private void timer_Tick(object sender, EventArgs e)
{
double time = stopwatch.Elapsed.TotalSeconds / 10;
field.Clear();
field.AddPotentialPoint(100 + 50 * Math.Cos(time) + 10 * Math.Cos(2.1 * time), 100 + 40 * Math.Sin(time), 1);
field.AddPotentialPoint(20, 10, -1);
field.AddPotentialPoint(180, 20, 3);
field.AddPotentialPoint(20, 180, -0.5);
field.AddPotentialPoint(180, 180, 2);
field.RaiseChanged();
}
