def test11(self):
instance = interface.TwoBody()
p = datamodel.Particles(2)
p.mass = [1, 0.0] | nbody_system.mass
p.radius = 0.001 | nbody_system.length
p.x = [1.0, 0.0] | nbody_system.length
p.y = [0.1, 0.0] | nbody_system.length
p.z = [-0.1, 0.0] | nbody_system.length
p.vx = [-0.1, 0.0] | nbody_system.speed
p.vy = [2.0, 0.0] | nbody_system.speed
p.vz = [-0.2, 0.0] | nbody_system.speed
instance.particles.add_particles(p)
instance.evolve_model(0.5 | nbody_system.time)
particles1 = instance.particles.copy()
instance.stop()
instance = interface.TwoBody()
instance.parameters.begin_time = 0.5 | nbody_system.time
instance.particles.add_particles(particles1)
instance.evolve_model(1.0 | nbody_system.time)
self.assertAlmostEqual(
instance.particles.x[0] - instance.particles.x[1],
0.611238439231 | nbody_system.length, 7)
self.assertAlmostEqual(
instance.particles.y[0] - instance.particles.y[1],
1.92873971354574 | nbody_system.length, 7)
self.assertAlmostEqual(
instance.particles.z[0] - instance.particles.z[1],
-0.2562478900031234 | nbody_system.length, 7)
instance.stop()
def test2(self):
convert_nbody = nbody_system.nbody_to_si(5.9742e24 | units.kg,
1e6 | units.m)
instance = interface.TwoBody(convert_nbody)
p = datamodel.Particle()
p.mass = 5.9742e24 | units.kg
p.radius = 6.371e6 | units.m
p.position = [0., 7.e6, -1.2124e7] | units.m
p.velocity = [0., 2.6679e3, 4.6210e3] | units.m / units.s
instance.particles.add_particle(p)
instance.evolve_model(3600.0 | units.s)
position = instance.particles[0].position
velocity = instance.particles[0].velocity
self.assertAlmostEqual(position.x.value_in(units.m), 0., 7)
self.assertAlmostEqual(
position.y.value_in(units.m) / (-3.30647600568e6), 1., 7)
self.assertAlmostEqual(
position.z.value_in(units.m) / 7.40831575351e6, 1., 7)
self.assertAlmostEqual(velocity.x.value_in(units.m / units.s), 0., 7)
self.assertAlmostEqual(
velocity.y.value_in(units.m / units.s) / (-8.29821376206e3), 1., 7)
self.assertAlmostEqual(
velocity.z.value_in(units.m / units.s) / (-0.972888312209e3), 1.,
7)
instance.stop()
def test8(self):
print("Test 8: get_potential_at_point")
instance = interface.TwoBody()
p = datamodel.Particles(2)
p.mass = 0.5 | nbody_system.mass
p.radius = 0 | nbody_system.length
p.position = [[1.0, 0, 0], [-1.0, 0, 0]] | nbody_system.length
p.velocity = [[0] * 3] * 2 | nbody_system.speed
instance.particles.add_particles(p)
zero = [0.0] | nbody_system.length
phi = instance.get_potential_at_point(zero, 0.5 | nbody_system.length,
zero, zero)
self.assertAlmostEqual(phi, -4 / 3.0 | nbody_system.potential)
zero = [0.0] * 4 | nbody_system.length
phi = instance.get_potential_at_point(
zero, [0, 0.5, 1.5, 2.5] | nbody_system.length, zero, zero)
self.assertAlmostEqual(phi, [-1, -4 / 3.0, -1.2, -0.47619047]
| nbody_system.potential)
zero = [0.0] | nbody_system.length
phi = instance.get_potential_at_point(zero, 1.0 | nbody_system.length,
zero, zero)
self.assertTrue(numpy.isinf(phi[0].value_in(nbody_system.potential)))
instance.stop()
def test6(self):
#from: Fundamentals of Celestial Mechanics, J.M.A. Danby 2nd edition
instance = interface.TwoBody()
p = datamodel.Particles(2)
p.mass = [1, 0.0] | nbody_system.mass
p.radius = 0.001 | nbody_system.length
p.x = [1.0, 0.0] | nbody_system.length
p.y = [0.1, 0.0] | nbody_system.length
p.z = [-0.1, 0.0] | nbody_system.length
p.vx = [-0.1, 0.0] | nbody_system.speed
p.vy = [2.0, 0.0] | nbody_system.speed
p.vz = [-0.2, 0.0] | nbody_system.speed
instance.particles.add_particles(p)
instance.evolve_model(1.0 | nbody_system.time)
self.assertAlmostEqual(
instance.particles.x[0] - instance.particles.x[1],
0.611238439231 | nbody_system.length, 7)
self.assertAlmostEqual(
instance.particles.y[0] - instance.particles.y[1],
1.92873971354574 | nbody_system.length, 7)
self.assertAlmostEqual(
instance.particles.z[0] - instance.particles.z[1],
-0.2562478900031234 | nbody_system.length, 7)
instance.stop()
def test10(self):
convert_nbody = nbody_system.nbody_to_si(1.0 | units.yr, 1.0 | units.AU)
instance = interface.TwoBody(convert_nbody)
value = instance.get_begin_time()
self.assertEquals(0.0| units.yr, value)
self.assertAlmostEquals(0.0 | units.yr, instance.parameters.begin_time, in_units=units.yr)
for x in [1.0, 10.0, 100.0]:
instance.parameters.begin_time = x | units.yr
self.assertAlmostEquals(x | units.yr, instance.parameters.begin_time, in_units=units.yr)
instance.stop()
def test9(self):
print "Test 9: TwoBody parameters"
instance = interface.TwoBody()
self.assertEqual(instance.parameters.epsilon_squared, zero)
self.assertRaises(AmuseException, setattr, instance.parameters, "epsilon_squared", zero,
expected_message = "Could not set value for parameter 'epsilon_squared' of a 'TwoBody' object, "
"parameter is read-only")
instance.stop()
def test5(self):
#from: Fundamentals of Celestial Mechanics, J.M.A. Danby 2nd edition
instance = interface.TwoBody()
p = datamodel.Particle()
p.mass = 1.0 | nbody_system.mass
p.radius = 0.001 | nbody_system.length
p.position = [1.0, 0.1, -0.1] | nbody_system.length
p.velocity = [-0.1, 2.0, -0.2] | nbody_system.speed
instance.particles.add_particle(p)
instance.evolve_model(1.0|nbody_system.time)
self.assertAlmostEqual(instance.particles.x, 0.611238439231|nbody_system.length, 7)
self.assertAlmostEqual(instance.particles.y, 1.92873971354574|nbody_system.length, 7)
self.assertAlmostEqual(instance.particles.z, -0.2562478900031234|nbody_system.length, 7)
instance.stop()
def test7(self):
print("Test 7: get_gravity_at_point")
instance = interface.TwoBody()
p = datamodel.Particles(2)
p.mass = 0.5 | nbody_system.mass
p.radius = 0 | nbody_system.length
p.position = [[1.0, 0, 0], [-1.0, 0, 0]] | nbody_system.length
p.velocity = [[0] * 3] * 2 | nbody_system.speed
instance.particles.add_particles(p)
zero = [0.0] | nbody_system.length
ax, ay, az = instance.get_gravity_at_point(zero,
0.5 | nbody_system.length,
zero, zero)
self.assertAlmostEqual(ax, 16 / 9.0 | nbody_system.acceleration)
self.assertAlmostEqual(ay, 0 | nbody_system.acceleration)
self.assertAlmostEqual(az, 0 | nbody_system.acceleration)
zero = [0.0] * 4 | nbody_system.length
ax, ay, az = instance.get_gravity_at_point(
zero, [0, 0.5, 1.5, 2.5] | nbody_system.length, zero, zero)
self.assertAlmostEqual(ax, [0, 16 / 9.0, -2.08, -0.26303854]
| nbody_system.acceleration)
self.assertAlmostEqual(ay, 0 | nbody_system.acceleration)
self.assertAlmostEqual(az, 0 | nbody_system.acceleration)
zero = [0.0] | nbody_system.length
ax, ay, az = instance.get_gravity_at_point(zero,
1.0 | nbody_system.length,
zero, zero)
self.assertTrue(numpy.isnan(ax[0].value_in(nbody_system.acceleration)))
self.assertTrue(numpy.isnan(ay[0].value_in(nbody_system.acceleration)))
self.assertTrue(numpy.isnan(az[0].value_in(nbody_system.acceleration)))
zero = [0.0] | nbody_system.length
eps = [0.1] | nbody_system.length
ax, ay, az = instance.get_gravity_at_point(eps,
1.0 | nbody_system.length,
zero, zero)
self.assertAlmostEqual(ax, -0.12453271 | nbody_system.acceleration)
self.assertAlmostEqual(ay, 0 | nbody_system.acceleration)
self.assertAlmostEqual(az, 0 | nbody_system.acceleration)
instance.stop()
def test3(self):
convert_nbody = nbody_system.nbody_to_si(5.9742e24 | units.kg, 1e6| units.m)
instance = interface.TwoBody(convert_nbody)
p = datamodel.Particle()
p.mass = 5.9742e24 | units.kg
p.radius = 7.1e6 | units.m
p.position = [0.,7.e6,-1.2124e7] | units.m
p.velocity = [0.,2.6679e3,4.6210e3] | units.m/units.s
instance.particles.add_particle(p)
instance.evolve_model(3600.0 | units.s)
dt = convert_nbody.to_si(instance.model_time)
self.assertAlmostEqual(dt.value_in(units.s)/2583.44780926,1.,7)
position = instance.particles[0].position
self.assertAlmostEqual(((position.x**2+position.y**2+position.z**2)/(7.1e6)**2).value_in(units.m**2),1.,7)
instance.stop()
def test4(self):
convert_nbody = nbody_system.nbody_to_si(5.9742e24 | units.kg, 1e6| units.m)
instance = interface.TwoBody(convert_nbody)
p = datamodel.Particle()
p.mass = 5.9742e24 | units.kg
p.radius = 7.1e6 | units.m
p.position = [0.,7.e6,-1.2124e7] | units.m
p.velocity = [0.,2.6679e3,4.6210e3] | units.m/units.s
instance.particles.add_particle(p)
instance.evolve_model(3600.0 | units.s)
dt = convert_nbody.to_si(instance.model_time)
self.assertEqual(instance.particles[0].mass,5.9742e24 | units.kg)
instance.particles[0].mass=0.8*5.9742e24 | units.kg
instance.evolve_model(4000.0 | units.s)
self.assertEqual(instance.particles.mass[0],0.8*5.9742e24 | units.kg)
instance.stop()
def test1(self):
convert_nbody = nbody_system.nbody_to_si(5.9742e24 | units.kg,
1e6 | units.m)
instance = interface.TwoBody(convert_nbody)
instance.stop()