def test15(self):
particles = datamodel.Particles(2)
particles.x = [0.0,10.0] | nbody_system.length
particles.y = 0.0 | nbody_system.length
particles.z = 0.0 | nbody_system.length
particles.vx = 0.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 1.0 | nbody_system.mass
instance = SmallN()
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertEquals(instance.particles[0].radius, 0.0 | nbody_system.length)
p = datamodel.Particle(
x = 1.0 | nbody_system.length,
y = 2.0 | nbody_system.length,
z = 3.0 | nbody_system.length,
vx = 1.0 | nbody_system.speed,
vy = 2.0 | nbody_system.speed,
vz = 3.0 | nbody_system.speed,
mass = 1.0 | nbody_system.mass,
radius = 4.0 | nbody_system.length,
)
instance.particles.add_particle(p)
self.assertEquals(instance.particles[0].radius, 0.0 | nbody_system.length)
self.assertEquals(instance.particles[1].radius, 0.0 | nbody_system.length)
self.assertEquals(instance.particles[2].radius, 4.0 | nbody_system.length)
instance.stop()
def test15(self):
particles = datamodel.Particles(2)
particles.x = [0.0, 10.0] | nbody_system.length
particles.y = 0.0 | nbody_system.length
particles.z = 0.0 | nbody_system.length
particles.vx = 0.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 1.0 | nbody_system.mass
instance = SmallN()
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertEqual(instance.particles[0].radius,
0.0 | nbody_system.length)
p = datamodel.Particle(
x=1.0 | nbody_system.length,
y=2.0 | nbody_system.length,
z=3.0 | nbody_system.length,
vx=1.0 | nbody_system.speed,
vy=2.0 | nbody_system.speed,
vz=3.0 | nbody_system.speed,
mass=1.0 | nbody_system.mass,
radius=4.0 | nbody_system.length,
)
instance.particles.add_particle(p)
self.assertEqual(instance.particles[0].radius,
0.0 | nbody_system.length)
self.assertEqual(instance.particles[1].radius,
0.0 | nbody_system.length)
self.assertEqual(instance.particles[2].radius,
4.0 | nbody_system.length)
instance.stop()
def test20(self):
p = datamodel.Particles(3)
p[0].mass = 6.667e-01 | nbody_system.mass
p[0].radius = 4.000e-03 | nbody_system.length
p[0].x = -1.309e+01 | nbody_system.length
p[0].y = 1.940e+01 | nbody_system.length
p[0].z = -1.163e+01 | nbody_system.length
p[0].vx = 2.366e-01 | nbody_system.speed
p[0].vy = -3.813e-01 | nbody_system.speed
p[0].vz = 2.486e-01 | nbody_system.speed
p[1].mass = 3.333e-01 | nbody_system.mass
p[1].radius = 1.000e-03 | nbody_system.length
p[1].x = -1.506e+01 | nbody_system.length
p[1].y = 1.937e+01 | nbody_system.length
p[1].z = -1.163e+01 | nbody_system.length
p[1].vx = 3.483e-01 | nbody_system.speed
p[1].vy = -4.513e-01 | nbody_system.speed
p[1].vz = 2.486e-01 | nbody_system.speed
p[2].mass = 5.000e-01 | nbody_system.mass
p[2].radius = 2.000e-03 | nbody_system.length
p[2].x = 2.749e+01 | nbody_system.length
p[2].y = -3.877e+01 | nbody_system.length
p[2].z = 2.325e+01 | nbody_system.length
p[2].vx = -5.476e-01 | nbody_system.speed
p[2].vy = 8.092e-01 | nbody_system.speed
p[2].vz = -4.972e-01 | nbody_system.speed
instance = SmallN()
instance.initialize_code()
instance.parameters.set_defaults
N = 3
t_begin = 0.0 | nbody_system.time
t_end = 100.0 | nbody_system.time
particles = p
instance.particles.add_particles(particles)
instance.commit_particles()
sc = instance.stopping_conditions.collision_detection
sc.enable()
isCollision = False
instance.evolve_model(t_end)
isCollision = sc.is_set()
instance.stop()
self.assertTrue(isCollision, "no collision detected")
def test20(self):
p = datamodel.Particles(3)
p[0].mass = 6.667e-01 | nbody_system.mass
p[0].radius = 4.000e-03 | nbody_system.length
p[0].x = -1.309e+01 | nbody_system.length
p[0].y = 1.940e+01 | nbody_system.length
p[0].z = -1.163e+01 | nbody_system.length
p[0].vx = 2.366e-01 | nbody_system.speed
p[0].vy = -3.813e-01 | nbody_system.speed
p[0].vz = 2.486e-01 | nbody_system.speed
p[1].mass = 3.333e-01 | nbody_system.mass
p[1].radius = 1.000e-03 | nbody_system.length
p[1].x = -1.506e+01 | nbody_system.length
p[1].y = 1.937e+01 | nbody_system.length
p[1].z = -1.163e+01 | nbody_system.length
p[1].vx = 3.483e-01 | nbody_system.speed
p[1].vy = -4.513e-01 | nbody_system.speed
p[1].vz = 2.486e-01 | nbody_system.speed
p[2].mass = 5.000e-01 | nbody_system.mass
p[2].radius = 2.000e-03 | nbody_system.length
p[2].x = 2.749e+01 | nbody_system.length
p[2].y = -3.877e+01 | nbody_system.length
p[2].z = 2.325e+01 | nbody_system.length
p[2].vx = -5.476e-01 | nbody_system.speed
p[2].vy = 8.092e-01 | nbody_system.speed
p[2].vz = -4.972e-01 | nbody_system.speed
instance = SmallN()
instance.initialize_code()
instance.parameters.set_defaults
N = 3
t_begin = 0.0 | nbody_system.time
t_end = 100.0 | nbody_system.time
particles = p
instance.particles.add_particles(particles)
instance.commit_particles()
sc = instance.stopping_conditions.collision_detection
sc.enable()
isCollision = False
instance.evolve_model(t_end)
isCollision = sc.is_set()
instance.stop()
self.assertTrue(isCollision, "no collision detected")
def run_smallN(
particles,
end_time = 1000 | nbody_system.time,
delta_t = 10 | nbody_system.time,
accuracy_parameter = 0.1
):
gravity = SmallN(redirection = "none") # , debugger="gdb")
gravity.initialize_code()
gravity.parameters.set_defaults()
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.cm_index = 2001
gravity.commit_parameters()
time = 0 | nbody_system.time
print "\nadding particles to smallN"
sys.stdout.flush()
gravity.set_time(time);
gravity.particles.add_particles(particles)
print "committing particles to smallN"
gravity.commit_particles()
print "smallN: number_of_stars =", len(particles)
print "smallN: evolving to time =", end_time.number,
print "in steps of", delta_t.number
sys.stdout.flush()
E0 = print_log('smallN', gravity)
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(particles)
while time < end_time:
time += delta_t
print 'evolving smallN to time', time.number
sys.stdout.flush()
gravity.evolve_model(time)
print_log('smallN', gravity, E0)
over = gravity.is_over()
if over.number:
print 'interaction is over\n'; sys.stdout.flush()
# Create a tree in the module representing the binary structure.
gravity.update_particle_tree()
# Return the tree structure to AMUSE. Children are
# identified by get_children_of_particle in interface.??,
# and the information is returned in the copy operation.
gravity.update_particle_set()
gravity.particles.synchronize_to(particles)
channel.copy()
channel.copy_attribute("index_in_code", "id")
gravity.stop()
# Basic diagnostics: BinaryTreesOnAParticleSet creates
# binary tree structure for all particles in the set; then
# we loop over roots (top-level nodes) and print data on
# all binaries below each.
print "smallN binaries:"; sys.stdout.flush()
x = trees.BinaryTreesOnAParticleSet(particles, "child1", "child2")
roots = list(x.iter_roots())
for r in roots:
for level, particle in r.iter_levels():
print ' '*level, int(particle.id.number),
if not particle.child1 is None:
M,a,e,r,E = get_cm_binary_elements(particle)
print " mass = %.5e" % (M.number)
m1 = particle.child1.mass
m2 = particle.child2.mass
print_elements(' ', a, e, r, E*m1*m2/M)
else:
print ''
sys.stdout.flush()
return E0
sys.stdout.flush()
gravity.stop()
raise Exception("Did not finish the small-N simulation "
+"before end time {0}".format(end_time))
def run_smallN(particles,
end_time=1000 | nbody_system.time,
delta_t=10 | nbody_system.time,
accuracy_parameter=0.1):
gravity = SmallN(redirection="none") # , debugger="gdb")
gravity.initialize_code()
gravity.parameters.set_defaults()
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.cm_index = 2001
gravity.commit_parameters()
time = 0 | nbody_system.time
print("\nadding particles to smallN")
sys.stdout.flush()
gravity.set_time(time)
gravity.particles.add_particles(particles)
print("committing particles to smallN")
gravity.commit_particles()
print("smallN: number_of_stars =", len(particles))
print("smallN: evolving to time =", end_time.number, end=' ')
print("in steps of", delta_t.number)
sys.stdout.flush()
E0 = print_log('smallN', gravity)
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(particles)
while time < end_time:
time += delta_t
print('evolving smallN to time', time.number)
sys.stdout.flush()
gravity.evolve_model(time)
print_log('smallN', gravity, E0)
over = gravity.is_over()
if over.number:
print('interaction is over\n')
sys.stdout.flush()
# Create a tree in the module representing the binary structure.
gravity.update_particle_tree()
# Return the tree structure to AMUSE. Children are
# identified by get_children_of_particle in interface.??,
# and the information is returned in the copy operation.
gravity.update_particle_set()
gravity.particles.synchronize_to(particles)
channel.copy()
channel.copy_attribute("index_in_code", "id")
gravity.stop()
# Basic diagnostics: BinaryTreesOnAParticleSet creates
# binary tree structure for all particles in the set; then
# we loop over roots (top-level nodes) and print data on
# all binaries below each.
print("smallN binaries:")
sys.stdout.flush()
x = trees.BinaryTreesOnAParticleSet(particles, "child1", "child2")
roots = list(x.iter_roots())
for r in roots:
for level, particle in r.iter_levels():
print(' ' * level, int(particle.id.number), end=' ')
if not particle.child1 is None:
M, a, e, r, E = get_cm_binary_elements(particle)
print(" mass = %.5e" % (M.number))
m1 = particle.child1.mass
m2 = particle.child2.mass
print_elements(' ', a, e, r, E * m1 * m2 / M)
else:
print('')
sys.stdout.flush()
return E0
sys.stdout.flush()
gravity.stop()
raise Exception("Did not finish the small-N simulation " +
"before end time {0}".format(end_time))
def run_collision(GravitatingBodies, end_time, delta_time, save_file, **kwargs):
# Define Additional User Options and Set Defaults Properly
converter = kwargs.get("converter", None)
doEncPatching = kwargs.get("doEncPatching", False)
doVerboseSaves = kwargs.get("doVerboseSaves", False)
if converter == None:
converter = nbody_system.nbody_to_si(GravitatingBodies.mass.sum(), 2 * np.max(GravitatingBodies.radius.number) | GravitatingBodies.radius.unit)
# Storing Initial Center of Mass Information for the Encounter
rCM_i = GravitatingBodies.center_of_mass()
vCM_i = GravitatingBodies.center_of_mass_velocity()
# Fixing Stored Encounter Particle Set to Feed into SmallN
GravitatingBodies = Particles(particles=GravitatingBodies)
if 'child1' in GravitatingBodies.get_attribute_names_defined_in_store():
del GravitatingBodies.child1, GravitatingBodies.child2
# Moving the Encounter's Center of Mass to the Origin and Setting it at Rest
GravitatingBodies.position -= rCM_i
GravitatingBodies.velocity -= vCM_i
# Setting Up Gravity Code
gravity = SmallN(redirection = 'none', convert_nbody = converter)
gravity.initialize_code()
gravity.parameters.set_defaults()
gravity.parameters.allow_full_unperturbed = 0
gravity.particles.add_particles(GravitatingBodies) # adds bodies to gravity calculations
gravity.commit_particles()
channel_from_grav_to_python = gravity.particles.new_channel_to(GravitatingBodies)
channel_from_grav_to_python.copy()
# Setting Coarse Timesteps
list_of_times = np.arange(0. | units.yr, end_time, delta_time)
stepNumber = 0
# Integrate the Encounter Until Over ...
for current_time in list_of_times:
# Evolve the Model to the Desired Current Time
gravity.evolve_model(current_time)
# Update Python Set in In-Code Set
channel_from_grav_to_python.copy() # original
channel_from_grav_to_python.copy_attribute("index_in_code", "id")
# Handle Writing Output of Integration
if doVerboseSaves:
# Write a Save Every Coarse Timestep
write_set_to_file(GravitatingBodies.savepoint(current_time), save_file, 'hdf5')
else:
# Write a Save at the Begninning, Middle & End Times
if stepNumber==0 or stepNumber==len(list_of_times) or stepNumber==len(list_of_times)/2:
# Write Set to File
write_set_to_file(GravitatingBodies.savepoint(current_time), save_file, 'hdf5')
# Check to See if the Encounter is Declared "Over" Every 50 Timesteps
if stepNumber%50:
over = gravity.is_over()
if over:
gravity.update_particle_tree()
gravity.update_particle_set()
gravity.particles.synchronize_to(GravitatingBodies)
channel_from_grav_to_python.copy()
print "Encounter has finished at Step #", stepNumber
break
else:
print "Encounter has NOT finished at Step #", stepNumber
stepNumber +=1
# Stop the Gravity Code Once the Encounter Finishes
gravity.stop()
# Seperate out the Systems to Prepare for Encounter Patching
if doEncPatching:
ResultingPSystems = stellar_systems.get_planetary_systems_from_set(GravitatingBodies, converter=converter, RelativePosition=True)
else:
ResultingPSystems = stellar_systems.get_planetary_systems_from_set(GravitatingBodies, converter=converter, RelativePosition=False)
return ResultingPSystems