//Does a mutation and calculates fitness
private Individual MutateByBitFlip(Individual child, int bitstoflip)
{
List<int> positions = new List<int>();
for(int i = 0; i < bitstoflip; i++)
{
int randpos;
do
{
randpos = randomgenerator.Next(child.Chromosome.Length);
} while(positions.Contains(randpos));
positions.Add(randpos);
}
foreach(int pos in positions)
{
if(child.Chromosome.IsSet(pos))
child.Chromosome.Clear(pos);
else
child.Chromosome.Set(pos);
}
int pathscut = 0;
child.Fitness = FitnessEvaluation(data.NetworkPaths, child.Chromosome, config.PenaltyCoefficient, out pathscut);
child.PathsCut = pathscut;
return child;
}
public bool Dominates(Individual other)
{
if(this.pathscut >= other.pathscut && this.chromosome.SetBits < other.chromosome.SetBits)
return true;
if(this.pathscut > other.pathscut && this.chromosome.SetBits <= other.chromosome.SetBits)
return true;
return false;
}
//Generates a child individual using uniform crossover
//DOES NOT SET FITNESS YET, THAT IS DONE AFTER MUTATION
private Individual GenerateChildUniform(Individual parentA, Individual parentB)
{
Individual child = new Individual();
child.Chromosome = new BetterBitArray(parentA.Chromosome.Length);
for(int i = 0; i < parentA.Chromosome.Length; i++)
{
//Either a 1 or 0. If it's one we take the bit from parent A, else we take it from parent B.
if(Convert.ToBoolean(randomgenerator.Next(2)))
{
if(parentA.Chromosome.IsSet(i))
{
child.Chromosome.Set(i);
}
else
{
child.Chromosome.Clear(i);
}
}
else
{
if(parentB.Chromosome.IsSet(i))
child.Chromosome.Set(i);
else
child.Chromosome.Clear(i);
}
}
return child;
}
//Generates a child individual using n-point crossover
//DOES NOT SET FITNESS YET, THAT IS DONE AFTER MUTATION
private Individual GenerateChildNPoint(Individual[] parents, int crossovers)
{
List<int> positions = new List<int>();
Individual child = new Individual();
child.Chromosome = new BetterBitArray(parents[0].Chromosome.Length);
//Get the positions to crossover at
for(int i = 0; i < crossovers; i++)
{
int randpos;
do
{
randpos = randomgenerator.Next(parents[0].Chromosome.Length);
} while(positions.Contains(randpos));
positions.Add(randpos);
}
positions.Sort();
int parentiter = 0;
int lastcrossover = 0;
//For each position
foreach(int point in positions)
{
//Create a mask
BetterBitArray mask = new BetterBitArray(parents[0].Chromosome.Length);
//Set the bits that are in the range of this crossover on for the mask.
//Ex: if the crossover point is 6 and we are currently at the front
// the mask looks like 1111110000...
for(int i = lastcrossover; i <= point; i++)
{
mask.Set(i);
}
//Clone the parent so we don't write over it.
BetterBitArray parent = parents[parentiter].Chromosome;
//Or the current child with the masked out part of the parent.
child.Chromosome = child.Chromosome.Or(parent.And(mask));
//Switch the parents (done this way because it was originally allowed to have more
//than 2 parents. /sigh
parentiter *= -1;
parentiter += 1;
}
return child;
}
//Distance between a and b using paths cut and routers turned off (chromosome set bits)
public double Distance(Individual a, Individual b)
{
return Math.Sqrt((a.PathsCut - b.PathsCut) * (a.PathsCut - b.PathsCut) + (a.Chromosome.SetBits - b.Chromosome.SetBits) * (a.Chromosome.SetBits - b.Chromosome.SetBits));
}
//Does a mutation and calculates fitness
private Individual MutateByBitFlip(Individual child, int bitstoflip)
{
List<int> positions = new List<int>();
for(int i = 0; i < bitstoflip; i++)
{
int randpos;
do
{
randpos = randomgenerator.Next(child.Chromosome.Count);
} while(positions.Contains(randpos));
positions.Add(randpos);
}
foreach(int pos in positions)
{
child.Chromosome.Set(pos, !child.Chromosome.Get(pos));
if(child.Chromosome.Get(pos))
child.BitsSet++;
else
child.BitsSet--;
}
child.Fitness = FitnessEvaluation(data.NetworkPaths, child.Chromosome, child.BitsSet, config.PenaltyCoefficient);
return child;
}
//Generates a child individual using uniform crossover
//DOES NOT SET FITNESS YET, THAT IS DONE AFTER MUTATION
private Individual GenerateChildUniform(Individual parentA, Individual parentB)
{
Individual child = new Individual();
child.Chromosome = new BitArray(parentA.Chromosome.Count);
child.BitsSet = 0;
for(int i = 0; i < parentA.Chromosome.Count; i++)
{
//Either a 1 or 0. If it's one we take the bit from parent A, else we take it from parent B.
if(Convert.ToBoolean(randomgenerator.Next(2)))
{
child.Chromosome.Set(i, parentA.Chromosome.Get(i));
if(parentA.Chromosome.Get(i))
child.BitsSet++;
}
else
{
child.Chromosome.Set(i, parentB.Chromosome.Get(i));
if(parentB.Chromosome.Get(i))
child.BitsSet++;
}
}
return child;
}
