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 test1(self):
print "Test collect_required_attributes"
in_memory = self.new_colliders()
gravity = BHTree(nbody_system.nbody_to_si(1|units.MSun, 1.0|units.RSun))
gravity.particles.add_particles(in_memory)
stellar = SeBa()
stellar.particles.add_particles(in_memory)
collision = StellarEncounterInHydrodynamics(None, None, verbose=True)
self.assertFalse(hasattr(in_memory, "radius"))
collision.collect_required_attributes(in_memory, gravity, stellar)
self.assertTrue(hasattr(in_memory, "radius"))
self.assertAlmostRelativeEqual(in_memory.radius.sum(), 4.2458 | units.RSun, 3)
from_stellar = stellar.particles.copy()
for attribute in ["x", "y", "z", "vx", "vy", "vz"]:
self.assertFalse(hasattr(from_stellar, attribute))
collision.collect_required_attributes(from_stellar, gravity, stellar)
gravity.stop()
stellar.stop()
for attribute in ["x", "y", "z", "vx", "vy", "vz"]:
self.assertTrue(hasattr(from_stellar, attribute))
self.assertAlmostEqual(from_stellar.position, in_memory.position)
self.assertAlmostEqual(from_stellar.velocity, in_memory.velocity)
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 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 test2(self):
print "Test backtrack_particles"
colliders = self.new_colliders()
colliders.radius = [1, 2] | units.RSun
collision = StellarEncounterInHydrodynamics(None, None, verbose=True)
relative_position = colliders[1].position - colliders[0].position
self.assertAlmostRelativeEqual(relative_position.length(),
1.0 | units.RSun, 7)
total_energy_before = colliders.kinetic_energy(
) + colliders.potential_energy()
self.assertTrue(total_energy_before > zero)
collision.backtrack_particles(colliders)
collision.kepler.stop()
relative_position = colliders[1].position - colliders[0].position
self.assertAlmostRelativeEqual(relative_position.length(),
15 | units.RSun, 3)
total_energy_after = colliders.kinetic_energy(
) + colliders.potential_energy()
self.assertAlmostRelativeEqual(total_energy_after, total_energy_before,
7)
def test4(self):
print "Test binary_will_collide"
collision = StellarEncounterInHydrodynamics(None, None, verbose=True)
collision.dynamical_timescale = zero
collision.start_kepler(7 | units.MSun, 10 | units.RSun)
# at periastron, close enough:
colliders = self.new_colliders()
colliders.radius = 1 | units.RSun
self.assertTrue(
collision.binary_will_collide(colliders[0], colliders[1]))
# at periastron, distance too large:
colliders.radius = 0.4 | units.RSun
self.assertFalse(
collision.binary_will_collide(colliders[0], colliders[1]))
# at apastron, will collide at periastron:
colliders.velocity = [[0.0, 0.0, 0.0], [0.0, 1000.0, 0.0]
] | units.km / units.s
self.assertTrue(
collision.binary_will_collide(colliders[0], colliders[1]))
# hyperbolic orbits, moving away from each other:
colliders.position = [[0.0, 0.0, 0.0], [1.0, 100.0, 0.0]] | units.RSun
self.assertFalse(
collision.binary_will_collide(colliders[0], colliders[1]))
# hyperbolic orbits, moving towards each other:
colliders.velocity = [[0.0, 0.0, 0.0], [0.0, -1000.0, 0.0]
] | units.km / units.s
self.assertTrue(
collision.binary_will_collide(colliders[0], colliders[1]))
collision.kepler.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 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 test2(self):
print "Test backtrack_particles"
colliders = self.new_colliders()
colliders.radius = [1, 2] | units.RSun
collision = StellarEncounterInHydrodynamics(None, None, verbose=True)
relative_position = colliders[1].position - colliders[0].position
self.assertAlmostRelativeEqual(relative_position.length(), 1.0 | units.RSun, 7)
total_energy_before = colliders.kinetic_energy() + colliders.potential_energy()
self.assertTrue(total_energy_before > zero)
collision.backtrack_particles(colliders)
collision.kepler.stop()
relative_position = colliders[1].position - colliders[0].position
self.assertAlmostRelativeEqual(relative_position.length(), 15 | units.RSun, 3)
total_energy_after = colliders.kinetic_energy() + colliders.potential_energy()
self.assertAlmostRelativeEqual(total_energy_after, total_energy_before, 7)
def test1(self):
print("Test collect_required_attributes")
in_memory = self.new_colliders()
gravity = BHTree(nbody_system.nbody_to_si(1|units.MSun, 1.0|units.RSun))
gravity.particles.add_particles(in_memory)
stellar = SeBa()
stellar.particles.add_particles(in_memory)
collision = StellarEncounterInHydrodynamics(None, None, verbose=True)
self.assertFalse(hasattr(in_memory, "radius"))
collision.collect_required_attributes(in_memory, gravity, stellar)
self.assertTrue(hasattr(in_memory, "radius"))
self.assertAlmostRelativeEqual(in_memory.radius.sum(), 4.2458 | units.RSun, 3)
from_stellar = stellar.particles.copy()
for attribute in ["x", "y", "z", "vx", "vy", "vz"]:
self.assertFalse(hasattr(from_stellar, attribute))
collision.collect_required_attributes(from_stellar, gravity, stellar)
gravity.stop()
stellar.stop()
for attribute in ["x", "y", "z", "vx", "vy", "vz"]:
self.assertTrue(hasattr(from_stellar, attribute))
self.assertAlmostEqual(from_stellar.position, in_memory.position)
self.assertAlmostEqual(from_stellar.velocity, in_memory.velocity)
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 test4(self):
print "Test binary_will_collide"
collision = StellarEncounterInHydrodynamics(None, None, verbose=True)
collision.dynamical_timescale = zero
collision.start_kepler(7 | units.MSun, 10 | units.RSun)
# at periastron, close enough:
colliders = self.new_colliders()
colliders.radius = 1 | units.RSun
self.assertTrue(collision.binary_will_collide(colliders[0], colliders[1]))
# at periastron, distance too large:
colliders.radius = 0.4 | units.RSun
self.assertFalse(collision.binary_will_collide(colliders[0], colliders[1]))
# at apastron, will collide at periastron:
colliders.velocity = [[0.0, 0.0, 0.0], [0.0, 1000.0, 0.0]] | units.km / units.s
self.assertTrue(collision.binary_will_collide(colliders[0], colliders[1]))
# hyperbolic orbits, moving away from each other:
colliders.position = [[0.0, 0.0, 0.0], [1.0, 100.0, 0.0]] | units.RSun
self.assertFalse(collision.binary_will_collide(colliders[0], colliders[1]))
# hyperbolic orbits, moving towards each other:
colliders.velocity = [[0.0, 0.0, 0.0], [0.0, -1000.0, 0.0]] | units.km / units.s
self.assertTrue(collision.binary_will_collide(colliders[0], colliders[1]))
collision.kepler.stop()
