public Particle(int dim, double minX, double maxX)
{
position = new double[dim];
velocity = new double[dim];
bestPartPos = new double[dim];
for (int i = 0; i < dim; ++i)
{
position[i] = (maxX - minX) * MultiSwarmProgram.ran.NextDouble() + minX;
}
for (int i = 0; i < dim; ++i)
{
velocity[i] = (maxX - minX) * MultiSwarmProgram.ran.NextDouble() + minX;
}
cost = MultiSwarmProgram.Cost(position);
bestPartCost = cost;
Array.Copy(position, bestPartPos, dim);
}
public void Solve(int maxLoop)
{
int ct = 0;
double w = 0.729; // inertia
double c1 = 1.49445; // particle / cogntive
double c2 = 1.49445; // swarm / social
double c3 = 0.3645; // multiswarm / global
double death = 0.005;; // prob of particle death
double immigrate = 0.005; // prob of particle immigration
while (ct < maxLoop)
{
++ct;
for (int i = 0; i < swarms.Length; ++i) // each swarm
{
for (int j = 0; j < swarms[i].particles.Length; ++j) // each particle
{
double p = MultiSwarmProgram.ran.NextDouble();
if (p < death)
{
swarms[i].particles[j] = new Particle(dim, minX, maxX);
}
double q = MultiSwarmProgram.ran.NextDouble();
if (q < immigrate)
{
Immigration(i, j); // swap curr particle with a random particle in diff swarm
}
for (int k = 0; k < dim; ++k) // update velocity. each x position component
{
double r1 = MultiSwarmProgram.ran.NextDouble();
double r2 = MultiSwarmProgram.ran.NextDouble();
double r3 = MultiSwarmProgram.ran.NextDouble();
swarms[i].particles[j].velocity[k] = (w * swarms[i].particles[j].velocity[k]) +
(c1 * r1 * (swarms[i].particles[j].bestPartPos[k] - swarms[i].particles[j].position[k])) +
(c2 * r2 * (swarms[i].bestSwarmPos[k] - swarms[i].particles[j].position[k])) +
(c3 * r3 * (bestMultiPos[k] - swarms[i].particles[j].position[k]));
if (swarms[i].particles[j].velocity[k] < minX)
{
swarms[i].particles[j].velocity[k] = minX;
}
else if (swarms[i].particles[j].velocity[k] > maxX)
{
swarms[i].particles[j].velocity[k] = maxX;
}
}
for (int k = 0; k < dim; ++k) // update position
{
swarms[i].particles[j].position[k] += swarms[i].particles[j].velocity[k];
}
// update cost
swarms[i].particles[j].cost = MultiSwarmProgram.Cost(swarms[i].particles[j].position);
// check if new best cost
if (swarms[i].particles[j].cost < swarms[i].particles[j].bestPartCost)
{
swarms[i].particles[j].bestPartCost = swarms[i].particles[j].cost;
Array.Copy(swarms[i].particles[j].position, swarms[i].particles[j].bestPartPos, dim);
}
if (swarms[i].particles[j].cost < swarms[i].bestSwarmCost)
{
swarms[i].bestSwarmCost = swarms[i].particles[j].cost;
Array.Copy(swarms[i].particles[j].position, swarms[i].bestSwarmPos, dim);
}
if (swarms[i].particles[j].cost < bestMultiCost)
{
bestMultiCost = swarms[i].particles[j].cost;
Array.Copy(swarms[i].particles[j].position, bestMultiPos, dim);
}
}
}
}
}
