Example #1
0
func (p *Particle) Move(gbest *optim.Point, vmax []float64, inertia, social, cognition float64) {
	// update velocity
	for i, currv := range p.Vel {
		// random numbers r1 and r2 MUST go inside this loop and be generated
		// uniquely for each dimension of p's velocity.
		r1 := optim.RandFloat()
		r2 := optim.RandFloat()
		p.Vel[i] = inertia*currv +
			cognition*r1*(p.Best.Pos[i]-p.Pos[i]) +
			social*r2*(gbest.Pos[i]-p.Pos[i])
		if math.Abs(p.Vel[i]) > vmax[i] {
			p.Vel[i] = math.Copysign(vmax[i], p.Vel[i])
		}
	}

	// update position
	for i := range p.Pos {
		p.Pos[i] += p.Vel[i]
	}
	p.Val = math.Inf(1)
}
Example #2
0
// NewPopulation initializes a population of particles using the given points
// and generates velocities for each dimension i initialized to uniform random
// values between minv[i] and maxv[i].  github.com/rwcarlsen/optim.Rand is
// used for random numbers.
func NewPopulation(points []*optim.Point, vmax []float64) Population {
	pop := make(Population, len(points))
	for i, p := range points {
		pop[i] = &Particle{
			Id:    i,
			Point: p,
			Best:  p.Clone(),
			Vel:   make([]float64, len(vmax)),
		}
		for j, v := range vmax {
			pop[i].Vel[j] = v * (1 - 2*optim.RandFloat())
		}
	}
	return pop
}