def test7(self):
instance = PhiGRAPE(**default_test_options)
instance.initialize_code()
instance.parameters.set_defaults()
particles = datamodel.Particles(2)
particles.mass = [1.0, 1.0] | nbody_system.mass
particles.radius = [0.0001, 0.0001] | nbody_system.length
particles.position = [[0.0,0.0,0.0], [2.0,0.0,0.0]] | nbody_system.length
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | nbody_system.speed
instance.particles.add_particles(particles)
instance.commit_particles()
zero = [0.0, 0.0, 0.0] | nbody_system.length
fx, fy, fz = instance.get_gravity_at_point(zero, [0.5, 1.0, 1.5] | nbody_system.length, zero, zero)
self.assertAlmostRelativeEqual(fx[0], -3.55555555556 | nbody_system.acceleration, 5)
self.assertAlmostRelativeEqual(fy[0], 0.0 | nbody_system.acceleration, 3)
self.assertAlmostRelativeEqual(fz[0], 0.0 | nbody_system.acceleration, 3)
self.assertAlmostRelativeEqual(fx[1], 0.0 | nbody_system.acceleration, 3)
self.assertAlmostRelativeEqual(fy[1], 0.0 | nbody_system.acceleration, 3)
self.assertAlmostRelativeEqual(fz[1], 0.0 | nbody_system.acceleration, 3)
self.assertAlmostRelativeEqual(fx[2], 3.55555555556 | nbody_system.acceleration, 5)
self.assertAlmostRelativeEqual(fy[2], 0.0 | nbody_system.acceleration, 3)
self.assertAlmostRelativeEqual(fz[2], 0.0 | nbody_system.acceleration, 3)
n = 512
x = nbody_system.length.new_quantity(numpy.linspace(0.1, 1.9, n))
zero = nbody_system.length.new_quantity(numpy.zeros(n))
fx, fy, fz = instance.get_gravity_at_point(zero, x, zero, zero)
for i in range(n//2):
self.assertAlmostRelativeEqual(fx[i], - fx[n - 1 - i], 5)
instance.stop()
def test5(self):
instance = PhiGRAPE(**default_test_options)
instance.initialize_code()
instance.parameters.set_defaults()
particles = datamodel.Particles(2)
particles.mass = [1.0, 1.0] | nbody_system.mass
particles.radius = [0.0001, 0.0001] | nbody_system.length
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]
] | nbody_system.length
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | nbody_system.speed
instance.particles.add_particles(particles)
instance.commit_particles()
zero = 0.0 | nbody_system.length
fx, fy, fz = instance.get_gravity_at_point(zero,
1.0 | nbody_system.length,
zero, zero)
self.assertAlmostEqual(fx, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fy, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fz, 0.0 | nbody_system.acceleration, 3)
for x in (0.25, 0.5, 0.75):
x0 = x | nbody_system.length
x1 = (2.0 - x) | nbody_system.length
potential0 = instance.get_potential_at_point(zero, x0, zero, zero)
potential1 = instance.get_potential_at_point(zero, x1, zero, zero)
fx0, fy0, fz0 = instance.get_gravity_at_point(zero, x0, zero, zero)
fx1, fy1, fz1 = instance.get_gravity_at_point(zero, x1, zero, zero)
self.assertAlmostEqual(fy0, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fz0, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fy1, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fz1, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fx0, -1.0 * fx1, 5)
fx = (-1.0 / (x0**2) + 1.0 /
(x1**2)) * (1.0
| nbody_system.length**3 / nbody_system.time**2)
self.assertAlmostEqual(fx, fx0, 2)
self.assertAlmostEqual(potential0, potential1, 5)
instance.stop()
