def create_binary(stars, binaries, primary_mass, mass_ratio, separation,
eccentricity):
"""
creates a single binary, the constituent stars will be accumulated
in the stars partice set, the binary will be added to the binaries
particle set.
"""
primary_star = datamodel.Particle()
primary_star.mass = primary_mass
# we add the particle to the stars set
# and we get a reference to the particle in the stars set
# back
# we want to use that star in constructing the
# binary, so that the binaries all refer to
# the stars in the "stars set"
primary_star = stars.add_particle(primary_star)
secondary_star = datamodel.Particle()
secondary_star.mass = primary_mass * mass_ratio
secondary_star = stars.add_particle(secondary_star)
binary = datamodel.Particle()
binary.eccentricity = eccentricity
binary.semi_major_axis = separation
binary.child1 = primary_star
binary.child2 = secondary_star
binaries.add_particle(binary)
def test5(self):
instance = self.code_factory()()
p1 = datamodel.Particle(mass=1. | units.MSun)
p2 = datamodel.Particle(mass=1. | units.MSun)
p1 = instance.particles.add_particle(p1)
instance.evolve_model(1. | units.Gyr)
p2 = instance.particles.add_particle(p2)
instance.evolve_model(2. | units.Gyr)
self.assertGreaterEqual(p1.age, (1. | units.Gyr))
self.assertGreaterEqual(p2.age, (1. | units.Gyr))
self.assertLess(p2.age, (2. | units.Gyr))
def test8(self):
instance1 = self.code_factory()()
instance2 = self.code_factory()()
p1 = datamodel.Particle(mass=1. | units.MSun)
p1 = instance1.particles.add_particle(p1)
p1.evolve_for(10. | units.Myr)
p2 = datamodel.Particle(mass=1. | units.MSun)
p2 = instance2.particles.add_particle(p2)
instance2.evolve_model(10. | units.Myr)
self.assertAlmostEqual(p1.mass, p2.mass)
self.assertAlmostEqual(p1.radius, p2.radius)
self.assertAlmostEqual(p1.luminosity, p2.luminosity)
def planet(ID, host_star, planet_mass, init_a, init_e, random_orientation=False):
''' Creates a planet as an AMUSE Particle with provided characteristics.
ID: Identifying number unique to this planet.
host_star: The AMUSE Particle that is the host star for the planet.
planet_mass: The mass of the planet (in the nbody units).
init_a: Initial semi-major axis (in nbody units).
init_e: Initial eccentricity (in nbody units).
random_orientation: Boolean to incline the planet in a random fashion.
'''
# Sets Planet Values to Provided Conditions
p = datamodel.Particle()
p.id = ID
p.type = "planet"
p.host_star = host_star.id
p.mass = planet_mass
# Calculates a Random Position in the Orbit & Gets the Orbital Speed
cosTheta = math.cos(np.random.random()*math.pi*2)
init_x = init_a*(1-init_e**2)/(1+init_e*cosTheta) # Need to Double Check ... Thornton 302
init_vy = np.sqrt(units.constants.G*host_star.mass*(2/init_x-1/init_a))
# Sets the Dynamical Radius to the Hill Sphere Approx.
p.radius = util.calc_HillRadius(init_a, init_e, p.mass, host_star.mass)
# Sets the Particle in "Orbit" Around the Origin
# May Need to Correct This Later to Accurately Depict Position in Orbit
p.position = [init_x.number, 0.0 , 0.0] | init_x.unit
p.velocity = [0.0 , init_vy.number, 0.0] | init_vy.unit
# Preforms a Euler Rotation on the Planet if Requested
# Not Working Properly due to Data Structure, Need to Fix
if random_orientation:
util.preform_EulerRotation(p)
# Moves the Planet to Orbit the Host Star
p.position = p.position + host_star.position
p.velocity = p.velocity + host_star.velocity
# Returns the Created AMUSE Particle
return p
def __init__(self):
self.load_integrator_and_units()
self.planets = []
self.planets_data = Horizons()
#Notable events
self.start_date = date(1971, 10, 26)
self.voyagerI_launch_date = date(1977, 9, 7)
self.stop_date = date(1989, 10, 26)
self.model_t0 = self.start_date
self.planets = datamodel.Stars(10)
self.voyagerI = datamodel.Particle()
#set I.C. using Horizons database
self.set_IC_at_date([self.planets_data.Sun, self.planets_data.Mercury, self.planets_data.Venus,
self.planets_data.Earth, self.planets_data.Moon, self.planets_data.Mars,
self.planets_data.Jupiter, self.planets_data.Saturn, self.planets_data.Uranus,
self.planets_data.Neptune],
self.planets,
self.start_date)
self.set_IC_at_date([self.planets_data.VoyagerI],self.voyagerI.as_set(), self.voyagerI_launch_date)
self.planets.synchronize_to(self.code.particles)
self.planets_from_code_to_model = self.code.particles.new_channel_to(self.planets)
#later we will add particles
self.all_particles = self.planets.copy()
self.P = planetarium.SolarSystemView((1600,1000))
def test3(self):
code = Hermite()
particles_in_binary = self.new_binary(0.1 | nbody_system.mass,
0.1 | nbody_system.mass,
0.01 | nbody_system.length,
keyoffset=1)
particles_in_binary.radius = 0.001 | nbody_system.length
binary = datamodel.Particle(key=3)
binary.child1 = particles_in_binary[0]
binary.child2 = particles_in_binary[1]
binary.radius = 0.5 | nbody_system.length
binary.mass = 0.2 | nbody_system.mass
encounter_code = encounters.HandleEncounter(
kepler_code=self.new_kepler(),
resolve_collision_code=self.new_smalln(),
interaction_over_code=None)
multiples_code = encounters.Multiples(
gravity_code=code, handle_encounter_code=encounter_code)
multiples_code.singles_in_binaries.add_particles(particles_in_binary)
multiples_code.binaries.add_particle(binary)
self.assertEquals(len(multiples_code.singles_in_binaries), 2)
self.assertEquals(id(multiples_code.binaries[0].child1.particles_set),
id(multiples_code.singles_in_binaries))
multiples_code.commit_particles()
self.assertEquals(len(multiples_code.multiples), 1)
self.assertEquals(len(multiples_code.components_of_multiples), 2)
def plottillagb():
sun = datamodel.Particle(
mass = 1 | units.MSun,
radius = 1 | units.RSun
)
sse = SSE()
sse.particles.add_particle(sun)
channel_from_se_to_memory = sse.particles.new_channel_to(sun.as_set())
channel_from_se_to_memory.copy()
masses = []|units.MSun
timerange = numpy.arange(11500, 13500,10) | units.Myr
for time in timerange:
sse.evolve_model(time)
channel_from_se_to_memory.copy()
masses.append(sun.mass)
print(time.as_quantity_in(units.Myr), sun.mass.as_quantity_in(units.MSun))
sse.stop()
figure = pyplot.figure(figsize= (6,6))
subplot = figure.add_subplot(1, 1, 1)
subplot.plot(timerange.value_in(units.Gyr), masses.value_in(units.MSun),'.')
subplot.set_xlabel('t (Gyr)')
subplot.set_ylabel('mass (MSun)')
pyplot.show()
def test22(self):
particles = datamodel.Particles(2)
particles.x = [0.0, 10.0] | nbody_system.length
particles.y = 0.0 | nbody_system.length
particles.z = 0.0 | nbody_system.length
particles.vx = 0.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 1.0 | nbody_system.mass
instance = BHTree()
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertEquals(instance.particles[0].radius,
0.0 | nbody_system.length)
p = datamodel.Particle(
x=1.0 | nbody_system.length,
y=2.0 | nbody_system.length,
z=3.0 | nbody_system.length,
vx=1.0 | nbody_system.speed,
vy=2.0 | nbody_system.speed,
vz=3.0 | nbody_system.speed,
mass=1.0 | nbody_system.mass,
radius=4.0 | nbody_system.length,
)
instance.particles.add_particle(p)
self.assertEquals(instance.particles[0].radius,
0.0 | nbody_system.length)
self.assertEquals(instance.particles[1].radius,
0.0 | nbody_system.length)
self.assertEquals(instance.particles[2].radius,
4.0 | nbody_system.length)
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 test3(self):
instance = self.new_instance_of_an_optional_code(
Mocassin) #, debugger = "xterm")
instance.initialize_code()
instance.set_random_seed(1)
instance.set_input_directory(instance.get_default_input_directory())
instance.set_mocassin_output_directory(instance.output_directory +
os.sep)
instance.set_initial_nebular_temperature(200.0 | units.K)
instance.parameters.nx = 7
instance.parameters.ny = 7
instance.parameters.nz = 7
print((0.95E+19 | units.cm).value_in(units.parsec))
instance.parameters.length_x = 0.95E+19 | units.cm
instance.parameters.length_y = 0.95E+19 | units.cm
instance.parameters.length_z = 0.95E+19 | units.cm
instance.set_high_limit_of_the_frequency_mesh(15
| mocassin_rydberg_unit)
instance.set_low_limit_of_the_frequency_mesh(1.001e-5
| mocassin_rydberg_unit)
instance.set_maximum_number_of_monte_carlo_iterations(1)
instance.set_total_number_of_photons(100)
#~ instance.set_constant_hydrogen_density(100 | units.cm**-3)
instance.commit_parameters()
instance.grid.hydrogen_density = 100 | units.cm**-3
instance.commit_grid()
p = datamodel.Particle()
p.x = 0 | units.cm
p.y = 0 | units.cm
p.z = 0 | units.cm
p.temperature = 20000 | units.K
p.luminosity = 1. | units.LSun
instance.particles.add_particle(p)
instance.commit_particles()
self.assertAlmostRelativeEquals(
1e-5, instance.ion_density_grid.density[3][1][2][0][0], 7)
self.assertAlmostRelativeEquals(
1e-5, instance.ion_density_grid.density[3][1][3][0][0], 7)
instance.step()
print(instance.grid.electron_density.mean())
self.assertAlmostRelativeEquals(0.0,
instance.get_percentage_converged())
self.assertGreater(instance.grid.electron_density.mean(),
65. | units.cm**-3)
self.assertLess(instance.grid.electron_density.mean(),
95. | units.cm**-3)
instance.stop()
def test22(self):
print(
"Testing zero-mass test particles in Huayno, can be used for removing particles when inside recursive evolve loop"
)
sun_and_earth = self.new_system_of_sun_and_earth()
period = (4.0 * math.pi**2 * (1.0 | units.AU)**3 /
(constants.G * sun_and_earth.total_mass())).sqrt()
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun,
1.0 | units.AU)
huayno = Huayno(convert_nbody)
huayno.parameters.epsilon_squared = 0.0 | units.AU**2
huayno.parameters.inttype_parameter = huayno.inttypes.SHARED8
test_particle = datamodel.Particle(mass=0 | units.MSun,
position=[4, 0, 0] | units.AU,
velocity=[0, 0, 0] | units.kms)
test_particle.vy = (constants.G * sun_and_earth.total_mass() /
(4.0 | units.AU)).sqrt()
sun_and_earth.add_particle(test_particle)
huayno.particles.add_particles(sun_and_earth)
huayno.evolve_model(period)
self.assertAlmostRelativeEqual(huayno.particles[:2].x,
sun_and_earth[:2].x, 13)
huayno.evolve_model(1.25 * period)
self.assertAlmostRelativeEqual(huayno.particles[1].y,
sun_and_earth[1].x, 13)
huayno.evolve_model(8.0 * period)
self.assertAlmostRelativeEqual(huayno.particles.x, sun_and_earth.x, 8)
huayno.stop()
def simulate_evolution_tracks():
stellar_evolution = SSE()
star = datamodel.Particle()
star.mass = stellar_mass
star = stellar_evolution.particles.add_particle(star)
luminosity_at_time = [] | units.LSun
temperature_at_time = [] | units.K
print("Evolving a star with mass:", stellar_mass)
is_evolving = True
while is_evolving and star.age < end_time:
luminosity_at_time.append(star.luminosity)
temperature_at_time.append(star.temperature)
previous_age = star.age
# if we do not specify an end_time in the evolve_model function
# a stellar evolution code will evolve to the next
# 'natural' timestep, this will ensure all interesting physics
# is seen in the hr diagram
stellar_evolution.evolve_model()
is_evolving = (star.age != previous_age)
stellar_evolution.stop()
return temperature_at_time, luminosity_at_time
def test20(self):
particles = datamodel.Particles(2)
particles.x = [0.0, 10.0] | nbody_system.length
particles.y = 0.0 | nbody_system.length
particles.z = 0.0 | nbody_system.length
particles.radius = 0.005 | nbody_system.length
particles.vx = 0.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 1.0 | nbody_system.mass
very_short_time_to_evolve = 1 | units.s
very_long_time_to_evolve = 1e9 | nbody_system.time
instance = BHTree()
instance.initialize_code()
instance.parameters.stopping_conditions_timeout = very_short_time_to_evolve
self.assertEquals(instance.parameters.stopping_conditions_timeout,
very_short_time_to_evolve)
instance.parameters.epsilon_squared = (0.01 | nbody_system.length)**2
instance.particles.add_particles(particles)
codeparticles1 = instance.particles
instance.particles.add_particle(
datamodel.Particle(position=[0, 1, 2] | nbody_system.length,
velocity=[0, 0, 0] | nbody_system.speed,
radius=0.005 | nbody_system.length,
mass=1 | nbody_system.mass))
codeparticles2 = instance.particles
self.assertTrue(codeparticles1 is codeparticles2)
instance.cleanup_code()
codeparticles3 = instance.particles
self.assertFalse(codeparticles1 is codeparticles3)
instance.stop()
def test4(self):
for m in ([0.2, 1., 5.] | units.MSun):
instance = self.code_factory()()
p = datamodel.Particle(mass=m)
p2 = instance.particles.add_particle(p)
self.assertAlmostEqual(p2.age, 0. | units.Myr)
instance.evolve_model(1. | units.Myr)
self.assertGreaterEqual(p2.age, (1. | units.Myr))
self.assertGreaterEqual(instance.model_time, (1. | units.Myr))
def test16(self):
print("Testing ph4 states")
stars = new_plummer_model(100)
black_hole = datamodel.Particle()
black_hole.mass = 1.0 | nbody_system.mass
black_hole.radius = 0.0 | nbody_system.length
black_hole.position = [0.0, 0.0, 0.0] | nbody_system.length
black_hole.velocity = [0.0, 0.0, 0.0] | nbody_system.speed
print("First do everything manually:")
instance = ph4()
self.assertEqual(instance.get_name_of_current_state(), 'UNINITIALIZED')
instance.initialize_code()
self.assertEqual(instance.get_name_of_current_state(), 'INITIALIZED')
instance.parameters.epsilon_squared = 0.0 | nbody_system.length**2
instance.parameters.timestep_parameter = 0.01
instance.commit_parameters()
self.assertEqual(instance.get_name_of_current_state(), 'EDIT')
instance.particles.add_particles(stars)
instance.commit_particles()
self.assertEqual(instance.get_name_of_current_state(), 'RUN')
instance.particles.remove_particle(stars[0])
instance.particles.add_particle(black_hole)
self.assertEqual(instance.get_name_of_current_state(), 'UPDATE')
instance.recommit_particles()
self.assertEqual(instance.get_name_of_current_state(), 'RUN')
instance.evolve_model(0.001 | nbody_system.time)
self.assertEqual(instance.get_name_of_current_state(), 'EVOLVED')
instance.synchronize_model()
self.assertEqual(instance.get_name_of_current_state(), 'RUN')
instance.cleanup_code()
self.assertEqual(instance.get_name_of_current_state(), 'END')
instance.stop()
print("initialize_code(), commit_parameters(), (re)commit_particles(), " \
"synchronize_model(), and cleanup_code() should be called " \
"automatically before editing parameters, new_particle(), get_xx(), and stop():")
instance = ph4()
self.assertEqual(instance.get_name_of_current_state(), 'UNINITIALIZED')
instance.parameters.epsilon_squared = 0.0 | nbody_system.length**2
instance.parameters.timestep_parameter = 0.01
self.assertEqual(instance.get_name_of_current_state(), 'INITIALIZED')
instance.particles.add_particles(stars)
self.assertEqual(instance.get_name_of_current_state(), 'EDIT')
mass = instance.particles[0].mass
self.assertEqual(instance.get_name_of_current_state(), 'RUN')
instance.particles.remove_particle(stars[0])
instance.particles.add_particle(black_hole)
self.assertEqual(instance.get_name_of_current_state(), 'UPDATE')
mass = instance.particles[0].mass
self.assertEqual(instance.get_name_of_current_state(), 'RUN')
instance.evolve_model(0.001 | nbody_system.time)
self.assertEqual(instance.get_name_of_current_state(), 'EVOLVED')
mass = instance.particles[0].mass
self.assertEqual(instance.get_name_of_current_state(), 'RUN')
instance.stop()
self.assertEqual(instance.get_name_of_current_state(), 'STOPPED')
def add_particle_with_parameters(self, subnode, parent):
added_particle = self.system.add_particle(datamodel.Particle())
self._recursive_parse_node_into_particles(subnode,
added_particle,
parent=added_particle)
if not parent is None:
parent.add_child(added_particle)
def test3(self):
instance = self.code_factory()()
p = datamodel.Particle(mass=1. | units.MSun)
p2 = instance.particles.add_particle(p)
self.assertAlmostEqual(p2.mass, p.mass)
self.assertTrue(hasattr(p2, "radius"))
self.assertTrue(hasattr(p2, "luminosity"))
self.assertTrue(hasattr(p2, "age"))
self.assertTrue(hasattr(p2, "stellar_type"))
self.assertEqual(str(p2.stellar_type), "Main Sequence star")
def test2(self):
for m in ([0.2, 1., 5., 25.] | units.MSun):
instance = self.code_factory()()
p = datamodel.Particle(mass=m)
p2 = instance.particles.add_particle(p)
self.assertAlmostEqual(p2.mass, p.mass)
self.assertTrue(hasattr(p2, "radius"))
self.assertTrue(hasattr(p2, "luminosity"))
self.assertTrue(hasattr(p2, "age"))
self.assertTrue(hasattr(p2, "stellar_type"))
def test24(self):
particle = datamodel.Particle()
particle.mass = 10 | units.kg
grid = datamodel.Grid(5, 4, 3)
grid.mass = 2.0 | units.kg
grid.nounit = 10
self.assertEquals(grid.nounit[0][1][2], 10)
self.assertEquals(grid[0][1][2].nounit, 10)
self.assertEquals(len(grid.nounit), 5)
def restore_pair(self, state, a_planet):
self.voyagerI = datamodel.Particle()
voyagerI_attrib = self.voyagerI.as_set()
rel_vr = ([state['vx'],state['vy'],state['vz']]|units.m/units.s).as_quantity_in(units.AUd)
rel_r = ([state['x'],state['y'],state['z']]|units.m).as_quantity_in(units.AU)
voyagerI_attrib[0].velocity = a_planet.velocity + rel_vr
voyagerI_attrib[0].position = a_planet.position + rel_r
self.all_particles.add_particle(self.voyagerI)
self.all_particles.synchronize_to(self.code.particles)
self.voyagerI_from_code_to_model = self.code.particles.new_channel_to(self.voyagerI.as_set())
def test3(self):
"""
In this test we will get a list from a particle
"""
instance = ExampleParticlesInterface()
self.assertEquals(len(instance.particles), 0)
theParticle = datamodel.Particle()
theParticle.mass = 10 | units.kg
theParticle.x = 0.1 | units.m
theParticle.y = 0.2 | units.m
theParticle.z = 0.5 | units.m
instance.particles.add_particle(theParticle)
theParticle = datamodel.Particle()
theParticle.mass = 11 | units.kg
theParticle.x = 0.1 | units.m
theParticle.y = 0.2 | units.m
theParticle.z = 0.5 | units.m
instance.particles.add_particle(theParticle)
self.assertEquals(len(instance.particles[0].element_list()), 10)
list = instance.particles[0].element_list()
self.assertEquals(list[0].value1, 0 | units.none)
self.assertEquals(list[0].value2, 0 | units.none)
self.assertEquals(list[1].value1, 0 | units.none)
self.assertEquals(list[1].value2, 1 | units.none)
for x in range(len(list)):
self.assertEquals(list[x].value1, 0 | units.none)
self.assertEquals(list[x].value2, x | units.none)
list = instance.particles[1].element_list()
for x in range(len(list)):
self.assertEquals(list[x].value1, 1 | units.none)
self.assertEquals(list[x].value2, x | units.none)
def test4(self):
"""
In this test we will get a list from a particle
"""
instance = ExampleParticlesInterface()
self.assertEqual(len(instance.particles), 0)
theParticle = datamodel.Particle()
theParticle.x = 0.1 | units.m
theParticle.y = 0.2 | units.m
theParticle.z = 0.5 | units.m
self.assertRaises(exceptions.AmuseException, instance.particles.add_particle, theParticle)
def test2(self):
"""
In this test we will set and get different properties
of the particle.
To limit overhead, the system will use the set_* or get_* calls
that are the closests match to the attributes queries.
"""
self.log("accessing attributes of a particle")
instance = ExampleParticlesInterface()
self.assertEquals(len(instance.particles), 0)
theParticle = datamodel.Particle()
theParticle.mass = 10 | units.kg
theParticle.x = 0.1 | units.m
theParticle.y = 0.2 | units.m
theParticle.z = 0.5 | units.m
instance.particles.add_particle(theParticle)
self.log(
"Getting the mass of particle with key {0}, get_mass should be called",
theParticle.key)
self.assertEquals(instance.particles[0].mass, 10 | units.kg)
self.log(
"Getting the position of particle with key {0}, get_position should be called",
theParticle.key)
self.assertEquals(instance.particles[0].position,
[0.1, 0.2, 0.5] | units.m)
self.log(
"Getting the only the x attribute of particle with key {0}, get_position should be called (y and z are discarded)",
theParticle.key)
self.assertEquals(instance.particles[0].x, 0.1 | units.m)
self.log(
"Setting the position of particle with key {0}, set_position should be called",
theParticle.key)
instance.particles[0].position = [0.2, 0.3, 0.6] | units.m
self.log(
"Setting the x of particle with key {0}, should fail as no function can set x and no others",
theParticle.key)
def block():
instance.particles[0].x = 0.1 | units.m
self.assertRaises(Exception, block)
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 test10(self):
factory = self.gravity_code_factory()
instance = self.new_instance_of_an_optional_code(factory)
particle = datamodel.Particle()
particle.position = [0, 0, 0] | self.length_unit
particle.velocity = [1, -2, 3.0] | self.speed_unit
particle.mass = 1 | self.mass_unit
particle.radius = 0.0 | self.length_unit
instance.particles.add_particle(particle)
instance.evolve_model(1 | self.time_unit)
self.assertAlmostEqual(instance.model_time, 1 | self.time_unit)
self.assertAlmostEqual(instance.kinetic_energy, 7.0 | self.mass_unit * self.speed_unit**2)
self.assertAlmostEqual(instance.potential_energy, 0.0 | self.mass_unit * self.speed_unit**2)
self.assertAlmostEqual(instance.particles[0].position, [1.0, -2.0, 3.0] | self.length_unit)
instance.stop()
def test24(self):
print("test massless particles/ kepler integrator")
N = 20
tend = 2. | units.yr
numpy.random.seed(12345)
conv = nbody_system.nbody_to_si(4. | units.MSun, 5. | units.AU)
orbiters = plummer.new_plummer_model(N, conv)
sun = datamodel.Particle(mass=1. | units.MSun)
sun.position = [12.3, 1., -.2] | units.AU
sun.velocity = [10, 50., -20.] | units.kms
orbiters.mass *= 0.
a0, eps0 = elements(sun.mass, orbiters.x, orbiters.y, orbiters.z,
orbiters.vx, orbiters.vy, orbiters.vz)
orbiters.position += sun.position
orbiters.velocity += sun.velocity
pos = dict()
for inttype in [20, 14]:
code = Huayno(conv)
code.parameters.inttype_parameter = inttype
code.parameters.timestep_parameter = 0.1
code.particles.add_particle(sun)
orbiters2 = code.particles.add_particles(orbiters).copy()
orbiters2.position -= sun.position
orbiters2.velocity -= sun.velocity
code.evolve_model(tend)
a, eps = elements(sun.mass, orbiters2.x, orbiters2.y, orbiters2.z,
orbiters2.vx, orbiters2.vy, orbiters2.vz)
da = abs((a - a0) / a0)
deps = abs(eps - eps0) / eps0
dev = numpy.where(da > 1.e-12)[0]
self.assertEqual(len(dev), 0)
dev = numpy.where(deps > 1.e-12)[0]
self.assertEqual(len(dev), 0)
pos[inttype] = [
orbiters2.x.value_in(units.AU),
orbiters2.y.value_in(units.AU),
orbiters2.z.value_in(units.AU)
]
self.assertAlmostEqual(pos[20][0], pos[14][0], 12)
self.assertAlmostEqual(pos[20][1], pos[14][1], 12)
self.assertAlmostEqual(pos[20][2], pos[14][2], 12)
def planet_v2(ID,
host_star,
planet_mass,
init_a,
init_e,
random_orientation=False):
''' Creates a planet as an AMUSE Particle with provided characteristics.
ID: Identifying number unique to this planet.
host_star: The AMUSE Particle that is the host star for the planet.
planet_mass: The mass of the planet (in the nbody units).
init_a: Initial semi-major axis (in nbody units).
init_e: Initial eccentricity (in nbody units).
random_orientation: Boolean to incline the planet in a random fashion.
'''
# Define the Host Star's Original Location & Position
rCM = host_star.position
vCM = host_star.velocity
# Sets Planet Values to Provided Conditions
p = datamodel.Particle()
p.id = ID
p.type = "planet"
p.host_star = host_star.id
p.mass = planet_mass
# Sets the Dynamical Radius to the Hill Sphere Approx.
p.radius = util.calc_HillRadius(init_a, init_e, p.mass, host_star.mass)
# Generate a Random Position on the Orbit (True Anomaly)
# This ensures that all the planets don't start out along the same joining line.
init_ta = 360 * np.random.random() | units.deg
# Get the Host Star & Planets Positions from Kepler Relative to the Origin
newPSystem = new_binary_from_orbital_elements(host_star.mass,
p.mass,
init_a,
eccentricity=init_e,
true_anomaly=init_ta,
G=constants.G)
# Rotate the Binary System & Move to the CoM's Position
if random_orientation:
util.preform_EulerRotation(newPSystem)
host_star.position = rCM + newPSystem[0].position
host_star.velocity = vCM + newPSystem[0].velocity
p.position = rCM + newPSystem[1].position
p.velocity = vCM + newPSystem[1].velocity
# Returns the Created AMUSE Particle
return p
def test16(self):
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun,
149.5e6 | units.km)
smalln = SmallN(convert_nbody)
smalln.initialize_code()
smalln.dt_dia = 5000
stars = self.new_system_of_sun_and_earth()
moon = datamodel.Particle()
moon.mass = units.kg(7.3477e22)
moon.radius = units.km(1737.10)
moon.position = units.km(numpy.array((149.5e6 + 384.399, 0.0, 0.0)))
moon.velocity = units.ms(numpy.array((0.0, 29800 + 1022, 0.0)))
stars.add_particle(moon)
earth = stars[1]
smalln.particles.add_particles(stars)
smalln.evolve_model(365.0 | units.day)
smalln.update_particle_tree()
smalln.update_particle_set()
self.assertEqual(len(smalln.particles), 5)
self.assertEarthAndMoonWasDetectedAsBinary(smalln.particles, stars)
inmemory = smalln.particles.copy()
self.assertEarthAndMoonWasDetectedAsBinary(inmemory, stars)
test_results_path = self.get_path_to_results()
output_file = os.path.join(test_results_path, "newsmalln-test16.hdf5")
if os.path.exists(output_file):
os.remove(output_file)
io.write_set_to_file(smalln.particles, output_file, "hdf5")
fromfile = io.read_set_from_file(output_file, "hdf5")
self.assertEarthAndMoonWasDetectedAsBinary(fromfile, stars)
smalln.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 test25(self):
print("test massless particles/ kepler integrator, smoothed")
N = 10
tend = 20. | units.yr
numpy.random.seed(12345)
conv = nbody_system.nbody_to_si(4. | units.MSun, 5. | units.AU)
orbiters = plummer.new_plummer_model(N, conv)
sun = datamodel.Particle(mass=1. | units.MSun)
sun.position = [0, 0, 0] | units.AU
sun.velocity = [0, 0, 0] | units.kms
orbiters.mass *= 0.
eps = (5. | units.AU)
e0 = energy(sun.mass, eps, orbiters)
l0 = angular_momentum(orbiters)
pos = dict()
for inttype in [20, 14]:
code = Huayno(conv)
code.parameters.inttype_parameter = inttype
code.parameters.timestep_parameter = 0.1
code.parameters.epsilon_squared = eps**2
code.particles.add_particle(sun)
orbiters2 = code.particles.add_particles(orbiters)
code.evolve_model(tend)
e1 = energy(sun.mass, eps, orbiters2)
l1 = angular_momentum(orbiters2)
de, dl = abs((e1 - e0) / e0).max(), abs((l1 - l0) / l1).max()
self.assertTrue(numpy.all(de < 1.e-8))
self.assertTrue(numpy.all(dl < 1.e-8))
pos[inttype] = [
orbiters2.x.value_in(units.AU),
orbiters2.y.value_in(units.AU),
orbiters2.z.value_in(units.AU)
]
self.assertAlmostRelativeEqual(pos[20][0], pos[14][0],
4) # still not clear why 4
self.assertAlmostRelativeEqual(pos[20][1], pos[14][1], 4)
self.assertAlmostRelativeEqual(pos[20][2], pos[14][2], 4)