def update_orb_elem(host_star, planets, converter=None, kepler_worker=None):
if kepler_worker == None:
if converter == None:
tot_sys = Particles(particles=(host_star, planets))
converter = nbody_system.nbody_to_si(tot_sys.mass.sum(),
2 * host_star.radius)
kep_p = Kepler(unit_converter=converter, redirection='none')
kep_p.initialize_code()
else:
kep_p = kepler_worker
for planet in planets:
total_mass = host_star.mass + planet.mass
kep_pos = host_star.position - planet.position
kep_vel = host_star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0], kep_pos[1],
kep_pos[2], kep_vel[0], kep_vel[1],
kep_vel[2])
planet.semimajor_axis, planet.eccentricity = kep_p.get_elements()
planet.period = kep_p.get_period()
planet.true_anomaly, planet.mean_anomaly = kep_p.get_angles()
if kepler_worker == None:
kep_p.stop()
def get_heirarchical_systems_from_set(bodies,
kepler_workers=None,
converter=None,
RelativePosition=False):
# Initialize Kepler
if kepler_workers == None:
if converter == None:
converter = nbody_system.nbody_to_si(
bodies.mass.sum(),
2 * np.max(bodies.radius.number) | bodies.radius.unit)
kep_p = Kepler(unit_converter=converter, redirection='none')
kep_p.initialize_code()
kep_s = Kepler(unit_converter=converter, redirection='none')
kep_s.initialize_code()
else:
kep_p = kepler_workers[0]
kep_s = kepler_workers[1]
# Seperate Out Planets and Stars from Bodies
stars, planets = util.get_stars(bodies), util.get_planets(bodies)
num_stars, num_planets = len(stars), len(planets)
# Initialize the Dictionary that Contains all Planetary Systems
systems = {}
# Initialize the List Used to Check Star IDs Against Already Classified Binaries
binary_ids = []
# Find Nearest Neighbors of the Set
closest_neighbours = stars.nearest_neighbour()
# Start Looping Through Stars to Find Bound Planets
for index, star in enumerate(stars):
# If the star is already in Binary_IDs, just go to the next star.
if star.id in binary_ids:
continue
# If not, Set the System ID and Set-up Data Structure.
system_id = star.id
current_system = systems.setdefault(system_id, Particles())
current_system.add_particle(star)
noStellarHierarchy = False
# If there is only one stars, there is obviously no stellar heirarchy in
# the encounter that is occuring.
if len(stars) == 1:
noStellarHierarchy = True
if not noStellarHierarchy:
# Check to see if the Nearest Neighbor is Mutual
star_neighbour_id = closest_neighbours[index].id
neighbour_neighbour_id = closest_neighbours[
stars.id == star_neighbour_id].id[0]
for other_star in (stars - star):
# Check to see if the two stars are bound.
kep_s.initialize_from_dyn(
star.mass + other_star.mass, star.x - other_star.x,
star.y - other_star.y, star.z - other_star.z,
star.vx - other_star.vx, star.vy - other_star.vy,
star.vz - other_star.vz)
a_s, e_s = kep_s.get_elements()
print(star.id, other_star.id, e_s)
# If they ARE NOT bound ...
if e_s >= 1.0:
noStellarHierarchy = True
# If they ARE bound ...
else:
# If the star is the star's neighbour's neighbour and visa-versa, then proceed.
print(star.id, other_star.id, star_neighbour_id,
neighbour_neighbour_id)
if star.id == neighbour_neighbour_id and other_star.id == star_neighbour_id:
noStellarHierarchy = False
print("Binary composed of Star", star.id, "and Star",
other_star.id, "has been detected!")
current_system.add_particle(other_star)
binary_ids.append(star.id)
binary_ids.append(other_star.id)
else:
print(
"!!! Alert: Bound Stars are not closest neighbours ..."
)
print("!!! Current Star:", star.id, "| Other Star:",
other_star.id)
print("!!! CS's Neighbour:", star_neighbour_id, \
"| CS's Neighbour's Neighbour:", neighbour_neighbour_id)
checked_planet_ids = []
for KeyID in systems.keys():
current_system = systems[KeyID]
sys_stars = util.get_stars(current_system)
noStellarHierarchy = False
# If there is only one stars, there is obviously no stellar heirarchy in
# the encounter that is occuring.
if len(sys_stars) == 1:
noStellarHierarchy = True
for planet in planets:
if planet.id in checked_planet_ids:
continue
star = sys_stars[sys_stars.id == KeyID][0]
total_mass = star.mass + planet.mass
kep_pos = star.position - planet.position
kep_vel = star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0], kep_pos[1],
kep_pos[2], kep_vel[0], kep_vel[1],
kep_vel[2])
a_p, e_p = kep_p.get_elements()
P_p = kep_p.get_period()
Ta_p, Ma_p = kep_p.get_angles()
host_star_id = star.id
if e_p < 1.0:
# Check to See if The Planetary System is tied to a Stellar Binary
# Note: Things get complicated if it is ...
if noStellarHierarchy:
# Get Additional Information on Orbit
planet.semimajor_axis = a_p
planet.eccentricity = e_p
planet.period = P_p
planet.true_anomaly = Ta_p
planet.mean_anomaly = Ma_p
planet.host_star = star.id
# Add the Planet to the System Set
current_system.add_particle(planet)
else:
# Handling for Planetary Systems in Stellar Heirarchical Structures
# Note: We check to see which other star in the current systems
# have a better boundness with the planet and choose that
# as the new host star.
for other_star in sys_stars - star:
total_mass = other_star.mass + planet.mass
kep_pos = other_star.position - planet.position
kep_vel = other_star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0],
kep_pos[1], kep_pos[2],
kep_vel[0], kep_vel[1],
kep_vel[2])
a_p2, e_p2 = kep_p.get_elements()
# Check to see if the planet is more bound to 'star' or
# 'other_star'. If its more bound to 'other_star',
# set the attributes to the more bound object. This will
# replace *_p with the better values with each loop.
if e_p2 < e_p:
a_p = a_p2
e_p = e_p2
P_p = kep_p.get_period()
Ta_p, Ma_p = kep_p.get_angles()
host_star_id = other_star.id
planet.semimajor_axis = a_p
planet.eccentricity = e_p
planet.period = P_p
planet.true_anomaly = Ta_p
planet.mean_anomaly = Ma_p
planet.host_star = host_star_id
# Add the Planet to the System Set
current_system.add_particle(planet)
checked_planet_ids.append(planet.id)
elif not noStellarHierarchy:
# Handling for Planetary Systems in Stellar Heirarchical Structures
# Note: We check to see which other star in the current systems
# have a better boundness with the planet and choose that
# as the new host star.
for other_star in sys_stars - star:
total_mass = other_star.mass + planet.mass
kep_pos = other_star.position - planet.position
kep_vel = other_star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0],
kep_pos[1], kep_pos[2],
kep_vel[0], kep_vel[1],
kep_vel[2])
a_p2, e_p2 = kep_p.get_elements()
# Check to see if the planet is more bound to 'star' or
# 'other_star'. If its more bound to 'other_star',
# set the attributes to the more bound object. This will
# replace *_p with the better values with each loop.
if e_p2 < e_p:
a_p = a_p2
e_p = e_p2
P_p = kep_p.get_period()
Ta_p, Ma_p = kep_p.get_angles()
host_star_id = other_star.id
planet.semimajor_axis = a_p
planet.eccentricity = e_p
planet.period = P_p
planet.true_anomaly = Ta_p
planet.mean_anomaly = Ma_p
planet.host_star = host_star_id
# Add the Planet to the System Set
current_system.add_particle(planet)
else:
print(
"!!! Alert: Planet is not bound nor is it bound to any other star."
)
if kepler_workers == None:
kep_p.stop()
kep_s.stop()
return systems
def compress_binary_components(comp1, comp2, scale):
# Compress the two-body system consisting of comp1 and comp2 to
# lie within distance scale of one another.
pos1 = comp1.position
pos2 = comp2.position
sep12 = ((pos2-pos1)**2).sum()
if sep12 > scale*scale:
print '\ncompressing components', int(comp1.id.number), \
'and', int(comp2.id.number), 'to separation', scale.number
sys.stdout.flush()
mass1 = comp1.mass
mass2 = comp2.mass
total_mass = mass1 + mass2
vel1 = comp1.velocity
vel2 = comp2.velocity
cmpos = (mass1*pos1+mass2*pos2)/total_mass
cmvel = (mass1*vel1+mass2*vel2)/total_mass
# For now, create and delete a temporary kepler
# process to handle the transformation. Obviously
# more efficient to define a single kepler at the
# start of the calculation and reuse it.
kep = Kepler(redirection = "none")
kep.initialize_code()
mass = comp1.mass + comp2.mass
rel_pos = pos2 - pos1
rel_vel = vel2 - vel1
kep.initialize_from_dyn(mass,
rel_pos[0], rel_pos[1], rel_pos[2],
rel_vel[0], rel_vel[1], rel_vel[2])
M,th = kep.get_angles()
a,e = kep.get_elements()
if e < 1:
peri = a*(1-e)
apo = a*(1+e)
else:
peri = a*(e-1)
apo = 2*a # OK - used ony to reset scale
limit = peri + 0.01*(apo-peri)
if scale < limit: scale = limit
if M < 0:
# print 'approaching'
kep.advance_to_periastron()
kep.advance_to_radius(limit)
else:
# print 'receding'
if kep.get_separation() < scale:
kep.advance_to_radius(limit)
else:
kep.return_to_radius(scale)
# a,e = kep.get_elements()
# r = kep.get_separation()
# E,J = kep.get_integrals()
# print 'kepler: a,e,r =', a.number, e.number, r.number
# print 'E, J =', E, J
# Note: if periastron > scale, we are now just past periastron.
new_rel_pos = kep.get_separation_vector()
new_rel_vel = kep.get_velocity_vector()
kep.stop()
# Enew = 0
# r2 = 0
# for k in range(3):
# Enew += 0.5*(new_rel_vel[k].number)**2
# r2 += (new_rel_pos[k].number)**2
# rnew = math.sqrt(r2)
# Enew -= mass.number/r1
# print 'E, Enew, rnew =', E.number, E1, r1
# Problem: the vectors returned by kepler are lists,
# not numpy arrays, and it looks as though we can say
# comp1.position = pos, but not comp1.position[k] =
# xxx, as we'd like... Also, we don't know how to
# copy a numpy array with units... TODO
newpos1 = pos1 - pos1 # stupid trick to create zero vectors
newpos2 = pos2 - pos2 # with the proper form and units...
newvel1 = vel1 - vel1
newvel2 = vel2 - vel2
frac2 = mass2/total_mass
for k in range(3):
dxk = new_rel_pos[k]
dvk = new_rel_vel[k]
newpos1[k] = cmpos[k] - frac2*dxk
newpos2[k] = cmpos[k] + (1-frac2)*dxk
newvel1[k] = cmvel[k] - frac2*dvk
newvel2[k] = cmvel[k] + (1-frac2)*dvk
# Perform the changes to comp1 and comp2, and recursively
# transmit them to the (currently absolute) coordinates of
# all lower components.
offset_particle_tree(comp1, newpos1-pos1, newvel1-vel1)
offset_particle_tree(comp2, newpos2-pos2, newvel2-vel2)
def get_planetary_systems_from_set(bodies,
converter=None,
RelativePosition=False):
# Initialize Kepler
if converter == None:
converter = nbody_system.nbody_to_si(
bodies.mass.sum(),
2 * np.max(bodies.radius.number) | bodies.radius.unit)
kep_p = Kepler(unit_converter=converter, redirection='none')
kep_p.initialize_code()
kep_s = Kepler(unit_converter=converter, redirection='none')
kep_s.initialize_code()
# Seperate Out Planets and Stars from Bodies
stars, planets = util.get_stars(bodies), util.get_planets(bodies)
num_stars, num_planets = len(stars), len(planets)
# Initialize the Dictionary that Contains all Planetary Systems
systems = {}
# Start Looping Through Stars to Find Bound Planets
for star in stars:
system_id = star.id
#star.semimajor_axis, star.eccentricity, star.period, star.true_anomaly, star.mean_anomaly, star.kep_energy, star.angular_momentum = \
# None, None, None, None, None, None, None
current_system = systems.setdefault(system_id, Particles())
current_system.add_particle(star)
for planet in planets:
total_mass = star.mass + planet.mass
kep_pos = star.position - planet.position
kep_vel = star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0], kep_pos[1],
kep_pos[2], kep_vel[0], kep_vel[1],
kep_vel[2])
a_p, e_p = kep_p.get_elements()
if e_p < 1.0:
# Check to See if The Stellar System is a Binary
# Note: Things get complicated if it is ...
noStellarHeirarchy = False
for other_star in (stars - star):
kep_s.initialize_from_dyn(
star.mass + other_star.mass, star.x - other_star.x,
star.y - other_star.y, star.z - other_star.z,
star.vx - other_star.vx, star.vy - other_star.vy,
star.vz - other_star.vz)
a_s, e_s = kep_s.get_elements()
r_apo = kep_s.get_apastron()
HillR = util.calc_HillRadius(a_s, e_s, other_star.mass,
star.mass)
if e_s >= 1.0 or HillR < r_apo:
noStellarHeirarchy = True
else:
noStellarHeirarchy = False
if noStellarHeirarchy:
# Get Additional Information on Orbit
planet.semimajor_axis = a_p
planet.eccentricity = e_p
planet.period = kep_p.get_period()
planet.true_anomaly, planet.mean_anomaly = kep_p.get_angles(
)
#planet.kep_energy, planet.angular_momentum = kep_p.get_integrals()
# Add the Planet to the System Set
current_system.add_particle(planet)
else:
# Handling for Planetary Systems in Stellar Heirarchical Structures
# Note: This is empty for now, maybe consider doing it by the heaviest bound stellar object as the primary.
pass
else:
continue
kep_p.stop()
kep_s.stop()
return systems
def compress_binary_components(comp1, comp2, scale):
# Compress the two-body system consisting of comp1 and comp2 to
# lie within distance scale of one another.
pos1 = comp1.position
pos2 = comp2.position
sep12 = ((pos2 - pos1)**2).sum()
if sep12 > scale * scale:
print('\ncompressing components', int(comp1.id.number), \
'and', int(comp2.id.number), 'to separation', scale.number)
sys.stdout.flush()
mass1 = comp1.mass
mass2 = comp2.mass
total_mass = mass1 + mass2
vel1 = comp1.velocity
vel2 = comp2.velocity
cmpos = (mass1 * pos1 + mass2 * pos2) / total_mass
cmvel = (mass1 * vel1 + mass2 * vel2) / total_mass
# For now, create and delete a temporary kepler
# process to handle the transformation. Obviously
# more efficient to define a single kepler at the
# start of the calculation and reuse it.
kep = Kepler(redirection="none")
kep.initialize_code()
mass = comp1.mass + comp2.mass
rel_pos = pos2 - pos1
rel_vel = vel2 - vel1
kep.initialize_from_dyn(mass, rel_pos[0], rel_pos[1], rel_pos[2],
rel_vel[0], rel_vel[1], rel_vel[2])
M, th = kep.get_angles()
a, e = kep.get_elements()
if e < 1:
peri = a * (1 - e)
apo = a * (1 + e)
else:
peri = a * (e - 1)
apo = 2 * a # OK - used ony to reset scale
limit = peri + 0.01 * (apo - peri)
if scale < limit: scale = limit
if M < 0:
# print 'approaching'
kep.advance_to_periastron()
kep.advance_to_radius(limit)
else:
# print 'receding'
if kep.get_separation() < scale:
kep.advance_to_radius(limit)
else:
kep.return_to_radius(scale)
# a,e = kep.get_elements()
# r = kep.get_separation()
# E,J = kep.get_integrals()
# print 'kepler: a,e,r =', a.number, e.number, r.number
# print 'E, J =', E, J
# Note: if periastron > scale, we are now just past periastron.
new_rel_pos = kep.get_separation_vector()
new_rel_vel = kep.get_velocity_vector()
kep.stop()
# Enew = 0
# r2 = 0
# for k in range(3):
# Enew += 0.5*(new_rel_vel[k].number)**2
# r2 += (new_rel_pos[k].number)**2
# rnew = math.sqrt(r2)
# Enew -= mass.number/r1
# print 'E, Enew, rnew =', E.number, E1, r1
# Problem: the vectors returned by kepler are lists,
# not numpy arrays, and it looks as though we can say
# comp1.position = pos, but not comp1.position[k] =
# xxx, as we'd like... Also, we don't know how to
# copy a numpy array with units... TODO
newpos1 = pos1 - pos1 # stupid trick to create zero vectors
newpos2 = pos2 - pos2 # with the proper form and units...
newvel1 = vel1 - vel1
newvel2 = vel2 - vel2
frac2 = mass2 / total_mass
for k in range(3):
dxk = new_rel_pos[k]
dvk = new_rel_vel[k]
newpos1[k] = cmpos[k] - frac2 * dxk
newpos2[k] = cmpos[k] + (1 - frac2) * dxk
newvel1[k] = cmvel[k] - frac2 * dvk
newvel2[k] = cmvel[k] + (1 - frac2) * dvk
# Perform the changes to comp1 and comp2, and recursively
# transmit them to the (currently absolute) coordinates of
# all lower components.
offset_particle_tree(comp1, newpos1 - pos1, newvel1 - vel1)
offset_particle_tree(comp2, newpos2 - pos2, newvel2 - vel2)
