def test16(self):
instance = Huayno()
instance.parameters.epsilon_squared = 0.0 | nbody_system.length**2
particles = datamodel.Particles(2)
particles.mass = [1.] | nbody_system.mass
particles.radius = [0.0] | nbody_system.length
particles.position = [[0.0,0.0,0.0],[1.0,0.0,0.0]] | nbody_system.length
particles.velocity = [[0.0, 0.0, 0.0]] | nbody_system.speed
instance.particles.add_particles(particles)
zero = 0.0 | nbody_system.length
for x in (0.25, 0.5, 0.75):
x0 = x | nbody_system.length
potential0 = instance.get_potential_at_point(zero, x0, zero, zero)
fx0, fy0, fz0 = instance.get_gravity_at_point(zero, x0, zero, zero)
self.assertAlmostEqual(fy0, 0.0 | nbody_system.acceleration,14)
self.assertAlmostEqual(fz0, 0.0 | nbody_system.acceleration,14)
fx = (-1.0 / (x0**2)+1.0 / (((1.0|nbody_system.length)-x0)**2)) * (1.0 | nbody_system.length ** 3 / nbody_system.time ** 2)
self.assertAlmostEqual(fx, fx0,14)
self.assertAlmostEqual(potential0, -nbody_system.G*(1.|nbody_system.mass)*(1./x0+1./((1.|nbody_system.length)-x0)),14)
instance.stop()
def test16(self):
instance = Huayno()
instance.parameters.epsilon_squared = 0.0 | nbody_system.length**2
particles = datamodel.Particles(2)
particles.mass = [1.] | nbody_system.mass
particles.radius = [0.0] | nbody_system.length
particles.position = [[0.0, 0.0, 0.0], [1.0, 0.0, 0.0]
] | nbody_system.length
particles.velocity = [[0.0, 0.0, 0.0]] | nbody_system.speed
instance.particles.add_particles(particles)
zero = 0.0 | nbody_system.length
for x in (0.25, 0.5, 0.75):
x0 = x | nbody_system.length
potential0 = instance.get_potential_at_point(zero, x0, zero, zero)
fx0, fy0, fz0 = instance.get_gravity_at_point(zero, x0, zero, zero)
self.assertAlmostEqual(fy0, 0.0 | nbody_system.acceleration, 14)
self.assertAlmostEqual(fz0, 0.0 | nbody_system.acceleration, 14)
fx = (-1.0 / (x0**2) + 1.0 /
(((1.0 | nbody_system.length) - x0)**2)) * (
1.0 | nbody_system.length**3 / nbody_system.time**2)
self.assertAlmostEqual(fx, fx0, 14)
self.assertAlmostEqual(
potential0, -nbody_system.G * (1. | nbody_system.mass) *
(1. / x0 + 1. / ((1. | nbody_system.length) - x0)), 14)
instance.stop()
