def sma_determinator(primary, secondary):
binary = Particles(0)
binary.add_particle(primary)
binary.add_particle(secondary)
orbital_params = get_orbital_elements_from_binary(binary, G=constants.G)
return orbital_params[2]
def create_pre_tack_giants_system():
#Create a pre_tack_giants_system by first recreating the sun.
pre_tack_giants_system = Particles(1)
pre_tack_giants_system[0].name = "Sun"
pre_tack_giants_system[0].mass = 1.0 | units.MSun
pre_tack_giants_system[0].radius = 1.0 | units.RSun
pre_tack_giants_system[0].position = (0, 0, 0) | units.AU
pre_tack_giants_system[0].velocity = (0, 0, 0) | units.kms
pre_tack_giants_system[0].density = 3 * pre_tack_giants_system[0].mass / (
4 * np.pi * pre_tack_giants_system[0].radius**3)
#The pre tack orbital elements for the planets as below
names = ["Jupiter", "Saturn", "Uranus", "Neptune"]
masses = np.array([317.8, 30, 5, 5]) | units.MEarth
radii = np.array([0.10049, 0.083703, 0.036455, 0.035392]) | units.RSun
a = np.array([3.5, 4.5, 6.013, 8.031]) | units.AU
inclinations = np.random.uniform(-5, 5, 4) | units.deg
true_anomalies = np.random.uniform(0, 360, 4) | units.deg
longs_of_ascending_node = np.random.uniform(0, 360, 4) | units.deg
args_of_periapsis = np.random.uniform(0, 360, 4) | units.deg
#Create the four planets as binaries with the sun and add them to the pre_tack_giants_system
for i in range(4):
sun_and_planet = new_binary_from_orbital_elements(
pre_tack_giants_system[0].mass,
masses[i],
a[i],
0,
true_anomalies[i],
inclinations[i],
longs_of_ascending_node[i],
args_of_periapsis[i],
G=constants.G)
planet = Particles(1)
planet.name = names[i]
planet.mass = masses[i]
planet.radius = radii[
i] # This is purely non-zero for collisional purposes
planet.position = (sun_and_planet[1].x - (0 | units.AU),
sun_and_planet[1].y - (0 | units.AU),
sun_and_planet[1].z - (0 | units.AU))
planet.velocity = (sun_and_planet[1].vx - (0 | units.kms),
sun_and_planet[1].vy - (0 | units.kms),
sun_and_planet[1].vz - (0 | units.kms))
planet.density = 3 * planet.mass / (4 * np.pi * planet.radius**3)
pre_tack_giants_system.add_particle(planet)
return pre_tack_giants_system
def create_system():
system = new_solar_system()
system = system[system.mass > 10**-5 | units.MSun] # Takes gas giants and Sun only
system.move_to_center()
sun = Particles(1)
sun.name = "Sun"
sun.mass = 1.0 | units.MSun
sun.radius = 1.0 | units.RSun
sun.position = (0, 0, 0) | units.AU
sun.velocity = (0, 0, 0) | units.kms
sun.density = 3*sun.mass/(4*np.pi*sun.radius**3)
names = ["Jupiter", "Saturn", "Uranus", "Neptune"]
masses = [317.8, 90, 15, 17] | units.MEarth
radii = [0.10049, 0.083703, 0.036455, 0.035392] | units.RSun
semis = [5.4, 7.1, 10.5, 13] | units.AU #[3.5, 4.9, 6.4, 8.4]
trues = [0, 90, 180, 270]| units.deg#np.random.uniform(0, 360, 4) | units.deg
longs = np.random.uniform(0, 360, 4) | units.deg
args = np.random.uniform(0, 360, 4) | units.deg
for i in range(4):
orbital_elements = get_orbital_elements_from_binary(system[0]+ system[i+1], G=constants.G)
eccentricity, inclination = 0, orbital_elements[5]
sun_and_plan = new_binary_from_orbital_elements(sun[0].mass, masses[i],
semis[i], 0, trues[i], inclination, longs[i], args[i], G=constants.G)
planet = Particles(1)
planet.name = system[i+1].name
planet.mass = system[i+1].mass
planet.radius = system[i+1].radius # This is purely non-zero for collisional purposes
planet.position = (sun_and_plan[1].x-sun_and_plan[0].x, sun_and_plan[1].y-sun_and_plan[0].y, sun_and_plan[1].z-sun_and_plan[0].z)
planet.velocity = (sun_and_plan[1].vx-sun_and_plan[0].vx, sun_and_plan[1].vy-sun_and_plan[0].vy, sun_and_plan[1].vz-sun_and_plan[0].vz)
planet.density = 3*planet.mass/(4*np.pi*planet.radius**3)
sun.add_particle(planet)
return sun
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 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 create_post_tack_giants_system():
#Create the present day solar system and keep only the sun and the giants
present_day_solar_system = new_solar_system()
present_day_solar_system = present_day_solar_system[present_day_solar_system.mass > 10**-5 | units.MSun] # Takes gas giants and Sun only
present_day_solar_system.move_to_center()
#Create a post_tack_giants_system by first recreating the sun.
post_tack_giants_system = Particles(1)
post_tack_giants_system[0].name = "Sun"
post_tack_giants_system[0].mass = 1.0 | units.MSun
post_tack_giants_system[0].radius = 1.0 | units.RSun
post_tack_giants_system[0].position = (0, 0, 0) | units.AU
post_tack_giants_system[0].velocity = (0, 0, 0) | units.kms
#The post tack orbital elements for the planets as below
a = np.array([5.4, 7.1, 10.5, 13]) | units.AU
true_anomalies = np.random.uniform(0, 360, 4) | units.deg
long_of_ascending_node = np.random.uniform(0, 360, 4) | units.deg
args_of_periapsis = np.random.uniform(0, 360, 4) | units.deg
#Create the four planets as binaries with the sun and add them to the post_tack_giants_system
for i in range(4):
orbital_elements = get_orbital_elements_from_binary(present_day_solar_system[0]+ present_day_solar_system[i+1], G=constants.G)
inclination = orbital_elements[5] #Make sure we have a sensable inclination for the giants
sun_and_planet = new_binary_from_orbital_elements(post_tack_giants_system.mass[0], present_day_solar_system[i+1].mass,
a[i], 0, true_anomalies[i], inclination, long_of_ascending_node[i], args_of_periapsis[i], G=constants.G)
planet = Particles(1)
planet.name = present_day_solar_system[i+1].name
planet.mass = present_day_solar_system[i+1].mass
planet.radius = present_day_solar_system[i+1].radius
planet.position = (sun_and_planet[1].x-sun_and_planet[0].x, sun_and_planet[1].y-sun_and_planet[0].y, sun_and_planet[1].z-sun_and_planet[0].z)
planet.velocity = (sun_and_planet[1].vx-sun_and_planet[0].vx, sun_and_planet[1].vy-sun_and_planet[0].vy, sun_and_planet[1].vz-sun_and_planet[0].vz)
post_tack_giants_system.add_particle(planet)
return post_tack_giants_system
def vanilla_tack_evolver(complete_pre_tack_system, converter, N_objects, times,
save_file_times):
#Initialise the gravity code and add the particles to it
gravity_code = MercuryWayWard(converter)
gravity_code.initialize_code()
gravity_code.central_particle.add_particle(complete_pre_tack_system[0])
gravity_code.orbiters.add_particles(complete_pre_tack_system[1:])
gravity_code.commit_particles
channel = gravity_code.particles.new_channel_to(complete_pre_tack_system)
#----------------------------------------------------------------------------------------------------
#Here we define the 'correct' sma's for the different migrations. Also, the initial
#planetary inclinations are stored for later use.
initial_sma = np.array([3.5, 4.5, 6.013, 8.031]) | units.AU
saturn_sma = np.array([1.5, 4.5, 6.013, 8.031]) | units.AU
outward_sma = np.array([1.5, 1.5 *
((3 / 2)**(2 / 3)), 6.013, 8.031]) | units.AU
post_tack_sma = np.array([5.4, 7.1, 10.5, 13.]) | units.AU
current_sma = [3.5, 4.5, 6.013, 8.031] | units.AU
inclinations = [0, 0, 0, 0] | units.deg
for k in range(4):
orbital_elements = get_orbital_elements_from_binary(
complete_pre_tack_system[0] + complete_pre_tack_system[k + 1],
G=constants.G)
inclinations[k] = orbital_elements[5]
#----------------------------------------------------------------------------------------------------
#Here we define the parameters used in the 'semi_major_axis_next_step' functions
#The sma's are based on exact resonances. The time_scales are taken from literature.
#The 0 values will be changed during the evolution of the model.
#pre_resonant is used in the outward migration, when jupiter and saturn are
#already in resonance with eachother, so that pre_resonant = True
a_start = [1.5, 1.5 * ((3 / 2)**(2 / 3)), 0, 0] | units.AU
a_end = [
5.4, 5.4 * ((3 / 2)**(2 / 3)), 5.4 *
((3 / 2)**(2 / 3) * (9 / 5)**(2 / 3)), 5.4 * ((3 / 2)**(2 / 3) *
(5 / 2)**(2 / 3))
] | units.AU
time_start = [1.025 * 10**5, 1.025 * 10**5, 0, 0] | units.yr
time_scale = [5 * 10**5, 5 * 10**5, 0, 0] | units.yr
resonances = [2 / 3, 3 / 2, 9 / 5, 5 / 2]
pre_resonant = [False, False, True, True]
outward_migration_started = False
dead_comets = []
#----------------------------------------------------------------------------------------------------
#Below, the evolution starts.
for i in tqdm(range(len(times) - 1)):
gravity_code.evolve_model(times[i])
channel.copy()
#Save the model when we want it to
if times[i] in save_file_times:
write_set_to_file(
gravity_code.orbiters,
directory + 'Vanilla_Tack_run' + str(run_number) + '_time=' +
str(np.log10(times[i].value_in(units.yr)))[0:5] + '.hdf5',
format='hdf5',
overwrite_file=True)
#For each timestep determine the current sma's
for j in range(4):
current_sma[j] = sma_determinator(gravity_code.central_particle,
gravity_code.orbiters[j])
#-----------------------------------------------------------------------------------------------------
#This chunk of code describes the inward migration of jupiter
#The first orbiter and the second particle in the gravity_code.
if times[i] < 10**5 | units.yr:
#This pushes Jupiter slightly inward
sma_next_step = semi_major_axis_next_step_in_jup(
times[i + 1], 10**5 | units.yr, 3.5 | units.AU, 1.5 | units.AU)
binary = Particles(0)
binary.add_particle(gravity_code.central_particle)
binary.add_particle(gravity_code.orbiters[0])
orbital_params = get_orbital_elements_from_binary(binary,
G=constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[4].in_(
units.deg), orbital_params[6].in_(
units.deg), orbital_params[7].in_(units.deg)
sun_and_planet = new_binary_from_orbital_elements(
1 | units.MSun,
orbital_params[1],
sma_next_step,
0,
true_anomaly,
inclinations[0],
ascending_node,
pericenter,
G=constants.G)
gravity_code.particles[1].position = (sun_and_planet[1].x -
(0 | units.AU),
sun_and_planet[1].y -
(0 | units.AU),
sun_and_planet[1].z -
(0 | units.AU))
gravity_code.particles[1].velocity = (sun_and_planet[1].vx -
(0 | units.kms),
sun_and_planet[1].vy -
(0 | units.kms),
sun_and_planet[1].vz -
(0 | units.kms))
#During the tack, the masses of the planets increase towards their current values
gravity_code.particles[2].mass *= 2**(1.5 / (10**5))
gravity_code.particles[3].mass *= 1.2**(1.5 / (10**5))
gravity_code.particles[4].mass *= 1.2**(1.5 / (10**5))
#This keeps the other planets in place
for j in range(3):
binary = Particles(0)
binary.add_particle(gravity_code.central_particle)
binary.add_particle(gravity_code.orbiters[j + 1])
orbital_params = get_orbital_elements_from_binary(
binary, G=constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[
4].in_(units.deg), orbital_params[6].in_(
units.deg), orbital_params[7].in_(units.deg)
sun_and_planet = new_binary_from_orbital_elements(
1 | units.MSun,
orbital_params[1],
initial_sma[1 + j],
0,
true_anomaly,
inclinations[j + 1],
ascending_node,
pericenter,
G=constants.G)
gravity_code.particles[j + 2].position = (sun_and_planet[1].x -
(0 | units.AU),
sun_and_planet[1].y -
(0 | units.AU),
sun_and_planet[1].z -
(0 | units.AU))
gravity_code.particles[j + 2].velocity = (
sun_and_planet[1].vx - (0 | units.kms),
sun_and_planet[1].vy - (0 | units.kms),
sun_and_planet[1].vz - (0 | units.kms))
#------------------------------------------------------------------------------------------------------------
#This chunk of code describes the inward migration of saturn
elif 1 * 10**5 | units.yr <= times[i] < 1.025 * 10**5 | units.yr:
#This pushes Saturn slightly inward
sma_next_step = semi_major_axis_next_step_in_sat(
times[i + 1], 2.5 * 10**3 | units.yr, 4.5 | units.AU,
1.5 * ((3 / 2)**(2 / 3)) | units.AU)
binary = Particles(0)
binary.add_particle(gravity_code.central_particle)
binary.add_particle(gravity_code.orbiters[1])
orbital_params = get_orbital_elements_from_binary(binary,
G=constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[4].in_(
units.deg), orbital_params[6].in_(
units.deg), orbital_params[7].in_(units.deg)
sun_and_planet = new_binary_from_orbital_elements(
1 | units.MSun,
orbital_params[1],
sma_next_step,
0,
true_anomaly,
inclinations[1],
ascending_node,
pericenter,
G=constants.G)
gravity_code.particles[2].position = (sun_and_planet[1].x -
(0 | units.AU),
sun_and_planet[1].y -
(0 | units.AU),
sun_and_planet[1].z -
(0 | units.AU))
gravity_code.particles[2].velocity = (sun_and_planet[1].vx -
(0 | units.kms),
sun_and_planet[1].vy -
(0 | units.kms),
sun_and_planet[1].vz -
(0 | units.kms))
gravity_code.particles[2].mass *= 1.5**(0.5 / (2500))
gravity_code.particles[3].mass *= (17.15 / 6)**(0.5 / (5 * 10**5))
gravity_code.particles[4].mass *= (14.54 / 6)**(0.5 / (5 * 10**5))
#This keeps the other planets in place
for j in [0, 2, 3]:
binary = Particles(0)
binary.add_particle(gravity_code.central_particle)
binary.add_particle(gravity_code.orbiters[j])
orbital_params = get_orbital_elements_from_binary(
binary, G=constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[
4].in_(units.deg), orbital_params[6].in_(
units.deg), orbital_params[7].in_(units.deg)
sun_and_planet = new_binary_from_orbital_elements(
1 | units.MSun,
orbital_params[1],
saturn_sma[j],
0,
true_anomaly,
inclinations[j],
ascending_node,
pericenter,
G=constants.G)
gravity_code.particles[j + 1].position = (sun_and_planet[1].x -
(0 | units.AU),
sun_and_planet[1].y -
(0 | units.AU),
sun_and_planet[1].z -
(0 | units.AU))
gravity_code.particles[j + 1].velocity = (
sun_and_planet[1].vx - (0 | units.kms),
sun_and_planet[1].vy - (0 | units.kms),
sun_and_planet[1].vz - (0 | units.kms))
#------------------------------------------------------------------------------------------------------------
#This chunk of code describes the outward migration of all planets
elif 1.025 * 10**5 | units.yr <= times[i] < 6 * 10**5 | units.yr:
#This bit checks if uranus and neptune already should start migrating
for k in range(4):
if pre_resonant[k] == True:
if current_sma[k] / current_sma[1] < (resonances[k])**(2 /
3):
pre_resonant[k] = False
a_start[k] = current_sma[k]
time_start[k] = times[i]
time_scale[k] = (6 * 10**5 | units.yr) - times[i]
#If pre_resonant == False, pushes the planet outward. If true, keeps it in place
for l in range(4):
if pre_resonant[l] == False:
sma_next_step = semi_major_axis_next_step_out(
times[i + 1], time_start[l], a_end[l], a_start[l],
time_scale[l])
binary = Particles(0)
binary.add_particle(gravity_code.central_particle)
binary.add_particle(gravity_code.orbiters[l])
orbital_params = get_orbital_elements_from_binary(
binary, G=constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[
4].in_(units.deg), orbital_params[6].in_(
units.deg), orbital_params[7].in_(units.deg)
sun_and_planet = new_binary_from_orbital_elements(
1 | units.MSun,
orbital_params[1],
sma_next_step,
0,
true_anomaly,
inclinations[l],
ascending_node,
pericenter,
G=constants.G)
gravity_code.particles[l + 1].position = (
sun_and_planet[1].x - (0 | units.AU),
sun_and_planet[1].y - (0 | units.AU),
sun_and_planet[1].z - (0 | units.AU))
gravity_code.particles[l + 1].velocity = (
sun_and_planet[1].vx - (0 | units.kms),
sun_and_planet[1].vy - (0 | units.kms),
sun_and_planet[1].vz - (0 | units.kms))
else:
binary = Particles(0)
binary.add_particle(gravity_code.central_particle)
binary.add_particle(gravity_code.orbiters[l])
orbital_params = get_orbital_elements_from_binary(
binary, G=constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[
4].in_(units.deg), orbital_params[6].in_(
units.deg), orbital_params[7].in_(units.deg)
sun_and_planet = new_binary_from_orbital_elements(
1 | units.MSun,
orbital_params[1],
outward_sma[l],
0,
true_anomaly,
inclinations[l],
ascending_node,
pericenter,
G=constants.G)
gravity_code.particles[l + 1].position = (
sun_and_planet[1].x - (0 | units.AU),
sun_and_planet[1].y - (0 | units.AU),
sun_and_planet[1].z - (0 | units.AU))
gravity_code.particles[l + 1].velocity = (
sun_and_planet[1].vx - (0 | units.kms),
sun_and_planet[1].vy - (0 | units.kms),
sun_and_planet[1].vz - (0 | units.kms))
gravity_code.particles[3].mass *= (17.15 / 6)**(15 / (5 * 10**5))
gravity_code.particles[4].mass *= (14.54 / 6)**(15 / (5 * 10**5))
#------------------------------------------------------------------------------------------------------------
else:
#---------------------------------------------------------------------------------------------------------------
for l in range(4):
if abs(current_sma[l] / post_tack_sma[l]) > 1.25 or abs(
current_sma[l] / post_tack_sma[l]
) < 0.75: #The orbits are too much perturbed, so we end the simulation
return
elif abs(current_sma[l] / post_tack_sma[l]) > 1.05 or abs(
current_sma[l] / post_tack_sma[l]
) < 0.95: #The orbits are slightly perturbed, so we redefinie them
print("Here", complete_pre_tack_system[l + 1].name,
"was redefined")
binary = Particles(0)
binary.add_particle(gravity_code.central_particle)
binary.add_particle(gravity_code.orbiters[l])
orbital_params = get_orbital_elements_from_binary(
binary, G=constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[
4].in_(units.deg), orbital_params[6].in_(
units.deg), orbital_params[7].in_(units.deg)
sun_and_planet = new_binary_from_orbital_elements(
1 | units.MSun,
orbital_params[1],
post_tack_sma[l],
0,
true_anomaly,
inclinations[l],
ascending_node,
pericenter,
G=constants.G)
gravity_code.particles[l + 1].position = (
sun_and_planet[1].x - (0 | units.AU),
sun_and_planet[1].y - (0 | units.AU),
sun_and_planet[1].z - (0 | units.AU))
gravity_code.particles[l + 1].velocity = (
sun_and_planet[1].vx - (0 | units.kms),
sun_and_planet[1].vy - (0 | units.kms),
sun_and_planet[1].vz - (0 | units.kms))
else:
pass
#----------------------------------------------------------------------------------------------------------------------
#Here we look for 'escaped' and 'out of bounds' comets
out_of_bounds, escaped_comets = [], []
for i in range(len(gravity_code.orbiters)):
if gravity_code.orbiters[i].position.length() > 500 | units.AU:
escaped_comets.append(gravity_code.orbiters[i])
if gravity_code.orbiters[i].position.length(
) > 250000 | units.AU:
out_of_bounds.append(gravity_code.orbiters[i])
dead_comets.append(gravity_code.orbiters[i])
for particle in out_of_bounds:
complete_pre_tack_system.remove_particle(particle)
complete_pre_tack_system.synchronize_to(gravity_code.particles)
if i % 1000 == 0:
print("The amount of currently escaped comets is ",
len(escaped_comets))
print("The amount of dead comets is ", len(dead_comets))
if i % 1000 == 0:
print("The sma's are: ", current_sma[0], current_sma[1],
current_sma[2], current_sma[3])
gravity_code.stop()
return complete_pre_tack_system
def vanilla_evolver(particle_system, converter, N_objects, end_time, time_step):
names = ['Sun', 'Jupiter', 'Saturn', 'Uranus', 'Neptune']
gravity_code = MercuryWayWard()
gravity_code.initialize_code()
gravity_code.central_particle.add_particle(particle_system[0])
gravity_code.orbiters.add_particles(particle_system[1:])
gravity_code.commit_particles
ch_g2l = gravity_code.particles.new_channel_to(particle_system)
times = np.arange(0., end_time, time_step) | units.yr
dead_comets = []
#---------------------------------------------------------------------------------------------------------
sma = [0, 0, 0, 0] | units.AU
correct_sma = [5.4, 7.1, 10.5, 13] | units.AU
eccentricities = [0, 0, 0, 0]
inclinations = [0, 0, 0, 0] | units.deg
system = new_solar_system()
system = system[system.mass > 10**-5 | units.MSun] # Takes gas giants and Sun only
system.move_to_center()
for k in range(4):
orbital_elements = get_orbital_elements_from_binary(system[0]+ system[k+1], G=constants.G)
inclinations[k] = orbital_elements[5]
#------------------------------------------------------------------------------------------------------------
for i in tqdm(range(len(times))):
gravity_code.evolve_model(times[i])
ch_g2l.copy()
#---------------------------------------------------------------------------------------------------------------
for j in range(4):
sma[j] = sma_determinator(gravity_code.central_particle, gravity_code.orbiters[j])
for l in range(4):
if abs(sma[l]/correct_sma[l]) > 1.25 or abs(sma[l]/correct_sma[l]) < 0.75:
return
elif abs(sma[l]/correct_sma[l]) > 1.05 or abs(sma[l]/correct_sma[l]) < 0.95:
print("Here", names[l+1], "was redefined")
binary = Particles(0)
binary.add_particle(gravity_code.central_particle)
binary.add_particle(gravity_code.orbiters[l])
orbital_params = get_orbital_elements_from_binary(binary, G = constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[4].in_(units.deg), orbital_params[6].in_(units.deg), orbital_params[7].in_(units.deg)
sun_and_plan = new_binary_from_orbital_elements(1 | units.MSun, orbital_params[1],
correct_sma[l], eccentricities[l], true_anomaly, inclinations[l], ascending_node, pericenter, G=constants.G)
gravity_code.particles[l+1].position = (sun_and_plan[1].x-sun_and_plan[0].x, sun_and_plan[1].y-sun_and_plan[0].y, sun_and_plan[1].z-sun_and_plan[0].z)
gravity_code.particles[l+1].velocity = (sun_and_plan[1].vx-sun_and_plan[0].vx, sun_and_plan[1].vy-sun_and_plan[0].vy, sun_and_plan[1].vz-sun_and_plan[0].vz)
else:
pass
#----------------------------------------------------------------------------------------------------------------------
if i%1000 == 0:
write_set_to_file(gravity_code.orbiters, directory + 'Vanilla_run16_time=' + str(np.log10(times[i].value_in(units.yr)))[0:5] + '.hdf5', format='hdf5', overwrite_file = True)
out_of_bounds, escaped_comets = [], []
for i in range(len(particle_system)):
if particle_system[i].position.length() > 500 | units.AU:
escaped_comets.append(particle_system[i].name)
if particle_system[i].position.length() > 250000 | units.AU:
out_of_bounds.append(particle_system[i])
dead_comets.append(particle_system[i])
for particle in out_of_bounds:
particle_system.remove_particle(particle)
particle_system.synchronize_to(gravity_code.particles)
print("The amount of currently escaped comets is ", len(escaped_comets))
print("The amount of dead comets is ", len(dead_comets))
print("The planetary positions are ", gravity_code.orbiters[0].position.length().in_(units.AU), gravity_code.orbiters[1].position.length().in_(units.AU), gravity_code.orbiters[2].position.length().in_(units.AU), gravity_code.orbiters[3].position.length().in_(units.AU))
gravity_code.stop()
write_set_to_file(gravity_code.orbiters, directory + 'Vanilla_run16_final.hdf5', format='hdf5', overwrite_file = True)
return particle_system
def MWG_evolver(complete_post_tack_system, converter, N_objects, potential, end_time, time_step):
#Initialise the gravity code and add the particles to it
gravity_code = Huayno(converter)
gravity_code.particles.add_particles(complete_post_tack_system)
channel = gravity_code.particles.new_channel_to(complete_post_tack_system)
gravity_bridge = 0
gravity_bridge = bridge.Bridge(use_threading=False)
gravity_bridge.add_system(gravity_code, (potential,))
gravity_bridge.timestep = 100 |units.yr
times = np.arange(0., end_time, time_step) | units.yr #All time steps to which we want to evolve the model
#---------------------------------------------------------------------------------------------------------
#Here we define the planetary orbital parameters that should be returned to if the planets start moving too much
current_sma = np.array([0, 0, 0, 0]) | units.AU
correct_sma = np.array([5.4, 7.1, 10.5, 13]) | units.AU
inclinations = np.array([0, 0, 0, 0]) | units.deg
system = new_solar_system()
system = system[system.mass > 10**-5 | units.MSun] # Takes gas giants and Sun only
system.move_to_center()
for k in range(4):
orbital_elements = get_orbital_elements_from_binary(system[0]+ system[k+1], G=constants.G)
inclinations[k] = orbital_elements[5]
#------------------------------------------------------------------------------------------------------------
dead_comets = [] #Here all 'dead' comets are stored
#Below the evolving starts
for i in tqdm(range(len(times))):
gravity_bridge.evolve_model(times[i])
channel.copy()
#---------------------------------------------------------------------------------------------------------------
#Here we check if the planetary orbits are still 'correct' and act for three degrees of incorrectness.
for j in range(4):
current_sma[j] = sma_determinator(gravity_code.particles[0], gravity_code.particles[j+1])
for l in range(4):
if abs(current_sma[l]/correct_sma[l]) > 1.25 or abs(current_sma[l]/correct_sma[l]) < 0.75: #The orbits are too much perturbed, so we end the simulation
return
elif abs(current_sma[l]/correct_sma[l]) > 1.05 or abs(current_sma[l]/correct_sma[l]) < 0.95: #The orbits are slightly perturbed, so we redefinie them
print("Here", complete_post_tack_system[l+1].name, "was redefined")
binary = Particles(0)
binary.add_particle(gravity_code.particles[0])
binary.add_particle(gravity_code.particles[l+1])
orbital_params = get_orbital_elements_from_binary(binary, G = constants.G)
true_anomaly, ascending_node, pericenter = orbital_params[4].in_(units.deg), orbital_params[6].in_(units.deg), orbital_params[7].in_(units.deg)
sun_and_plan = new_binary_from_orbital_elements(1 | units.MSun, orbital_params[1], #We keep the current angles, but change the a, e and i back
correct_sma[l], 0, true_anomaly, inclinations[l], ascending_node, pericenter, G=constants.G)
gravity_code.particles[l+1].position = (sun_and_plan[1].x+gravity_code.particles[0].x, sun_and_plan[1].y+gravity_code.particles[0].y, sun_and_plan[1].z+gravity_code.particles[0].z)
gravity_code.particles[l+1].velocity = (sun_and_plan[1].vx+gravity_code.particles[0].vx, sun_and_plan[1].vy+gravity_code.particles[0].vy, sun_and_plan[1].vz+gravity_code.particles[0].vz)
else: #The orbits do not need changing
pass
#----------------------------------------------------------------------------------------------------------------------
#Once we checked for the orbital correctness, we can save data
if i%4000 == 0:
write_set_to_file(gravity_code.particles, directory + 'MWG_run' + str(run_number) +'_time=' + str(np.log10(times[i].value_in(units.yr)))[0:5] + '.hdf5', format='hdf5', overwrite_file = True)
#--------------------------------------------------------------------------------------------------------------------
#Here we look for 'escaped' and 'out of bounds' comets
out_of_bounds, escaped_comets = [], []
for i in range(len(gravity_code.particles)):
if (gravity_code.particles[i].position-gravity_code.particles[0].position).length() > 500 | units.AU:
escaped_comets.append(gravity_code.particles[i])
if (gravity_code.particles[i].position-gravity_code.particles[0].position).length() > 250000 | units.AU:
out_of_bounds.append(gravity_code.particles[i])
dead_comets.append(gravity_code.particles[i])
for particle in out_of_bounds: #Out of bounds comets are removed completely
complete_post_tack_system.remove_particle(particle)
complete_post_tack_system.synchronize_to(gravity_code.particles)
if i%100 == 0:
print("The amount of currently escaped comets is ", len(escaped_comets))
print("The amount of dead comets is ", len(dead_comets))
for m in range(4):
print(complete_post_tack_system[m+1].name, " is at ", (gravity_code.particles[m+1].position-gravity_code.particles[0].position).length().in_(units.AU))
gravity_code.stop()
write_set_to_file(gravity_code.orbiters, directory + 'MWG_run' + str(run_number) +'_final.hdf5', format='hdf5', overwrite_file = True)
return complete_post_tack