// Creates new minimizer
// cost - function to minimize
// n - number of entities in population
// min, max - area for initial population
func NewMinimizer(cost Cost, n int, min, max *matrix.Dense) *Minimizer {
if n < 4 {
log.Panic("population too small: ", n)
}
m := new(Minimizer)
m.CR = 0.9
m.Pop = make([]*Agent, n)
// Initialization of population
max.AddTo(min, -1) // calculate width of initial area
for i := range m.Pop {
m.Pop[i] = newAgent(min, max, cost)
}
m.rnd = rand.New(rand.NewSource(time.Now().UnixNano()))
return m
}
func newAgent(min, width *matrix.Dense, cost Cost) *Agent {
a := new(Agent)
a.X = matrix.DenseZero(min.Size())
a.x = a.X.Hvec() // crossover operates on vectorized matrix
a.in = make(chan args, 1)
a.out = make(chan float64, 1)
a.rnd = rand.New(rand.NewSource(time.Now().UnixNano()))
a.cost = cost
// Place this agent in random place on the initial area
a.x.Rand(0, 1)
a.X.MulBy(width)
a.X.AddTo(min, 1)
// Run crossover loop
go a.crossoverLoop()
return a
}
func cost(m *matrix.Dense) float64 {
return Cost(m.Elems())
}
func perturb(u *matrix.Dense, in args, start, stop int) {
v := u.Vslice(start, stop)
v.Sub(in.b.Vslice(start, stop), in.c.Vslice(start, stop), in.f)
v.AddTo(in.a.Vslice(start, stop), 1)
}