def test_kepler(N=10000, tend=1.| units.yr,method=0):
numpy.random.seed(12345)
conv=nbody_system.nbody_to_si(2.| units.MSun, 5.|units.AU)
comets=new_plummer_model(N,conv)
sun=Particle(mass=1.|units.MSun)
sun.position=[0,0,0]|units.AU
sun.velocity=[0,0,0]|units.kms
comets.mass*=0.
code=Kepler(conv,redirection="none")
code.set_method(method)
code.central_particle.add_particle(sun)
code.orbiters.add_particles(comets)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz)
# print code.orbiters.x[0]
print orbital_elements_from_binary(code.particles[0:2],constants.G)
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2],constants.G)
# print code.orbiters.x[0]
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
dev=numpy.where(da > 0.00001)[0]
print len(dev)
print a0[dev].value_in(units.AU)
print eps0[dev]
# pyplot.plot(a0[dev].value_in(units.AU),eps0[dev],"ro")
# pyplot.plot(a[dev].value_in(units.AU),eps[dev],"g+")
print "max da,deps:",da.max(), deps.max()
print "time:",t2-t1
# pyplot.show()
return t2-t1,da.max(),deps.max()
def supernova_in_binary_nbody(M0, m0, a0, tsn):
stars = make_circular_binary(M0, m0, a0)
M, m, a, e, ta_out, inc, lan_out, aop_out = orbital_elements_from_binary(stars, G=constants.G)
print "Initial binary: a=", a.in_(units.AU), "e=", e, "M=", stars[0].mass, "and m=", stars[1].mass
converter = nbody_system.nbody_to_si(M+m, a)
gravity = Hermite(converter)
gravity.particles.add_particles(stars)
print "Integrate binary to t=", tsn.in_(units.day)
gravity.evolve_model(tsn)
M, m, a, e, ta_out, inc, lan_out, aop_out = orbital_elements_from_binary(stars, G=constants.G)
print "Pre supernova orbit: a=", a.in_(units.AU), "e=", e
stars[0].mass *= 0.1
print "Reduce stellar mass to: M=", stars[0].mass, "and m=", stars[1].mass
v_kick = (0, 0, 0) | units.kms
stars[0].velocity += v_kick
gravity.evolve_model(2*tsn)
M, m, a, e, ta_out, inc, lan_out, aop_out = orbital_elements_from_binary(stars, G=constants.G)
print "Post supernova orbit: a=", a.in_(units.AU), "e=", e
r0 = a
a_ana = post_supernova_semimajor_axis(M0, m0, stars[0].mass, stars[1].mass, a, r0)
e_ana = post_supernova_eccentricity(M0, m0, stars[0].mass, stars[1].mass, a, r0)
print "Analytic solution to post orbit orbital parameters: a=", a_ana, "e=", e_ana
gravity.stop()
def crash_test(method=1):
code=Kepler(redirection="none")
code.set_method(method)
smu=1.224744871391589
mu=smu**2
r0=2.787802728537455
rv0=-0.9899959571994231
alpha=0.01380749549277993
smudt=2.809925892593303
v02=(mu*(2/r0-alpha))
vx=rv0
vy=(v02-vx**2)**0.5
sun=Particle()
sun.mass=mu | nbody_system.mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=r0| nbody_system.length
comet.y=0. | nbody_system.length
comet.z=0. | nbody_system.length
comet.vx=vx | nbody_system.speed
comet.vy=vy | nbody_system.speed
comet.vz=0. | nbody_system.speed
tend=(smudt/smu) | nbody_system.time
print tend
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def supernova_in_binary_nbody(M0, m0, a0, tsn):
stars = make_circular_binary(M0, m0, a0)
M, m, a, e, ta_out, inc, lan_out, aop_out = orbital_elements_from_binary(
stars, G=constants.G)
print "Initial binary: a=", a.in_(
units.AU), "e=", e, "M=", stars[0].mass, "and m=", stars[1].mass
converter = nbody_system.nbody_to_si(M + m, a)
gravity = Hermite(converter)
gravity.particles.add_particles(stars)
print "Integrate binary to t=", tsn.in_(units.day)
gravity.evolve_model(tsn)
M, m, a, e, ta_out, inc, lan_out, aop_out = orbital_elements_from_binary(
stars, G=constants.G)
print "Pre supernova orbit: a=", a.in_(units.AU), "e=", e
stars[0].mass *= 0.1
print "Reduce stellar mass to: M=", stars[0].mass, "and m=", stars[1].mass
v_kick = (0, 0, 0) | units.kms
stars[0].velocity += v_kick
gravity.evolve_model(2 * tsn)
M, m, a, e, ta_out, inc, lan_out, aop_out = orbital_elements_from_binary(
stars, G=constants.G)
print "Post supernova orbit: a=", a.in_(units.AU), "e=", e
r0 = a
a_ana = post_supernova_semimajor_axis(M0, m0, stars[0].mass, stars[1].mass,
a, r0)
e_ana = post_supernova_eccentricity(M0, m0, stars[0].mass, stars[1].mass,
a, r0)
print "Analytic solution to post orbit orbital parameters: a=", a_ana, "e=", e_ana
gravity.stop()
def get_orbital_elements_of_triple(stars):
inner_binary = stars[0] + stars[1]
outer_binary = Particles(1)
outer_binary[0].mass = inner_binary.mass.sum()
outer_binary[0].position = inner_binary.center_of_mass()
outer_binary[0].velocity = inner_binary.center_of_mass_velocity()
outer_binary.add_particle(stars[2])
M1, M2, ain, ein, ta_in, inc_in, lan_in, aop_in = orbital_elements_from_binary(inner_binary, G=constants.G)
M12, M3, aout, eout, ta_out, outc_out, lan_out, aop_out = orbital_elements_from_binary(outer_binary, G=constants.G)
return ain, ein, aout, eout
def test_kepler_almost_parabolic(tend=1, method=0):
code = Kepler(redirection="none")
code.set_method(method)
mass1 = 1. | nbody_system.mass
mass2 = 0 | nbody_system.mass
semimajor_axis = 1. | nbody_system.length
eccentricity = 0.9999999
p = 2 * numpy.pi * (semimajor_axis**3 / nbody_system.G / mass1)**0.5
tend = tend * p
print(tend)
parts = new_binary_from_orbital_elements(mass1,
mass2,
semimajor_axis,
eccentricity=eccentricity,
true_anomaly=0.0102121)
code.central_particle.add_particle(parts[0])
code.orbiters.add_particle(parts[1])
a0, eps0 = elements(mass1,
code.orbiters.x,
code.orbiters.y,
code.orbiters.z,
code.orbiters.vx,
code.orbiters.vy,
code.orbiters.vz,
G=nbody_system.G)
print(orbital_elements_from_binary(code.particles[0:2]))
t1 = time.time()
code.evolve_model(tend)
t2 = time.time()
print(orbital_elements_from_binary(code.particles[0:2]))
print(code.orbiters.position)
a, eps = elements(mass1,
code.orbiters.x,
code.orbiters.y,
code.orbiters.z,
code.orbiters.vx,
code.orbiters.vy,
code.orbiters.vz,
G=nbody_system.G)
da = abs((a - a0) / a0)
deps = abs(eps - eps0) / eps0
print(da, deps)
print("time:", t2 - t1)
def get_orbital_elements_of_triple(stars):
inner_binary = stars[0]+stars[1]
outer_binary = Particles(1)
outer_binary[0].mass = inner_binary.mass.sum()
outer_binary[0].position = inner_binary.center_of_mass()
outer_binary[0].velocity = inner_binary.center_of_mass_velocity()
outer_binary.add_particle(stars[2])
M1, M2, ain, ein, ta_in, inc_in, lan_in, aop_in \
= orbital_elements_from_binary(inner_binary, G=constants.G)
M12, M3, aout, eout, ta_out, outc_out, lan_out, aop_out \
= orbital_elements_from_binary(outer_binary, G=constants.G)
return ain, ein, aout, eout
def test_kepler_parabolic( tend=1,method=0, sign=+1):
code=Kepler(redirection="none")
code.set_method(method)
sun=Particle()
sun.mass=1. | nbody_system.mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=1. | nbody_system.length
comet.y=0. | nbody_system.length
comet.z=0. | nbody_system.length
comet.vx=0. | nbody_system.speed
comet.vy=(1.0 + sign * 1.0e-10)*(2*nbody_system.G*sun.mass/comet.x)**0.5
comet.vz=0. | nbody_system.speed
tend=tend | nbody_system.time
print tend
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def kepler_orbital_elements_from_binary(two_bodies, angle=True):
"""
Kepler orbital elements from two bodies
If angle, return angle. else return cos(angle) for angle orbital elements
"""
if not angle:
return (orbital_elements_from_binary(two_bodies))
else:
mass1, mass2, semimajor_axis, eccentricity, \
true_anomaly, inclination, long_asc_node, arg_per \
= orbital_elements_from_binary(two_bodies)
return mass1, mass2, semimajor_axis, eccentricity, \
math.acos(true_anomaly), math.acos(inclination), \
math.acos(long_asc_node), math.acos(arg_per)
def kepler_orbital_elements_from_binary(two_bodies, angle = True):
"""
Kepler orbital elements from two bodies
If angle, return angle. else return cos(angle) for angle orbital elements
"""
if not angle:
return (orbital_elements_from_binary(two_bodies))
else:
mass1, mass2, semimajor_axis, eccentricity, \
true_anomaly, inclination, long_asc_node, arg_per \
= orbital_elements_from_binary(two_bodies)
return mass1, mass2, semimajor_axis, eccentricity, \
math.acos(true_anomaly), math.acos(inclination), \
math.acos(long_asc_node), math.acos(arg_per)
def evolve_model(end_time, double_star, stars):
converter = nbody_system.nbody_to_si(double_star.mass,
double_star.semimajor_axis)
gravity = Hermite(converter)
gravity.particles.add_particle(stars)
to_stars = gravity.particles.new_channel_to(stars)
# from_stars = stars.new_channel_to(gravity.particles)
time = 0 | units.yr
dt = end_time / 100.
a = [] | units.au
t = [] | units.yr
while time < end_time:
time += dt
gravity.evolve_model(1 | units.yr)
to_stars.copy()
orbital_elements = orbital_elements_from_binary(stars, G=constants.G)
a.append(orbital_elements[2])
t.append(time)
gravity.stop()
from matplotlib import pyplot
pyplot.scatter(t.value_in(units.yr), a.value_in(units.au))
pyplot.show()
def resolve_close_encounter(time, bodies):
orbital_elements = orbital_elements_from_binary(bodies, G=constants.G)
a = orbital_elements[2]
e = orbital_elements[3]
p = a*(1-e)
print "Close encounter at t=", time.in_(units.Myr), "a=", a.in_(units.AU), "e=", e, "p=", p.in_(units.AU), "M=", bodies.mass.max().in_(units.MSun), bodies.mass.min().in_(units.MSun)
truncate_disks_due_to_encounter(bodies, p)
def calculate_orbital_elements(star, planet):
p = Particles()
p.add_particle(star)
p.add_particle(planet)
M, m, a, e, ta_out, inc_out, lan_out, aop_out \
= orbital_elements_from_binary(p, G=constants.G)
return a, e
def orbital_elements(*args, **kwargs):
if 'G' not in kwargs:
kwargs['G'] = constants.G
m1, m2, a, e, f, i, W, w = orbital_elements_amuse.orbital_elements_from_binary(
*args, **kwargs)
if f < 0:
f += 360
if i < 0:
i += 360
if w < 0:
w += 360
if W < 0:
W += 360
if 'angle' in kwargs:
if kwargs['angle'] == 'radians':
i_rad = numpy.radians(i)
W_rad = numpy.radians(W)
w_rad = numpy.radians(w)
f_rad = numpy.radians(f)
return a, e, i_rad, w_rad, W_rad, f_rad
else:
return a, e, i, w, W, f
else:
return a, e, i, w, W, f
def calculate_orbital_elements(star, planet):
p = Particles()
p.add_particle(star)
p.add_particle(planet)
M, m, a, e, ta_out, outc_out, lan_out, aop_out = orbital_elements_from_binary(p, G=constants.G)
return a, e
def main(t_end, dt):
stars = init_sun_jupiter()
Sun = stars[0]
Jupiter = stars[1]
orbit0 = orbital_elements_from_binary(stars, G=constants.G)
a0 = orbit0[2].in_(units.AU)
e0 = orbit0[3]
Hill_radius0 = a0 * (1 - e0) * (
(1.0 | units.MJupiter).value_in(units.MSun) / 3.)**(1. / 3.)
eps = 1 | units.RSun
gravity = Gravity(ph4, stars, eps)
N = 500
Rmin = 1.0
Rmax = 100.0
converter = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
np.random.seed(1)
disk = ProtoPlanetaryDisk(N, convert_nbody=converter, densitypower=1.5,\
Rmin=Rmin, Rmax=Rmax, q_out=1., discfraction=0.01)
gas = disk.result
gas.h_smooth = 0.06 | units.AU
hydro = Hydro(Fi, gas, eps, dt)
sink = init_sink_particle(0. | units.MSun, Hill_radius0, Jupiter.position,
Jupiter.velocity)
hydro.particles.add_particles(sink)
a_Jup, e_Jup, times = gravity_hydro_bridge(gravity, hydro, t_end, dt)
return a_Jup, e_Jup, times
def orbital_elements(*args, **kwargs):
if 'G' not in kwargs:
kwargs['G'] = constants.G
m1, m2, a, e, f, i, W, w = orbital_elements_amuse.orbital_elements_from_binary(*args, **kwargs)
if f < 0:
f += 360
if i < 0:
i += 360
if w < 0:
w += 360
if W < 0:
W += 360
if 'angle' in kwargs:
if kwargs['angle'] == 'radians':
i_rad = numpy.radians(i)
W_rad = numpy.radians(W)
w_rad = numpy.radians(w)
f_rad = numpy.radians(f)
return a, e, i_rad, w_rad, W_rad, f_rad
else:
return a, e, i, w, W, f
else:
return a, e, i, w, W, f
def calculate_orbital_elements(star, planet):
from amuse.ext.orbital_elements import orbital_elements_from_binary
p = Particles()
p.add_particle(star)
p.add_particle(planet)
M, m, a, e, ta_out, inc, lan_out, aop_out = orbital_elements_from_binary(p, G=constants.G)
#print "Orbital elements:", M, m, a, e, ta_out, inc, lan_out, aop_out
return a, e, inc
def test_kepler_almost_parabolic( tend=1,method=0):
code=Kepler(redirection="none")
code.set_method(method)
mass1=1.| nbody_system.mass
mass2=0| nbody_system.mass
semimajor_axis=1.|nbody_system.length
eccentricity=0.9999999
p=2*numpy.pi*(semimajor_axis**3/nbody_system.G/mass1)**0.5
tend=tend*p
print tend
parts=new_binary_from_orbital_elements(
mass1,
mass2,
semimajor_axis,
eccentricity = eccentricity,
true_anomaly = 0.0102121
)
code.central_particle.add_particle(parts[0])
code.orbiters.add_particle(parts[1])
a0,eps0=elements(mass1,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(mass1,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def gravity_hydro_bridge(gravity, hydro, t_end, dt):
model_time = 0 | units.yr
filename = "gravhydro.hdf5"
#write_set_to_file(stars.savepoint(model_time), filename, 'amuse')
#write_set_to_file(gas, filename, 'amuse')
gravhydro = bridge.Bridge(use_threading=False)
gravhydro.add_system(gravity, (hydro, ))
gravhydro.add_system(hydro, (gravity, ))
gravhydro.timestep = 2 * hydro.get_timestep()
a_Jup = list()
e_Jup = list()
disk_size = list()
# start evolotuion
print 'Start evolving...'
times = quantities.arange(0. | units.yr, t_end + dt, dt)
while model_time < t_end:
stars = gravity.local_particles
orbit = orbital_elements_from_binary(stars, G=constants.G)
a = orbit[2].value_in(units.AU)
e = orbit[3]
if model_time.value_in(units.yr) % 50 == 0:
print "Time:", model_time.in_(units.yr), \
"ae=", a ,e
a_Jup.append(a)
e_Jup.append(e)
model_time += gravhydro.timestep
gravhydro.evolve_model(model_time)
gravity.copy_to_framework()
hydro.copy_to_framework()
sink = hydro.local_particles[0]
_ = hydro_sink_particles([sink], hydro.local_particles[1:])
Jupiter = gravity.local_particles[1]
Jupiter.mass += sink.mass
sink.position = Jupiter.position
sink.radius = a * (1 - e) * (
(1.0 | units.MJupiter).value_in(units.MSun) / 3.)**(1. /
3.) | units.au
gravity.copy_to_framework()
hydro.copy_to_framework()
write_set_to_file(stars.savepoint(model_time), filename, 'amuse')
write_set_to_file(ism, filename, 'amuse')
print "P=", model_time.in_(units.yr), gravity.particles.x.in_(units.au)
gravity.stop()
hydro.stop()
return a_Jup, e_Jup, times
def main(t_end=1000. | units.yr, dt=10. | units.yr):
print 'Initializing...'
converter = nbody_system.nbody_to_si(1. | units.MSun, 1. | units.AU)
# Initialize the gravity system
Sun_and_Jupiter = init_sun_jupiter()
Sun = Sun_and_Jupiter[0]
Jupiter = Sun_and_Jupiter[1]
orbit0 = orbital_elements_from_binary(Sun_and_Jupiter, G=constants.G)
a0 = orbit0[2].in_(units.AU)
e0 = orbit0[3]
Hill_radius0 = a0 * (1 - e0) * (
(1.0 | units.MJupiter).value_in(units.MSun) / 3.)**(1. / 3.)
# Initialising the direct N-body integrator
gravity = ph4(converter)
gravity.particles.add_particle(Jupiter)
gravity.timestep = dt
# Setting proto-disk parameters
N = 4000
Mstar = 1. | units.MSun
Mdisk = 0.01 * Mstar
Rmin = 2.
Rmax = 100.
# Initialising the proto-planetary disk
np.random.seed(1)
disk = ProtoPlanetaryDisk(N,
convert_nbody=converter,
densitypower=1.5,
Rmin=Rmin,
Rmax=Rmax,
q_out=1.,
discfraction=Mdisk / Mstar)
disk_gas = disk.result
# Initialize the sink particle
sink = init_sink_particle(0. | units.MSun, Hill_radius0, Jupiter.position,
Jupiter.velocity)
# Initialising the SPH code
sph = Fi(converter, mode="openmp")
sph.gas_particles.add_particles(disk_gas)
sph.dm_particles.add_particle(Sun)
sph.parameters.timestep = dt
# bridge and evolve
a_Jup, e_Jup, disk_size, times, accreted_mass = gravity_hydro_bridge(
gravity, sph, sink, [Sun_and_Jupiter, disk_gas], Rmin, t_end, dt)
return a_Jup, e_Jup, disk_size, times, accreted_mass
def evolve_model(end_time, double_star, stars):
time = 0 | units.yr
dt = end_time/100.
converter = nbody_system.nbody_to_si(double_star.mass,
double_star.semimajor_axis)
gravity = Hermite(converter)
gravity.particles.add_particle(stars)
to_stars = gravity.particles.new_channel_to(stars)
# from_stars = stars.new_channel_to(gravity.particles)
massloss_code = CodeWithMassLoss(gravity, ())
gravml = bridge.Bridge(use_threading=False)
gravml.timestep = 0.5*dt
gravml.add_system(gravity,)
gravml.add_code(massloss_code)
a = [] | units.au
e = []
m = [] | units.MSun
t = [] | units.yr
while time < end_time:
time += dt
gravml.evolve_model(time)
to_stars.copy()
orbital_elements = orbital_elements_from_binary(stars,
G=constants.G)
a.append(orbital_elements[2])
e.append(orbital_elements[3])
m.append(stars.mass.sum())
t.append(time)
print("time=", time.in_(units.yr),
"a=", a[-1].in_(units.RSun),
"e=", e[-1],
"m=", stars.mass.in_(units.MSun))
gravity.stop()
from matplotlib import pyplot
fig, axis = pyplot.subplots(nrows=2, ncols=2, sharex=True)
axis[0][0].scatter(t.value_in(units.yr), a.value_in(units.RSun))
axis[0][0].set_ylabel("a [$R_\odot$]")
axis[0][1].scatter(t.value_in(units.yr), m.value_in(units.MSun))
axis[0][1].set_ylabel("M [$M_\odot$]")
axis[1][1].scatter(t.value_in(units.yr), e)
axis[1][1].set_ylabel("e")
axis[1][1].set_xlabel("time [yr]")
axis[1][0].set_xlabel("time [yr]")
pyplot.savefig("mloss_bridge.png")
pyplot.show()
def main(t_end=1000. | units.yr, dt=10. | units.yr):
print 'Initializing...'
converter = nbody_system.nbody_to_si(1. | units.MSun, 1. | units.AU)
# Initialize the gravity system
Sun_and_Jupiter = init_sun_jupiter()
Sun = Sun_and_Jupiter[0]
Jupiter = Sun_and_Jupiter[1]
orbit0 = orbital_elements_from_binary(Sun_and_Jupiter, G=constants.G)
a0 = orbit0[2].in_(units.AU)
e0 = orbit0[3]
Hill_radius0 = a0 * (1 - e0) * (
(1.0 | units.MJupiter).value_in(units.MSun) / 3.)**(1. / 3.)
gravity = ph4(converter)
gravity.particles.add_particles(Sun_and_Jupiter)
gravity.timestep = dt
# initialize the hydrodynamics(SPH) system
# initialize the protoplanetary disk
N = 1000
Mstar = 1. | units.MSun
Mdisk = 0.01 * Mstar
Rmin = 2.
Rmax = 100.
np.random.seed(1)
disk = ProtoPlanetaryDisk(N,
convert_nbody=converter,
densitypower=1.5,
Rmin=Rmin,
Rmax=Rmax,
q_out=1.)
disk_gas = disk.result
disk_gas.h_smooth = 0.06 | units.AU
# initialize the sink particle
sink = init_sink_particle(0. | units.MSun, Hill_radius0, Jupiter.position,
Jupiter.velocity)
sph = Fi(converter)
sph.particles.add_particles(sink)
sph.gas_particles.add_particles(disk_gas)
sph.parameters.timestep = dt
# bridge and evolve
a_Jup, e_Jup, disk_size, times = gravity_hydro_bridge(gravity, sph, \
[Sun_and_Jupiter, disk_gas], Rmin, t_end, dt)
return a_Jup, e_Jup, disk_size, times
def gravity_hydro_bridge(Mprim, Msec, a, ecc, t_end, n_steps, Rgas, Mgas,
Ngas):
stars = new_binary_from_orbital_elements(Mprim,
Msec,
a,
ecc,
G=constants.G)
eps = 1 | units.RSun
gravity = Gravity(ph4, stars, eps)
converter = nbody_system.nbody_to_si(1.0 | units.MSun, Rgas)
ism = new_plummer_gas_model(Ngas, convert_nbody=converter)
ism.move_to_center()
ism = ism.select(lambda r: r.length() < 2 * a, ["position"])
hydro = Hydro(Fi, ism, eps)
model_time = 0 | units.Myr
filename = "gravhydro.hdf5"
write_set_to_file(stars.savepoint(model_time), filename, 'amuse')
write_set_to_file(ism, filename, 'amuse')
gravhydro = bridge.Bridge(use_threading=False)
gravhydro.add_system(gravity, (hydro, ))
gravhydro.add_system(hydro, (gravity, ))
gravhydro.timestep = 2 * hydro.get_timestep()
while model_time < t_end:
orbit = orbital_elements_from_binary(stars, G=constants.G)
a = orbit[2]
ecc = orbit[3]
dE_gravity = gravity.initial_total_energy / gravity.total_energy
dE_hydro = hydro.initial_total_energy / hydro.total_energy
print "Time:", model_time.in_(units.yr), "ae=", a.in_(
units.AU), ecc, "dE=", dE_gravity, dE_hydro
model_time += 10 * gravhydro.timestep
gravhydro.evolve_model(model_time)
gravity.copy_to_framework()
hydro.copy_to_framework()
write_set_to_file(stars.savepoint(model_time), filename, 'amuse')
write_set_to_file(ism, filename, 'amuse')
gravity.stop()
hydro.stop()
def test5(self):
numpy.random.seed(4567893)
N=100
mass1=random.random(N) | units.MSun
mass2=random.random(N) | units.MSun
semi_major_axis=(-numpy.log(random.random(N))) | units.AU
eccentricity = random.random(N)
true_anomaly = 360.*random.random(N)-180.
inclination = 180*random.random(N)
longitude_of_the_ascending_node = 360*random.random(N)-180
argument_of_periapsis = 360*random.random(N)-180
for arg in zip(mass1,mass2,semi_major_axis,eccentricity,true_anomaly,inclination,
longitude_of_the_ascending_node,argument_of_periapsis):
arg_=orbital_elements_from_binary(new_binary_from_orbital_elements(*arg,G=constants.G),G=constants.G)
for i,(copy,org) in enumerate(zip(arg_,arg)):
self.assertAlmostEquals(copy,org)
def test_distribution(bodies):
from determine_orbital_elements import calculate_orbital_elements_for_single_planet
asteroids = bodies[bodies.type == b"debris"]
star = bodies[bodies.type == b"star"]
print(star)
print(asteroids)
p = Particles()
p.add_particle(star)
from amuse.ext.orbital_elements import orbital_elements_from_binary
sma = [] | units.au
ecc = []
for ai in asteroids:
p.add_particle(ai)
M, m, a, e, ta_out, inc, lan_out, aop_out = orbital_elements_from_binary(
p, G=constants.G)
sma.append(a)
ecc.append(e)
p.remove_particle(ai)
"""
def test4(self):
numpy.random.seed(3456789)
N = 100
mass1 = random.random(N) | nbody_system.mass
mass2 = random.random(N) | nbody_system.mass
semi_major_axis = (-numpy.log(random.random(N))) | nbody_system.length
eccentricity = random.random(N)
true_anomaly = 360. * random.random(N) - 180.
inclination = 180 * random.random(N)
longitude_of_the_ascending_node = 360 * random.random(N) - 180
argument_of_periapsis = 360 * random.random(N) - 180
for arg in zip(mass1, mass2, semi_major_axis, eccentricity,
true_anomaly, inclination,
longitude_of_the_ascending_node, argument_of_periapsis):
arg_ = orbital_elements_from_binary(
new_binary_from_orbital_elements(*arg))
for i, (copy, org) in enumerate(zip(arg_, arg)):
self.assertAlmostEquals(copy, org)
def gravity_hydro_bridge(Mprim, Msec, a, ecc, t_end, n_steps, Rgas, Mgas, Ngas):
stars = new_binary_from_orbital_elements(Mprim, Msec, a, ecc, G=constants.G)
eps = 1 | units.RSun
gravity = Gravity(ph4, stars, eps)
converter=nbody_system.nbody_to_si(1.0|units.MSun, Rgas)
ism = new_plummer_gas_model(Ngas, convert_nbody=converter)
ism.move_to_center()
ism = ism.select(lambda r: r.length()<2*a,["position"])
hydro = Hydro(Fi, ism, eps)
model_time = 0 | units.Myr
filename = "gravhydro.hdf5"
write_set_to_file(stars.savepoint(model_time), filename, 'amuse')
write_set_to_file(ism, filename, 'amuse')
gravhydro = bridge.Bridge(use_threading=False)
gravhydro.add_system(gravity, (hydro,) )
gravhydro.add_system(hydro, (gravity,) )
gravhydro.timestep = 2*hydro.get_timestep()
while model_time < t_end:
orbit = orbital_elements_from_binary(stars, G=constants.G)
a = orbit[2]
ecc = orbit[3]
dE_gravity = gravity.initial_total_energy/gravity.total_energy
dE_hydro = hydro.initial_total_energy/hydro.total_energy
print "Time:", model_time.in_(units.yr), "ae=", a.in_(units.AU), ecc, "dE=", dE_gravity, dE_hydro
model_time += 10*gravhydro.timestep
gravhydro.evolve_model(model_time)
gravity.copy_to_framework()
hydro.copy_to_framework()
write_set_to_file(stars.savepoint(model_time), filename, 'amuse')
write_set_to_file(ism, filename, 'amuse')
gravity.stop()
hydro.stop()
def evolve_sun_jupiter(particles, tend, dt):
SunJupiter = Particles()
SunJupiter.add_particle(particles[0])
SunJupiter.add_particle(particles[1])
converter=nbody_system.nbody_to_si(particles.mass.sum(), particles[1].position.length())
gravity = ph4(converter)
gravity.particles.add_particles(particles)
channel_from_to_SunJupiter = gravity.particles.new_channel_to(SunJupiter)
semi_major_axis = list()
eccentricity = list()
times = quantities.arange(0|units.yr, tend+dt, dt)
for i,t in enumerate(times):
#print "Time =", t.in_(units.yr)
channel_from_to_SunJupiter.copy()
orbital_elements = orbital_elements_from_binary(SunJupiter, G=constants.G)
a = orbital_elements[2]
e = orbital_elements[3]
semi_major_axis.append(a.value_in(units.AU))
eccentricity.append(e)
gravity.evolve_model(t, timestep=dt)
gravity.stop()
# save the data: times, semi_major_axis and eccentricity of Jupiter's orbit
t_a_e = np.column_stack((times.value_in(units.yr), semi_major_axis, eccentricity))
np.savetxt('t_a_e.txt', t_a_e, delimiter=',')
# make plots
fig = plt.figure(figsize = (8, 6))
ax1 = fig.add_subplot(211, xlabel = 'time(yr)', ylabel = 'semi major axis (AU)')
ax1.plot(times.value_in(units.yr), semi_major_axis)
ax2 = fig.add_subplot(212, xlabel = 'time(yr)', ylabel = 'eccentriity')
ax2.plot(times.value_in(units.yr), eccentricity)
plt.show()
def evolve_sun_jupiter(particles, tend, dt):
SunJupiter = Particles()
SunJupiter.add_particle(particles[0])
SunJupiter.add_particle(particles[1])
converter = nbody_system.nbody_to_si(particles.mass.sum(),
particles[1].position.length())
gravity = ph4(converter)
gravity.particles.add_particles(particles)
channel_from_to_SunJupiter = gravity.particles.new_channel_to(SunJupiter)
semi_major_axis = []
eccentricity = []
times = quantities.arange(0 | units.yr, tend, dt)
for i, t in enumerate(times):
print "Time=", t.in_(units.yr)
channel_from_to_SunJupiter.copy()
orbital_elements = orbital_elements_from_binary(SunJupiter,
G=constants.G)
a = orbital_elements[2]
e = orbital_elements[3]
semi_major_axis.append(a.value_in(units.AU))
eccentricity.append(e)
gravity.evolve_model(t, timestep=dt)
# Plot
fig = plt.figure(figsize=(8, 6))
ax1 = fig.add_subplot(211,
xlabel='time(yr)',
ylabel='semi major axis (AU)')
ax1.plot(times.value_in(units.yr), semi_major_axis)
ax2 = fig.add_subplot(212, xlabel='time(yr)', ylabel='eccentriity')
ax2.plot(times.value_in(units.yr), eccentricity)
plt.show()
gravity.stop()
def test2(self):
m_star = 0.666 | units.MSun
a_min = 666. | units.AU
a_max = 6666. | units.AU
q_min = 6. | units.AU
cloud = new_isotropic_cloud(66,
m_star=m_star,
a_min=a_min,
a_max=a_max,
q_min=q_min)
binary = Particles(1)
binary[0].mass = m_star
binary[0].position = (0., 0., 0.) | units.AU
binary[0].velocity = (0., 0., 0.) | units.kms
for comet in cloud:
binary.add_particle(comet)
mass1, mass2, semimajor_axis, eccentricity, true_anomaly, inclination, long_asc_node, arg_per = \
orbital_elements_from_binary(binary, G=constants.G)
print mass1, mass2, semimajor_axis, eccentricity, true_anomaly, inclination, long_asc_node, arg_per
self.assertTrue(a_min < semimajor_axis < a_max)
self.assertTrue(q_min < semimajor_axis * (1. - eccentricity))
binary.remove_particle(comet)
def test2(self):
m_star = 0.666|units.MSun
a_min=666.|units.AU
a_max=6666.|units.AU
q_min=6.|units.AU
cloud = new_isotropic_cloud(66,
m_star=m_star,
a_min=a_min,
a_max=a_max,
q_min=q_min)
binary = Particles(1)
binary[0].mass = m_star
binary[0].position = (0.,0.,0.) | units.AU
binary[0].velocity = (0.,0.,0.) | units.kms
for comet in cloud:
binary.add_particle(comet)
mass1, mass2, semimajor_axis, eccentricity, true_anomaly, inclination, long_asc_node, arg_per = \
orbital_elements_from_binary(binary, G=constants.G)
print mass1, mass2, semimajor_axis, eccentricity, true_anomaly, inclination, long_asc_node, arg_per
self.assertTrue( a_min < semimajor_axis < a_max )
self.assertTrue( q_min < semimajor_axis*(1.-eccentricity) )
binary.remove_particle(comet)
def init_body_solar_disk_planetary(Ndisk, Mdisk, Rmin, Rmax):
print 'Initializing...'
#converter = nbody_system.nbody_to_si(1.|units.MJupiter, 1.|units.AU)
# Initialize the solar system
Sun_Jupiter = init_sun_jupiter()
Sun = Sun_Jupiter[0]
Jupiter = Sun_Jupiter[1]
orbit = orbital_elements_from_binary(Sun_Jupiter, G=constants.G)
a = orbit[2].in_(units.AU)
e = orbit[3]
hr = Hill_radius(a, e, Sun_Jupiter)
# Initialize the proto-planetary disk
np.random.seed(1)
disk_converter = nbody_system.nbody_to_si(Sun.mass, Rmin)
disk = ProtoPlanetaryDisk(Ndisk,
convert_nbody=disk_converter,
densitypower=1.5,
Rmin=1.0,
Rmax=Rmax / Rmin,
q_out=1.0,
discfraction=Mdisk / Sun.mass)
disk_gas = disk.result
# Initialize the sink particle
sink = init_sink_particle(0. | units.MSun, hr, Jupiter.position,
Jupiter.velocity)
# Initizalize the passing star
e = 1.2
Mstar = 2.0 | units.MSun
pericenter = 200.0 | units.AU
Pstar = init_passing_star(pericenter, e, Mstar)
return Sun_Jupiter, disk_gas, sink, Pstar
def get_ffp_in_orbit(m0, m_ffp, b, r_inf, parabolic_velocity):
m0_and_ffp_in_orbit = Particles(2)
zero_p = 0.0 | nbody_system.length
zero_v = 0.0 | nbody_system.speed
#Central star
m0_and_ffp_in_orbit[0].mass = m0
m0_and_ffp_in_orbit[0].position = (zero_p,zero_p,zero_p)
m0_and_ffp_in_orbit[0].velocity = (zero_v,zero_v,zero_v)
#Free-floating planet
m0_and_ffp_in_orbit[1].mass = m_ffp
m0_and_ffp_in_orbit[1].position = (-r_inf,-b,zero_p)
m0_and_ffp_in_orbit[1].velocity = (parabolic_velocity,zero_v,zero_v)
m1, m2, sma, e, ta, i, lan, ap = orbital_elements_from_binary(m0_and_ffp_in_orbit)
#For the star it sets the initial values of semimajoraxis and eccentricity of the ffp
m0_and_ffp_in_orbit.eccentricity = e
m0_and_ffp_in_orbit.semimajoraxis = sma
return m0_and_ffp_in_orbit
def t_linear(tend=1, N=100, method=0):
code = Kepler(redirection="none")
code.set_method(method)
mass = 1. | nbody_system.mass
x = 1. | nbody_system.length
vx = 0 | nbody_system.speed
e = 0.5 * vx**2 - nbody_system.G * mass / x
semimajor_axis = -nbody_system.G * mass / 2 / e
p = 2 * numpy.pi * (semimajor_axis**3 / nbody_system.G / mass)**0.5
print(semimajor_axis)
print(p)
tend = tend * p
dt = p / N
sun = Particle()
sun.mass = mass
sun.x = 0. | nbody_system.length
sun.y = 0. | nbody_system.length
sun.z = 0. | nbody_system.length
sun.vx = 0. | nbody_system.speed
sun.vy = 0. | nbody_system.speed
sun.vz = 0. | nbody_system.speed
comet = Particle()
comet.mass = 0 | nbody_system.mass
comet.x = x
comet.y = 0. | nbody_system.length
comet.z = 0. | nbody_system.length
comet.vx = vx
comet.vy = 0. | nbody_system.speed
comet.vz = 0. | nbody_system.speed
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0, eps0 = elements(sun.mass,
code.orbiters.x,
code.orbiters.y,
code.orbiters.z,
code.orbiters.vx,
code.orbiters.vy,
code.orbiters.vz,
G=nbody_system.G)
print(orbital_elements_from_binary(code.particles[0:2]))
#pyplot.ion()
#f=pyplot.figure(figsize=(8,6))
#pyplot.show()
tnow = 0 * tend
time = []
xs = []
while tnow < tend:
tnow += dt
print(tnow, int(tnow / dt))
code.evolve_model(tnow)
#f.clf()
time.append(tnow / tend)
xs.append(code.orbiters.x[0].number)
#pyplot.plot(time,xs,"r+")
#pyplot.xlim(-0.1,1.1)
#pyplot.ylim(-1.1,3.1)
#pyplot.draw()
print(orbital_elements_from_binary(code.particles[0:2]))
print(code.orbiters.position)
a, eps = elements(sun.mass,
code.orbiters.x,
code.orbiters.y,
code.orbiters.z,
code.orbiters.vx,
code.orbiters.vy,
code.orbiters.vz,
G=nbody_system.G)
da = abs((a - a0) / a0)
deps = abs(eps - eps0) / eps0
print(da, deps)
input()
def crash_test2(method=1):
code=Kepler(redirection="none")
code.set_method(method)
"""
mu=struct.unpack('!d','3ff7ffffffffffff'.decode('hex'))[0]
dt=struct.unpack('!d','40025ab746b00001'.decode('hex'))[0]
pos1=struct.unpack('!d','bfed36dc82998ed4'.decode('hex'))[0]
pos2=struct.unpack('!d','40051297fc6e5256'.decode('hex'))[0]
pos3=struct.unpack('!d','0000000000000000'.decode('hex'))[0]
vel1=struct.unpack('!d','3fb09d8008ba33b9'.decode('hex'))[0]
vel2=struct.unpack('!d','bff06788b551b81d'.decode('hex'))[0]
vel3=struct.unpack('!d','0000000000000000'.decode('hex'))[0]
"""
mu=float.fromhex("0x1.8p+0")
dt=float.fromhex("0x1.25ab746bp+1")
pos1=float.fromhex("-0x1.d36dc82998ed4p-1")
pos2=float.fromhex("0x1.51297fc6e5256p+1")
pos3=float.fromhex("0x0p+0")
vel1=float.fromhex("0x1.09d8008ba33b9p-4")
vel2=float.fromhex("-0x1.06788b551b81ep+0")
vel3=float.fromhex("0x0p+0")
sun=Particle()
sun.mass=mu | nbody_system.mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=pos1 | nbody_system.length
comet.y=pos2 | nbody_system.length
comet.z=pos3 | nbody_system.length
comet.vx=vel1 | nbody_system.speed
comet.vy=vel2 | nbody_system.speed
comet.vz=vel3 | nbody_system.speed
tend=dt | nbody_system.time
print tend,mu
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def evolve_gravity(bodies, number_of_planets, converter, t_end, n_steps, n_snapshots, bodies_filename):
#Particles that will be saved in the file
bodies_to_save = Particles(number_of_planets+2)
#Positions and velocities centered on the center of mass
bodies.move_to_center()
time = 0. | nbody_system.time
dt = t_end / float(n_steps)
dt_snapshots = t_end / float(n_snapshots)
gravity = initialize_code(bodies, timestep_parameter = dt.value_in(nbody_system.time))
channel_from_gr_to_framework = gravity.particles.new_channel_to(bodies)
x = AdaptingVectorQuantity()
y = AdaptingVectorQuantity()
times = AdaptingVectorQuantity()
system_energies = AdaptingVectorQuantity()
E_initial = gravity.kinetic_energy + gravity.potential_energy
DeltaE_max = 0.0 | nbody_system.energy
while time<=t_end:
gravity.evolve_model(time)
channel_from_gr_to_framework.copy()
bodies.collection_attributes.timestamp = time
gravity.particles.collection_attributes.timestamp = time
x.append(bodies.x)
y.append(bodies.y)
times.append(time)
star = bodies[0]
ffp = bodies[1]
bp = bodies[2]
#Orbital elements for star and bounded_planet
binary = [star, bp]
m1, m2, sma, e, ta, i, lan, ap = orbital_elements_from_binary(binary)
bodies[2].eccentricity = e
bodies[2].semimajoraxis = sma
#Orbital elements for star+bp and ffp
cm_x = (star.mass*star.x + bp.mass*bp.x)/(star.mass+bp.mass)
cm_y = (star.mass*star.y + bp.mass*bp.y)/(star.mass+bp.mass)
cm_vx = (star.mass*star.vx + bp.mass*bp.vx)/(star.mass+bp.mass)
cm_vy = (star.mass*star.vy + bp.mass*bp.vy)/(star.mass+bp.mass)
star_bp = Particles(1)
star_bp.mass = star.mass + bp.mass
star_bp.position = [cm_x, cm_y, 0.0 | units.AU]
star_bp.velocity = [cm_vx, cm_vy, 0.0 | units.kms]
binary = [star_bp, ffp]
m1, m2, sma, e, ta, i, lan, ap = orbital_elements_from_binary(binary)
bodies[1].eccentricity = e
bodies[1].semimajoraxis = sma
print star.mass, bp.mass, ffp.mass
print m1, m2
E = gravity.kinetic_energy + gravity.potential_energy
system_energies.append(E)
DeltaE = abs(E-E_initial)
if ( DeltaE > DeltaE_max ):
DeltaE_max = DeltaE
save_particles_to_file(bodies, bodies_to_save, bodies_filename, time, converter)
time += dt_snapshots
max_energy_change = DeltaE_max/E_initial
gravity.stop()
return x,y,times,system_energies,max_energy_change
def evolve_gravity(bodies, number_of_planets, converter, t_end, n_steps):
#Positions and velocities centered on the center of mass
bodies.move_to_center()
time = 0. | nbody_system.time
dt = t_end / float(n_steps)
gravity = initialize_code(bodies, timestep_parameter = dt.value_in(nbody_system.time))
channel_from_gr_to_framework = gravity.particles.new_channel_to(bodies)
x = AdaptingVectorQuantity()
y = AdaptingVectorQuantity()
times = AdaptingVectorQuantity()
#Order: 12, 23, 31
eccentricities = []
semimajoraxes = []
Etot_init = gravity.kinetic_energy + gravity.potential_energy
Etot = Etot_init
DeltaE_max = 0.0 | nbody_system.energy
times.append(time)
system_energies = [Etot.value_in(nbody_system.energy)]
while time<=t_end:
gravity.evolve_model(time)
channel_from_gr_to_framework.copy()
bodies.collection_attributes.timestamp = time
gravity.particles.collection_attributes.timestamp = time
x.append(bodies.x)
y.append(bodies.y)
times.append(time)
for i in range(0,number_of_planets+2):
for j in range(i+1,number_of_planets+2):
binary = [bodies[i], bodies[j]]
massA, massB, semimajor_axis, eccentricity, true_anomaly, inclination, long_asc_node, arg_per = orbital_elements_from_binary(binary)
eccentricities.append(eccentricity)
semimajoraxes.append(semimajor_axis.value_in(nbody_system.length))
Etot = gravity.kinetic_energy + gravity.potential_energy
DeltaE = abs(Etot-Etot_init)
system_energies.append(Etot.value_in(nbody_system.energy))
if ( DeltaE > DeltaE_max ):
DeltaE_max = DeltaE
time += dt
print "Energy Change: max(|E_j - E_initial|)/E_initial = ", DeltaE_max/Etot_init
results = ['flyby', 'temporary capture', 'exchange','nothing']
#results = [0,1,2,-1]
planets_star_energies = []
for i in range(0,number_of_planets):
planet_star_energy = energies_binaries(bodies, 0, i+2).value_in(nbody_system.energy)
planets_star_energies.append(planet_star_energy)
planets_star_energy = sum(planets_star_energies)
ffp_star_energy = energies_binaries(bodies, 0, 1).value_in(nbody_system.energy)
if (planets_star_energy<0 and ffp_star_energy>0):
res = results[0]
elif (planets_star_energy<0 and ffp_star_energy<0):
res = results[1]
elif (planets_star_energy>0 and ffp_star_energy<0):
res = results[2]
else:
#res = 'something that is not flyby, exchange or temporary capture has happened!'
res = results[3]
print res
gravity.stop()
return x,y,times,numpy.array(system_energies),numpy.array(eccentricities),numpy.array(semimajoraxes)
def test_softening(method=1):
code=Kepler(redirection="none")
code.set_method(method)
dt=float.fromhex("0x1.67b39e372f04dp+4")
mu=float.fromhex("0x1.fffffffffffdfp-3")
e2=float.fromhex("0x1.0000000000003p+0")
pos1=float.fromhex("0x1.1b76542265052p-1")
pos2=float.fromhex("0x1.0c4dbda42097cp-6")
pos3=float.fromhex("0x1.54fd66cd1e212p-3")
vel1=float.fromhex("0x1.d6ef43d58ca7ep-2")
vel2=float.fromhex("0x1.7a85379e59794p-2")
vel3=float.fromhex("-0x1.5421044d1acffp-1")
sun=Particle()
sun.mass=mu | nbody_system.mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=pos1 | nbody_system.length
comet.y=pos2 | nbody_system.length
comet.z=pos3 | nbody_system.length
comet.vx=vel1 | nbody_system.speed
comet.vy=vel2 | nbody_system.speed
comet.vz=vel3 | nbody_system.speed
tend=dt | nbody_system.time
print tend,mu
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
code.parameters.epsilon_squared = e2 | nbody_system.length**2
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def main(t_end=1000. | units.yr, dt=10. | units.yr):
print 'Initializing...'
#converter = nbody_system.nbody_to_si(1.|units.MSun, 1.|units.AU)
# Initialize the Sun and Jupiter system
Sun, Jupiter = init_star_planet()
Sun_and_Jupiter0 = Particles()
Sun_and_Jupiter0.add_particle(Sun)
Sun_and_Jupiter0.add_particle(Jupiter)
orbit0 = orbital_elements_from_binary(Sun_and_Jupiter0, G=constants.G)
a0 = orbit0[2].in_(units.AU)
e0 = orbit0[3]
Hill_radius0 = a0 * (1 - e0) * (
(1.0 | units.MJupiter).value_in(units.MSun) / 3.)**(1. / 3.)
# Initialize the passing star
PassStar = Particle()
PassStar.mass = 2.0 | units.MSun
r_ps = 200. | units.AU
a_ps = 1000. | units.AU
mu = PassStar.mass * Sun.mass / (PassStar.mass + Sun.mass)
vx = np.sqrt(constants.G * mu * (2. / r_ps - 1. / a_ps)).in_(units.kms)
PassStar.velocity = (-vx, 0. | units.kms, 0. | units.kms)
ds = (Jupiter.position - Sun.position).value_in(units.AU)
sin_theta = ds[2] / np.sqrt(ds[0]**2 + ds[1]**2)
cos_theta = np.sqrt(1 - sin_theta**2)
PassStar.position = (Sun.position).in_(units.AU) + (
(0., 200. * cos_theta, 200. * sin_theta) | units.AU)
# Initialize the direct N-body integrator
gravity_particles = Particles()
gravity_particles.add_particle(Jupiter)
gravity_particles.add_particle(PassStar)
converter_gravity = nbody_system.nbody_to_si(
gravity_particles.mass.sum(), gravity_particles.position.length())
gravity = ph4(converter_gravity)
gravity.particles.add_particles(gravity_particles)
gravity.timestep = dt
# Set proto-disk parameters
N = 4000
Mstar = 1. | units.MSun
Mdisk = 0.01 * Mstar
Rmin = 1. | units.AU
Rmax = 100. | units.AU
# Initialize the proto-planetary disk
np.random.seed(1)
converter_disk = nbody_system.nbody_to_si(Mstar, Rmin)
disk = ProtoPlanetaryDisk(N,
convert_nbody=converter_disk,
densitypower=1.5,
Rmin=1.,
Rmax=Rmax / Rmin,
q_out=1.,
discfraction=Mdisk / Mstar)
disk_gas = disk.result
disk_star = Particles()
disk_star.add_particle(Sun)
# Initialize the sink particle
sink = init_sink_particle(0. | units.MSun, Hill_radius0, Jupiter.position,
Jupiter.velocity)
# Initialising the SPH code
#converter_hydro = nbody_system.nbody_to_si(Mdisk, Rmax)
sph = Fi(converter_disk, mode="openmp")
sph.gas_particles.add_particles(disk_gas)
sph.dm_particles.add_particle(disk_star)
sph.parameters.timestep = dt
# bridge and evolve
times, a_Jup, e_Jup, disk_size, accreted_mass = gravity_hydro_bridge(gravity, sph, sink,\
[gravity_particles, disk_star, disk_gas], Rmin, t_end, dt)
return times, a_Jup, e_Jup, disk_size, accreted_mass
def gravity_hydro_bridge(gravity,
hydro,
sink,
local_particles,
Rmin,
t_end=1000. | units.yr,
dt=10. | units.yr):
# Set the local particles in each system
gravity_particles, disk_star, disk_gas = local_particles
Sun = disk_star[0]
Jupiter = gravity_particles[0]
PassStar = gravity_particles[1]
Mstar = Sun.mass.in_(units.MSun)
Sun_and_Jupiter = Particles()
Sun_and_Jupiter.add_particle(Sun)
Sun_and_Jupiter.add_particle(Jupiter)
print 'Bridging...'
# Build up the bridge between gravity and hydrodynamics
grav_hydro = bridge.Bridge(use_threading=False)
grav_hydro.add_system(gravity, (hydro, ))
grav_hydro.add_system(hydro, (gravity, ))
grav_hydro.timestep = dt
# Set up channels for updating the particles
channel_to_grav = gravity.particles.new_channel_to(gravity_particles)
channel_from_grav = gravity_particles.new_channel_to(gravity.particles)
channel_to_hydro_gas = hydro.gas_particles.new_channel_to(disk_gas)
channel_from_hydro_gas = disk_gas.new_channel_to(hydro.gas_particles)
channel_to_hydro_star = hydro.dm_particles.new_channel_to(disk_star)
chennel_from_hydro_star = disk_star.new_channel_to(hydro.dm_particles)
# Sanity checks:
print('Sanity checks:')
print('Sun coordinates (AU)', Sun.x.value_in(units.AU),
Sun.y.value_in(units.AU), Sun.z.value_in(units.AU))
print('Jupiter coordinates (AU)', Jupiter.x.value_in(units.AU),
Jupiter.y.value_in(units.AU), Jupiter.z.value_in(units.AU))
print('Disk particle map saved to: initial_check_disk.png')
plot_map(hydro, [Sun, Jupiter, PassStar], N=400, L=400,\
title='initial_check_disk.png', show=True)
times = list(
np.arange(0.0,
t_end.value_in(units.yr) + dt.value_in(units.yr),
dt.value_in(units.yr)))
a_Jup = list()
e_Jup = list()
disk_size = list()
accreted_mass = list()
# start evolotuion
print 'Start evolving...'
model_time = 0.0 | units.yr
while model_time <= t_end:
# Save the data for plots
orbit = orbital_elements_from_binary(Sun_and_Jupiter, G=constants.G)
a = orbit[2].value_in(units.AU)
e = orbit[3]
lr9 = return_L9_radius(disk_gas, Mstar, Rmin)
a_Jup.append(a)
e_Jup.append(e)
disk_size.append(lr9)
accreted_mass.append((sink.mass).value_in(units.MJupiter)[0])
#if model_time.value_in(units.yr) % 50 == 0:
print 'Time = %.1f yr:'%model_time.value_in(units.yr), \
'a = %.2f au, e = %.3f,'%(a, e), \
'disk size = %.2f au'%lr9, \
'accreted mass = %.2f M_Jupiter'%sink.mass.value_in(units.MJupiter)
plot_map(hydro, [Sun, Jupiter, PassStar], N=400, L=400,\
title='test_plots/%d.png'%model_time.value_in(units.yr), show=False)
# Evolve the bridge system for one step
model_time += dt
grav_hydro.evolve_model(model_time)
channel_to_grav.copy()
channel_to_hydro_gas.copy()
channel_to_hydro_star.copy()
# Add the 'sinked' mass to Jupiter & keep the sink particle along with Jupiter
removed_particles = hydro_sink_particles(sink, disk_gas)
Jupiter.mass += sink.mass
sink.position = Jupiter.position
sink.radius = a * (1 - e) * (
(1.0 | units.MJupiter).value_in(units.MSun) / 3.)**(1. /
3.) | units.au
channel_from_grav.copy()
gravity.stop()
hydro.stop()
return times, a_Jup, e_Jup, disk_size, accreted_mass
def evolve_model(end_time, double_star, stars):
time = 0 | units.yr
converter = nbody_system.nbody_to_si(double_star.mass,
double_star.semimajor_axis)
#time = 10.0017596364 | units.yr
#inname = "binstar_10.0017596364.hdf5"
#stars = read_set_from_file(inname, "hdf5")
gravity = Hermite(converter)
gravity.particles.add_particle(stars)
to_stars = gravity.particles.new_channel_to(stars)
from_stars = stars.new_channel_to(gravity.particles)
period = (2 * numpy.pi *
(double_star.semimajor_axis * double_star.semimajor_axis *
double_star.semimajor_axis /
(constants.G * double_star.mass)).sqrt())
print("Period =", period.as_string_in(units.yr))
dt = period / 32.
print("Mass loss timestep =", dt)
print("Steps per period: = {:1.2f}".format(period / dt))
print("Radii", stars.radius)
print("Taulag", stars.taulag)
print("K", stars.kaps)
QT = QuickTides(double_star.semimajor_axis, double_star.eccentricity,
stars[0].mass, stars[1].mass, stars[0].radius,
stars[1].radius, stars[0].kaps, stars[1].kaps,
stars[0].taulag, stars[1].taulag)
print(stars)
a_an = [] | units.au
e_an = []
atemp = double_star.semimajor_axis
etemp = double_star.eccentricity
a = [] | units.au
e = []
m = [] | units.MSun
t = [] | units.yr
while time < end_time:
time += dt
gravity.evolve_model(time)
to_stars.copy()
dadt, dedt = QT.dadt_dedt(atemp, etemp)
atemp = atemp + dadt * dt
etemp = etemp + dedt * dt
a_an.append(atemp)
e_an.append(etemp)
kick_stars_tides(stars, dt)
from_stars.copy()
orbital_elements = orbital_elements_from_binary(stars, G=constants.G)
a.append(orbital_elements[2])
e.append(orbital_elements[3])
m.append(stars.mass.sum())
t.append(time)
if check_collision(stars): break
print("time=",
time.in_(units.yr),
"a=",
a[-1].in_(units.RSun),
"e=",
e[-1],
"m=",
stars.mass.in_(units.MSun),
end="\r")
gravity.stop()
from matplotlib import pyplot
fig, axis = pyplot.subplots(nrows=2, ncols=2, sharex=True)
axis[0][0].plot(t.value_in(units.yr), a.value_in(units.au), label="nbody")
axis[0][0].plot(t.value_in(units.yr),
a_an.value_in(units.au),
label="analytic")
axis[0][0].set_ylabel("a [$R_\odot$]")
axis[0][0].legend()
write_set_to_file(stars,
"binstar_" + str(time.value_in(units.yr)) + ".hdf5",
"hdf5")
numpy.savetxt(
"ae_{:d}.txt".format(numpy.random.randint(0, 1000)),
numpy.vstack([t.value_in(units.yr),
a.value_in(units.au), e]).T)
axis[0][1].plot(t.value_in(units.yr), m.value_in(units.MSun))
axis[0][1].set_ylabel("M [$M_\odot$]")
axis[1][1].plot(t.value_in(units.yr), e)
axis[1][1].plot(t.value_in(units.yr), e_an)
axis[1][1].set_ylabel("e")
axis[1][1].set_xlabel("time [yr]")
axis[1][0].set_xlabel("time [yr]")
pyplot.savefig("mloss.png")
pyplot.show()
def t_linear(tend=1,N=100,method=0):
code=Kepler(redirection="none")
code.set_method(method)
mass=1. | nbody_system.mass
x=1. | nbody_system.length
vx=0 | nbody_system.speed
e=0.5*vx**2-nbody_system.G*mass/x
semimajor_axis=-nbody_system.G*mass/2/e
p=2*numpy.pi*(semimajor_axis**3/nbody_system.G/mass)**0.5
print semimajor_axis
print p
tend=tend*p
dt=p/N
sun=Particle()
sun.mass=mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=x
comet.y=0. | nbody_system.length
comet.z=0. | nbody_system.length
comet.vx=vx
comet.vy=0. | nbody_system.speed
comet.vz=0. | nbody_system.speed
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
#pyplot.ion()
#f=pyplot.figure(figsize=(8,6))
#pyplot.show()
tnow=0*tend
time=[]
xs=[]
while tnow<tend:
tnow+=dt
print tnow,int(tnow/dt)
code.evolve_model(tnow)
#f.clf()
time.append(tnow/tend)
xs.append(code.orbiters.x[0].number)
#pyplot.plot(time,xs,"r+")
#pyplot.xlim(-0.1,1.1)
#pyplot.ylim(-1.1,3.1)
#pyplot.draw()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
raw_input()
def gravity_hydro_bridge(gravity,
hydro,
sink,
local_particles,
Rmin,
t_end=1000. | units.yr,
dt=10. | units.yr):
Sun_and_Jupiter, disk_gas = local_particles
Mstar = 1.0 | units.MSun
print 'Bridging...'
# Build up the bridge between gravity and hydrodynamics
grav_hydro = bridge.Bridge(use_threading=False)
grav_hydro.add_system(gravity, (hydro, ))
grav_hydro.add_system(hydro, (gravity, ))
grav_hydro.timestep = dt
# Set up channels for updating the particles
channel_from_grav = gravity.particles.new_channel_to(Sun_and_Jupiter)
channel_from_hydro = hydro.gas_particles.new_channel_to(disk_gas)
channel_to_grav = Sun_and_Jupiter.new_channel_to(gravity.particles)
channel_to_hydro = disk_gas.new_channel_to(hydro.gas_particles)
# Preparing lists for data-recording
a_Jup = []
e_Jup = []
disk_size = []
accreted_mass = []
accreted_mass.append((sink.mass).value_in(units.MJupiter)[0])
sink0_mass = 0 | units.MJupiter
# Start evolution
print 'Start evolving...'
times = quantities.arange(0. | units.yr, t_end + 1 * dt, dt)
model_time = 0.0 | units.yr
while model_time <= t_end:
# Save the data for plots
orbit = orbital_elements_from_binary(Sun_and_Jupiter, G=constants.G)
a = orbit[2].value_in(units.AU)
e = orbit[3]
lr9 = return_L9_radius(disk_gas, Mstar, Rmin | units.AU)
a_Jup.append(a)
e_Jup.append(e)
disk_size.append(lr9)
am = (sink.mass[0]).value_in(units.MJupiter)
accreted_mass.append(am)
# Plotting system
print 'Time = %.1f yr:'%model_time.value_in(units.yr), \
'a = %.2f au, e = %.2f,'%(a, e), \
'disk size = %.2f au'%lr9
plot_map(hydro,
Sun_and_Jupiter,
'{0}'.format(int(model_time.value_in(units.yr))),
show=False)
# Evolve the bridge system for one step
model_time += dt
grav_hydro.evolve_model(model_time)
channel_from_grav.copy()
channel_from_hydro.copy()
# Calculating accreted mass in new position
Jupiter = gravity.particles[0]
sink.position = Jupiter.position
sink.radius = Hill_radius(a, e, Sun_and_Jupiter) | units.AU
removed_particles = hydro_sink_particles(sink, disk_gas)
Jupiter.mass += sink.mass - sink0_mass
sink0_mass = sink.mass.copy()
channel_to_grav.copy()
channel_to_hydro.copy()
gravity.stop()
hydro.stop()
return a_Jup, e_Jup, disk_size, times, accreted_mass
def evolve_gravity(bodies, number_of_planets, converter, t_end, n_steps, n_snapshots, path):
#Particles that will be saved in the file
bodies_to_save = Particles(number_of_planets+2)
#Positions and velocities centered on the center of mass
bodies.move_to_center()
time = 0. | nbody_system.time
dt = t_end / float(n_steps)
dt_snapshots = t_end / float(n_snapshots)
gravity = initialize_code(bodies, timestep_parameter = dt.value_in(nbody_system.time))
channel_from_gr_to_framework = gravity.particles.new_channel_to(bodies)
x = AdaptingVectorQuantity()
y = AdaptingVectorQuantity()
times = AdaptingVectorQuantity()
system_energies = AdaptingVectorQuantity()
E_initial = gravity.kinetic_energy + gravity.potential_energy
DeltaE_max = 0.0 | nbody_system.energy
snapshot_number = 1
os.system('mkdir ./files/'+path)
while time<=t_end:
gravity.evolve_model(time)
channel_from_gr_to_framework.copy()
bodies.collection_attributes.timestamp = time
gravity.particles.collection_attributes.timestamp = time
x.append(bodies.x)
y.append(bodies.y)
times.append(time)
E = gravity.kinetic_energy + gravity.potential_energy
system_energies.append(E)
DeltaE = abs(E-E_initial)
if ( DeltaE > DeltaE_max ):
DeltaE_max = DeltaE
#Orbital Elements
star = bodies[0]
ffp = bodies[1]
bp = bodies[2]
#Star and FFP
binary = [star, ffp]
m1, m2, sma_star_ffp, e_star_ffp = my_orbital_elements_from_binary(binary)
bodies[1].eccentricity = e_star_ffp
bodies[1].semimajoraxis = sma_star_ffp
#Star and BP
binary = [star, bp]
m1, m2, sma_star_bp, e_star_bp = my_orbital_elements_from_binary(binary)
bodies[2].eccentricity = e_star_bp
bodies[2].semimajoraxis = sma_star_bp
save_particles_to_file(bodies, bodies_to_save, './files/'+path+'/'+str(snapshot_number)+'.hdf5', time, converter)
# if (snapshot_number == 5):
# break
time += dt_snapshots
snapshot_number += 1
#To get last orbital elements
#Star and FFP
binary = [star, ffp]
b1_mass1, b1_mass2, b1_semimajor_axis, b1_eccentricity, b1_true_anomaly, b1_inclination, b1_long_asc_node, b1_arg_per = orbital_elements_from_binary(binary)
#Star and BP
binary = [star, bp]
b2_mass1, b2_mass2, b2_semimajor_axis, b2_eccentricity, b2_true_anomaly, b2_inclination, b2_long_asc_node, b2_arg_per = orbital_elements_from_binary(binary)
#To check Hill stability
#Star+BP and FFP
cm_x = (star.mass*star.x + bp.mass*bp.x)/(star.mass+bp.mass)
cm_y = (star.mass*star.y + bp.mass*bp.y)/(star.mass+bp.mass)
cm_vx = (star.mass*star.vx + bp.mass*bp.vx)/(star.mass+bp.mass)
cm_vy = (star.mass*star.vy + bp.mass*bp.vy)/(star.mass+bp.mass)
star_bp = Particles(1)
star_bp.mass = star.mass + bp.mass
star_bp.position = [cm_x, cm_y, 0.0 | nbody_system.length]
star_bp.velocity = [cm_vx, cm_vy, 0.0 | nbody_system.speed]
binary = [star_bp[0], ffp]
m1, m2, sma_starbp_ffp, e_starbp_ffp = my_orbital_elements_from_binary(binary)
bodies[1].eccentricity = e_starbp_ffp
bodies[1].semimajoraxis = sma_starbp_ffp
max_energy_change = DeltaE_max/E_initial
is_stable = is_hill_stable(bodies.mass, bodies.semimajoraxis, bodies.eccentricity, converter)
gravity.stop()
return x, y, times, system_energies, max_energy_change, is_stable,converter.to_si(b1_semimajor_axis).value_in(units.AU), b1_eccentricity, b1_true_anomaly, b1_inclination, b1_long_asc_node, b1_arg_per, converter.to_si(b2_semimajor_axis).value_in(units.AU), b2_eccentricity, b2_true_anomaly, b2_inclination, b2_long_asc_node, b2_arg_per
def evolve_model(end_time, double_star, stars):
time = 0 | units.yr
dt = 0.5 * end_time / 1000. * 2
converter = nbody_system.nbody_to_si(double_star.mass,
double_star.semimajor_axis)
stars2 = stars.copy()
gravity = Hermite(converter)
gravity.particles.add_particle(stars)
to_stars = gravity.particles.new_channel_to(stars)
from_stars = stars.new_channel_to(gravity.particles)
gravity2 = Hermite(converter)
gravity2.particles.add_particle(stars2)
to_stars2 = gravity2.particles.new_channel_to(stars2)
from_stars2 = stars2.new_channel_to(gravity2.particles)
period = (2 * numpy.pi *
(double_star.semimajor_axis * double_star.semimajor_axis *
double_star.semimajor_axis /
(constants.G * double_star.mass)).sqrt())
print("Period =", period.as_string_in(units.yr))
print("Mass loss timestep =", dt)
print("Steps per period: = {:1.2f}".format(period / dt))
a_an = [] | units.au
e_an = []
atemp = double_star.semimajor_axis
etemp = double_star.eccentricity
a = [] | units.au
e = []
ome = []
a2 = [] | units.au
e2 = []
ome2 = []
m1 = [] | units.MSun
m2 = [] | units.MSun
t = [] | units.yr
while time < end_time:
time += dt
gravity.evolve_model(time)
gravity2.evolve_model(time)
to_stars.copy()
to_stars2.copy()
dmdtloss = mass_loss_rate(stars.mass)
dmdtacc = dmdt_acc(dmdtloss)
orbital_elements = orbital_elements_from_binary(stars, G=constants.G)
orbital_elements2 = orbital_elements_from_binary(stars2, G=constants.G)
# etemp = orbital_elements[3]
# atemp = orbital_elements[2]
dadt = dadt_masschange(atemp, stars.mass, dmdtloss + dmdtacc)
dedt = dedt_masschange(etemp, stars.mass, dmdtloss + dmdtacc)
dadt += dadt_momentumchange(atemp, etemp, stars.mass, dmdtacc)
dedt += dedt_momentumchange(etemp, stars.mass, dmdtacc)
h = (constants.G * stars.mass.sum() * atemp * (1 - etemp * etemp))**0.5
dhdt = dhdt_momentumchange(h, stars.mass, dmdtacc)
atemp = atemp + dadt * dt
etemp = etemp + dedt * dt
a_an.append(atemp)
e_an.append(etemp)
kick_from_accretion(stars, dmdtacc, dt)
dhdt_dadt_to_kick(stars2, dhdt, dadt, dmdtloss + dmdtacc, dt)
stars.mass += (dmdtloss + dmdtacc) * dt
stars2.mass += (dmdtloss + dmdtacc) * dt
from_stars.copy()
from_stars2.copy()
a.append(orbital_elements[2])
e.append(orbital_elements[3])
ome.append(orbital_elements[7])
a2.append(orbital_elements2[2])
e2.append(orbital_elements2[3])
ome2.append(orbital_elements2[7])
m1.append(stars[0].mass)
m2.append(stars[1].mass)
t.append(time)
print("time=", time.in_(units.yr), "a=", a[-1].in_(units.RSun), "e=",
e[-1], "m=", stars.mass.in_(units.MSun), "end=\r")
gravity.stop()
gravity2.stop()
from matplotlib import pyplot
pyplot.rc('text', usetex=True)
pyplot.rcParams.update({'font.size': 16})
fig, axis = pyplot.subplots(nrows=2, ncols=2, sharex=True, figsize=(13, 6))
axis[0][0].plot(t.value_in(units.yr),
a.value_in(units.RSun),
label="nbody (direct)",
lw=2)
axis[0][0].plot(t.value_in(units.yr),
a2.value_in(units.RSun),
label="nbody (heuristic)",
lw=2,
ls="--")
axis[0][0].plot(t.value_in(units.yr),
a_an.value_in(units.RSun),
label="analytic",
lw=2,
ls="-.")
axis[0][0].set_ylabel("a [$R_\odot$]")
axis[0][0].legend()
axis[0][1].plot(t.value_in(units.yr),
m1.value_in(units.MSun),
label="m1",
lw=2,
c="tab:red")
axis[0][1].plot(t.value_in(units.yr),
m2.value_in(units.MSun),
label="m2",
lw=2,
c="tab:cyan")
axis[0][1].set_ylabel("M [$M_\odot$]")
axis[0][1].legend()
axis[1][1].plot(t.value_in(units.yr), e, lw=2)
axis[1][1].plot(t.value_in(units.yr), e2, lw=2, ls="--")
axis[1][1].plot(t.value_in(units.yr), e_an, lw=2, ls="-.")
axis[1][1].set_ylabel("e")
axis[1][0].plot(t.value_in(units.yr), ome, lw=2, label="nbody (direct)")
axis[1][0].plot(t.value_in(units.yr),
ome2,
lw=2,
ls="--",
label="nbody (heuristic)")
axis[1][0].set_ylabel("$\omega$ [degrees]")
axis[1][1].set_xlabel("time [yr]")
axis[1][0].set_xlabel("time [yr]")
pyplot.tight_layout()
pyplot.subplots_adjust(hspace=0, top=0.93, bottom=0.1)
pyplot.suptitle("mloss+macc+momentum change, same model")
pyplot.savefig("comparisons.png")
pyplot.show()
def run_pyth(te=100):
dt = 0.01 | nbody_system.time
t_end = te | nbody_system.time
code = ph4()
code.parameters.timestep_parameter = dt.value_in(nbody_system.time)
code.particles.add_particles(new_particles())
x = AdaptingVectorQuantity()
y = AdaptingVectorQuantity()
t = 0. | nbody_system.time
eccents_12 = []
eccents_23 = []
eccents_31 = []
semmajaxs_12 = []
semmajaxs_23 = []
semmajaxs_31 = []
times = []
while(t < t_end-dt/2):
t=t+dt
code.evolve_model(t)
x.append(code.particles.x)
y.append(code.particles.y)
mass1, mass2, semimajor_axis_12, eccentricity_12, true_anomaly, inclination, long_asc_node, arg_per = orbital_elements_from_binary([code.particles[0], code.particles[1]])
mass2, mass3, semimajor_axis_23, eccentricity_23, true_anomaly, inclination, long_asc_node, arg_per = orbital_elements_from_binary([code.particles[1], code.particles[2]])
mass3, mass1, semimajor_axis_31, eccentricity_31, true_anomaly, inclination, long_asc_node, arg_per = orbital_elements_from_binary([code.particles[2], code.particles[0]])
eccents_12.append(eccentricity_12)
eccents_23.append(eccentricity_23)
eccents_31.append(eccentricity_31)
semmajaxs_12.append(semimajor_axis_12.value_in(nbody_system.length))
semmajaxs_23.append(semimajor_axis_23.value_in(nbody_system.length))
semmajaxs_31.append(semimajor_axis_31.value_in(nbody_system.length))
times.append(t.value_in(nbody_system.time))
code.stop()
return x,y,times,semmajaxs_12,semmajaxs_23,semmajaxs_31,eccents_12,eccents_23,eccents_31
