Bits, CrossBit);
      if Child2 <> nil then
         Child2.Bits.CrossOver(Parent2.Bits, Parent1.Bits, CrossBit);
 end;

expandingSee Also

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