def new_colliders(self):
colliders = Particles(2)
colliders.mass = [5, 2] | units.MSun
colliders.position = [[0.0, 0.0, 0.0], [1.0, 0.0, 0.0]] | units.RSun
colliders.velocity = [[0.0, 0.0, 0.0], [0.0, 2000.0, 0.0]] | units.km / units.s
colliders.move_to_center()
return colliders
def set_up_initial_conditions(orbital_period, kinetic_to_potential_ratio):
print("Setting up initial conditions")
stars = Particles(2)
stars.mass = [10.0, 1.0] | units.MSun
stars.radius = 0 | units.RSun
stars.position = [0.0, 0.0, 0.0] | units.AU
stars.velocity = [0.0, 0.0, 0.0] | units.km / units.s
print("Binary with masses: " + str(stars.mass) +
", and orbital period: ", orbital_period)
semimajor_axis = ((constants.G * stars.total_mass() *
(orbital_period / (2 * pi))**2.0)**(1.0 / 3.0))
separation = 2 * semimajor_axis * (1 - kinetic_to_potential_ratio)
print("Initial separation:", separation.as_quantity_in(units.AU))
relative_velocity = (
(kinetic_to_potential_ratio / (1.0 - kinetic_to_potential_ratio))
* constants.G * stars.total_mass() / semimajor_axis
).sqrt()
print("Initial relative velocity:",
relative_velocity.as_quantity_in(units.km / units.s))
stars[0].x = separation
stars[0].vy = relative_velocity
stars.move_to_center()
return stars
def test5(self):
print "Testing MI6 evolve_model, 2 particles, no SMBH"
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.km / units.s
particles[1].vy = (constants.G * (2.0 | units.MSun) / (2.0 | units.AU)).sqrt()
particles.move_to_center()
print particles
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
instance = MI6(converter, **default_options)
instance.initialize_code()
instance.parameters.smbh_mass = 0.0 | units.MSun
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
position_at_start = primary.position.x
instance.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y, 3)
instance.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x, 3)
instance.evolve_model(P)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x, 3)
instance.cleanup_code()
instance.stop()
def test4(self):
print "Testing Pikachu evolve_model, 2 particles"
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.km / units.s
particles[1].vy = (constants.G * (2.0 | units.MSun) / (2.0 | units.AU)).sqrt()
particles.move_to_center()
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
instance = self.new_instance_of_an_optional_code(Pikachu, converter, **default_options)
instance.initialize_code()
instance.parameters.timestep = 0.0125 * math.pi * particles[0].x / particles[0].vy
instance.parameters.rcut_out_star_star = 10.0 | units.AU
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
position_at_start = primary.position.x
instance.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y, 3)
instance.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x, 3)
instance.evolve_model(P)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x, 3)
instance.cleanup_code()
instance.stop()
def test4(self):
print "Testing Adaptb evolve_model, 2 particles"
particles = Particles(2)
particles.mass = 0.5 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [1.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.km / units.s
particles[1].vy = (constants.G * (1.0 | units.MSun) / (1.0 | units.AU)).sqrt()
particles.move_to_center()
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
instance = self.new_instance_of_an_optional_code(Adaptb, convert_nbody)
instance.initialize_code()
instance.parameters.dt_print = 0.1 | units.yr
instance.parameters.bs_tolerance = 1.0e-8
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
position_at_start = primary.position.x
instance.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y, 6)
instance.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x, 6)
instance.evolve_model(P)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x, 6)
instance.cleanup_code()
instance.stop()
def test9(self):
print "Testing FastKick for Bridge: evolving a binary"
particles = Particles(2)
particles.mass = [3.0, 1.0] | units.MSun
particles.position = [0, 0, 0] | units.AU
particles.velocity = [0, 0, 0] | units.km / units.s
particles[1].x = 2.0 | units.AU
particles[1].vy = (constants.G * (4.0 | units.MSun) / (2.0 | units.AU)).sqrt()
particles.move_to_center()
primary_sys = new_gravity_code(particles[:1])
secondary_sys = new_gravity_code(particles[1:])
primary = primary_sys.particles[0]
P = 2 * math.pi * primary.x / primary.vy
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
kick_from_primary = CalculateFieldForCodesUsingReinitialize(self.new_fastkick_instance(converter), (primary_sys,))
kick_from_secondary = CalculateFieldForCodesUsingReinitialize(self.new_fastkick_instance(converter), (secondary_sys,))
bridgesys = Bridge(timestep = P / 64.0)
bridgesys.add_system(primary_sys, (kick_from_secondary,))
bridgesys.add_system(secondary_sys, (kick_from_primary,))
position_at_start = primary.position.x
bridgesys.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y, 2)
bridgesys.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x, 2)
bridgesys.evolve_model(P)
kick_from_primary.code.stop()
kick_from_secondary.code.stop()
self.assertAlmostRelativeEqual(position_at_start, primary.position.x, 2)
def solar_system_in_time(time_JD=2457099.5|units.day): """ Initial conditions of Solar system -- particle set with the sun + eight planets, at the center-of-mass reference frame. Defined attributes: name, mass, radius, x, y, z, vx, vy, vz """ time_0 = 2457099.5 | units.day delta_JD = time_JD-time_0 sun, planets = get_sun_and_planets(delta_JD=delta_JD) solar_system = Particles() solar_system.add_particle(sun) solar_system.add_particles(planets) solar_system.move_to_center() ### to compare with JPL, relative positions and velocities need to be corrected for the # Sun's vectors with respect to the barycenter #r_s = (3.123390770608490E-03, -4.370830943817017E-04, -1.443425433116342E-04) | units.AU #v_s = (3.421633816761503E-06, 5.767414405893875E-06, -8.878039607570240E-08) | (units.AU / units.day) #print sun #print planets.position.in_(units.AU) + r_s #print planets.velocity.in_(units.AU/units.day) + v_s return solar_system
def set_up_initial_conditions(orbital_period, kinetic_to_potential_ratio):
print("Setting up initial conditions")
stars = Particles(2)
stars.mass = [10.0, 1.0] | units.MSun
stars.radius = 0 | units.RSun
stars.position = [0.0, 0.0, 0.0] | units.AU
stars.velocity = [0.0, 0.0, 0.0] | units.km / units.s
print("Binary with masses: "+str(stars.mass) +
", and orbital period: ", orbital_period)
semimajor_axis = ((constants.G * stars.total_mass() *
(orbital_period / (2 * pi))**2.0)**(1.0/3.0))
separation = 2 * semimajor_axis * (1 - kinetic_to_potential_ratio)
print("Initial separation:", separation.as_quantity_in(units.AU))
relative_velocity = (
(kinetic_to_potential_ratio / (1.0 - kinetic_to_potential_ratio))
* constants.G * stars.total_mass() / semimajor_axis
).sqrt()
print("Initial relative velocity:",
relative_velocity.as_quantity_in(units.km / units.s))
stars[0].x = separation
stars[0].vy = relative_velocity
stars.move_to_center()
return stars
def new_colliders(self):
colliders = Particles(2)
colliders.mass = [5, 2] | units.MSun
colliders.position = [[0.0, 0.0, 0.0], [1.0, 0.0, 0.0]] | units.RSun
colliders.velocity = [[0.0, 0.0, 0.0], [0.0, 2000.0, 0.0]] | units.km / units.s
colliders.move_to_center()
return colliders
def sun_and_planets(self):
particles = Particles(9)
sun = particles[0]
mercury = particles[1]
venus = particles[2]
earth = particles[3]
mars = particles[4]
jupiter = particles[5]
saturn = particles[6]
uranus = particles[7]
neptune = particles[8]
sun.mass = 1047.517| units.MJupiter
sun.radius = 1.0 | units.RSun
sun.position = ( 0.005717 , -0.00538 , -2.130e-5 ) | units.AU
sun.velocity = ( 0.007893 , 0.01189 , 0.0002064 ) | units.kms
mercury.mass = 0.000174 | units.MJupiter
mercury.radius = 0 | units.RSun
mercury.position = ( -0.31419 , 0.14376 , 0.035135 ) | units.AU
mercury.velocity = ( -30.729 , -41.93 , -2.659 ) | units.kms
venus.mass = 0.002564 | units.MJupiter
venus.radius = 0 | units.RSun
venus.position = ( -0.3767 , 0.60159 , 0.0393 ) | units.AU
venus.velocity = ( -29.7725 , -18.849 , 0.795 ) | units.kms
earth.mass = 0.003185 | units.MJupiter
earth.radius = 0 | units.RSun
earth.position = ( -0.98561 , 0.0762 , -7.847e-5 ) | units.AU
earth.velocity = ( -2.927 , -29.803 , -0.000533 ) | units.kms
mars.mass = 0.000338 | units.MJupiter
mars.radius = 0 | units.RSun
mars.position = ( -1.2895 , -0.9199 , -0.048494 ) | units.AU
mars.velocity = ( 14.9 , -17.721 , 0.2979 ) | units.kms
jupiter.mass = 1 | units.MJupiter
jupiter.radius = 0 | units.RSun
jupiter.position = ( -4.9829 , 2.062 , -0.10990 ) | units.AU
jupiter.velocity = ( -5.158 , -11.454 , -0.13558 ) | units.kms
saturn.mass = 0.29947 | units.MJupiter
saturn.radius = 0 | units.RSun
saturn.position = ( -2.075 , 8.7812 , 0.3273 ) | units.AU
saturn.velocity = ( -9.9109 , -2.236 , -0.2398 ) | units.kms
uranus.mass = 0.045737 | units.MJupiter
uranus.radius = 0 | units.RSun
uranus.position = ( -12.0872 , -14.1917 , 0.184214 ) | units.AU
uranus.velocity = ( 5.1377 , -4.7387 , -0.06108 ) | units.kms
neptune.mass = 0.053962 | units.MJupiter
neptune.radius = 0 | units.RSun
neptune.position = ( 3.1652 , 29.54882 , 0.476391 ) | units.AU
neptune.velocity = ( -5.443317 , 0.61054 , -0.144172 ) | units.kms
particles.move_to_center()
return particles
def get_galaxies_in_orbit(m_a=10.e11|units.MSun,
m_b=10.e11|units.MSun,
ecc=0.5,
r_min=25.|units.kpc,
t_start=None):
"""
binary galaxy with orbit of given parameters
-- if ecc=>1, start at t_start (p625, t_start=-10=-10*100Myr)
-- if ecc<1, start at apocenter (p644)
"""
converter=nbody_system.nbody_to_si(m_a+m_b,1|units.kpc)
semi = r_min/(1.-ecc)
# relative position and velocity vectors at the pericenter using kepler
kepler = Kepler_twobody(converter)
kepler.initialize_code()
kepler.initialize_from_elements(mass=(m_a+m_b), semi=semi, ecc=ecc, periastron=r_min) # at periastron
# evolve back till initial position
if ( ecc<1. ):
kepler.return_to_apastron()
else:
kepler.transform_to_time(t_start)
# get time of the orbit
t_orbit = kepler.get_time()
rl = kepler.get_separation_vector()
r = [rl[0].value_in(units.AU), rl[1].value_in(units.AU), rl[2].value_in(units.AU)] | units.AU
vl = kepler.get_velocity_vector()
v = [vl[0].value_in(units.kms), vl[1].value_in(units.kms), vl[2].value_in(units.kms)] | units.kms
kepler.stop()
# assign particle atributes
galaxies = Particles(2)
galaxies[0].mass = m_a
galaxies[0].position = (0,0,0) | units.AU
galaxies[0].velocity = (0,0,0) | units.kms
galaxies[1].mass = m_b
galaxies[1].position = r
galaxies[1].velocity = v
# identification
galaxies[0].id = 'a0'
galaxies[1].id = 'b0'
galaxies.move_to_center()
return galaxies, t_orbit
def evolve_with_kepler(self, hydro):
if self.verbose: print("evolve_with_kepler")
indices_two_most_massive = self.stars_after_encounter.mass.argsort()[-2:]
groups = [self.groups_after_encounter[i] for i in indices_two_most_massive]
old_particles = self.stars_after_encounter[indices_two_most_massive]
new_particles = Particles(2)
new_particles.mass = old_particles.mass
new_particles[0].position, new_particles[0].velocity = self.skip_to_relative_position_velocity
new_particles.move_to_center()
for group, old_particle, new_particle in zip(groups, old_particles, new_particles):
in_hydro = group.get_intersecting_subset_in(hydro.gas_particles)
if self.verbose: print(in_hydro.center_of_mass().as_quantity_in(units.RSun), old_particle.position.as_quantity_in(units.RSun), new_particle.position.as_quantity_in(units.RSun))
in_hydro.position += new_particle.position - old_particle.position
in_hydro.velocity += new_particle.velocity - old_particle.velocity
def evolve_with_kepler(self, hydro):
if self.verbose: print "evolve_with_kepler"
indices_two_most_massive = self.stars_after_encounter.mass.argsort()[-2:]
groups = [self.groups_after_encounter[i] for i in indices_two_most_massive]
old_particles = self.stars_after_encounter[indices_two_most_massive]
new_particles = Particles(2)
new_particles.mass = old_particles.mass
new_particles[0].position, new_particles[0].velocity = self.skip_to_relative_position_velocity
new_particles.move_to_center()
for group, old_particle, new_particle in zip(groups, old_particles, new_particles):
in_hydro = group.get_intersecting_subset_in(hydro.gas_particles)
if self.verbose: print in_hydro.center_of_mass().as_quantity_in(units.RSun), old_particle.position.as_quantity_in(units.RSun), new_particle.position.as_quantity_in(units.RSun)
in_hydro.position += new_particle.position - old_particle.position
in_hydro.velocity += new_particle.velocity - old_particle.velocity
def set_up_inner_binary(inclination):
semimajor_axis = triple_parameters["a_in"]
masses = triple_parameters["masses_in"]
print " Initializing inner binary"
stars = Particles(2)
stars.mass = masses
stars.position = [0.0, 0.0, 0.0] | units.AU
stars.velocity = [0.0, 0.0, 0.0] | units.km / units.s
stars[0].y = semimajor_axis
stars[0].vx = -math.cos(inclination) * get_relative_velocity_at_apastron(
stars.total_mass(), semimajor_axis, 0)
stars[0].vz = math.sin(inclination) * get_relative_velocity_at_apastron(
stars.total_mass(), semimajor_axis, 0)
stars.move_to_center()
return stars
def test4(self):
print("Testing Brutus evolve_model, 2 particles")
particles = Particles(2)
particles.mass = 0.5 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [1.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.km / units.s
particles[1].vy = (constants.G * (1.0 | units.MSun) /
(1.0 | units.AU)).sqrt()
particles.move_to_center()
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun,
1.0 | units.AU)
instance = self.new_instance_of_an_optional_code(Brutus, convert_nbody)
instance.initialize_code()
instance.parameters.bs_tolerance = 1e-6
instance.parameters.word_length = 56
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
position_at_start = primary.position.x
instance.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y,
6)
instance.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x,
6)
instance.evolve_model(P)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x,
6)
instance.cleanup_code()
instance.stop()
def set_up_inner_binary():
semimajor_axis = 0.133256133158 | units.AU
eccentricity = 0
masses = [3.2, 3.1] | units.MSun
orbital_period = (4 * numpy.pi**2 * semimajor_axis**3 /
(constants.G * masses.sum())).sqrt().as_quantity_in(units.day)
print(" Initializing inner binary")
print(" Orbital period inner binary:", orbital_period)
stars = Particles(2)
stars.mass = masses
stars.position = [0.0, 0.0, 0.0] | units.AU
stars.velocity = [0.0, 0.0, 0.0] | units.km / units.s
stars[0].x = semimajor_axis
stars[0].vy = get_relative_velocity(stars.total_mass(), semimajor_axis, eccentricity)
stars.move_to_center()
return stars
def make_circular_binary(M, m, a):
masses = [M.value_in(units.MSun), m.value_in(units.MSun)] | units.MSun
orbital_period = (
4 * numpy.pi**2 * a**3
/ (constants.G * masses.sum())
).sqrt().as_quantity_in(units.day)
print(" Initializing inner binary")
print(" Orbital period inner binary:", orbital_period)
stars = Particles(2)
stars.mass = masses
stars.position = [0.0, 0.0, 0.0] | units.AU
stars.velocity = [0.0, 0.0, 0.0] | units.km / units.s
stars[0].x = a
stars[0].vy = get_relative_velocity(stars.total_mass(), a, 0.0)
stars.move_to_center()
return stars
def set_up_inner_binary():
semimajor_axis = 0.133256133158 | units.AU
eccentricity = 0
masses = [3.2, 3.1] | units.MSun
orbital_period = (4 * numpy.pi**2 * semimajor_axis**3 /
(constants.G * masses.sum())).sqrt().as_quantity_in(units.day)
print " Initializing inner binary"
print " Orbital period inner binary:", orbital_period
stars = Particles(2)
stars.mass = masses
stars.position = [0.0, 0.0, 0.0] | units.AU
stars.velocity = [0.0, 0.0, 0.0] | units.km / units.s
stars[0].x = semimajor_axis
stars[0].vy = get_relative_velocity(stars.total_mass(), semimajor_axis, eccentricity)
stars.move_to_center()
return stars
def make_circular_binary(M, m, a):
masses = [M.value_in(units.MSun), m.value_in(units.MSun)] | units.MSun
orbital_period = (
4 * numpy.pi**2 * a**3
/ (constants.G * masses.sum())
).sqrt().as_quantity_in(units.day)
print " Initializing inner binary"
print " Orbital period inner binary:", orbital_period
stars = Particles(2)
stars.mass = masses
stars.position = [0.0, 0.0, 0.0] | units.AU
stars.velocity = [0.0, 0.0, 0.0] | units.km / units.s
stars[0].x = a
stars[0].vy = get_relative_velocity(stars.total_mass(), a, 0.0)
stars.move_to_center()
return stars
def set_up_inner_binary():
orbital_period = 835.0 | units.day
masses = [10.0, 1.1] | units.MSun
semimajor_axis = (((constants.G * masses.sum() * orbital_period**2) /
(4 * numpy.pi**2))**(1.0 / 3.0)).as_quantity_in(
units.RSun)
print " Initializing inner binary"
print " Semimajor axis inner binary:", semimajor_axis
stars = Particles(2)
stars.mass = masses
stars.position = [0.0, 0.0, 0.0] | units.AU
stars.velocity = [0.0, 0.0, 0.0] | units.km / units.s
stars[0].y = semimajor_axis
stars[0].vx = -get_relative_velocity(stars.total_mass(), semimajor_axis, 0)
stars.move_to_center()
return stars
def xtest04(self):
if MODULES_MISSING:
self.skip("Failed to import a module required for Tupan")
print("Testing Tupan evolve_model, 2 particles orbiting the SMBH")
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.km / units.s
particles[1].vy = ((constants.G * (10001.0 | units.MSun) /
(1.0 | units.AU)).sqrt() +
(constants.G * (10000.0 | units.MSun) /
(1.0 | units.AU)).sqrt())
particles.move_to_center()
print(particles)
instance = self.new_instance_of_an_optional_code(
Tupan, self.default_converter)
instance.initialize_code()
# instance.parameters.include_smbh = True
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
P_corrected = (P) * (2.0 / (1.0 + math.sqrt(1.0001)))
position_at_start = primary.position.x
instance.evolve_model(P_corrected / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y,
3)
instance.evolve_model(P_corrected / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x,
3)
instance.evolve_model(P_corrected)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x,
3)
instance.cleanup_code()
instance.stop()
def test4(self):
print "Testing MI6 evolve_model, 2 particles orbiting the SMBH"
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.km / units.s
particles[1].vy = ((constants.G * (10001.0 | units.MSun) /
(1.0 | units.AU)).sqrt() +
(constants.G * (10000.0 | units.MSun) /
(1.0 | units.AU)).sqrt())
particles.move_to_center()
print particles
instance = MI6(self.default_converter, **default_options)
instance.initialize_code()
instance.parameters.include_smbh = True
instance.parameters.lightspeed = constants.c
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
P_corrected = (P) * (2.0 / (1.0 + math.sqrt(1.0001)))
position_at_start = primary.position.x
instance.evolve_model(P_corrected / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y,
3)
instance.evolve_model(P_corrected / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x,
3)
instance.evolve_model(P_corrected)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x,
3)
instance.cleanup_code()
instance.stop()
def test05(self):
if MODULES_MISSING:
self.skip("Failed to import a module required for Sakura")
print("Testing Sakura evolve_model, 2 particles, no SMBH")
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.km / units.s
particles[1].vy = (constants.G * (2.0 | units.MSun) /
(2.0 | units.AU)).sqrt()
particles.move_to_center()
print(particles)
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
instance = self.new_instance_of_an_optional_code(
Sakura, converter, **default_options)
instance.initialize_code()
# instance.parameters.integrator_method = "asakura"
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
position_at_start = primary.position.x
instance.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y,
3)
instance.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x,
3)
instance.evolve_model(P)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x,
3)
instance.cleanup_code()
instance.stop()
def old_new_solar_system():
"""
Create initial conditions describing the solar system. Returns a single
particle set containing the sun, planets and Pluto. The model is centered at
the origin (center-of-mass(-velocity) coordinates).
Defined attributes:
name, mass, radius, x, y, z, vx, vy, vz
"""
sun = Particle()
sun.name = 'SUN'
sun.mass = 1.0 | units.MSun
sun.radius = 1.0 | units.RSun
planets = _planets_only()
particles = Particles()
particles.add_particle(sun)
particles.add_particles(planets)
particles.move_to_center()
return particles
def test4(self):
print "Testing Pikachu evolve_model, 2 particles"
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.km / units.s
particles[1].vy = (constants.G * (2.0 | units.MSun) /
(2.0 | units.AU)).sqrt()
particles.move_to_center()
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
instance = self.new_instance_of_an_optional_code(
Pikachu, converter, **default_options)
instance.initialize_code()
instance.parameters.timestep = 0.0125 * math.pi * particles[
0].x / particles[0].vy
instance.parameters.rcut_out_star_star = 10.0 | units.AU
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
position_at_start = primary.position.x
instance.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y,
3)
instance.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x,
3)
instance.evolve_model(P)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x,
3)
instance.cleanup_code()
instance.stop()
def test9(self):
print("Testing FastKick for Bridge: evolving a binary")
particles = Particles(2)
particles.mass = [3.0, 1.0] | units.MSun
particles.position = [0, 0, 0] | units.AU
particles.velocity = [0, 0, 0] | units.km / units.s
particles[1].x = 2.0 | units.AU
particles[1].vy = (constants.G * (4.0 | units.MSun) /
(2.0 | units.AU)).sqrt()
particles.move_to_center()
primary_sys = new_gravity_code(particles[:1])
secondary_sys = new_gravity_code(particles[1:])
primary = primary_sys.particles[0]
P = 2 * math.pi * primary.x / primary.vy
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
kick_from_primary = CalculateFieldForCodesUsingReinitialize(
self.new_fastkick_instance(converter), (primary_sys, ))
kick_from_secondary = CalculateFieldForCodesUsingReinitialize(
self.new_fastkick_instance(converter), (secondary_sys, ))
bridgesys = Bridge(timestep=P / 64.0)
bridgesys.add_system(primary_sys, (kick_from_secondary, ))
bridgesys.add_system(secondary_sys, (kick_from_primary, ))
position_at_start = primary.position.x
bridgesys.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y,
2)
bridgesys.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x,
2)
bridgesys.evolve_model(P)
kick_from_primary.code.stop()
kick_from_secondary.code.stop()
self.assertAlmostRelativeEqual(position_at_start, primary.position.x,
2)
def test5(self):
print "Testing MI6 evolve_model, 2 particles, no SMBH"
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.km / units.s
particles[1].vy = (constants.G * (2.0 | units.MSun) /
(2.0 | units.AU)).sqrt()
particles.move_to_center()
print particles
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
instance = MI6(converter, **default_options)
instance.initialize_code()
instance.parameters.smbh_mass = 0.0 | units.MSun
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
position_at_start = primary.position.x
instance.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y,
3)
instance.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x,
3)
instance.evolve_model(P)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x,
3)
instance.cleanup_code()
instance.stop()
def xtest04(self):
if MODULES_MISSING:
self.skip("Failed to import a module required for Sakura")
print "Testing Sakura evolve_model, 2 particles orbiting the SMBH"
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.km / units.s
particles[1].vy = (constants.G * (10001.0 | units.MSun) / (1.0 | units.AU)).sqrt() + (
constants.G * (10000.0 | units.MSun) / (1.0 | units.AU)
).sqrt()
particles.move_to_center()
print particles
instance = Sakura(self.default_converter)
instance.initialize_code()
# instance.parameters.include_smbh = True
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
P_corrected = (P) * (2.0 / (1.0 + math.sqrt(1.0001)))
position_at_start = primary.position.x
instance.evolve_model(P_corrected / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y, 3)
instance.evolve_model(P_corrected / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x, 3)
instance.evolve_model(P_corrected)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x, 3)
instance.cleanup_code()
instance.stop()
def test4(self):
print "Testing MI6 evolve_model, 2 particles orbiting the SMBH"
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.km / units.s
particles[1].vy = (constants.G * (10001.0 | units.MSun) / (1.0 | units.AU)).sqrt() + (
constants.G * (10000.0 | units.MSun) / (1.0 | units.AU)
).sqrt()
particles.move_to_center()
print particles
instance = MI6(self.default_converter, **default_options)
instance.initialize_code()
instance.parameters.include_smbh = True
instance.parameters.lightspeed = constants.c
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
P_corrected = (P) * (2.0 / (1.0 + math.sqrt(1.0001)))
position_at_start = primary.position.x
instance.evolve_model(P_corrected / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y, 3)
instance.evolve_model(P_corrected / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x, 3)
instance.evolve_model(P_corrected)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x, 3)
instance.cleanup_code()
instance.stop()
def test05(self):
if MODULES_MISSING:
self.skip("Failed to import a module required for Sakura")
print "Testing Sakura evolve_model, 2 particles, no SMBH"
particles = Particles(2)
particles.mass = 1.0 | units.MSun
particles.radius = 1.0 | units.RSun
particles.position = [[0.0, 0.0, 0.0], [2.0, 0.0, 0.0]] | units.AU
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.km / units.s
particles[1].vy = (constants.G * (2.0 | units.MSun) / (2.0 | units.AU)).sqrt()
particles.move_to_center()
print particles
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
instance = Sakura(converter)
instance.initialize_code()
# instance.parameters.integrator_method = "asakura"
instance.commit_parameters()
instance.particles.add_particles(particles)
instance.commit_particles()
primary = instance.particles[0]
P = 2 * math.pi * primary.x / primary.vy
position_at_start = primary.position.x
instance.evolve_model(P / 4.0)
self.assertAlmostRelativeEqual(position_at_start, primary.position.y, 3)
instance.evolve_model(P / 2.0)
self.assertAlmostRelativeEqual(position_at_start, -primary.position.x, 3)
instance.evolve_model(P)
self.assertAlmostRelativeEqual(position_at_start, primary.position.x, 3)
instance.cleanup_code()
instance.stop()
def randomparticles_w_ss(N=20, L=1000. | units.AU, dv=2.5 | units.kms):
from amuse.ic.salpeter import new_salpeter_mass_distribution
conv = nbody_system.nbody_to_si(N * 1. | units.MSun, 1000. | units.AU)
conv_sub = nbody_system.nbody_to_si(1. | units.MSun, 50. | units.AU)
dt = smaller_nbody_power_of_two(1000. | units.day, conv)
print(dt.in_(units.day))
dt_param = 0.02
LL = L.value_in(units.AU)
def radius(sys, eta=dt_param, _G=constants.G):
radius = ((_G * sys.total_mass() * dt**2 / eta**2)**(1. / 3.))
# xcm,ycm,zcm=sys.center_of_mass()
# r2max=((sys.x-xcm)**2+(sys.y-ycm)**2+(sys.z-zcm)**2).max()
# if radius < 10 | units.AU:
# radius=20. | units.AU
# return max(radius,r2max**0.5)
return radius * ((len(sys) + 1) / 2.)**0.75
def timestep(ipart, jpart, eta=dt_param / 2, _G=constants.G):
dx = ipart.x - jpart.x
dy = ipart.y - jpart.y
dz = ipart.z - jpart.z
dr2 = dx**2 + dy**2 + dz**2
# if dr2>0:
dr = dr2**0.5
dr3 = dr * dr2
mu = _G * (ipart.mass + jpart.mass)
tau = eta / 2. / 2.**0.5 * (dr3 / mu)**0.5
return tau
numpy.random.seed(7654304)
masses = new_salpeter_mass_distribution(N,
mass_min=0.3 | units.MSun,
mass_max=10. | units.MSun)
#masses=([1.]*10) | units.MSun
stars = Particles(N, mass=masses)
stars.x = L * numpy.random.uniform(-1., 1., N)
stars.y = L * numpy.random.uniform(-1., 1., N)
stars.z = L * 0.
stars.vx = dv * numpy.random.uniform(-1., 1., N)
stars.vy = dv * numpy.random.uniform(-1., 1., N)
stars.vz = dv * 0.
stars.radius = (1. | units.RSun) * (stars.mass /
(1. | units.MSun))**(1. / 3.)
stars.move_to_center()
parts = HierarchicalParticles(stars)
# ss=new_solar_system()[[0,5,6,7,8]]
# parts.assign_subsystem(ss,parts[0])
def parent_worker():
code = Hermite(conv)
code.parameters.epsilon_squared = 0. | units.AU**2
code.parameters.end_time_accuracy_factor = 0.
code.parameters.dt_param = 0.001
print(code.parameters.dt_dia.in_(units.yr))
return code
def sub_worker(parts):
mode = system_type(parts)
if mode == "twobody":
code = TwoBody(conv_sub)
elif mode == "solarsystem":
code = Mercury(conv_sub)
elif mode == "nbody":
code = Huayno(conv_sub)
code.parameters.inttype_parameter = code.inttypes.SHARED4
return code
def py_worker():
code = CalculateFieldForParticles(gravity_constant=constants.G)
return code
nemesis = Nemesis(parent_worker, sub_worker, py_worker)
nemesis.timestep = dt
nemesis.distfunc = timestep
nemesis.threshold = dt
nemesis.radius = radius
nemesis.commit_parameters()
nemesis.particles.add_particles(parts)
nemesis.commit_particles()
tend = 3200. | units.yr
t = 0 | units.yr
dtdiag = dt * 2
time = [0.]
allparts = nemesis.particles.all()
E = allparts.potential_energy() + allparts.kinetic_energy()
E1 = nemesis.potential_energy + nemesis.kinetic_energy
com = allparts.center_of_mass()
mom = allparts.total_momentum()
ang = allparts.total_angular_momentum()
E0 = E
A0 = (ang[0]**2 + ang[1]**2 + ang[2]**2)**0.5
P0 = mom[0].value_in(units.MSun * units.kms)
totalE = [0.]
totalA = [0.]
totalP = [0.]
ss = nemesis.particles.all()
x = (ss.x).value_in(units.AU)
xx = [x]
y = (ss.y).value_in(units.AU)
yy = [y]
nstep = 0
while t < tend - dtdiag / 2:
t += dtdiag
nemesis.evolve_model(t)
print(t.in_(units.yr))
print(len(nemesis.particles))
time.append(t.value_in(units.yr))
allparts = nemesis.particles.all()
E = allparts.potential_energy() + allparts.kinetic_energy()
E1 = nemesis.potential_energy + nemesis.kinetic_energy
ang = allparts.total_angular_momentum()
mom = allparts.total_momentum()
A = (ang[0]**2 + ang[1]**2 + ang[2]**2)**0.5
P = mom[0].value_in(units.MSun * units.kms)
totalE.append(abs((E0 - E) / E0))
totalA.append(abs((A0 - A) / A0))
totalP.append(abs(P0 - P))
print(totalE[-1], (E - E1) / E)
# print allparts.potential_energy(),nemesis.potential_energy
ss = nemesis.particles.all()
x = (ss.x).value_in(units.AU)
y = (ss.y).value_in(units.AU)
lowm = numpy.where(ss.mass.value_in(units.MSun) < 0.1)[0]
highm = numpy.where(ss.mass.value_in(units.MSun) >= 0.1)[0]
xcm = nemesis.particles.x.value_in(units.AU)
ycm = nemesis.particles.y.value_in(units.AU)
r = (nemesis.particles.radius).value_in(units.AU)
xx.append(x)
yy.append(y)
key = ss.key
f = pyplot.figure(figsize=(8, 8))
ax = f.gca()
circles = []
# for i in range(len(xx[0])):
# pyplot.plot(xx[-1][i],yy[-1][i],colors[key[i]%numpy.uint64(len(colors))]+
# markerstyles[key[i]%numpy.uint64(len(markerstyles))],markersize=8,mew=2)
pyplot.plot(xx[-1][highm], yy[-1][highm], 'go', markersize=8, mew=2)
pyplot.plot(xx[-1][lowm], yy[-1][lowm], 'b+', markersize=6, mew=1.5)
for p in nemesis.particles:
# if nemesis.particles.collection_attributes.subsystems.has_key(p):
c = 'k'
ls = 'solid'
code_colors = dict(TwoBody='b',
Mercury='r',
Huayno='g',
Hermite='y')
code_ls = dict(TwoBody='dotted',
Mercury='dashed',
Huayno='dashdot',
Hermite='solid')
if nemesis.subcodes.has_key(p):
c = code_colors[nemesis.subcodes[p].__class__.__name__]
ls = code_ls[nemesis.subcodes[p].__class__.__name__]
x = p.x.value_in(units.AU)
y = p.y.value_in(units.AU)
r = p.radius.value_in(units.AU)
circles.append(
pyplot.Circle((x, y), r, color=c, lw=0.8, ls=ls, fill=False))
for c in circles:
ax.add_artist(c)
# pyplot.plot(xcm,ycm,'k+', markersize=4,mew=1)
pyplot.xlim(-1.2 * LL, 1.2 * LL)
pyplot.ylim(-1.2 * LL, 1.2 * LL)
pyplot.xlabel("AU")
pyplot.text(-580, -580, '%8.2f' % t.value_in(units.yr), fontsize=18)
# pyplot.text(-400,-400,len(nemesis.particles),fontsize=18)
pyplot.savefig('xy%6.6i.png' % nstep, bbox_inches='tight')
f.clear()
pyplot.close(f)
nstep += 1
time = numpy.array(time)
totalE = numpy.array(totalE)
totalA = numpy.array(totalA)
totalP = numpy.array(totalP)
xx = numpy.array(xx)
yy = numpy.array(yy)
f = pyplot.figure(figsize=(8, 8))
pyplot.semilogy(time, totalE, 'r')
pyplot.semilogy(time, totalA, 'g')
pyplot.semilogy(time, totalP, 'b')
pyplot.savefig('dEdA.png')
f = pyplot.figure(figsize=(8, 8))
for i in range(len(xx[0])):
pyplot.plot(xx[:, i], yy[:, i],
colors[i % len(colors)] + linestyles[i % len(linestyles)])
pyplot.xlim(-LL, LL)
pyplot.ylim(-LL, LL)
pyplot.savefig('all-xy.png')
E_n[i] = M_to_E(M_n[i], e)
f_n = E_to_f(E_n, e)
## Generate n sets of binaries
# - fixed primary particle
primary = Particle(mass=m1,
position=[0, 0, 0] | units.AU,
velocity=[0, 0, 0] | units.AU / units.s)
secondary = Particle(mass=m2)
# - generated secondary particle and formed set
Pset_n = []
Pcenter_n = []
M_tot = []
redu_m = []
for i in range(n):
M_tot.append(primary.mass + secondary.mass)
redu_m.append(primary.mass * secondary.mass /
(primary.mass + secondary.mass))
Pset = Particles(0)
Pset.add_particle(primary)
secondary_i = kepl_to_cart(secondary, primary, a, e, i_n[i], omg_n[i],
OMG_n[i], f_n[i])
Pset.add_particle(secondary_i)
Pset_n.append(Pset)
Pcenter = Particles(0)
Pcenter.add_particle(primary)
Pcenter.add_particle(secondary_i)
Pcenter.move_to_center()
Pcenter_n.append(Pcenter)
def evolve_triple_with_wind(M1, M2, M3, Pora, Pin_0, ain_0, aout_0,
ein_0, eout_0, t_end, nsteps, scheme, integrator,
t_stellar, dt_se, dtse_fac, interp):
import random
from amuse.ext.solarsystem import get_position
numpy.random.seed(42)
print("Initial masses:", M1, M2, M3)
triple = Particles(3)
triple[0].mass = M1
triple[1].mass = M2
triple[2].mass = M3
stellar = SeBa()
stellar.particles.add_particles(triple)
channel_from_stellar = stellar.particles.new_channel_to(triple)
# Evolve to t_stellar.
stellar.evolve_model(t_stellar)
channel_from_stellar.copy_attributes(["mass"])
M1 = triple[0].mass
M2 = triple[1].mass
M3 = triple[2].mass
print("t=", stellar.model_time.in_(units.Myr))
print("M=", stellar.particles.mass.in_(units.MSun))
print("R=", stellar.particles.radius.in_(units.RSun))
print("L=", stellar.particles.luminosity.in_(units.LSun))
print("T=", stellar.particles.temperature.in_(units.K))
print("Mdot=", \
-stellar.particles.wind_mass_loss_rate.in_(units.MSun/units.yr))
# Start the dynamics.
# Inner binary:
tmp_stars = Particles(2)
tmp_stars[0].mass = M1
tmp_stars[1].mass = M2
if Pora == 1:
ain_0 = semimajor_axis(Pin_0, M1+M2)
else:
Pin_0 = orbital_period(ain_0, M1+M2)
print('Pin =', Pin_0)
print('ain_0 =', ain_0)
print('M1+M2 =', M1+M2)
print('Pin_0 =', Pin_0.value_in(units.day), '[day]')
#print 'semi:', semimajor_axis(Pin_0, M1+M2).value_in(units.AU), 'AU'
#print 'period:', orbital_period(ain_0, M1+M2).value_in(units.day), '[day]'
dt_init = 0.01*Pin_0
ma = 180
inc = 60
aop = 180
lon = 0
r,v = get_position(M1, M2, ein_0, ain_0, ma, inc, aop, lon, dt_init)
tmp_stars[1].position = r
tmp_stars[1].velocity = v
tmp_stars.move_to_center()
# Outer binary:
r,v = get_position(M1+M2, M3, eout_0, aout_0, 0, 0, 0, 0, dt_init)
tertiary = Particle()
tertiary.mass = M3
tertiary.position = r
tertiary.velocity = v
tmp_stars.add_particle(tertiary)
tmp_stars.move_to_center()
triple.position = tmp_stars.position
triple.velocity = tmp_stars.velocity
Mtriple = triple.mass.sum()
Pout = orbital_period(aout_0, Mtriple)
print("T=", stellar.model_time.in_(units.Myr))
print("M=", stellar.particles.mass.in_(units.MSun))
print("Pout=", Pout.in_(units.Myr))
print('tK =', ((M1+M2)/M3)*Pout**2*(1-eout_0**2)**1.5/Pin_0)
converter = nbody_system.nbody_to_si(triple.mass.sum(), aout_0)
if integrator == 0:
gravity = Hermite(converter)
gravity.parameters.timestep_parameter = 0.01
elif integrator == 1:
gravity = SmallN(converter)
gravity.parameters.timestep_parameter = 0.01
gravity.parameters.full_unperturbed = 0
elif integrator == 2:
gravity = Huayno(converter)
gravity.parameters.inttype_parameter = 20
gravity.parameters.timestep = (1./256)*Pin_0
else:
gravity = symple(converter)
gravity.parameters.integrator = 10
#gravity.parameters.timestep_parameter = 0.
gravity.parameters.timestep = (1./128)*Pin_0
print(gravity.parameters)
gravity.particles.add_particles(triple)
channel_from_framework_to_gd = triple.new_channel_to(gravity.particles)
channel_from_gd_to_framework = gravity.particles.new_channel_to(triple)
Etot_init = gravity.kinetic_energy + gravity.potential_energy
Etot_prev = Etot_init
gravity.particles.move_to_center()
# Note: time = t_diag = 0 at the start of the dynamical integration.
dt_diag = t_end/float(nsteps)
t_diag = dt_diag
time = 0.0 | t_end.unit
t_se = t_stellar + time
print('t_end =', t_end)
print('dt_diag =', dt_diag)
ain, ein, aout, eout = get_orbital_elements_of_triple(triple)
print("Triple elements t=", time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, \
"outer:", triple[2].mass, aout, eout)
t = [time.value_in(units.Myr)]
Mtot = triple.mass.sum()
mtot = [Mtot.value_in(units.MSun)]
smai = [ain/ain_0]
ecci = [ein/ein_0]
smao = [aout/aout_0]
ecco = [eout/eout_0]
if interp:
# Create arrays of stellar times and masses for interpolation.
times = [time]
masses = [triple.mass.copy()]
while time < t_end:
time += dt_se
stellar.evolve_model(t_stellar+time)
channel_from_stellar.copy_attributes(["mass"])
times.append(time)
masses.append(triple.mass.copy())
time = 0.0 | t_end.unit
print('\ntimes:', times, '\n')
# Evolve the system.
def advance_stellar(t_se, dt):
E0 = gravity.kinetic_energy + gravity.potential_energy
t_se += dt
if interp:
t = t_se-t_stellar
i = int(t/dt_se)
mass = masses[i] + (t-times[i])*(masses[i+1]-masses[i])/dt_se
triple.mass = mass
#print 't_se =', t_se, 'masses =', mass
else:
stellar.evolve_model(t_se)
channel_from_stellar.copy_attributes(["mass"])
channel_from_framework_to_gd.copy_attributes(["mass"])
return t_se, gravity.kinetic_energy + gravity.potential_energy - E0
def advance_gravity(tg, dt):
tg += dt
gravity.evolve_model(tg)
channel_from_gd_to_framework.copy()
return tg
while time < t_end:
if scheme == 1:
# Advance to the next diagnostic time.
dE_se = zero
dt = t_diag - time
if dt > 0|dt.unit:
time = advance_gravity(time, dt)
elif scheme == 2:
# Derive dt from Pin using dtse_fac.
dt = dtse_fac*Pin_0
if time + dt > t_diag: dt = t_diag - time
if dt > 0|dt.unit:
t_se, dE_se = advance_stellar(t_se, dt)
time = advance_gravity(time, dt)
elif scheme == 3:
# Derive dt from Pin using dtse_fac.
dt = dtse_fac*Pin_0
if time + dt > t_diag: dt = t_diag - time
if dt > 0|dt.unit:
time = advance_gravity(time, dt)
t_se, dE_se = advance_stellar(t_se, dt)
elif scheme == 4:
# Derive dt from Pin using dtse_fac.
dt = dtse_fac*Pin_0
if time + dt > t_diag: dt = t_diag - time
if dt > 0|dt.unit:
t_se, dE_se = advance_stellar(t_se, 0.5*dt)
time = advance_gravity(time, dt)
t_se, dE_se2 = advance_stellar(t_se, 0.5*dt)
dE_se += dE_se2
elif scheme == 5:
# Use the specified dt_se.
dE_se = zero
dt = dt_se
if time + dt > t_diag: dt = t_diag - time
if dt > 0|dt.unit:
# For use with symple only: set up average mass loss.
channel_from_stellar.copy_attributes(["mass"])
m0 = triple.mass.copy()
stellar.evolve_model(t_se+dt)
channel_from_stellar.copy_attributes(["mass"])
t_se = stellar.model_time
m1 = triple.mass
dmdt = (m1-m0)/dt
for i in range(len(dmdt)):
gravity.set_dmdt(i, dmdt[i])
time = advance_gravity(time, dt)
else:
print('unknown option')
sys.exit(0)
if time >= t_diag:
t_diag = time + dt_diag
Ekin = gravity.kinetic_energy
Epot = gravity.potential_energy
Etot = Ekin + Epot
dE = Etot_prev - Etot
Mtot = triple.mass.sum()
print("T=", time, end=' ')
print("M=", Mtot, "(dM[SE]=", Mtot/Mtriple, ")", end=' ')
print("E= ", Etot, "Q= ", Ekin/Epot, end=' ')
print("dE=", (Etot_init-Etot)/Etot, "ddE=", (Etot_prev-Etot)/Etot, end=' ')
print("(dE[SE]=", dE_se/Etot, ")")
Etot_init -= dE
Etot_prev = Etot
ain, ein, aout, eout = get_orbital_elements_of_triple(triple)
print("Triple elements t=", t_stellar + time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, \
"outer:", triple[2].mass, aout, eout)
t.append(time.value_in(units.yr))
mtot.append(Mtot.value_in(units.MSun))
smai.append(ain/ain_0)
ecci.append(ein/ein_0)
smao.append(aout/aout_0)
ecco.append(eout/eout_0)
if eout > 1 or aout <= zero:
print("Binary ionized or merged")
break
gravity.stop()
stellar.stop()
return t, mtot, smai, ecci, smao, ecco
def get_orbit_ini(m0,
m1,
peri,
ecc,
incl,
omega,
rel_force=0.01,
r_disk=50 | units.AU):
converter = nbody_system.nbody_to_si(1 | units.MSun, 1 | units.AU)
# semi-major axis
if ecc != 1.0:
semi = peri / (1.0 - ecc)
else:
semi = 1.0e10 | units.AU
# relative position and velocity vectors at the pericenter using kepler
kepler = Kepler_twobody(converter)
kepler.initialize_code()
kepler.initialize_from_elements(mass=(m0 + m1),
semi=semi,
ecc=ecc,
periastron=peri) # at pericenter
# moving particle backwards to radius r where: F_m1(r) = rel_force*F_m0(r_disk)
#r_disk = peri
r_ini = r_disk * (1.0 + numpy.sqrt(m1 / m0) / rel_force)
kepler.return_to_radius(radius=r_ini)
rl = kepler.get_separation_vector()
r = [
rl[0].value_in(units.AU), rl[1].value_in(units.AU), rl[2].value_in(
units.AU)
] | units.AU
vl = kepler.get_velocity_vector()
v = [
vl[0].value_in(units.kms), vl[1].value_in(units.kms), vl[2].value_in(
units.kms)
] | units.kms
period_kepler = kepler.get_period()
time_peri = kepler.get_time()
kepler.stop()
# rotation of the orbital plane by inclination and argument of periapsis
a1 = ([1.0, 0.0,
0.0], [0.0, numpy.cos(incl),
-numpy.sin(incl)], [0.0,
numpy.sin(incl),
numpy.cos(incl)])
a2 = ([numpy.cos(omega), -numpy.sin(omega),
0.0], [numpy.sin(omega), numpy.cos(omega), 0.0], [0.0, 0.0, 1.0])
rot = numpy.dot(a1, a2)
r_au = numpy.reshape(r.value_in(units.AU), 3, 1)
v_kms = numpy.reshape(v.value_in(units.kms), 3, 1)
r_rot = numpy.dot(rot, r_au) | units.AU
v_rot = numpy.dot(rot, v_kms) | units.kms
bodies = Particles(2)
bodies[0].mass = m0
bodies[0].radius = 1.0 | units.RSun
bodies[0].position = (0, 0, 0) | units.AU
bodies[0].velocity = (0, 0, 0) | units.kms
bodies[1].mass = m1
bodies[1].radius = 1.0 | units.RSun
bodies[1].x = r_rot[0]
bodies[1].y = r_rot[1]
bodies[1].z = r_rot[2]
bodies[1].vx = v_rot[0]
bodies[1].vy = v_rot[1]
bodies[1].vz = v_rot[2]
bodies.age = 0.0 | units.yr
bodies.move_to_center()
print "\t r_rel_ini = ", r_rot.in_(units.AU)
print "\t v_rel_ini = ", v_rot.in_(units.kms)
print "\t time since peri = ", time_peri.in_(units.yr)
a_orbit, e_orbit, p_orbit = orbital_parameters(r_rot, v_rot, (m0 + m1))
print "\t a = ", a_orbit.in_(
units.AU), "\t e = ", e_orbit, "\t period = ", p_orbit.in_(units.yr)
return bodies, time_peri
def new_binary_from_orbital_elements(mass1,
mass2,
semimajor_axis,
eccentricity=0,
true_anomaly=0,
inclination=0,
longitude_of_the_ascending_node=0,
argument_of_periapsis=0,
G=nbody_system.G):
"""
Function that returns two-particle Particle set, with the second
particle position and velocities computed from the input orbital
elements. angles in degrees, inclination between 0 and 180
"""
inclination = numpy.radians(inclination)
argument_of_periapsis = numpy.radians(argument_of_periapsis)
longitude_of_the_ascending_node = numpy.radians(
longitude_of_the_ascending_node)
true_anomaly = numpy.radians(true_anomaly)
cos_true_anomaly = numpy.cos(true_anomaly)
sin_true_anomaly = numpy.sin(true_anomaly)
cos_inclination = numpy.cos(inclination)
sin_inclination = numpy.sin(inclination)
cos_arg_per = numpy.cos(argument_of_periapsis)
sin_arg_per = numpy.sin(argument_of_periapsis)
cos_long_asc_nodes = numpy.cos(longitude_of_the_ascending_node)
sin_long_asc_nodes = numpy.sin(longitude_of_the_ascending_node)
### alpha is a unit vector directed along the line of node ###
alphax = cos_long_asc_nodes * cos_arg_per - sin_long_asc_nodes * sin_arg_per * cos_inclination
alphay = sin_long_asc_nodes * cos_arg_per + cos_long_asc_nodes * sin_arg_per * cos_inclination
alphaz = sin_arg_per * sin_inclination
alpha = [alphax, alphay, alphaz]
### beta is a unit vector perpendicular to alpha and the orbital angular momentum vector ###
betax = -cos_long_asc_nodes * sin_arg_per - sin_long_asc_nodes * cos_arg_per * cos_inclination
betay = -sin_long_asc_nodes * sin_arg_per + cos_long_asc_nodes * cos_arg_per * cos_inclination
betaz = cos_arg_per * sin_inclination
beta = [betax, betay, betaz]
# print 'alpha',alphax**2+alphay**2+alphaz**2 # For debugging; should be 1
# print 'beta',betax**2+betay**2+betaz**2 # For debugging; should be 1
### Relative position and velocity ###
separation = semimajor_axis * (1.0 - eccentricity**2) / (
1.0 + eccentricity * cos_true_anomaly
) # Compute the relative separation
position_vector = separation * cos_true_anomaly * alpha + separation * sin_true_anomaly * beta
velocity_tilde = (G * (mass1 + mass2) /
(semimajor_axis *
(1.0 - eccentricity**2))).sqrt() # Common factor
velocity_vector = -1.0 * velocity_tilde * sin_true_anomaly * alpha + velocity_tilde * (
eccentricity + cos_true_anomaly) * beta
result = Particles(2)
result[0].mass = mass1
result[1].mass = mass2
result[1].position = position_vector
result[1].velocity = velocity_vector
result.move_to_center()
return result
def evolve_triple_with_wind(M1, M2, M3, Pora, Pin_0, ain_0, aout_0, ein_0,
eout_0, t_end, nsteps, scheme, dtse_fac):
import random
from amuse.ext.solarsystem import get_position
time_framework = 0
print "Initial masses:", M1, M2, M3
t_stellar = 4.0 | units.Myr
triple = Particles(3)
triple[0].mass = M1
triple[1].mass = M2
triple[2].mass = M3
stellar = SeBa()
stellar.particles.add_particles(triple)
channel_from_stellar = stellar.particles.new_channel_to(triple)
t0 = ctime.time()
stellar.evolve_model(t_stellar)
delta_t = ctime.time() - t0
time_framework += delta_t
channel_from_stellar.copy_attributes(["mass"])
M1 = triple[0].mass
M2 = triple[1].mass
M3 = triple[2].mass
print "T=", stellar.model_time.in_(units.Myr)
print "M=", stellar.particles.mass.in_(units.MSun)
print "Masses at time T:", M1, M2, M3
# Inner binary
tmp_stars = Particles(2)
tmp_stars[0].mass = M1
tmp_stars[1].mass = M2
if Pora == 1:
ain_0 = semimajor_axis(Pin_0, M1 + M2)
else:
Pin_0 = orbital_period(ain_0, M1 + M2)
print 'ain_0 =', ain_0
print 'M1+M2 =', M1 + M2
print 'Pin_0 =', Pin_0.value_in(units.day), '[day]'
#print 'semi:', semimajor_axis(Pin_0, M1+M2).value_in(units.AU), 'AU'
#print 'period:', orbital_period(ain_0, M1+M2).value_in(units.day), '[day]'
dt = 0.1 * Pin_0
ma = 180
inc = 30
aop = 180
lon = 0
r, v = get_position(M1, M2, ein_0, ain_0, ma, inc, aop, lon, dt)
tmp_stars[1].position = r
tmp_stars[1].velocity = v
tmp_stars.move_to_center()
# Outer binary
r, v = get_position(M1 + M2, M3, eout_0, aout_0, 0, 0, 0, 0, dt)
tertiary = Particle()
tertiary.mass = M3
tertiary.position = r
tertiary.velocity = v
tmp_stars.add_particle(tertiary)
tmp_stars.move_to_center()
triple.position = tmp_stars.position
triple.velocity = tmp_stars.velocity
Mtriple = triple.mass.sum()
Pout = orbital_period(aout_0, Mtriple)
print "T=", stellar.model_time.in_(units.Myr)
print "M=", stellar.particles.mass.in_(units.MSun)
print "Pout=", Pout.in_(units.Myr)
converter = nbody_system.nbody_to_si(triple.mass.sum(), aout_0)
gravity = Huayno(converter)
gravity.particles.add_particles(triple)
channel_from_framework_to_gd = triple.new_channel_to(gravity.particles)
channel_from_gd_to_framework = gravity.particles.new_channel_to(triple)
Etot_init = gravity.kinetic_energy + gravity.potential_energy
Etot_prev = Etot_init
gravity.particles.move_to_center()
time = 0.0 | t_end.unit
ts = t_stellar + time # begin when stars have formed after 4.0 Myr years
ain, ein, aout, eout, iin, iout = get_orbital_elements_of_triple(triple)
print "Triple elements t=", time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, iin, \
"outer:", triple[2].mass, aout, eout, iout
dt_diag = t_end / float(
nsteps) # how often we want to save the generated data
t_diag = dt_diag
t = [time.value_in(units.Myr)]
smai = [ain / ain_0]
ecci = [ein / ein_0]
smao = [aout / aout_0]
ecco = [eout / eout_0]
inci = [iin]
inco = [iout]
ain = ain_0
def advance_stellar(ts, dt):
E0 = gravity.kinetic_energy + gravity.potential_energy
ts += dt
stellar.evolve_model(ts)
channel_from_stellar.copy_attributes(["mass"])
channel_from_framework_to_gd.copy_attributes(["mass"])
return ts, gravity.kinetic_energy + gravity.potential_energy - E0
def advance_stellar_with_massloss(
ts,
time_framework,
dt_massloss=15e-9 | units.Myr,
max_massloss=3e-4
| units.MSun): # Scheme 3: dt 8*10^-7, dm = 2*10^-5 (
max_massloss = 0.0 | units.MSun # massloss over full gravtiational time step massloss0
#max_massloss= 3e-6 | units.MSun # massloss over full gravtiational time step massloss1
#max_massloss= 1e-6 | units.MSun # massloss over full gravtiational time step massloss2
E0 = gravity.kinetic_energy + gravity.potential_energy
massloss = -1 | units.MSun
mass_0 = numpy.sum(stellar.particles.mass)
dt_stellar = 0 | units.Myr
niter = 0
while massloss < max_massloss:
ts += dt_massloss
dt_stellar += dt_massloss # counter for full time
niter += 1
t0 = ctime.time()
stellar.evolve_model(ts)
delta_t = ctime.time() - t0
time_framework += delta_t
massloss = 2. * (
mass_0 - numpy.sum(stellar.particles.mass)
) # massloss over full gravtiational time step is x2
channel_from_stellar.copy_attributes(["mass"])
channel_from_framework_to_gd.copy_attributes(["mass"])
print 'Tstellar:', dt_stellar, ', Total Mloss:', massloss, ' Niter:', niter
return ts, time_framework, gravity.kinetic_energy + gravity.potential_energy - E0, dt_stellar
def advance_gravity(tg, dt):
tg += dt
gravity.evolve_model(tg)
channel_from_gd_to_framework.copy()
return tg
global_time = []
global_massloss = []
global_dmdt = []
while time < t_end:
Pin = orbital_period(ain, triple[0].mass + triple[1].mass)
dt = dtse_fac * Pin
dt *= random.random(
) # time step is chosen random between 0 and 50*Pin
if scheme == 1:
ts, dE_se = advance_stellar(ts, dt)
time = advance_gravity(time, dt)
elif scheme == 2:
time = advance_gravity(time, dt)
ts, dE_se = advance_stellar(ts, dt)
elif scheme == 3:
# inital mass
mass_init = stellar.particles.mass.sum()
# perform step
ts, dE_se = advance_stellar(ts, dt / 2)
time = advance_gravity(time, dt)
ts, dE = advance_stellar(ts, dt / 2)
dE_se += dE
# add right vlaues
global_time = numpy.append(global_time, time.value_in(units.Myr))
global_massloss = numpy.append(
global_massloss,
mass_init.value_in(units.MSun) -
numpy.sum(stellar.particles.mass).value_in(units.MSun))
else: # our scheme is 4
# inital mass
mass_init = stellar.particles.mass.sum()
time_init = time.value_in(units.Myr) | units.Myr
# get optimal dt to perform a time step without losing too much mass
ts, time_framework, dE_se, dt_stellar = advance_stellar_with_massloss(
ts, time_framework)
# perform time step dt
t0 = ctime.time()
time = advance_gravity(time, dt_stellar * 2)
ts, dE = advance_stellar(ts, dt_stellar)
delta_t = ctime.time() - t0
time_framework += delta_t
dE_se += dE
# save everything
global_time = numpy.append(global_time, time.value_in(units.Myr))
global_massloss = numpy.append(
global_massloss,
mass_init.value_in(units.MSun) -
numpy.sum(stellar.particles.mass).value_in(units.MSun))
global_dmdt = numpy.append(
global_dmdt,
(mass_init.value_in(units.MSun) -
numpy.sum(stellar.particles.mass).value_in(units.MSun)) /
(time.value_in(units.Myr) - time_init.value_in(units.Myr)))
if time >= t_diag:
t_diag = time + dt_diag
Ekin = gravity.kinetic_energy
Epot = gravity.potential_energy
Etot = Ekin + Epot
dE = Etot_prev - Etot
Mtot = triple.mass.sum()
print "T=", time #,
#print "M=", Mtot, "(dM[SE]=", Mtot/Mtriple, ")",
#print "E= ", Etot, "Q= ", Ekin/Epot,
#print "dE=", (Etot_init-Etot)/Etot, "ddE=", (Etot_prev-Etot)/Etot,
#print "(dE[SE]=", dE_se/Etot, ")"
Etot_init -= dE
Etot_prev = Etot
ain, ein, aout, eout, iin, iout = get_orbital_elements_of_triple(
triple)
#print "Triple elements t=", (4|units.Myr) + time, \
# "inner:", triple[0].mass, triple[1].mass, ain, ein, \
# "outer:", triple[2].mass, aout, eout
t.append(time.value_in(units.Myr))
smai.append(ain / ain_0)
ecci.append(ein / ein_0)
smao.append(aout / aout_0)
ecco.append(eout / eout_0)
inci.append(iin)
inco.append(iout)
if eout > 1.0 or aout <= zero:
print "Binary ionized or merged"
break
pyplot.close()
data = numpy.array(zip(global_time, global_massloss, global_dmdt))
numpy.save('massloss0', data)
return t, smai, ecci, smao, ecco, inci, inco, time_framework
def new_binary_from_orbital_elements(
mass1,
mass2,
semimajor_axis,
eccentricity = 0,
true_anomaly = 0,
inclination = 0,
longitude_of_the_ascending_node = 0,
argument_of_periapsis = 0,
G=nbody_system.G
):
"""
Function that returns two-particle Particle set, with the second
particle position and velocities computed from the input orbital
elements. angles in degrees, inclination between 0 and 180
"""
inclination = numpy.radians(inclination)
argument_of_periapsis = numpy.radians(argument_of_periapsis)
longitude_of_the_ascending_node = numpy.radians(longitude_of_the_ascending_node)
true_anomaly = numpy.radians(true_anomaly)
cos_true_anomaly = numpy.cos(true_anomaly)
sin_true_anomaly = numpy.sin(true_anomaly)
cos_inclination = numpy.cos(inclination)
sin_inclination = numpy.sin(inclination)
cos_arg_per = numpy.cos(argument_of_periapsis)
sin_arg_per = numpy.sin(argument_of_periapsis)
cos_long_asc_nodes = numpy.cos(longitude_of_the_ascending_node)
sin_long_asc_nodes = numpy.sin(longitude_of_the_ascending_node)
### alpha is a unit vector directed along the line of node ###
alphax = cos_long_asc_nodes*cos_arg_per - sin_long_asc_nodes*sin_arg_per*cos_inclination
alphay = sin_long_asc_nodes*cos_arg_per + cos_long_asc_nodes*sin_arg_per*cos_inclination
alphaz = sin_arg_per*sin_inclination
alpha = [alphax,alphay,alphaz]
### beta is a unit vector perpendicular to alpha and the orbital angular momentum vector ###
betax = -cos_long_asc_nodes*sin_arg_per - sin_long_asc_nodes*cos_arg_per*cos_inclination
betay = -sin_long_asc_nodes*sin_arg_per + cos_long_asc_nodes*cos_arg_per*cos_inclination
betaz = cos_arg_per*sin_inclination
beta = [betax,betay,betaz]
# print 'alpha',alphax**2+alphay**2+alphaz**2 # For debugging; should be 1
# print 'beta',betax**2+betay**2+betaz**2 # For debugging; should be 1
### Relative position and velocity ###
separation = semimajor_axis*(1.0 - eccentricity**2)/(1.0 + eccentricity*cos_true_anomaly) # Compute the relative separation
position_vector = separation*cos_true_anomaly*alpha + separation*sin_true_anomaly*beta
velocity_tilde = (G*(mass1 + mass2)/(semimajor_axis*(1.0 - eccentricity**2))).sqrt() # Common factor
velocity_vector = -1.0*velocity_tilde*sin_true_anomaly*alpha + velocity_tilde*(eccentricity + cos_true_anomaly)*beta
result = Particles(2)
result[0].mass = mass1
result[1].mass = mass2
result[1].position = position_vector
result[1].velocity = velocity_vector
result.move_to_center()
return result
def evolve_triple_with_wind(M1, M2, M3, Pora, Pin_0, ain_0, aout_0,
ein_0, eout_0, t_end, nsteps, scheme, integrator,
t_stellar, dt_se, dtse_fac, interp):
import random
from amuse.ext.solarsystem import get_position
numpy.random.seed(42)
print "Initial masses:", M1, M2, M3
triple = Particles(3)
triple[0].mass = M1
triple[1].mass = M2
triple[2].mass = M3
stellar = SeBa()
stellar.particles.add_particles(triple)
channel_from_stellar = stellar.particles.new_channel_to(triple)
# Evolve to t_stellar.
stellar.evolve_model(t_stellar)
channel_from_stellar.copy_attributes(["mass"])
M1 = triple[0].mass
M2 = triple[1].mass
M3 = triple[2].mass
print "t=", stellar.model_time.in_(units.Myr)
print "M=", stellar.particles.mass.in_(units.MSun)
print "R=", stellar.particles.radius.in_(units.RSun)
print "L=", stellar.particles.luminosity.in_(units.LSun)
print "T=", stellar.particles.temperature.in_(units.K)
print "Mdot=", \
-stellar.particles.wind_mass_loss_rate.in_(units.MSun/units.yr)
# Start the dynamics.
# Inner binary:
tmp_stars = Particles(2)
tmp_stars[0].mass = M1
tmp_stars[1].mass = M2
if Pora == 1:
ain_0 = semimajor_axis(Pin_0, M1+M2)
else:
Pin_0 = orbital_period(ain_0, M1+M2)
print 'Pin =', Pin_0
print 'ain_0 =', ain_0
print 'M1+M2 =', M1+M2
print 'Pin_0 =', Pin_0.value_in(units.day), '[day]'
#print 'semi:', semimajor_axis(Pin_0, M1+M2).value_in(units.AU), 'AU'
#print 'period:', orbital_period(ain_0, M1+M2).value_in(units.day), '[day]'
dt_init = 0.01*Pin_0
ma = 180
inc = 60
aop = 180
lon = 0
r,v = get_position(M1, M2, ein_0, ain_0, ma, inc, aop, lon, dt_init)
tmp_stars[1].position = r
tmp_stars[1].velocity = v
tmp_stars.move_to_center()
# Outer binary:
r,v = get_position(M1+M2, M3, eout_0, aout_0, 0, 0, 0, 0, dt_init)
tertiary = Particle()
tertiary.mass = M3
tertiary.position = r
tertiary.velocity = v
tmp_stars.add_particle(tertiary)
tmp_stars.move_to_center()
triple.position = tmp_stars.position
triple.velocity = tmp_stars.velocity
Mtriple = triple.mass.sum()
Pout = orbital_period(aout_0, Mtriple)
print "T=", stellar.model_time.in_(units.Myr)
print "M=", stellar.particles.mass.in_(units.MSun)
print "Pout=", Pout.in_(units.Myr)
print 'tK =', ((M1+M2)/M3)*Pout**2*(1-eout_0**2)**1.5/Pin_0
converter = nbody_system.nbody_to_si(triple.mass.sum(), aout_0)
if integrator == 0:
gravity = Hermite(converter)
gravity.parameters.timestep_parameter = 0.01
elif integrator == 1:
gravity = SmallN(converter)
gravity.parameters.timestep_parameter = 0.01
gravity.parameters.full_unperturbed = 0
elif integrator == 2:
gravity = Huayno(converter)
gravity.parameters.inttype_parameter = 20
gravity.parameters.timestep = (1./256)*Pin_0
else:
gravity = symple(converter)
gravity.parameters.integrator = 10
#gravity.parameters.timestep_parameter = 0.
gravity.parameters.timestep = (1./128)*Pin_0
print gravity.parameters
gravity.particles.add_particles(triple)
channel_from_framework_to_gd = triple.new_channel_to(gravity.particles)
channel_from_gd_to_framework = gravity.particles.new_channel_to(triple)
Etot_init = gravity.kinetic_energy + gravity.potential_energy
Etot_prev = Etot_init
gravity.particles.move_to_center()
# Note: time = t_diag = 0 at the start of the dynamical integration.
dt_diag = t_end/float(nsteps)
t_diag = dt_diag
time = 0.0 | t_end.unit
t_se = t_stellar + time
print 't_end =', t_end
print 'dt_diag =', dt_diag
ain, ein, aout, eout = get_orbital_elements_of_triple(triple)
print "Triple elements t=", time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, \
"outer:", triple[2].mass, aout, eout
t = [time.value_in(units.Myr)]
Mtot = triple.mass.sum()
mtot = [Mtot.value_in(units.MSun)]
smai = [ain/ain_0]
ecci = [ein/ein_0]
smao = [aout/aout_0]
ecco = [eout/eout_0]
if interp:
# Create arrays of stellar times and masses for interpolation.
times = [time]
masses = [triple.mass.copy()]
while time < t_end:
time += dt_se
stellar.evolve_model(t_stellar+time)
channel_from_stellar.copy_attributes(["mass"])
times.append(time)
masses.append(triple.mass.copy())
time = 0.0 | t_end.unit
print '\ntimes:', times, '\n'
# Evolve the system.
def advance_stellar(t_se, dt):
E0 = gravity.kinetic_energy + gravity.potential_energy
t_se += dt
if interp:
t = t_se-t_stellar
i = int(t/dt_se)
mass = masses[i] + (t-times[i])*(masses[i+1]-masses[i])/dt_se
triple.mass = mass
#print 't_se =', t_se, 'masses =', mass
else:
stellar.evolve_model(t_se)
channel_from_stellar.copy_attributes(["mass"])
channel_from_framework_to_gd.copy_attributes(["mass"])
return t_se, gravity.kinetic_energy + gravity.potential_energy - E0
def advance_gravity(tg, dt):
tg += dt
gravity.evolve_model(tg)
channel_from_gd_to_framework.copy()
return tg
while time < t_end:
if scheme == 1:
# Advance to the next diagnostic time.
dE_se = zero
dt = t_diag - time
if dt > 0|dt.unit:
time = advance_gravity(time, dt)
elif scheme == 2:
# Derive dt from Pin using dtse_fac.
dt = dtse_fac*Pin_0
if time + dt > t_diag: dt = t_diag - time
if dt > 0|dt.unit:
t_se, dE_se = advance_stellar(t_se, dt)
time = advance_gravity(time, dt)
elif scheme == 3:
# Derive dt from Pin using dtse_fac.
dt = dtse_fac*Pin_0
if time + dt > t_diag: dt = t_diag - time
if dt > 0|dt.unit:
time = advance_gravity(time, dt)
t_se, dE_se = advance_stellar(t_se, dt)
elif scheme == 4:
# Derive dt from Pin using dtse_fac.
dt = dtse_fac*Pin_0
if time + dt > t_diag: dt = t_diag - time
if dt > 0|dt.unit:
t_se, dE_se = advance_stellar(t_se, 0.5*dt)
time = advance_gravity(time, dt)
t_se, dE_se2 = advance_stellar(t_se, 0.5*dt)
dE_se += dE_se2
elif scheme == 5:
# Use the specified dt_se.
dE_se = zero
dt = dt_se
if time + dt > t_diag: dt = t_diag - time
if dt > 0|dt.unit:
# For use with symple only: set up average mass loss.
channel_from_stellar.copy_attributes(["mass"])
m0 = triple.mass.copy()
stellar.evolve_model(t_se+dt)
channel_from_stellar.copy_attributes(["mass"])
t_se = stellar.model_time
m1 = triple.mass
dmdt = (m1-m0)/dt
for i in range(len(dmdt)):
gravity.set_dmdt(i, dmdt[i])
time = advance_gravity(time, dt)
else:
print 'unknown option'
sys.exit(0)
if time >= t_diag:
t_diag = time + dt_diag
Ekin = gravity.kinetic_energy
Epot = gravity.potential_energy
Etot = Ekin + Epot
dE = Etot_prev - Etot
Mtot = triple.mass.sum()
print "T=", time,
print "M=", Mtot, "(dM[SE]=", Mtot/Mtriple, ")",
print "E= ", Etot, "Q= ", Ekin/Epot,
print "dE=", (Etot_init-Etot)/Etot, "ddE=", (Etot_prev-Etot)/Etot,
print "(dE[SE]=", dE_se/Etot, ")"
Etot_init -= dE
Etot_prev = Etot
ain, ein, aout, eout = get_orbital_elements_of_triple(triple)
print "Triple elements t=", t_stellar + time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, \
"outer:", triple[2].mass, aout, eout
t.append(time.value_in(units.yr))
mtot.append(Mtot.value_in(units.MSun))
smai.append(ain/ain_0)
ecci.append(ein/ein_0)
smao.append(aout/aout_0)
ecco.append(eout/eout_0)
if eout > 1 or aout <= zero:
print "Binary ionized or merged"
break
gravity.stop()
stellar.stop()
return t, mtot, smai, ecci, smao, ecco
def make_model(self):
call=[self._exec]+self.arguments()
print(call)
mameclot=Popen(call, stdout=PIPE,stderr=PIPE,executable=os.path.join(self._bin_path,self._exec))
(out,err)=mameclot.communicate()
print(err)
outsplit=out.decode().strip().split("\n")
errsplit=err.decode().strip().split("\n")
if self.mass_ratio==0:
nline=errsplit[6].split()
mline=errsplit[7].split()
rline=errsplit[8].split()
N1=int(nline[2])
N2=0
mscale=(float(mline[4])/float(mline[2])) | units.MSun
rscale=(float(rline[4])/float(mline[2])) | units.parsec
else:
nline=errsplit[8].split()
n2line=errsplit[22].split()
mline=errsplit[9].split()
rline=errsplit[10].split()
N1=int(nline[2])
N2=int(n2line[2])
mscale=(float(mline[4])/float(mline[2])) | units.MSun
rscale=(float(rline[4])/float(mline[2])) | units.parsec
print(N1,N2)
N=len( outsplit)
parts=Particles(N)
masses=numpy.zeros((N,))
energy=numpy.zeros((N,))
position=numpy.zeros((N,3))
velocity=numpy.zeros((N,3))
for i,line in enumerate(outsplit):
l=line.split()
masses[i]=float(l[0])
position[i,0:3]=[float(l[1]),float(l[2]),float(l[3])]
velocity[i,0:3]=[float(l[4]),float(l[5]),float(l[6])]
energy[i]=float(l[7])
parts.mass=masses | nbody_system.mass
parts.position=position | nbody_system.length
parts.velocity=velocity | nbody_system.speed
parts.specific_energy=energy| nbody_system.specific_energy
parts.move_to_center()
if self.convert_to_physical:
print("mass scale:", mscale)
print("length scale:", rscale)
convert_nbody=nbody_system.nbody_to_si(mscale,rscale)
parts = ParticlesWithUnitsConverted(parts, convert_nbody.as_converter_from_si_to_generic())
parts = parts.copy()
self._all=parts
self._cluster1=parts[:N1]
self._cluster2=parts[N1:]
def make_model(self):
call = [self._exec] + self.arguments()
print call
mameclot = Popen(call, stdout=PIPE, stderr=PIPE, executable=os.path.join(self._bin_path, self._exec))
(out, err) = mameclot.communicate()
print err
outsplit = out.strip().split("\n")
errsplit = err.strip().split("\n")
if self.mass_ratio == 0:
nline = errsplit[6].split()
mline = errsplit[7].split()
rline = errsplit[8].split()
N1 = int(nline[2])
N2 = 0
mscale = (float(mline[4]) / float(mline[2])) | units.MSun
rscale = (float(rline[4]) / float(mline[2])) | units.parsec
else:
nline = errsplit[8].split()
n2line = errsplit[22].split()
mline = errsplit[9].split()
rline = errsplit[10].split()
N1 = int(nline[2])
N2 = int(n2line[2])
mscale = (float(mline[4]) / float(mline[2])) | units.MSun
rscale = (float(rline[4]) / float(mline[2])) | units.parsec
print N1, N2
N = len(outsplit)
parts = Particles(N)
masses = numpy.zeros((N,))
energy = numpy.zeros((N,))
position = numpy.zeros((N, 3))
velocity = numpy.zeros((N, 3))
for i, line in enumerate(outsplit):
l = line.split()
masses[i] = float(l[0])
position[i, 0:3] = [float(l[1]), float(l[2]), float(l[3])]
velocity[i, 0:3] = [float(l[4]), float(l[5]), float(l[6])]
energy[i] = float(l[7])
parts.mass = masses | nbody_system.mass
parts.position = position | nbody_system.length
parts.velocity = velocity | nbody_system.speed
parts.specific_energy = energy | nbody_system.specific_energy
parts.move_to_center()
if self.convert_to_physical:
print "mass scale:", mscale
print "length scale:", rscale
convert_nbody = nbody_system.nbody_to_si(mscale, rscale)
parts = ParticlesWithUnitsConverted(parts, convert_nbody.as_converter_from_si_to_generic())
parts = parts.copy()
self._all = parts
self._cluster1 = parts[:N1]
self._cluster2 = parts[N1:]
def evolve_triple_with_wind(M1, M2, M3, Pora, Pin_0, ain_0, aout_0,
ein_0, eout_0, t_end, nsteps, scheme, dtse_fac):
import random
from amuse.ext.solarsystem import get_position
print "Initial masses:", M1, M2, M3
t_stellar = 4.0|units.Myr
triple = Particles(3)
triple[0].mass = M1
triple[1].mass = M2
triple[2].mass = M3
stellar = SeBa()
stellar.particles.add_particles(triple)
channel_from_stellar = stellar.particles.new_channel_to(triple)
stellar.evolve_model(t_stellar)
channel_from_stellar.copy_attributes(["mass"])
M1 = triple[0].mass
M2 = triple[1].mass
M3 = triple[2].mass
print "T=", stellar.model_time.in_(units.Myr)
print "M=", stellar.particles.mass.in_(units.MSun)
print "Masses at time T:", M1, M2, M3
# Inner binary
tmp_stars = Particles(2)
tmp_stars[0].mass = M1
tmp_stars[1].mass = M2
if Pora == 1:
ain_0 = semimajor_axis(Pin_0, M1+M2)
else:
Pin_0 = orbital_period(ain_0, M1+M2)
print 'ain_0 =', ain_0
print 'M1+M2 =', M1+M2
print 'Pin_0 =', Pin_0.value_in(units.day), '[day]'
#print 'semi:', semimajor_axis(Pin_0, M1+M2).value_in(units.AU), 'AU'
#print 'period:', orbital_period(ain_0, M1+M2).value_in(units.day), '[day]'
dt = 0.1*Pin_0
ma = 180
inc = 30
aop = 180
lon = 0
r, v = get_position(M1, M2, ein_0, ain_0, ma, inc, aop, lon, dt)
tmp_stars[1].position = r
tmp_stars[1].velocity = v
tmp_stars.move_to_center()
# Outer binary
r, v = get_position(M1+M2, M3, eout_0, aout_0, 0, 0, 0, 0, dt)
tertiary = Particle()
tertiary.mass = M3
tertiary.position = r
tertiary.velocity = v
tmp_stars.add_particle(tertiary)
tmp_stars.move_to_center()
triple.position = tmp_stars.position
triple.velocity = tmp_stars.velocity
Mtriple = triple.mass.sum()
Pout = orbital_period(aout_0, Mtriple)
print "T=", stellar.model_time.in_(units.Myr)
print "M=", stellar.particles.mass.in_(units.MSun)
print "Pout=", Pout.in_(units.Myr)
converter = nbody_system.nbody_to_si(triple.mass.sum(), aout_0)
gravity = Hermite(converter)
gravity.particles.add_particles(triple)
channel_from_framework_to_gd = triple.new_channel_to(gravity.particles)
channel_from_gd_to_framework = gravity.particles.new_channel_to(triple)
Etot_init = gravity.kinetic_energy + gravity.potential_energy
Etot_prev = Etot_init
gravity.particles.move_to_center()
time = 0.0 | t_end.unit
ts = t_stellar + time
ain, ein, aout, eout = get_orbital_elements_of_triple(triple)
print "Triple elements t=", time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, \
"outer:", triple[2].mass, aout, eout
dt_diag = t_end/float(nsteps)
t_diag = dt_diag
t = [time.value_in(units.Myr)]
smai = [ain/ain_0]
ecci = [ein/ein_0]
smao = [aout/aout_0]
ecco = [eout/eout_0]
ain = ain_0
def advance_stellar(ts, dt):
E0 = gravity.kinetic_energy + gravity.potential_energy
ts += dt
stellar.evolve_model(ts)
channel_from_stellar.copy_attributes(["mass"])
channel_from_framework_to_gd.copy_attributes(["mass"])
return ts, gravity.kinetic_energy + gravity.potential_energy - E0
def advance_gravity(tg, dt):
tg += dt
gravity.evolve_model(tg)
channel_from_gd_to_framework.copy()
return tg
while time < t_end:
Pin = orbital_period(ain, triple[0].mass+triple[1].mass)
dt = dtse_fac*Pin
dt *= random.random()
if scheme == 1:
ts, dE_se = advance_stellar(ts, dt)
time = advance_gravity(time, dt)
elif scheme == 2:
time = advance_gravity(time, dt)
ts, dE_se = advance_stellar(ts, dt)
else:
dE_se = zero
#ts, dE_se = advance_stellar(ts, dt/2)
time = advance_gravity(time, dt)
#ts, dE = advance_stellar(ts, dt/2)
#dE_se += dE
if time >= t_diag:
t_diag = time + dt_diag
Ekin = gravity.kinetic_energy
Epot = gravity.potential_energy
Etot = Ekin + Epot
dE = Etot_prev - Etot
Mtot = triple.mass.sum()
print "T=", time,
print "M=", Mtot, "(dM[SE]=", Mtot/Mtriple, ")",
print "E= ", Etot, "Q= ", Ekin/Epot,
print "dE=", (Etot_init-Etot)/Etot, "ddE=", (Etot_prev-Etot)/Etot,
print "(dE[SE]=", dE_se/Etot, ")"
Etot_init -= dE
Etot_prev = Etot
ain, ein, aout, eout = get_orbital_elements_of_triple(triple)
print "Triple elements t=", (4|units.Myr) + time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, \
"outer:", triple[2].mass, aout, eout
t.append(time.value_in(units.Myr))
smai.append(ain/ain_0)
ecci.append(ein/ein_0)
smao.append(aout/aout_0)
ecco.append(eout/eout_0)
if eout > 1.0 or aout <= zero:
print "Binary ionized or merged"
break
gravity.stop()
stellar.stop()
return t, smai, ecci, smao, ecco
def get_orbit_ini(m0, m1, peri, ecc, incl, omega,
rel_force=0.01, r_disk=50|units.AU):
converter=nbody_system.nbody_to_si(1|units.MSun,1|units.AU)
# semi-major axis
if ecc!=1.0:
semi = peri/(1.0-ecc)
else:
semi = 1.0e10 | units.AU
# relative position and velocity vectors at the pericenter using kepler
kepler = Kepler_twobody(converter)
kepler.initialize_code()
kepler.initialize_from_elements(mass=(m0+m1), semi=semi, ecc=ecc, periastron=peri) # at pericenter
# moving particle backwards to radius r where: F_m1(r) = rel_force*F_m0(r_disk)
#r_disk = peri
r_ini = r_disk*(1.0 + numpy.sqrt(m1/m0)/rel_force)
kepler.return_to_radius(radius=r_ini)
rl = kepler.get_separation_vector()
r = [rl[0].value_in(units.AU), rl[1].value_in(units.AU), rl[2].value_in(units.AU)] | units.AU
vl = kepler.get_velocity_vector()
v = [vl[0].value_in(units.kms), vl[1].value_in(units.kms), vl[2].value_in(units.kms)] | units.kms
period_kepler = kepler.get_period()
time_peri = kepler.get_time()
kepler.stop()
# rotation of the orbital plane by inclination and argument of periapsis
a1 = ([1.0, 0.0, 0.0], [0.0, numpy.cos(incl), -numpy.sin(incl)], [0.0, numpy.sin(incl), numpy.cos(incl)])
a2 = ([numpy.cos(omega), -numpy.sin(omega), 0.0], [numpy.sin(omega), numpy.cos(omega), 0.0], [0.0, 0.0, 1.0])
rot = numpy.dot(a1,a2)
r_au = numpy.reshape(r.value_in(units.AU), 3, 1)
v_kms = numpy.reshape(v.value_in(units.kms), 3, 1)
r_rot = numpy.dot(rot, r_au) | units.AU
v_rot = numpy.dot(rot, v_kms) | units.kms
bodies = Particles(2)
bodies[0].mass = m0
bodies[0].radius = 1.0|units.RSun
bodies[0].position = (0,0,0) | units.AU
bodies[0].velocity = (0,0,0) | units.kms
bodies[1].mass = m1
bodies[1].radius = 1.0|units.RSun
bodies[1].x = r_rot[0]
bodies[1].y = r_rot[1]
bodies[1].z = r_rot[2]
bodies[1].vx = v_rot[0]
bodies[1].vy = v_rot[1]
bodies[1].vz = v_rot[2]
bodies.age = 0.0 | units.yr
bodies.move_to_center()
print "\t r_rel_ini = ", r_rot.in_(units.AU)
print "\t v_rel_ini = ", v_rot.in_(units.kms)
print "\t time since peri = ", time_peri.in_(units.yr)
a_orbit, e_orbit, p_orbit = orbital_parameters(r_rot, v_rot, (m0+m1))
print "\t a = ", a_orbit.in_(units.AU), "\t e = ", e_orbit, "\t period = ", p_orbit.in_(units.yr)
return bodies, time_peri
def evolve_triple_with_wind(M1, M2, M3, Pora, Pin_0, ain_0, aout_0,
ein_0, eout_0, t_end, nsteps, scheme, dtse_fac):
import random
from amuse.ext.solarsystem import get_position
print "Initial masses:", M1, M2, M3
t_stellar = 4.0|units.Myr
triple = Particles(3)
triple[0].mass = M1
triple[1].mass = M2
triple[2].mass = M3
stellar = SeBa()
stellar.particles.add_particles(triple)
channel_from_stellar = stellar.particles.new_channel_to(triple)
stellar.evolve_model(t_stellar)
channel_from_stellar.copy_attributes(["mass"])
M1 = triple[0].mass
M2 = triple[1].mass
M3 = triple[2].mass
print "T=", stellar.model_time.in_(units.Myr)
print "M=", stellar.particles.mass.in_(units.MSun)
print "Masses at time T:", M1, M2, M3
# Inner binary
tmp_stars = Particles(2)
tmp_stars[0].mass = M1
tmp_stars[1].mass = M2
if Pora == 1:
ain_0 = semimajor_axis(Pin_0, M1+M2)
else:
Pin_0 = orbital_period(ain_0, M1+M2)
print 'ain_0 =', ain_0
print 'M1+M2 =', M1+M2
print 'Pin_0 =', Pin_0.value_in(units.day), '[day]'
#print 'semi:', semimajor_axis(Pin_0, M1+M2).value_in(units.AU), 'AU'
#print 'period:', orbital_period(ain_0, M1+M2).value_in(units.day), '[day]'
dt = 0.1*Pin_0
ma = 180
inc = 30
aop = 180
lon = 0
r, v = get_position(M1, M2, ein_0, ain_0, ma, inc, aop, lon, dt)
tmp_stars[1].position = r
tmp_stars[1].velocity = v
tmp_stars.move_to_center()
# Outer binary
r, v = get_position(M1+M2, M3, eout_0, aout_0, 0, 0, 0, 0, dt)
tertiary = Particle()
tertiary.mass = M3
tertiary.position = r
tertiary.velocity = v
tmp_stars.add_particle(tertiary)
tmp_stars.move_to_center()
triple.position = tmp_stars.position
triple.velocity = tmp_stars.velocity
Mtriple = triple.mass.sum()
Pout = orbital_period(aout_0, Mtriple)
print "T=", stellar.model_time.in_(units.Myr)
print "M=", stellar.particles.mass.in_(units.MSun)
print "Pout=", Pout.in_(units.Myr)
converter = nbody_system.nbody_to_si(triple.mass.sum(), aout_0)
gravity = Hermite(converter)
gravity.particles.add_particles(triple)
channel_from_framework_to_gd = triple.new_channel_to(gravity.particles)
channel_from_gd_to_framework = gravity.particles.new_channel_to(triple)
Etot_init = gravity.kinetic_energy + gravity.potential_energy
Etot_prev = Etot_init
gravity.particles.move_to_center()
time = 0.0 | t_end.unit
ts = t_stellar + time
ain, ein, aout, eout = get_orbital_elements_of_triple(triple)
print "Triple elements t=", time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, \
"outer:", triple[2].mass, aout, eout
dt_diag = t_end/float(nsteps)
t_diag = dt_diag
t = [time.value_in(units.Myr)]
smai = [ain/ain_0]
ecci = [ein/ein_0]
smao = [aout/aout_0]
ecco = [eout/eout_0]
ain = ain_0
def advance_stellar(ts, dt):
E0 = gravity.kinetic_energy + gravity.potential_energy
ts += dt
stellar.evolve_model(ts)
channel_from_stellar.copy_attributes(["mass"])
channel_from_framework_to_gd.copy_attributes(["mass"])
return ts, gravity.kinetic_energy + gravity.potential_energy - E0
def advance_gravity(tg, dt):
tg += dt
gravity.evolve_model(tg)
channel_from_gd_to_framework.copy()
return tg
while time < t_end:
Pin = orbital_period(ain, triple[0].mass+triple[1].mass)
dt = dtse_fac*Pin
dt *= random.random()
if scheme == 1:
ts, dE_se = advance_stellar(ts, dt)
time = advance_gravity(time, dt)
elif scheme == 2:
time = advance_gravity(time, dt)
ts, dE_se = advance_stellar(ts, dt)
else:
dE_se = zero
#ts, dE_se = advance_stellar(ts, dt/2)
time = advance_gravity(time, dt)
#ts, dE = advance_stellar(ts, dt/2)
#dE_se += dE
if time >= t_diag:
t_diag = time + dt_diag
Ekin = gravity.kinetic_energy
Epot = gravity.potential_energy
Etot = Ekin + Epot
dE = Etot_prev - Etot
Mtot = triple.mass.sum()
print "T=", time,
print "M=", Mtot, "(dM[SE]=", Mtot/Mtriple, ")",
print "E= ", Etot, "Q= ", Ekin/Epot,
print "dE=", (Etot_init-Etot)/Etot, "ddE=", (Etot_prev-Etot)/Etot,
print "(dE[SE]=", dE_se/Etot, ")"
Etot_init -= dE
Etot_prev = Etot
ain, ein, aout, eout = get_orbital_elements_of_triple(triple)
print "Triple elements t=", (4|units.Myr) + time, \
"inner:", triple[0].mass, triple[1].mass, ain, ein, \
"outer:", triple[2].mass, aout, eout
t.append(time.value_in(units.Myr))
smai.append(ain/ain_0)
ecci.append(ein/ein_0)
smao.append(aout/aout_0)
ecco.append(eout/eout_0)
if eout > 1.0 or aout <= zero:
print "Binary ionized or merged"
break
gravity.stop()
stellar.stop()
return t, smai, ecci, smao, ecco
