individual.go

package staticneurogenetic

import (
	"math/rand"
)

type Individual struct {
	Fitness float64
	Genome  []float64
}

func NewIndividual(genome_size int) Individual {
	return Individual{
		Genome: make([]float64, genome_size),
	}
}

func (p *Individual) Randomize() {
	for i := range p.Genome {
		p.Genome[i] = rand.Float64()*2 - 1
	}
}

func (p *Individual) Output(
	input []float64,
	layers []int,
	activation ActivationFunction,
) []float64 {
	var (
		offset = 0
		in     = input
		out    []float64
	)

	for l := 1; l < len(layers); l++ {
		out = make([]float64, layers[l])

		for o := 0; o < layers[l]; o++ {
			out[o] = p.Genome[offset] // bias
			offset++

			for i := 0; i < layers[l-1]; i++ {
				out[o] += in[i] * p.Genome[offset]
				offset++
			}

			out[o] = activation(out[o]) // activation
		}

		in = out // this output is the input for the next layer
	}

	return out
}

func (p *Individual) MonoParentCross(father *Individual) {
	copy(p.Genome, father.Genome)
}

func (p *Individual) DivPointCross(father, mother *Individual) {
	point := rand.Intn(len(p.Genome))
	for i := 0; i < point; i++ {
		p.Genome[i] = father.Genome[i]
	}
	for i := point; i < len(p.Genome); i++ {
		p.Genome[i] = mother.Genome[i]
	}
}

func (p *Individual) AritmeticCross(father, mother *Individual) {
	alpha := rand.Float64()
	for i := 0; i < len(p.Genome); i++ {
		p.Genome[i] = father.Genome[i]*alpha + mother.Genome[i]*(1-alpha)
	}
}

func (p *Individual) RandomCross(father, mother *Individual) {
	for i := 0; i < len(p.Genome); i++ {
		if rand.Float32() < 0.5 {
			p.Genome[i] = father.Genome[i]
		} else {
			p.Genome[i] = mother.Genome[i]
		}
	}
}

func (p *Individual) OneMutate(mut_rate float32, mut_size float64) {
	if rand.Float32() < mut_rate {
		p.Genome[rand.Intn(len(p.Genome))] += rand.NormFloat64() * mut_size
	}
}

func (p *Individual) MultiMutate(mut_rate float32, mut_size float64) {
	for i := 0; i < len(p.Genome); i++ {
		if rand.Float32() < mut_rate {
			p.Genome[rand.Intn(len(p.Genome))] += rand.NormFloat64() * mut_size
		}
	}
}