public double Potential(Particle particle)
{
var xyDistance = Position - particle.Position;
// charges with different signs create a negative potential
return Charge * particle.Charge
/ Math.Sqrt(xyDistance.LengthSquared + Z * Z);
}
public Vector2D Force(Particle particle)
{
var xyDistance = Position - particle.Position;
if(xyDistance.IsZero) return Vector2D.ZeroVector;
var xyProjectionCoefficient = xyDistance.Length / Math.Sqrt(xyDistance.LengthSquared + Z * Z);
// charges with different signs attract each other
return -Charge * particle.Charge * xyProjectionCoefficient
/ (xyDistance.LengthSquared + Z * Z)
* xyDistance.Unity;
}
public Pendulum(int attractorCount)
{
Attractors = new AttractorSet();
for (int i = 0; i < attractorCount; i++)
{
var angle = i * 2 * Math.PI / attractorCount;
Attractors.Add(new Attractor { Position = new Vector2D(Math.Cos(angle), Math.Sin(angle)) });
}
Particle = new Particle { Force = ForceOnParticle };
Friction = new FluidFriction();
}
public override Vector2D Force(Particle particle)
{
return -Coefficient * particle.Velocity.Length * particle.Velocity;
}
public abstract Vector2D Force(Particle particle);
private Vector2D ForceOnParticle(Particle particle)
{
return Attractors.Force(particle) + Friction.Force(particle);
}