def test6(self):
print("Test handle_collision")
position_offset = [100.0, 200.0, 300.0] | units.RSun
velocity_offset = [10000.0, 20000.0, 30000.0] | units.km / units.s
colliders = self.new_colliders()
colliders.position *= 1.5 # Grazing collision
colliders.position += position_offset
colliders.velocity += velocity_offset
class GravityCodeStub(object):
def __init__(self, particles):
self.particles = particles
gravity = GravityCodeStub(colliders)
stellar = EVtwin()
stellar.particles.add_particles(colliders)
collision = StellarEncounterInHydrodynamics(280, # For speed
Gadget2,
relax_sph_models=False, # For speed
verbose=True)
collision.extra_steps_when_encounter_is_over = 0 # For speed, no extra steps...
collision.dynamical_timescales_per_step = 1.3 # ... but then we need to evolve a bit longer in the first step
result = collision.handle_collision(colliders[0], colliders[1], gravity_code=gravity, stellar_evolution_code=stellar)
stellar.stop()
print(result)
self.assertTrue(isinstance(result, Particles))
self.assertEqual(len(result), 2)
self.assertAlmostEqual(result.mass, [5.0, 2.0] | units.MSun, 1)
self.assertAlmostRelativeEqual(result.center_of_mass(), position_offset, 2)
self.assertAlmostRelativeEqual(result.center_of_mass_velocity(), velocity_offset, 2)
def slowtest5(self):
print "Test convert_SPH_to_stellar_model result in EVtwin"
stellar_evolution = EVtwin()
stellar_evolution.parameters.verbosity = True
stellar_evolution.particles.add_particle(
Particle(mass=1.0 | units.MSun)) # reference particle
stellar_evolution.evolve_model(100.0 | units.Myr)
model = convert_SPH_to_stellar_model(
self.new_particles()) # model is from center to surface
stellar_evolution.new_particle_from_model(model, 0.0 | units.Myr)
print stellar_evolution.particles
self.assertAlmostEqual(stellar_evolution.particles.age,
[100.0, 0.0] | units.Myr, 1)
stellar_evolution.evolve_model(200.0 | units.Myr)
print stellar_evolution.particles
self.assertAlmostEqual(stellar_evolution.particles.age,
[200.0, 100.0] | units.Myr, 1)
self.assertAlmostRelativeEqual(
stellar_evolution.particles[0].temperature,
stellar_evolution.particles[1].temperature, 2)
self.assertAlmostRelativeEqual(
stellar_evolution.particles[0].luminosity,
stellar_evolution.particles[1].luminosity, 2)
stellar_evolution.stop()
def slowtest7(self):
print("Test handle_collision")
position_offset = [100.0, 200.0, 300.0] | units.RSun
velocity_offset = [10000.0, 20000.0, 30000.0] | units.km / units.s
colliders = self.new_colliders()
colliders.position += position_offset
colliders.velocity += velocity_offset
class GravityCodeStub(object):
def __init__(self, particles):
self.particles = particles
gravity = GravityCodeStub(colliders)
stellar = EVtwin()
stellar.particles.add_particles(colliders)
collision = StellarEncounterInHydrodynamics(
#28000, # Bit too slow, even for a slowtest...
2800,
new_plotting_hydrodynamics_code(Gadget2, 0.2|units.hour,
plot_function = pynbody_column_density_plot if HAS_PYNBODY else None,
plot_function_arguments = dict(width=20|units.RSun, vmin=29, vmax=35) if HAS_PYNBODY else dict(width=20|units.RSun)),
hydrodynamics_arguments = dict(redirection="file", redirect_file="hydro_collision_slowtest7_gadget_out.log"),
hydrodynamics_parameters = dict(time_limit_cpu=1|units.day, gas_epsilon=0.01|units.RSun),
verbose=True,
debug=False
)
result = collision.handle_collision(colliders[0], colliders[1], gravity_code=gravity, stellar_evolution_code=stellar)
stellar.stop()
print(result)
self.assertTrue(isinstance(result, Particles))
self.assertEqual(len(result), 2)
self.assertTrue((result.mass < [5.0, 2.0] | units.MSun).all())
self.assertAlmostRelativeEqual(result.center_of_mass(), position_offset, 2)
self.assertAlmostRelativeEqual(result.center_of_mass_velocity(), velocity_offset, 2)
def evtwin(self, number_of_stars):
result = EVtwin()
result.initialize_code()
if number_of_stars > result.parameters.maximum_number_of_stars:
result.parameters.maximum_number_of_stars = number_of_stars
warnings.warn("You're simulating a large number of stars with EVtwin. This may not be such a good idea...")
return result
def test6(self):
print "Test for obtaining the stellar structure model"
stars = Particles(2)
stars.mass = [1.0, 10.0] | units.MSun
instance = EVtwin()
instance.initialize_code()
instance.commit_parameters()
instance.particles.add_particles(stars)
instance.commit_particles()
self.assertEquals(instance.particles.get_number_of_zones(), [199, 199])
self.assertEquals(len(instance.particles[0].get_radius_profile()), 199)
self.assertRaises(AmuseException, instance.particles.get_radius_profile,
expected_message = "Querying radius profiles of more than one particle at a time is not supported.")
self.assertEquals(len(instance.particles[1].get_density_profile()), 199)
self.assertIsOfOrder(instance.particles[0].get_radius_profile()[-1], 1.0 | units.RSun)
self.assertIsOfOrder(instance.particles[0].get_temperature_profile()[0], 1.0e7 | units.K)
self.assertIsOfOrder(instance.particles[0].get_temperature_profile()[-1], 5.0e3 | units.K)
radius1 = instance.particles[0].get_radius_profile()
radius2 = radius1[:-1]
radius2.prepend(0|units.m)
delta_radius_cubed = (radius1**3 - radius2**3)
total_mass = (4./3. * pi * instance.particles[0].get_density_profile() * delta_radius_cubed).sum()
self.assertAlmostRelativeEqual(total_mass, stars[0].mass, places = 1)
self.assertAlmostEquals(instance.particles[0].get_mu_profile()[:100], [0.62]*100 | units.amu, places=1)
instance.stop()
def xtest19(self):
print "Testing EVtwin central_temperature and central_density"
instance = EVtwin()
stars = instance.particles.add_particles(Particles(mass=[0.1, 1, 10]|units.MSun))
self.assertIsOfOrder(stars.central_temperature, [4e6, 13e6, 31e6] | units.K)
self.assertIsOfOrder(stars.central_density, [400, 77, 9] | units.g * units.cm**-3)
instance.stop()
def test6(self):
print "Test handle_collision"
position_offset = [100.0, 200.0, 300.0] | units.RSun
velocity_offset = [10000.0, 20000.0, 30000.0] | units.km / units.s
colliders = self.new_colliders()
colliders.position *= 1.5 # Grazing collision
colliders.position += position_offset
colliders.velocity += velocity_offset
class GravityCodeStub(object):
def __init__(self, particles):
self.particles = particles
gravity = GravityCodeStub(colliders)
stellar = EVtwin()
stellar.particles.add_particles(colliders)
collision = StellarEncounterInHydrodynamics(280, # For speed
Gadget2,
relax_sph_models=False, # For speed
verbose=True)
collision.extra_steps_when_encounter_is_over = 0 # For speed, no extra steps...
collision.dynamical_timescales_per_step = 1.3 # ... but then we need to evolve a bit longer in the first step
result = collision.handle_collision(colliders[0], colliders[1], gravity_code=gravity, stellar_evolution_code=stellar)
stellar.stop()
print result
self.assertTrue(isinstance(result, Particles))
self.assertEqual(len(result), 2)
self.assertAlmostEqual(result.mass, [5.0, 2.0] | units.MSun, 1)
self.assertAlmostRelativeEqual(result.center_of_mass(), position_offset, 2)
self.assertAlmostRelativeEqual(result.center_of_mass_velocity(), velocity_offset, 2)
def slowtest7(self):
print "Test handle_collision"
position_offset = [100.0, 200.0, 300.0] | units.RSun
velocity_offset = [10000.0, 20000.0, 30000.0] | units.km / units.s
colliders = self.new_colliders()
colliders.position += position_offset
colliders.velocity += velocity_offset
class GravityCodeStub(object):
def __init__(self, particles):
self.particles = particles
gravity = GravityCodeStub(colliders)
stellar = EVtwin()
stellar.particles.add_particles(colliders)
collision = StellarEncounterInHydrodynamics(
#28000, # Bit too slow, even for a slowtest...
2800,
new_plotting_hydrodynamics_code(Gadget2, 0.2|units.hour,
plot_function = pynbody_column_density_plot if HAS_PYNBODY else None,
plot_function_arguments = dict(width=20|units.RSun, vmin=29, vmax=35) if HAS_PYNBODY else dict(width=20|units.RSun)),
hydrodynamics_arguments = dict(redirection="file", redirect_file="hydro_collision_slowtest7_gadget_out.log"),
hydrodynamics_parameters = dict(time_limit_cpu=1|units.day, gas_epsilon=0.01|units.RSun),
verbose=True,
debug=False
)
result = collision.handle_collision(colliders[0], colliders[1], gravity_code=gravity, stellar_evolution_code=stellar)
stellar.stop()
print result
self.assertTrue(isinstance(result, Particles))
self.assertEqual(len(result), 2)
self.assertTrue((result.mass < [5.0, 2.0] | units.MSun).all())
self.assertAlmostRelativeEqual(result.center_of_mass(), position_offset, 2)
self.assertAlmostRelativeEqual(result.center_of_mass_velocity(), velocity_offset, 2)
def test5(self):
print "Test group_bound_particles"
colliders = self.new_colliders()
colliders.position = [[0.0, 0.0, 0.0], [1.1, 0.0, 0.0]] | units.RSun
colliders.velocity = [[0.0, 0.0, 0.0], [10000, 0.0, 0.0]] | units.km / units.s
stellar = EVtwin()
stellar.particles.add_particles(colliders)
collision = StellarEncounterInHydrodynamics(7000, None, relax_sph_models=False, verbose=True,
star_to_sph_arguments=dict(base_grid_options=dict(type="sobol")))
collision.dynamical_timescale = zero
gas_particles = collision.convert_stars(colliders, stellar)
stellar.stop()
collision.hop = collision.new_hop(gas_particles)
collision.start_kepler(7 | units.MSun, 10 | units.RSun)
self.assertTrue(collision.encounter_is_over(gas_particles))
collision.hop.stop()
collision.kepler.stop()
groups = collision.groups_after_encounter
self.assertEqual(len(groups), 2)
self.assertTrue(4500 < len(groups[0]) < 5000)
self.assertTrue(1800 < len(groups[1]) < 2000)
self.assertEqual(len(gas_particles - groups[0] - groups[1]), 346)
self.assertAlmostEqual(groups[0].center_of_mass()[0], 0 | units.RSun, 1)
self.assertAlmostEqual(groups[1].center_of_mass()[0], 1.1 | units.RSun, 0)
self.assertIsOfOrder(groups[1].center_of_mass_velocity()[0], 10000 | units.km / units.s)
def test11(self):
print "Test for importing new stellar models"
instance = EVtwin()
#~ instance.parameters.import_model_entropy_force = 1.0
#~ instance.parameters.import_model_entropy_accuracy = 1.0e-1
instance.parameters.verbosity = True
instance.particles.add_particles(Particles(mass = [0.8] | units.MSun))
instance.evolve_model()
instance.new_particle_from_model(instance.particles[0].get_internal_structure())
# The above line is equivalent with:
#copy = Particles(1)
#copy.internal_structure = instance.particles[0].get_internal_structure()
#instance.particles.add_particles(copy)
number_of_zones = instance.particles[0].get_number_of_zones()
self.assertEqual(len(instance.particles), 2)
self.assertEqual(instance.particles[1].get_number_of_zones(), number_of_zones)
self.assertIsOfOrder(instance.particles[1].get_radius_profile()[-1], 1.0 | units.RSun)
self.assertIsOfOrder(instance.particles[1].get_temperature_profile()[0], 1.0e7 | units.K)
self.assertIsOfOrder(instance.particles[1].get_pressure_profile()[0], 1.0e17 | units.barye)
instance.evolve_model(keep_synchronous = False)
self.assertAlmostRelativeEqual(
instance.particles[0].temperature, instance.particles[1].temperature, 2)
self.assertAlmostRelativeEqual(
instance.particles[0].luminosity, instance.particles[1].luminosity, 2)
instance.stop()
def xtest13(self):
print "Test evolve_model optional arguments: end_time and keep_synchronous"
stars = Particles(3)
stars.mass = [1.0, 2.0, 3.0] | units.MSun
instance = EVtwin()
instance.particles.add_particles(stars)
self.assertAlmostEqual(instance.particles.age, [0.0, 0.0, 0.0] | units.yr)
self.assertAlmostEqual(instance.particles.time_step, [70465.105509, 6063.68785133, 1876.53255132] | units.yr, 3)
print "evolve_model without arguments: use shared timestep = 0.99*min(particles.time_step)"
instance.evolve_model()
self.assertAlmostEqual(instance.particles.age, 0.99*([1876.53255132,1876.53255132,1876.53255132] | units.yr), 3)
self.assertAlmostEqual(instance.particles.time_step, [70465.105509,6063.68785133,1876.53255132] | units.yr, 3)
self.assertAlmostEqual(instance.model_time, 0.99*1876.53255132 | units.yr, 3)
print "evolve_model with end_time: take timesteps, until end_time is reached exactly"
instance.evolve_model(15000 | units.yr)
self.assertAlmostEqual(instance.particles.age, [15000.0, 15000.0, 15000.0] | units.yr, 3)
self.assertAlmostEqual(instance.particles.time_step, [ 84558.1266108,7276.4254216,2251.83906159] | units.yr, 3)
self.assertAlmostEqual(instance.model_time, 15000.0 | units.yr, 3)
print "evolve_model with keep_synchronous: use non-shared timestep, particle ages will typically diverge"
instance.evolve_model(keep_synchronous = False)
self.assertAlmostEqual(instance.particles.age, (15000 | units.yr) + ([ 84558.1266108,7276.4254216,2251.83906159] | units.yr), 3)
self.assertAlmostRelativeEquals(instance.particles.time_step, [101469.751933,8731.71050591,2702.2068739] | units.yr, 1)
self.assertAlmostEqual(instance.model_time, 15000.0 | units.yr, 3) # Unchanged!
instance.stop()
def test5(self):
print("Test group_bound_particles")
colliders = self.new_colliders()
colliders.position = [[0.0, 0.0, 0.0], [1.1, 0.0, 0.0]] | units.RSun
colliders.velocity = [[0.0, 0.0, 0.0], [10000, 0.0, 0.0]] | units.km / units.s
stellar = EVtwin()
stellar.particles.add_particles(colliders)
collision = StellarEncounterInHydrodynamics(7000, None, relax_sph_models=False, verbose=True,
star_to_sph_arguments=dict(base_grid_options=dict(type="sobol")))
collision.dynamical_timescale = zero
gas_particles = collision.convert_stars(colliders, stellar)
stellar.stop()
collision.hop = collision.new_hop(gas_particles)
collision.start_kepler(7 | units.MSun, 10 | units.RSun)
self.assertTrue(collision.encounter_is_over(gas_particles))
collision.hop.stop()
collision.kepler.stop()
groups = collision.groups_after_encounter
self.assertEqual(len(groups), 2)
self.assertTrue(4500 < len(groups[0]) < 5000)
self.assertTrue(1800 < len(groups[1]) < 2000)
self.assertEqual(len(gas_particles - groups[0] - groups[1]), 346)
self.assertAlmostEqual(groups[0].center_of_mass()[0], 0 | units.RSun, 1)
self.assertAlmostEqual(groups[1].center_of_mass()[0], 1.1 | units.RSun, 0)
self.assertIsOfOrder(groups[1].center_of_mass_velocity()[0], 10000 | units.km / units.s)
def test3(self):
print "Test convert_stars"
colliders = self.new_colliders()
colliders.position = [[-100.0, 0.0, 0.0], [100.0, 0.0, 0.0]
] | units.RSun
stellar = EVtwin()
stellar.particles.add_particles(colliders)
collision = StellarEncounterInHydrodynamics(700,
None,
relax_sph_models=False,
verbose=True)
gas_particles = collision.convert_stars(colliders, stellar)
stellar.stop()
self.assertEqual(gas_particles.mass, 0.01 | units.MSun)
self.assertTrue(numpy.all(gas_particles[:500].x < zero))
self.assertTrue(numpy.all(gas_particles[500:].x > zero))
self.assertIsOfOrder((
gas_particles[:500].position -
([-100.0, 0.0, 0.0] | units.RSun)).lengths_squared().amax().sqrt(),
1 | units.RSun)
self.assertIsOfOrder(
(gas_particles[500:].position -
([100.0, 0.0, 0.0] | units.RSun)).lengths_squared().amax().sqrt(),
1 | units.RSun)
self.assertAlmostEqual(
gas_particles[500:].center_of_mass_velocity().y -
gas_particles[:500].center_of_mass_velocity().y,
2000.0 | units.km / units.s)
def set_up_stellar_evolution_code(stars):
stellar_evolution = EVtwin()
stellar_evolution.initialize_code()
# if you run with mesa, you can play with the wind efficiency
# stellar_evolution.parameters.RGB_wind_scheme = 1
# stellar_evolution.parameters.reimers_wind_efficiency = 1.0e6 # ridiculous, but instructive
stellar_evolution.particles.add_particles(stars)
return stellar_evolution
def set_up_stellar_evolution_code(stars):
stellar_evolution = EVtwin()
stellar_evolution.initialize_code()
# if you run with mesa, you can play with the wind efficiency
# stellar_evolution.parameters.RGB_wind_scheme = 1
# stellar_evolution.parameters.reimers_wind_efficiency = 1.0e6 # ridiculous, but instructive
stellar_evolution.particles.add_particles(stars)
return stellar_evolution
def evtwin(self, number_of_stars):
result = EVtwin()
result.initialize_code()
if number_of_stars > result.parameters.maximum_number_of_stars:
result.parameters.maximum_number_of_stars = number_of_stars
warnings.warn(
"You're simulating a large number of stars with EVtwin. This may not be such a good idea...")
return result
def xslowtest16(self):
print "test full evolution of 1000 star sampled over flattish IMF"
number_of_stars=1000
from amuse.ic.salpeter import new_salpeter_mass_distribution
import numpy
class notsorandom(object):
def random(self,N):
return numpy.array(range(N))/(N-1.)
masses = new_salpeter_mass_distribution(
number_of_stars,
mass_min = 0.1 | units.MSun,
mass_max = 100.0 | units.MSun,
alpha = -1.01,random=notsorandom()
)
stars = Particles(mass=masses)
instance=EVtwin()
instance.parameters.maximum_number_of_stars=number_of_stars
instance.particles.add_particles(stars)
for p in instance.particles:
p.evolve_for(13.2 | units.Gyr)
def structure_from_star(mass, age):
stellar_evolution = EVtwin()
star = stellar_evolution.particles.add_particle(Particle(mass=mass))
star.evolve_for(age)
radius_profile = star.get_radius_profile()
density_profile = star.get_density_profile()
if hasattr(star, "get_mass_profile"):
mass_profile = star.get_mass_profile() * star.mass
else:
radii_cubed = radius_profile**3
radii_cubed.prepend(0 | units.m**3)
mass_profile = (
(4.0 / 3.0 * numpy.pi) * density_profile
* (radii_cubed[1:] - radii_cubed[:-1])
)
print("Derived mass profile from density and radius.")
return dict(
radius=radius_profile.as_quantity_in(units.RSun),
density=density_profile,
mass=mass_profile,
temperature=star.get_temperature_profile(),
pressure=star.get_pressure_profile(),
composition=star.get_chemical_abundance_profiles(),
species_names=star.get_names_of_species()
)
def test2(self):
print "Testing basic operations"
instance = EVtwin()
instance.initialize_code()
instance.commit_parameters()
stars = Particles(1)
stars.mass = 10 | units.MSun
instance.particles.add_particles(stars)
instance.commit_particles()
self.assertEquals(instance.particles.mass, 10 | units.MSun)
self.assertAlmostEquals(instance.particles.luminosity, 5695.19757302 | units.LSun, 6)
self.assertAlmostEquals(instance.particles.radius, 4.07378590 | units.RSun, 6)
instance.stop()
def create_particles():
star = Particle()
star.mass = 3.0 | units.MSun
stellar_evolution = EVtwin()
se_star = stellar_evolution.particles.add_particle(star)
print("Evolving", star.mass, "star with", stellar_evolution.__class__.__name__, "up to", 100 | units.Myr)
stellar_evolution.evolve_model(100 | units.Myr)
print("Creating SPH particles from the (1D) stellar evolution model")
sph_particles = convert_stellar_model_to_SPH(
se_star,
1000
).gas_particles
stellar_evolution.stop()
return sph_particles
def slowtest17(self):
"""
We add multiple particles to evtwin and evolve the stars
individualy. Evtwin crashes on some combinaties of
star masses and which star is evolved first.
"""
exceptions = []
for i, (masses, indices) in enumerate(
[
([1.21372730283, 1.22207032494, 11.21372730283] | units.MSun, (0, 1)),
([1.21372730283, 1.22207032494, 1.21372730283] | units.MSun, (0, 1)),
([1.21372730283, 1.22207032494, 1.21372730283] | units.MSun, (1, 0)),
([1.21372730283, 1.22207032494] | units.MSun, (0, 1)),
([1.21372730283, 11.22207032494, 1.21372730283] | units.MSun, (0, 1)),
([1.21372730283, 1.21372730283, 1.21372730283] | units.MSun, (0, 1)),
([1.21372730283, 1.22207032494, 1.21372730283] | units.MSun, (0, 1)),
([0.101, 1.22207032494, 1.21372730283] | units.MSun, (0, 1)),
]
):
stars = Particles(mass=masses)
instance = EVtwin()
instance.particles.add_particles(stars)
try:
index_in_indices = 0
instance.particles[indices[index_in_indices]].evolve_for(0.1 | units.Myr)
index_in_indices = 1
instance.particles[indices[index_in_indices]].evolve_for(0.1 | units.Myr)
except AmuseException as ex:
exceptions.append([i, masses, indices, index_in_indices])
instance.stop()
if len(exceptions) > 0:
failure_message = ""
for index, masses, indices, index_in_indices in exceptions:
failure_message += "[{0}]: error in ".format(index)
failure_message += "first" if index_in_indices == 0 else "second"
failure_message += " evolve_for,"
failure_message += " index: {0},".format(indices[index_in_indices])
failure_message += " masses (MSun): {0}.\n".format(masses.value_in(units.MSun))
self.fail(failure_message)
def slowtest11(self):
print "Test for importing new stellar models, also check long-term evolution"
instance = EVtwin()
instance.parameters.verbosity = True
instance.particles.add_particles(Particles(mass = [0.8] | units.MSun))
instance.evolve_model()
copy = Particles(1)
copy.internal_structure = instance.particles[0].get_internal_structure()
instance.particles.add_particles(copy)
number_of_zones = instance.particles[0].get_number_of_zones()
self.assertEqual(len(instance.particles), 2)
self.assertEqual(instance.particles[1].get_number_of_zones(), number_of_zones)
self.assertIsOfOrder(instance.particles[1].get_radius_profile()[-1], 1.0 | units.RSun)
self.assertIsOfOrder(instance.particles[1].get_temperature_profile()[0], 1.0e7 | units.K)
self.assertIsOfOrder(instance.particles[1].get_pressure_profile()[0], 1.0e17 | units.barye)
t1, l1 = simulate_evolution_tracks(instance.particles[0], end_time=26.5|units.Gyr)
t2, l2 = simulate_evolution_tracks(instance.particles[1], end_time=26.5|units.Gyr)
instance.stop()
i1 = t1.argmax() # Maximum temperature ~ turnoff main sequence
i2 = t2.argmax()
self.assertAlmostRelativeEqual(t1[i1], t2[i2], 2)
self.assertAlmostRelativeEqual(l1[i1], l2[i2], 2)
def xtest18(self):
print "Testing EVtwin calculate_core_mass"
instance = EVtwin()#redirection="none")
star = instance.particles.add_particle(Particle(mass=1|units.MSun))
instance.evolve_model(0.4|units.Gyr) # VERY short, for test speed up
central_hydrogen_abundance = star.get_chemical_abundance_profiles()[0][0]
self.assertTrue(central_hydrogen_abundance < 0.68) # some hydrogen is burned
self.assertTrue(central_hydrogen_abundance > 0.67) # ... but not that much yet
self.assertEqual(star.calculate_core_mass(core_H_abundance_limit=0.67), 0 | units.MSun)
self.assertAlmostEqual(star.calculate_core_mass(core_H_abundance_limit=0.71), 1 | units.MSun, 1)
# For test speed up, we use a weird core_H_abundance_limit to define the "hydrogen exhausted core"
limit = 0.68
expected_core_mass = 0.0123182798542 | units.MSun
self.assertAlmostEqual(star.calculate_core_mass(core_H_abundance_limit=limit), expected_core_mass, 3)
species_names = star.get_names_of_species()
self.assertEquals(species_names, ['h1', 'he4', 'c12', 'n14', 'o16', 'ne20', 'mg24', 'si28', 'fe56'])
h1_core_mass = star.calculate_core_mass(species=["h1"], core_H_abundance_limit=limit)
he4_core_mass = star.calculate_core_mass(species=["he4"], core_H_abundance_limit=limit)
c12_core_mass = star.calculate_core_mass(species=["c12"], core_H_abundance_limit=limit)
n14_core_mass = star.calculate_core_mass(species=["n14"], core_H_abundance_limit=limit)
o16_core_mass = star.calculate_core_mass(species=["o16"], core_H_abundance_limit=limit)
ne20_core_mass = star.calculate_core_mass(species=["ne20"], core_H_abundance_limit=limit)
mg24_core_mass = star.calculate_core_mass(species=["mg24"], core_H_abundance_limit=limit)
si28_core_mass = star.calculate_core_mass(species=["si28"], core_H_abundance_limit=limit)
fe56_core_mass = star.calculate_core_mass(species=["fe56"], core_H_abundance_limit=limit)
metal_core_mass = star.calculate_core_mass(species=["c12", "n14", "o16", "ne20", "mg24", "si28", "fe56"], core_H_abundance_limit=limit)
instance.stop()
self.assertAlmostRelativeEqual(h1_core_mass, expected_core_mass*0.68, 2)
self.assertAlmostRelativeEqual(he4_core_mass, expected_core_mass*0.30, 2)
self.assertAlmostRelativeEqual(metal_core_mass, expected_core_mass*0.02, 1)
self.assertAlmostRelativeEqual(expected_core_mass, he4_core_mass + metal_core_mass + h1_core_mass, 7)
self.assertAlmostRelativeEqual(metal_core_mass, c12_core_mass + n14_core_mass +
o16_core_mass + ne20_core_mass + mg24_core_mass + si28_core_mass + fe56_core_mass, 7)
def new_particles(self):
input_file = os.path.join(get_path_to_results(), "test_sph_to_star_input.hdf5")
if os.path.exists(input_file):
return read_set_from_file(input_file, "hdf5")
stellar_evolution = EVtwin()
stellar_evolution.particles.add_particle(Particle(mass=1.0|units.MSun))
stellar_evolution.evolve_model(100.0|units.Myr)
particles = convert_stellar_model_to_SPH(
stellar_evolution.particles[0],
500,
seed=12345
).gas_particles
stellar_evolution.stop()
hydrodynamics = Gadget2(ConvertBetweenGenericAndSiUnits(1.0|units.MSun, 1.0|units.RSun, 1.0e3|units.s))
hydrodynamics.gas_particles.add_particles(particles)
hydrodynamics.evolve_model(1.0|units.s)
hydrodynamics.gas_particles.copy_values_of_attributes_to(["density", "u", "pressure"], particles)
hydrodynamics.stop()
write_set_to_file(particles, input_file, "hdf5")
return particles
def xtest12b(self):
print "Testing basic operations: evolve_one_step and evolve_for (on subset, WIP: Ticket 304)"
stars = Particles(2)
stars.mass = 1.0 | units.MSun
instance = EVtwin()
se_stars = instance.particles.add_particles(stars)
self.assertAlmostEqual(se_stars.age, [0.0, 0.0] | units.yr)
for i in range(3):
se_stars[0].evolve_one_step()
self.assertAlmostEqual(se_stars.age, [225488.337629, 0.0] | units.yr, 3)
number_of_steps = 10
step_size = se_stars[0].age / number_of_steps
for i in range(1, number_of_steps + 1):
se_stars[1:].evolve_for(step_size)
self.assertAlmostEqual(se_stars.age, [number_of_steps, i] * step_size)
print se_stars
self.assertAlmostRelativeEqual(se_stars[0].age, se_stars[1].age)
self.assertAlmostRelativeEqual(se_stars[0].luminosity, se_stars[1].luminosity, 3)
self.assertAlmostRelativeEqual(se_stars[0].radius, se_stars[1].radius, 3)
self.assertAlmostRelativeEqual(se_stars[0].temperature, se_stars[1].temperature, 3)
instance.stop()
def convert_star_to_hydro_model(M, t_end):
stellar_evolution = EVtwin()
star = stellar_evolution.particles.add_particle(Particle(mass=M))
stellar_evolution.evolve_model(t_end)
Ngas = 10000
sph_particles = convert_stellar_model_to_SPH(star, Ngas).gas_particles
stellar_evolution.stop()
return sph_particles
def slowtest5(self):
print "Test convert_SPH_to_stellar_model result in EVtwin"
stellar_evolution = EVtwin()
stellar_evolution.parameters.verbosity = True
stellar_evolution.particles.add_particle(Particle(mass=1.0|units.MSun)) # reference particle
stellar_evolution.evolve_model(100.0|units.Myr)
model = convert_SPH_to_stellar_model(self.new_particles()) # model is from center to surface
stellar_evolution.new_particle_from_model(model, 0.0|units.Myr)
print stellar_evolution.particles
self.assertAlmostEqual(stellar_evolution.particles.age, [100.0, 0.0] | units.Myr, 1)
stellar_evolution.evolve_model(200.0|units.Myr)
print stellar_evolution.particles
self.assertAlmostEqual(stellar_evolution.particles.age, [200.0, 100.0] | units.Myr, 1)
self.assertAlmostRelativeEqual(stellar_evolution.particles[0].temperature,
stellar_evolution.particles[1].temperature, 2)
self.assertAlmostRelativeEqual(stellar_evolution.particles[0].luminosity,
stellar_evolution.particles[1].luminosity, 2)
stellar_evolution.stop()
def test1(self):
print "Testing assigned default parameter values..."
instance = EVtwin()
instance.initialize_code()
instance.parameters.set_defaults()
self.assertEquals(10, instance.parameters.maximum_number_of_stars)
instance.parameters.maximum_number_of_stars = 12
self.assertEquals(12, instance.parameters.maximum_number_of_stars)
instance.stop()
def test20(self):
print "Testing EVtwin manual mass transfer rate"
instance = EVtwin()
instance.parameters.verbosity = True
stars = instance.particles.add_particles(Particles(mass=[0.8, 0.8]|units.MSun))
stars[0].mass_transfer_rate = -1e-8|units.MSun/units.yr
instance.evolve_model()
# NOTE! no mass transfer during the initial step:
self.assertEqual(stars[0].mass, stars[1].mass)
age = stars[0].age
mass = stars[0].mass
instance.evolve_model()
self.assertTrue(stars[0].mass < stars[1].mass)
# NOTE 2! actual mass transfer rate 10x lower:
self.assertAlmostRelativeEqual((stars[0].mass-mass) / (stars[0].age-age), -1.0e-9|units.MSun/units.yr, 4)
instance.stop()
def test3(self):
print "Test convert_stars"
colliders = self.new_colliders()
colliders.position = [[-100.0, 0.0, 0.0], [100.0, 0.0, 0.0]] | units.RSun
stellar = EVtwin()
stellar.particles.add_particles(colliders)
collision = StellarEncounterInHydrodynamics(700, None, relax_sph_models=False, verbose=True)
gas_particles = collision.convert_stars(colliders, stellar)
stellar.stop()
self.assertEqual(gas_particles.mass, 0.01 | units.MSun)
self.assertTrue(numpy.all(gas_particles[:500].x < zero))
self.assertTrue(numpy.all(gas_particles[500:].x > zero))
self.assertIsOfOrder((
gas_particles[:500].position - ([-100.0, 0.0, 0.0] | units.RSun)
).lengths_squared().amax().sqrt(), 1 | units.RSun)
self.assertIsOfOrder((
gas_particles[500:].position - ([100.0, 0.0, 0.0] | units.RSun)
).lengths_squared().amax().sqrt(), 1 | units.RSun)
self.assertAlmostEqual(gas_particles[500:].center_of_mass_velocity().y -
gas_particles[:500].center_of_mass_velocity().y, 2000.0 | units.km / units.s)
def test7(self):
print "Test for obtaining the stellar composition structure"
stars = Particles(1)
stars.mass = 1.0 | units.MSun
instance = EVtwin()
instance.initialize_code()
instance.commit_parameters()
instance.particles.add_particles(stars)
instance.commit_particles()
number_of_zones = instance.particles.get_number_of_zones()[0]
number_of_species = instance.particles.get_number_of_species()[0]
composition = instance.particles[0].get_chemical_abundance_profiles()
species_names = instance.particles[0].get_names_of_species()
self.assertEquals(number_of_zones, 199)
self.assertEquals(number_of_species, 9)
self.assertEquals(len(species_names), number_of_species)
self.assertEquals(len(composition), number_of_species)
self.assertEquals(len(composition[0]), number_of_zones)
self.assertEquals(species_names, ['h1', 'he4', 'c12', 'n14', 'o16', 'ne20', 'mg24', 'si28', 'fe56'])
self.assertAlmostEquals(composition[0, -1], 0.7, 3)
self.assertAlmostEquals(composition[1, -1], 0.3 - instance.parameters.metallicity, 3)
self.assertAlmostEquals(composition[2:,-1].sum(), instance.parameters.metallicity, 3)
self.assertAlmostEquals(composition.sum(axis=0), [1.0]*number_of_zones)
instance.stop()
def test9(self):
print "Test for saving and loading the stellar structure model"
filenames = ["test1.dump", "test2.dump"]
filenames = [os.path.join(get_path_to_results(), name) for name in filenames]
instance = EVtwin(redirection="none")
instance.parameters.verbosity = True
instance.particles.add_particles(Particles(mass=[0.5, 0.8] | units.MSun))
instance.evolve_model()
instance.particles.write_star_to_file(filenames)
copies = Particles(2)
copies.filename = filenames
instance.particles.add_particles(copies)
instance.evolve_model()
print instance.particles
self.assertAlmostRelativeEquals(instance.particles.temperature, [3644, 4783, 3644, 4783] | units.K, 3)
instance.stop()
def test9(self):
print "Test for saving and loading the stellar structure model"
filenames = ["test1.dump", "test2.dump"]
filenames = [os.path.join(get_path_to_results(), name) for name in filenames]
instance = EVtwin()#redirection="none")
instance.parameters.verbosity = True
instance.particles.add_particles(Particles(mass = [0.5, 0.8] | units.MSun))
instance.evolve_model()
instance.particles.write_star_to_file(filenames)
copies = Particles(2)
copies.filename = filenames
instance.particles.add_particles(copies)
instance.evolve_model()
print instance.particles
import warnings
warnings.warn("this test's precision has been temporarily (2017) decreased")
# the reason for this is that the deviation is compiler dependend (and does only happen
# on some machine/compiler/OS combinations)
# it may have something to do with initialization of variables in evtwin
#~ self.assertAlmostRelativeEquals(instance.particles.temperature, [3644, 4783, 3644, 4783] | units.K, 3)
self.assertAlmostRelativeEquals(instance.particles.temperature, [3644, 4783, 3644, 4783] | units.K, 2)
instance.stop()
def create_particles():
star = Particle()
star.mass = 3.0 | units.MSun
stellar_evolution = EVtwin()
se_star = stellar_evolution.particles.add_particle(star)
print("Evolving", star.mass, "star with",
stellar_evolution.__class__.__name__, "up to", 100 | units.Myr)
stellar_evolution.evolve_model(100 | units.Myr)
print("Creating SPH particles from the (1D) stellar evolution model")
sph_particles = convert_stellar_model_to_SPH(se_star, 1000).gas_particles
stellar_evolution.stop()
return sph_particles
def __init__(self, pEVtwin = None, pSSE = None):
# specifying the stellar evolution objects as parameters in the constructor
# allows setting up caching in a convenient way
if pEVtwin is None:
self._EVtwin = EVtwin()
else:
self._EVtwin = pEVtwin
if pSSE is None:
self._SSE = SSE()
else:
self._SSE = pSSE
# initialize member variables
self.particles = datamodel.Particles()
self.EVtwinAgeAtSwitch = float("nan") | units.Myr
self.EVtwinException = None
self.ActiveModel = self._EVtwin # self.ActiveModel.__class__.__name__ contains name of active model
self._EVtwin_particlesh = None
self._SSE_particlesh = None
def new_particles(self):
input_file = os.path.join(get_path_to_results(),
"test_sph_to_star_input.hdf5")
if os.path.exists(input_file):
return read_set_from_file(input_file, "hdf5")
stellar_evolution = EVtwin()
stellar_evolution.particles.add_particle(
Particle(mass=1.0 | units.MSun))
stellar_evolution.evolve_model(100.0 | units.Myr)
particles = convert_stellar_model_to_SPH(
stellar_evolution.particles[0], 500, seed=12345).gas_particles
stellar_evolution.stop()
hydrodynamics = Gadget2(
ConvertBetweenGenericAndSiUnits(1.0 | units.MSun, 1.0 | units.RSun,
1.0e3 | units.s))
hydrodynamics.gas_particles.add_particles(particles)
hydrodynamics.evolve_model(1.0 | units.s)
hydrodynamics.gas_particles.copy_values_of_attributes_to(
["density", "u", "pressure"], particles)
hydrodynamics.stop()
write_set_to_file(particles, input_file, "hdf5")
return particles
def slowtest17(self):
"""
We add multiple particles to evtwin and evolve the stars
individualy. Evtwin crashes on some combinaties of
star masses and which star is evolved first.
"""
exceptions = []
for i, (masses, indices) in enumerate([
(
[1.21372730283, 1.22207032494, 11.21372730283] | units.MSun,
(0,1)
),
(
[1.21372730283, 1.22207032494, 1.21372730283] | units.MSun,
(0,1)
),
(
[1.21372730283, 1.22207032494, 1.21372730283] | units.MSun,
(1,0)
),
(
[1.21372730283, 1.22207032494] | units.MSun,
(0,1)
),
(
[1.21372730283, 11.22207032494, 1.21372730283] | units.MSun,
(0,1)
),
(
[1.21372730283, 1.21372730283, 1.21372730283] | units.MSun,
(0,1)
),
(
[1.21372730283, 1.22207032494, 1.21372730283] | units.MSun,
(0,1)
),
(
[0.101, 1.22207032494, 1.21372730283] | units.MSun,
(0,1)
)
]):
stars = Particles(mass=masses)
instance=EVtwin()
instance.particles.add_particles(stars)
try:
index_in_indices = 0
instance.particles[indices[index_in_indices]].evolve_for(0.1| units.Myr)
index_in_indices = 1
instance.particles[indices[index_in_indices]].evolve_for(0.1| units.Myr)
except AmuseException as ex:
exceptions.append( [i, masses, indices, index_in_indices] )
instance.stop()
if len(exceptions) > 0:
failure_message = ''
for index, masses, indices, index_in_indices in exceptions:
failure_message += '[{0}]: error in '.format(index)
failure_message += 'first' if index_in_indices == 0 else 'second'
failure_message += ' evolve_for,'
failure_message += ' index: {0},'.format(indices[index_in_indices])
failure_message += ' masses (MSun): {0}.\n'.format(masses.value_in(units.MSun))
self.fail(failure_message)
def test14(self):
print "Testing EVtwin states"
stars = Particles(2)
stars.mass = 1.0 | units.MSun
instance = EVtwin()
print "First do everything manually:",
self.assertEquals(instance.get_name_of_current_state(), 'UNINITIALIZED')
instance.initialize_code()
self.assertEquals(instance.get_name_of_current_state(), 'INITIALIZED')
instance.commit_parameters()
self.assertEquals(instance.get_name_of_current_state(), 'EDIT')
instance.particles.add_particle(stars[0])
instance.commit_particles()
self.assertEquals(instance.get_name_of_current_state(), 'RUN')
instance.cleanup_code()
self.assertEquals(instance.get_name_of_current_state(), 'END')
instance.stop()
print "ok"
print "initialize_code(), commit_parameters(), (re)commit_particles(), " \
"and cleanup_code() should be called automatically:",
instance = EVtwin()
self.assertEquals(instance.get_name_of_current_state(), 'UNINITIALIZED')
instance.parameters.RGB_wind_setting = -0.5
self.assertEquals(instance.get_name_of_current_state(), 'INITIALIZED')
instance.particles.add_particle(stars[0])
self.assertEquals(instance.get_name_of_current_state(), 'EDIT')
mass = instance.particles[0].mass
self.assertEquals(instance.get_name_of_current_state(), 'RUN')
instance.particles.add_particle(stars[1])
self.assertEquals(instance.get_name_of_current_state(), 'UPDATE')
mass = instance.particles[0].mass
self.assertEquals(instance.get_name_of_current_state(), 'RUN')
instance.stop()
self.assertEquals(instance.get_name_of_current_state(), 'STOPPED')
print "ok"
def slowtest8(self):
print "Test for obtaining the stellar composition structure - evolved star"
stars = Particles(1)
stars.mass = 1.0 | units.MSun
instance = EVtwin()
instance.initialize_code()
instance.commit_parameters()
instance.particles.add_particles(stars)
instance.commit_particles()
instance.evolve_model(11.7 | units.Gyr)
self.assertTrue(instance.particles[0].age >= 11.7 | units.Gyr)
print instance.particles[0].stellar_type
#~ self.assertTrue(str(instance.particles[0].stellar_type) == "First Giant Branch")
number_of_zones = instance.particles.get_number_of_zones()[0]
number_of_species = instance.particles.get_number_of_species()[0]
composition = instance.particles[0].get_chemical_abundance_profiles()
species_names = instance.particles[0].get_names_of_species()
self.assertEquals(number_of_zones, 199)
self.assertEquals(number_of_species, 9)
self.assertEquals(len(species_names), number_of_species)
self.assertEquals(len(composition), number_of_species)
self.assertEquals(len(composition[0]), number_of_zones)
self.assertEquals(species_names, ['h1', 'he4', 'c12', 'n14', 'o16', 'ne20', 'mg24', 'si28', 'fe56'])
self.assertAlmostRelativeEquals(composition[0, -1], 0.7 | units.none, 1)
self.assertAlmostRelativeEquals(composition[1, -1], 0.3 - instance.parameters.metallicity, 1)
self.assertAlmostRelativeEquals(composition[2:,-1].sum(), instance.parameters.metallicity, 1)
self.assertAlmostEquals(composition.sum(axis=0), [1.0]*number_of_zones | units.none)
self.assertAlmostEquals(composition[0, 0], 0.00 | units.none)
self.assertAlmostEquals(composition[1, 0], 1.00 - instance.parameters.metallicity, 3)
self.assertAlmostEquals(composition[2:,0].sum(), instance.parameters.metallicity, 3)
instance.stop()
def xslowtest11(self):
print "Test 11: Continue the stellar evolution of a 'merger product' - WIP"
instance = EVtwin()
instance.initialize_code()
instance.commit_parameters()
instance.parameters.min_timestep_stop_condition = 1.0 | units.s
stars = Particles(3)
stars.mass = [1.0, 2.0, 1.0] | units.MSun
instance.particles.add_particles(stars)
instance.commit_particles()
instance.evolve_model(1.0 | units.Myr)
stellar_models = instance.native_stars.get_internal_structure()
self.assertEqual(len(stellar_models), 3)
self.assertEqual(len(stellar_models[0]), 199)
self.assertEqual(len(stellar_models[1]), 199)
self.assertAlmostEqual(stellar_models[0].mass[198], 1.0 | units.MSun, 2)
self.assertAlmostEqual(stellar_models[1].mass[198], 2.0 | units.MSun, 2)
self.assertAlmostEqual(stellar_models[0].mass[0], 0.0 | units.MSun, 2)
instance.new_particle_from_model(stellar_models[0], instance.particles[0].age)
self.assertEqual(len(instance.particles), 4)
self.assertEqual(len(instance.imported_stars), 1)
imported_stellar_model = instance.imported_stars[0].get_internal_structure()
self.assertEqual(len(imported_stellar_model), 199)
self.assertAlmostEqual(imported_stellar_model.mass[198], 1.0 | units.MSun, 2)
self.assertAlmostEqual(imported_stellar_model.mass[0], 0.0 | units.MSun, 2)
self.assertAlmostRelativeEqual(imported_stellar_model.X_H, stellar_models[0].X_H, 5)
self.assertAlmostRelativeEqual(imported_stellar_model.X_He, stellar_models[0].X_He, 5)
self.assertAlmostRelativeEqual(imported_stellar_model.mass, stellar_models[0].mass, 2)
self.assertAlmostRelativeEqual(imported_stellar_model.radius[1:], stellar_models[0].radius[1:], 2)
# instance.evolve_model(2.0 | units.Myr)
print instance.particles
instance.stop()
del instance
def test5(self):
print "Testing adding and removing particles from stellar evolution code..."
particles = Particles(3)
particles.mass = 0.3 | units.MSun
instance = EVtwin()#redirection="none")
instance.initialize_code()
instance.parameters.verbosity = True
instance.commit_parameters()
stars = instance.particles
self.assertEquals(len(stars), 0) # before creation
stars.add_particles(particles[:-1])
instance.commit_particles()
instance.evolve_model(1.0 | units.Myr)
self.assertEquals(len(stars), 2) # before remove
self.assertAlmostEqual(stars.age, 1.0 | units.Myr)
stars.remove_particle(particles[0])
self.assertEquals(len(stars), 1)
self.assertEquals(instance.get_number_of_particles(), 1)
instance.evolve_model(2.0 | units.Myr)
self.assertAlmostEqual(stars[0].age, 2.0 | units.Myr)
stars.add_particles(particles[::2])
self.assertEquals(len(stars), 3) # it's back...
self.assertAlmostEqual(stars[0].age, 2.0 | units.Myr)
self.assertAlmostEqual(stars[1].age, 0.0 | units.Myr)
self.assertAlmostEqual(stars[2].age, 0.0 | units.Myr) # ... and rejuvenated.
instance.evolve_model(3.0 | units.Myr) # The young stars keep their age offset from the old star
self.assertAlmostEqual(stars.age, [3.0, 1.0, 1.0] | units.Myr)
instance.evolve_model(4.0 | units.Myr)
self.assertAlmostEqual(stars.age, [4.0, 2.0, 2.0] | units.Myr)
instance.stop()
def xtest10(self):
print "Test for changing the stellar composition (not yet implemented)"
star = Particles(1)
star.mass = 1.0 | units.MSun
instance = EVtwin()
instance.initialize_code()
instance.commit_parameters()
instance.particles.add_particles(star)
instance.commit_particles()
instance.evolve_model()
composition = instance.particles[0].get_chemical_abundance_profiles()
h1_profile = composition[0] * 1
he4_profile = composition[1] * 1
k_surface = -1 # index to the outer mesh cell (surface)
self.assertAlmostEquals(composition[0, k_surface], 0.7 | units.none, 4)
self.assertAlmostEquals(composition[1, k_surface], (0.3 | units.none) - instance.parameters.metallicity, 4)
self.assertAlmostEquals(composition[2: , k_surface].sum(), instance.parameters.metallicity, 4)
composition[0] = he4_profile
composition[1] = h1_profile
instance.particles[0].set_chemical_abundance_profiles(composition)
instance.evolve_model()
composition = instance.particles[0].get_chemical_abundance_profiles()
self.assertAlmostEquals(composition[0, k_surface], (0.3 | units.none) - instance.parameters.metallicity, 4)
self.assertAlmostEquals(composition[1, k_surface], 0.7 | units.none, 4)
self.assertAlmostEquals(composition[2: , k_surface].sum(), instance.parameters.metallicity, 4)
self.assertAlmostEquals(composition.sum(axis=0), 1.0 | units.none)
self.assertRaises(AmuseException, instance.particles[0].set_chemical_abundance_profiles, composition[:7],
expected_message = "The length of the supplied vector (7) does not match the number of "
"chemical species of the star (8).")
instance.stop()
del instance
def xtest9(self):
print "Test for changing the stellar structure model (not yet implemented)"
star = Particles(1)
star.mass = 1.0 | units.MSun
instance = EVtwin()
instance.initialize_code()
instance.commit_parameters()
instance.particles.add_particles(star)
instance.commit_particles()
instance.evolve_model()
density_profile = instance.particles[0].get_density_profile()
self.assertRaises(AmuseException, instance.particles[0].set_density_profile, density_profile[2:],
expected_message = "The length of the supplied vector (197) does not match the number of "
"mesh zones of the star (199).")
mass_factor = 1.1
instance.particles[0].set_density_profile(mass_factor*density_profile)
self.assertAlmostRelativeEqual(instance.particles[0].get_density_profile(), density_profile*mass_factor, places=10)
instance.particles.mass *= mass_factor
instance.evolve_model()
outer_radius = instance.particles[0].get_radius_profile()
inner_radius = outer_radius[:-1]
inner_radius.prepend(0|units.m)
delta_radius_cubed = (outer_radius**3 - inner_radius**3)
integrated_mass = (4./3.*pi*delta_radius_cubed*instance.particles[0].get_density_profile()).sum()
self.assertAlmostRelativeEqual(integrated_mass, star.mass*mass_factor, places = 3)
instance.stop()
del instance