func makeRandomPopulation(size int, accountId int64, originalPerson *database.Person) (pop *Population) {
db := database.OpenDB()
defer db.Close()
pop = &Population{}
genomes := make([]*Genome, size)
for i := 0; i < size; i++ {
// seed with the original person
persMap := make(map[string]*database.Person)
persMap[originalPerson.MonetateId] = originalPerson
// seed with the original person's products
prodMap := make(map[string]*database.Product)
// TODO: Don't requery for every genome
products := database.QueryProductsViewedAndPurchased(db, accountId, originalPerson)
for i := 0; i < len(products); i++ {
prodMap[products[i].Pid] = products[i]
}
rs := &RecoSet{products: prodMap, people: persMap}
genome := &Genome{rs: rs, score: 0.0}
genome.addRandomTrait()
genomes[i] = genome
}
pop.genomes = genomes
return
}
func (pop *Population) evolve(maxPopulation int, maxGenerations int, accountId int64,
originalPerson *database.Person) {
db := database.OpenDB()
defer db.Close()
for g := 0; g < maxGenerations; g++ {
fmt.Printf("processing generation %d\n", g)
ch := make(chan bool)
for i := 0; i < len(pop.genomes); i++ {
go func(ch chan bool, genome *Genome) {
// apply the update of the last (current) trait a genome
genome.getCurrentTrait().update(db, genome.rs, accountId, originalPerson)
genome.checkFitness(db, accountId, originalPerson)
ch <- true
}(ch, pop.genomes[i])
}
// drain the channel
for i := 0; i < len(pop.genomes); i++ {
<-ch
}
pop.display()
if g == (maxGenerations - 1) {
pop.displayFinal()
} else {
// select genomes to carry forward to the next generation
pop.makeSelection()
// add new traits to the surviving genomes
for i := 0; i < len(pop.genomes); i++ {
pop.genomes[i].addRandomTrait()
}
// have the successful ones reproduce to fill out the remainder of the population
childrenGenomes := make([]*Genome, 0)
for i := 0; i < (maxPopulation - len(pop.genomes)); i++ {
r1 := rand.Intn(len(pop.genomes))
r2 := rand.Intn(len(pop.genomes))
newGenome := reproduce(pop.genomes[r1], pop.genomes[r2])
childrenGenomes = append(childrenGenomes, newGenome)
}
pop.appendGenomes(childrenGenomes)
}
}
}