def run_ph4(infile=None,
number_of_stars=40,
end_time=10 | nbody_system.time,
delta_t=1 | nbody_system.time,
n_workers=1,
use_gpu=1,
gpu_worker=1,
gpu_id=-1,
accuracy_parameter=0.1,
softening_length=-1 | nbody_system.length,
manage_encounters=1):
if infile != None: print "input file =", infile
print "end_time =", end_time.number
print "delta_t =", delta_t.number
print "n_workers =", n_workers
print "use_gpu =", use_gpu
print "manage_encounters =", manage_encounters
print "\ninitializing the gravity module"
sys.stdout.flush()
# Note that there are actually three GPU options to test:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
#print "1"; sys.stdout.flush()
gpu = 0
if gpu_worker == 1:
try:
gravity = grav(number_of_workers=n_workers,
redirection="none",
mode="gpu")
# debugger='valgrind')
gpu = 1
except Exception as ex:
print '*** GPU worker code not found. Reverting to non-GPU code. ***'
gpu = 0
if gpu == 0:
gravity = grav(number_of_workers=n_workers, redirection="none")
# debugger='valgrind')
#print "2"; sys.stdout.flush()
gravity.initialize_code()
#print "3"; sys.stdout.flush()
gravity.parameters.set_defaults()
gravity.parameters.gpu_id = gpu_id
#-----------------------------------------------------------------
#print "4"; sys.stdout.flush()
if infile == None:
print "making a Plummer model"
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id + 1
print "setting particle masses and radii"
stars.mass = (1.0 / number_of_stars) | nbody_system.mass
if 0:
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars)
stars.mass = scaled_mass
stars.radius = 0.0 | nbody_system.length
print "centering stars"
stars.move_to_center()
if 0:
print "scaling stars to virial equilibrium"
stars.scale_to_standard(
smoothing_length_squared=gravity.parameters.epsilon_squared)
time = 0.0 | nbody_system.time
sys.stdout.flush()
else:
# Read the input data. Units are dynamical.
print "reading file", infile
id = []
mass = []
pos = []
vel = []
f = open(infile, 'r')
count = 0
for line in f:
if len(line) > 0:
count += 1
cols = line.split()
if count == 1: snap = int(cols[0])
elif count == 2: number_of_stars = int(cols[0])
elif count == 3: time = float(cols[0]) | nbody_system.time
else:
if len(cols) >= 8:
id.append(int(cols[0]))
mass.append(float(cols[1]))
pos.append(
(float(cols[2]), float(cols[3]), float(cols[4])))
vel.append(
(float(cols[5]), float(cols[6]), float(cols[7])))
f.close()
stars = datamodel.Particles(number_of_stars)
stars.id = id
stars.mass = mass | nbody_system.mass
stars.position = pos | nbody_system.length
stars.velocity = vel | nbody_system.speed
stars.radius = 0. | nbody_system.length
# print "IDs:", stars.id.number
sys.stdout.flush()
#-----------------------------------------------------------------
#print "5"; sys.stdout.flush()
if softening_length == -1 | nbody_system.length:
eps2 = 0.25*(float(number_of_stars))**(-0.666667) \
| nbody_system.length**2
else:
eps2 = softening_length * softening_length
#print "6"; sys.stdout.flush()
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.epsilon_squared = eps2
gravity.parameters.use_gpu = use_gpu
gravity.parameters.manage_encounters = manage_encounters
print "adding particles"
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print ''
print "number_of_stars =", number_of_stars
print "evolving to time =", end_time.number, \
"in steps of", delta_t.number
sys.stdout.flush()
E0, cpu0, wall0 = print_log('', time, gravity)
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
while time < end_time:
time += delta_t
gravity.evolve_model(time)
# Ensure that the stars list is consistent with the internal
# data in the module.
ls = len(stars)
# Update the bookkeeping: synchronize stars with the module data.
try:
gravity.update_particle_set()
gravity.particles.synchronize_to(stars)
except:
pass
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
if stopping_condition.is_set():
star1 = stopping_condition.particles(0)[0]
star2 = stopping_condition.particles(1)[0]
print '\nstopping condition set at time', \
gravity.get_time().number,'for:\n'
print star1
print ''
print star2
print ''
raise Exception("no encounter handling")
if len(stars) != ls:
if 0:
print "stars:"
for s in stars:
print " ", s.id.number, s.mass.number, \
s.x.number, s.y.number, s.z.number
else:
print "number of stars =", len(stars)
sys.stdout.flush()
print_log('', time, gravity, E0, cpu0, wall0)
sys.stdout.flush()
print ''
gravity.stop()
def run_ph4(infile = None, outfile = None,
number_of_stars = 100, number_of_binaries = 0,
end_time = 10 | nbody_system.time,
delta_t = 1 | nbody_system.time,
n_workers = 1, use_gpu = 1, gpu_worker = 1,
salpeter = 0,
accuracy_parameter = 0.1,
softening_length = 0.0 | nbody_system.length,
manage_encounters = 1, random_seed = 1234):
if random_seed <= 0:
numpy.random.seed()
random_seed = numpy.random.randint(1, pow(2,31)-1)
numpy.random.seed(random_seed)
print "random seed =", random_seed
if infile != None: print "input file =", infile
print "end_time =", end_time.number
print "delta_t =", delta_t.number
print "n_workers =", n_workers
print "use_gpu =", use_gpu
print "manage_encounters =", manage_encounters
print "\ninitializing the gravity module"
sys.stdout.flush()
init_smalln()
# Note that there are actually three GPU options:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
if gpu_worker == 1:
try:
gravity = grav(number_of_workers = n_workers,
redirection = "none", mode = "gpu")
except Exception as ex:
gravity = grav(number_of_workers = n_workers,
redirection = "none")
else:
gravity = grav(number_of_workers = n_workers,
redirection = "none")
gravity.initialize_code()
gravity.parameters.set_defaults()
#-----------------------------------------------------------------
if infile == None:
print "making a Plummer model"
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id+1
print "setting particle masses and radii"
if salpeter == 0:
print 'equal masses'
total_mass = 1.0 | nbody_system.mass
scaled_mass = total_mass / number_of_stars
else:
print 'salpeter mass function'
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars)
stars.mass = scaled_mass
print "centering stars"
stars.move_to_center()
print "scaling stars to virial equilibrium"
stars.scale_to_standard(smoothing_length_squared
= gravity.parameters.epsilon_squared)
else:
# Read the input data. Units are dynamical (sorry).
# Format: id mass pos[3] vel[3]
print "reading file", infile
id = []
mass = []
pos = []
vel = []
f = open(infile, 'r')
count = 0
for line in f:
if len(line) > 0:
count += 1
cols = line.split()
if count == 1: snap = int(cols[0])
elif count == 2: number_of_stars = int(cols[0])
elif count == 3: time = float(cols[0]) | nbody_system.time
else:
if len(cols) >= 8:
id.append(int(cols[0]))
mass.append(float(cols[1]))
pos.append((float(cols[2]),
float(cols[3]), float(cols[4])))
vel.append((float(cols[5]),
float(cols[6]), float(cols[7])))
f.close()
stars = datamodel.Particles(number_of_stars)
stars.id = id
stars.mass = mass | nbody_system.mass
stars.position = pos | nbody_system.length
stars.velocity = vel | nbody_system.speed
#stars.radius = 0. | nbody_system.length
total_mass = stars.mass.sum()
ke = pa.kinetic_energy(stars)
kT = ke/(1.5*number_of_stars)
if number_of_binaries > 0:
# Turn selected stars into binary components.
# Only tested for equal-mass case.
kep = Kepler(redirection = "none")
kep.initialize_code()
added_mass = 0.0 | nbody_system.mass
# Work with energies rather than semimajor axes.
Emin = 10*kT
Emax = 20*kT
ecc = 0.1
id_count = number_of_stars
nbin = 0
for i in range(0, number_of_stars,
number_of_stars/number_of_binaries):
# Star i is CM, becomes component, add other star at end.
nbin += 1
mass = stars[i].mass
new_mass = numpy.random.uniform()*mass # uniform q?
mbin = mass + new_mass
fac = new_mass/mbin
E = Emin + numpy.random.uniform()*(Emax-Emin)
a = 0.5*nbody_system.G*mass*new_mass/E
kep.initialize_from_elements(mbin, a, ecc)
dr = quantities.AdaptingVectorQuantity()
dr.extend(kep.get_separation_vector())
dv = quantities.AdaptingVectorQuantity()
dv.extend(kep.get_velocity_vector())
newstar = datamodel.Particles(1)
newstar.mass = new_mass
newstar.position = stars[i].position + (1-fac)*dr
newstar.velocity = stars[i].velocity + (1-fac)*dv
# stars[i].mass = mass
stars[i].position = stars[i].position - fac*dr
stars[i].velocity = stars[i].velocity - fac*dv
id_count += 1
newstar.id = id_count
stars.add_particles(newstar)
added_mass += new_mass
if nbin >= number_of_binaries: break
kep.stop()
print 'created', nbin, 'binaries'
sys.stdout.flush()
stars.mass = stars.mass * total_mass/(total_mass+added_mass)
number_of_stars += nbin
# Set dynamical radii (assuming virial equilibrium and standard
# units). Note that this choice should be refined, and updated
# as the system evolves. Probably the choice of radius should be
# made entirely in the multiples module. TODO. In these units,
# M = 1 and <v^2> = 0.5, so the mean 90-degree turnaround impact
# parameter is
#
# b_90 = G (m_1+m_2) / vrel^2
# = 2 <m> / 2<v^2>
# = 2 / N for equal masses
#
# Taking r_i = m_i / 2<v^2> = m_i in virial equilibrium means
# that, approximately, "contact" means a 90-degree deflection (r_1
# + r_2 = b_90). A more conservative choice with r_i less than
# this value will isolates encounters better, but also place more
# load on the large-N dynamical module.
stars.radius = stars.mass.number | nbody_system.length
time = 0.0 | nbody_system.time
# print "IDs:", stars.id.number
print "recentering stars"
stars.move_to_center()
sys.stdout.flush()
#-----------------------------------------------------------------
if softening_length < 0.0 | nbody_system.length:
# Use ~interparticle spacing. Assuming standard units here. TODO
eps2 = 0.25*(float(number_of_stars))**(-0.666667) \
| nbody_system.length**2
else:
eps2 = softening_length*softening_length
print 'softening length =', eps2.sqrt()
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.epsilon_squared = eps2
gravity.parameters.use_gpu = use_gpu
# gravity.parameters.manage_encounters = manage_encounters
print ''
print "adding particles"
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print ''
print "number_of_stars =", number_of_stars
print "evolving to time =", end_time.number, \
"in steps of", delta_t.number
sys.stdout.flush()
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
# Debugging: prevent the multiples code from being called.
if 0:
stopping_condition.disable()
print 'stopping condition disabled'
sys.stdout.flush()
# -----------------------------------------------------------------
# Create the coupled code and integrate the system to the desired
# time, managing interactions internally.
kep = init_kepler(stars[0], stars[1])
multiples_code = multiples.Multiples(gravity, new_smalln, kep)
multiples_code.neighbor_perturbation_limit = 0.1
#multiples_code.neighbor_distance_factor = 1.0
#multiples_code.neighbor_veto = False
#multiples_code.neighbor_distance_factor = 2.0
multiples_code.neighbor_veto = True
print ''
print 'multiples_code.initial_scale_factor =', \
multiples_code.initial_scale_factor
print 'multiples_code.neighbor_perturbation_limit =', \
multiples_code.neighbor_perturbation_limit
print 'multiples_code.neighbor_veto =', \
multiples_code.neighbor_veto
print 'multiples_code.final_scale_factor =', \
multiples_code.final_scale_factor
print 'multiples_code.initial_scatter_factor =', \
multiples_code.initial_scatter_factor
print 'multiples_code.final_scatter_factor =', \
multiples_code.final_scatter_factor
print 'multiples_code.retain_binary_apocenter =', \
multiples_code.retain_binary_apocenter
print 'multiples_code.wide_perturbation_limit =', \
multiples_code.wide_perturbation_limit
pre = "%%% "
E0,cpu0 = print_log(pre, time, multiples_code)
while time < end_time:
time += delta_t
multiples_code.evolve_model(time)
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
print_log(pre, time, multiples_code, E0, cpu0)
sys.stdout.flush()
#-----------------------------------------------------------------
if not outfile == None:
# Write data to a file.
f = open(outfile, 'w')
#--------------------------------------------------
# Need to save top-level stellar data and parameters.
# Need to save multiple data and parameters.
f.write('%.15g\n'%(time.number))
for s in multiples_code.stars: write_star(s, f)
#--------------------------------------------------
f.close()
print 'wrote file', outfile
print ''
gravity.stop()
def run_ph4(infile = None, outfile = None,
number_of_stars = 100, number_of_binaries = 0,
end_time = 10 | nbody_system.time,
delta_t = 1 | nbody_system.time,
n_workers = 1, use_gpu = 1, gpu_worker = 1,
salpeter = 0,
accuracy_parameter = 0.1,
softening_length = 0.0 | nbody_system.length,
manage_encounters = 1, random_seed = 1234):
if random_seed <= 0:
numpy.random.seed()
random_seed = numpy.random.randint(1, pow(2,31)-1)
numpy.random.seed(random_seed)
print "random seed =", random_seed
if infile != None: print "input file =", infile
print "end_time =", end_time.number
print "delta_t =", delta_t.number
print "n_workers =", n_workers
print "use_gpu =", use_gpu
print "manage_encounters =", manage_encounters
print "\ninitializing the gravity module"
sys.stdout.flush()
init_smalln()
# Note that there are actually three GPU options:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
if gpu_worker == 1:
try:
gravity = grav(number_of_workers = n_workers,
redirection = "none", mode = "gpu")
except Exception as ex:
gravity = grav(number_of_workers = n_workers,
redirection = "none")
else:
gravity = grav(number_of_workers = n_workers,
redirection = "none")
gravity.initialize_code()
gravity.parameters.set_defaults()
#-----------------------------------------------------------------
if infile == None:
print "making a Plummer model"
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id+1
print "setting particle masses and radii"
if salpeter == 0:
print 'equal masses'
total_mass = 1.0 | nbody_system.mass
scaled_mass = total_mass / number_of_stars
else:
print 'salpeter mass function'
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars)
stars.mass = scaled_mass
print "centering stars"
stars.move_to_center()
print "scaling stars to virial equilibrium"
stars.scale_to_standard(smoothing_length_squared
= gravity.parameters.epsilon_squared)
else:
# Read the input data. Units are dynamical (sorry).
# Format: id mass pos[3] vel[3]
print "reading file", infile
id = []
mass = []
pos = []
vel = []
f = open(infile, 'r')
count = 0
for line in f:
if len(line) > 0:
count += 1
cols = line.split()
if count == 1: snap = int(cols[0])
elif count == 2: number_of_stars = int(cols[0])
elif count == 3: time = float(cols[0]) | nbody_system.time
else:
if len(cols) >= 8:
id.append(int(cols[0]))
mass.append(float(cols[1]))
pos.append((float(cols[2]),
float(cols[3]), float(cols[4])))
vel.append((float(cols[5]),
float(cols[6]), float(cols[7])))
f.close()
stars = datamodel.Particles(number_of_stars)
stars.id = id
stars.mass = mass | nbody_system.mass
stars.position = pos | nbody_system.length
stars.velocity = vel | nbody_system.speed
#stars.radius = 0. | nbody_system.length
total_mass = stars.mass.sum()
ke = pa.kinetic_energy(stars)
kT = ke/(1.5*number_of_stars)
if number_of_binaries > 0:
# Turn selected stars into binary components.
# Only tested for equal-mass case.
kep = Kepler(redirection = "none")
kep.initialize_code()
added_mass = 0.0 | nbody_system.mass
# Work with energies rather than semimajor axes.
Emin = 10*kT
Emax = 20*kT
ecc = 0.1
id_count = number_of_stars
nbin = 0
for i in range(0, number_of_stars,
number_of_stars/number_of_binaries):
# Star i is CM, becomes component, add other star at end.
nbin += 1
mass = stars[i].mass
new_mass = numpy.random.uniform()*mass # uniform q?
mbin = mass + new_mass
fac = new_mass/mbin
E = Emin + numpy.random.uniform()*(Emax-Emin)
a = 0.5*nbody_system.G*mass*new_mass/E
kep.initialize_from_elements(mbin, a, ecc)
dr = quantities.AdaptingVectorQuantity()
dr.extend(kep.get_separation_vector())
dv = quantities.AdaptingVectorQuantity()
dv.extend(kep.get_velocity_vector())
newstar = datamodel.Particles(1)
newstar.mass = new_mass
newstar.position = stars[i].position + (1-fac)*dr
newstar.velocity = stars[i].velocity + (1-fac)*dv
# stars[i].mass = mass
stars[i].position = stars[i].position - fac*dr
stars[i].velocity = stars[i].velocity - fac*dv
id_count += 1
newstar.id = id_count
stars.add_particles(newstar)
added_mass += new_mass
if nbin >= number_of_binaries: break
kep.stop()
print 'created', nbin, 'binaries'
sys.stdout.flush()
stars.mass = stars.mass * total_mass/(total_mass+added_mass)
number_of_stars += nbin
# Set dynamical radii (assuming virial equilibrium and standard
# units). Note that this choice should be refined, and updated
# as the system evolves. Probably the choice of radius should be
# made entirely in the multiples module. TODO. In these units,
# M = 1 and <v^2> = 0.5, so the mean 90-degree turnaround impact
# parameter is
#
# b_90 = G (m_1+m_2) / vrel^2
# = 2 <m> / 2<v^2>
# = 2 / N for equal masses
#
# Taking r_i = m_i / 2<v^2> = m_i in virial equilibrium means
# that, approximately, "contact" means a 90-degree deflection (r_1
# + r_2 = b_90). A more conservative choice with r_i less than
# this value will isolates encounters better, but also place more
# load on the large-N dynamical module.
stars.radius = stars.mass.number | nbody_system.length
time = 0.0 | nbody_system.time
# print "IDs:", stars.id.number
print "recentering stars"
stars.move_to_center()
sys.stdout.flush()
#-----------------------------------------------------------------
if softening_length < 0.0 | nbody_system.length:
# Use ~interparticle spacing. Assuming standard units here. TODO
eps2 = 0.25*(float(number_of_stars))**(-0.666667) \
| nbody_system.length**2
else:
eps2 = softening_length*softening_length
print 'softening length =', eps2.sqrt()
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.epsilon_squared = eps2
gravity.parameters.use_gpu = use_gpu
# gravity.parameters.manage_encounters = manage_encounters
print ''
print "adding particles"
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print ''
print "number_of_stars =", number_of_stars
print "evolving to time =", end_time.number, \
"in steps of", delta_t.number
sys.stdout.flush()
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
# Debugging: prevent the multiples code from being called.
if 0:
stopping_condition.disable()
print 'stopping condition disabled'
sys.stdout.flush()
# -----------------------------------------------------------------
# Create the coupled code and integrate the system to the desired
# time, managing interactions internally.
kep = init_kepler(stars[0], stars[1])
multiples_code = multiples.Multiples(gravity, new_smalln, kep)
multiples_code.neighbor_perturbation_limit = 0.1
#multiples_code.neighbor_distance_factor = 1.0
#multiples_code.neighbor_veto = False
#multiples_code.neighbor_distance_factor = 2.0
multiples_code.neighbor_veto = True
print ''
print 'multiples_code.initial_scale_factor =', \
multiples_code.initial_scale_factor
print 'multiples_code.neighbor_perturbation_limit =', \
multiples_code.neighbor_perturbation_limit
print 'multiples_code.neighbor_veto =', \
multiples_code.neighbor_veto
print 'multiples_code.final_scale_factor =', \
multiples_code.final_scale_factor
print 'multiples_code.initial_scatter_factor =', \
multiples_code.initial_scatter_factor
print 'multiples_code.final_scatter_factor =', \
multiples_code.final_scatter_factor
print 'multiples_code.retain_binary_apocenter =', \
multiples_code.retain_binary_apocenter
print 'multiples_code.wide_perturbation_limit =', \
multiples_code.wide_perturbation_limit
pre = "%%% "
E0,cpu0 = print_log(pre, time, multiples_code)
while time < end_time:
time += delta_t
multiples_code.evolve_model(time)
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
print_log(pre, time, multiples_code, E0, cpu0)
sys.stdout.flush()
#-----------------------------------------------------------------
if not outfile == None:
# Write data to a file.
f = open(outfile, 'w')
#--------------------------------------------------
# Need to save top-level stellar data and parameters.
# Need to save multiple data and parameters.
f.write('%.15g\n'%(time.number))
for s in multiples_code.stars: write_star(s, f)
#--------------------------------------------------
f.close()
print 'wrote file', outfile
print ''
gravity.stop()
def make_nbody(number_of_stars=100,
time=0.0,
n_workers=1,
use_gpu=1,
gpu_worker=1,
salpeter=0,
delta_t=1.0 | nbody_system.time,
timestep_parameter=0.1,
softening_length=0.0 | nbody_system.length,
random_seed=1234):
# Make an N-body system, print out some statistics on it, and save
# it in a restart file. The restart file name is of the form
# 't=nnnn.n.xxx', where the default time is 0.0.
if random_seed <= 0:
numpy.random.seed()
random_seed = numpy.random.randint(1, pow(2, 31) - 1)
numpy.random.seed(random_seed)
print "random seed =", random_seed
init_smalln()
# Note that there are actually three GPU options:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
if gpu_worker == 1:
try:
gravity = grav(number_of_workers=n_workers,
redirection="none",
mode="gpu")
except Exception as ex:
gravity = grav(number_of_workers=n_workers, redirection="none")
else:
gravity = grav(number_of_workers=n_workers, redirection="none")
gravity.initialize_code()
gravity.parameters.set_defaults()
#-----------------------------------------------------------------
# Make a standard N-body system.
print "making a Plummer model"
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id + 1
print "setting particle masses and radii"
if salpeter == 0:
print 'equal masses'
total_mass = 1.0 | nbody_system.mass
scaled_mass = total_mass / number_of_stars
else:
print 'salpeter mass function'
mmin = 0.5 | nbody_system.mass
mmax = 10.0 | nbody_system.mass
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars,
mass_min=mmin,
mass_max=mmax)
stars.mass = scaled_mass
print "centering stars"
stars.move_to_center()
print "scaling stars to virial equilibrium"
stars.scale_to_standard(
smoothing_length_squared=gravity.parameters.epsilon_squared)
# Set dynamical radii (assuming virial equilibrium and standard
# units). Note that this choice should be refined, and updated
# as the system evolves. Probably the choice of radius should be
# made entirely in the multiples module. TODO. In these units,
# M = 1 and <v^2> = 0.5, so the mean 90-degree turnaround impact
# parameter is
#
# b_90 = G (m_1+m_2) / vrel^2
# = 2 <m> / 2<v^2>
# = 2 / N for equal masses
#
# Taking r_i = m_i / 2<v^2> = m_i in virial equilibrium means
# that, approximately, "contact" means a 90-degree deflection (r_1
# + r_2 = b_90). A more conservative choice with r_i less than
# this value will isolate encounters better, but also place more
# load on the large-N dynamical module.
stars.radius = 0.5 * stars.mass.number | nbody_system.length
time = 0.0 | nbody_system.time
# print "IDs:", stars.id.number
print "recentering stars"
stars.move_to_center()
sys.stdout.flush()
#-----------------------------------------------------------------
if softening_length < 0.0 | nbody_system.length:
# Use ~interparticle spacing. Assuming standard units here. TODO
softening_length = 0.5*float(number_of_stars)**(-0.3333333) \
| nbody_system.length
print 'softening length =', softening_length
gravity.parameters.timestep_parameter = timestep_parameter
gravity.parameters.epsilon_squared = softening_length * softening_length
gravity.parameters.use_gpu = use_gpu
print ''
print "adding particles"
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print ''
print "number_of_stars =", number_of_stars
sys.stdout.flush()
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
# -----------------------------------------------------------------
# Create the coupled code and integrate the system to the desired
# time, managing interactions internally.
kep = init_kepler(stars[0], stars[1])
multiples_code = multiples.Multiples(gravity, new_smalln, kep)
multiples_code.neighbor_perturbation_limit = 0.1
multiples_code.neighbor_veto = True
print ''
print 'multiples_code.initial_scale_factor =', \
multiples_code.initial_scale_factor
print 'multiples_code.neighbor_perturbation_limit =', \
multiples_code.neighbor_perturbation_limit
print 'multiples_code.neighbor_veto =', \
multiples_code.neighbor_veto
print 'multiples_code.final_scale_factor =', \
multiples_code.final_scale_factor
print 'multiples_code.initial_scatter_factor =', \
multiples_code.initial_scatter_factor
print 'multiples_code.final_scatter_factor =', \
multiples_code.final_scatter_factor
print 'multiples_code.retain_binary_apocenter =', \
multiples_code.retain_binary_apocenter
print 'multiples_code.wide_perturbation_limit =', \
multiples_code.wide_perturbation_limit
# Take a dummy step, just in case...
multiples_code.evolve_model(time)
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
pre = "%%% "
E0, cpu0 = print_log(pre, time, multiples_code)
sys.stdout.flush()
# file = 't='+'{:07.2f}'.format(time.number) # fails in Python 2.6
file = 't=%07.2f' % time.number
write_state_to_file(time, stars, gravity, multiples_code, file, delta_t,
E0, cpu0)
tree_copy = multiples_code.root_to_tree.copy()
del multiples_code
sys.stdout.flush()
gravity.stop()
kep.stop()
stop_smalln()
print ''
def run_ph4(infile=None,
number_of_stars=40,
end_time=10 | nbody_system.time,
delta_t=1 | nbody_system.time,
n_workers=1,
use_gpu=1,
gpu_worker=1,
accuracy_parameter=0.1,
softening_length=-1 | nbody_system.length,
manage_encounters=1,
random_seed=1234):
if random_seed <= 0:
numpy.random.seed()
random_seed = numpy.random.randint(1, pow(2, 31) - 1)
numpy.random.seed(random_seed)
print("random seed =", random_seed)
if infile != None: print("input file =", infile)
print("end_time =", end_time.number)
print("delta_t =", delta_t.number)
print("n_workers =", n_workers)
print("use_gpu =", use_gpu)
print("manage_encounters =", manage_encounters)
print("\ninitializing the gravity module")
sys.stdout.flush()
# Note that there are actually three GPU options to test:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
if gpu_worker == 1:
try:
gravity = grav(number_of_workers=n_workers,
redirection="none",
mode="gpu")
except Exception as ex:
gravity = grav(number_of_workers=n_workers, redirection="none")
else:
gravity = grav(number_of_workers=n_workers, redirection="none")
gravity.initialize_code()
gravity.parameters.set_defaults()
#-----------------------------------------------------------------
if infile == None:
print("making a Plummer model")
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id + 1
print("setting particle masses and radii")
#stars.mass = (1.0 / number_of_stars) | nbody_system.mass
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars)
stars.mass = scaled_mass
stars.radius = 0.02 | nbody_system.length
print("centering stars")
stars.move_to_center()
print("scaling stars to virial equilibrium")
stars.scale_to_standard(
smoothing_length_squared=gravity.parameters.epsilon_squared)
time = 0.0 | nbody_system.time
sys.stdout.flush()
else:
# Read the input data. Units are dynamical.
print("reading file", infile)
id = []
mass = []
pos = []
vel = []
f = open(infile, 'r')
count = 0
for line in f:
if len(line) > 0:
count += 1
cols = line.split()
if count == 1: snap = int(cols[0])
elif count == 2: number_of_stars = int(cols[0])
elif count == 3: time = float(cols[0]) | nbody_system.time
else:
if len(cols) >= 8:
id.append(int(cols[0]))
mass.append(float(cols[1]))
pos.append(
(float(cols[2]), float(cols[3]), float(cols[4])))
vel.append(
(float(cols[5]), float(cols[6]), float(cols[7])))
f.close()
stars = datamodel.Particles(number_of_stars)
stars.id = id
stars.mass = mass | nbody_system.mass
stars.position = pos | nbody_system.length
stars.velocity = vel | nbody_system.speed
stars.radius = 0. | nbody_system.length
# print "IDs:", stars.id.number
sys.stdout.flush()
#-----------------------------------------------------------------
if softening_length == -1 | nbody_system.length:
eps2 = 0.25*(float(number_of_stars))**(-0.666667) \
| nbody_system.length**2
else:
eps2 = softening_length * softening_length
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.epsilon_squared = eps2
gravity.parameters.use_gpu = use_gpu
# gravity.parameters.manage_encounters = manage_encounters
print("adding particles")
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print('')
print("number_of_stars =", number_of_stars)
print("evolving to time =", end_time.number, \
"in steps of", delta_t.number)
sys.stdout.flush()
E0 = print_log(time, gravity)
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
kep = Kepler(redirection="none")
kep.initialize_code()
multiples_code = multiples.Multiples(gravity, new_smalln, kep)
while time < end_time:
time += delta_t
multiples_code.evolve_model(time)
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
print_log(time, gravity, E0)
sys.stdout.flush()
print('')
gravity.stop()
def run_ph4(infile = None, number_of_stars = 40,
end_time = 10 | nbody_system.time,
delta_t = 1 | nbody_system.time,
n_workers = 1, use_gpu = 1, gpu_worker = 1, gpu_id = -1,
accuracy_parameter = 0.1,
softening_length = -1 | nbody_system.length,
manage_encounters = 1):
if infile != None: print "input file =", infile
print "end_time =", end_time.number
print "delta_t =", delta_t.number
print "n_workers =", n_workers
print "use_gpu =", use_gpu
print "manage_encounters =", manage_encounters
print "\ninitializing the gravity module"
sys.stdout.flush()
# Note that there are actually three GPU options to test:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
#print "1"; sys.stdout.flush()
gpu = 0
if gpu_worker == 1:
try:
gravity = grav(number_of_workers = n_workers,
redirection = "none", mode = "gpu")
# debugger='valgrind')
gpu = 1
except Exception as ex:
print '*** GPU worker code not found. Reverting to non-GPU code. ***'
gpu = 0
if gpu == 0:
gravity = grav(number_of_workers = n_workers,
redirection = "none")
# debugger='valgrind')
#print "2"; sys.stdout.flush()
gravity.initialize_code()
#print "3"; sys.stdout.flush()
gravity.parameters.set_defaults()
gravity.parameters.gpu_id = gpu_id
#-----------------------------------------------------------------
#print "4"; sys.stdout.flush()
if infile == None:
print "making a Plummer model"
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id+1
print "setting particle masses and radii"
stars.mass = (1.0 / number_of_stars) | nbody_system.mass
if 0:
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars)
stars.mass = scaled_mass
stars.radius = 0.0 | nbody_system.length
print "centering stars"
stars.move_to_center()
if 0:
print "scaling stars to virial equilibrium"
stars.scale_to_standard(smoothing_length_squared
= gravity.parameters.epsilon_squared)
time = 0.0 | nbody_system.time
sys.stdout.flush()
else:
# Read the input data. Units are dynamical.
print "reading file", infile
id = []
mass = []
pos = []
vel = []
f = open(infile, 'r')
count = 0
for line in f:
if len(line) > 0:
count += 1
cols = line.split()
if count == 1: snap = int(cols[0])
elif count == 2: number_of_stars = int(cols[0])
elif count == 3: time = float(cols[0]) | nbody_system.time
else:
if len(cols) >= 8:
id.append(int(cols[0]))
mass.append(float(cols[1]))
pos.append((float(cols[2]),
float(cols[3]), float(cols[4])))
vel.append((float(cols[5]),
float(cols[6]), float(cols[7])))
f.close()
stars = datamodel.Particles(number_of_stars)
stars.id = id
stars.mass = mass | nbody_system.mass
stars.position = pos | nbody_system.length
stars.velocity = vel | nbody_system.speed
stars.radius = 0. | nbody_system.length
# print "IDs:", stars.id.number
sys.stdout.flush()
#-----------------------------------------------------------------
#print "5"; sys.stdout.flush()
if softening_length == -1 | nbody_system.length:
eps2 = 0.25*(float(number_of_stars))**(-0.666667) \
| nbody_system.length**2
else:
eps2 = softening_length*softening_length
#print "6"; sys.stdout.flush()
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.epsilon_squared = eps2
gravity.parameters.use_gpu = use_gpu
gravity.parameters.manage_encounters = manage_encounters
print "adding particles"
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print ''
print "number_of_stars =", number_of_stars
print "evolving to time =", end_time.number, \
"in steps of", delta_t.number
sys.stdout.flush()
E0,cpu0,wall0 = print_log('', time, gravity)
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
while time < end_time:
time += delta_t
gravity.evolve_model(time)
# Ensure that the stars list is consistent with the internal
# data in the module.
ls = len(stars)
# Update the bookkeeping: synchronize stars with the module data.
try:
gravity.update_particle_set()
gravity.particles.synchronize_to(stars)
except:
pass
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
if stopping_condition.is_set():
star1 = stopping_condition.particles(0)[0]
star2 = stopping_condition.particles(1)[0]
print '\nstopping condition set at time', \
gravity.get_time().number,'for:\n'
print star1
print ''
print star2
print ''
raise Exception("no encounter handling")
if len(stars) != ls:
if 0:
print "stars:"
for s in stars:
print " ", s.id.number, s.mass.number, \
s.x.number, s.y.number, s.z.number
else:
print "number of stars =", len(stars)
sys.stdout.flush()
print_log('', time, gravity, E0, cpu0, wall0)
sys.stdout.flush()
print ''
gravity.stop()
def run_ph4(initial_file=None,
end_time=0 | nbody_system.time,
input_delta_t=0.0 | nbody_system.time,
input_Delta_t=1.0 | nbody_system.time,
input_timestep_parameter=0.0,
input_softening_length=-1.0 | nbody_system.length,
n_workers=1,
use_gpu=1,
gpu_worker=1,
use_multiples=True,
save_restart=False,
strict_restart=False):
# Read an N-body system from a file and run it to the specified
# time using the specified steps. Print log information and
# optionally save a restart file after every step. If the
# specified time is less than the time in the initial file, don't
# take a step, but still print out the log info. (Hence run_ph4
# also functions like Starlab sys_stats.)
print "initial_file =", initial_file
print "end_time =", end_time.number
print "n_workers =", n_workers
print "use_gpu =", use_gpu
print "use_multiples =", use_multiples
print "save_restart =", save_restart
print "strict_restart =", strict_restart
print "\ninitializing the gravity module"
sys.stdout.flush()
init_smalln()
# Note that there are actually three GPU options:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
if gpu_worker == 1:
try:
gravity = grav(number_of_workers=n_workers,
redirection="none",
mode="gpu")
except Exception as ex:
gravity = grav(number_of_workers=n_workers, redirection="none")
else:
gravity = grav(number_of_workers=n_workers, redirection="none")
gravity.initialize_code()
gravity.parameters.set_defaults()
kep = Kepler(None, redirection="none")
kep.initialize_code()
stars, time, delta_t, E0, cpu0, multiples_code \
= read_state_from_file(initial_file, gravity, kep)
# Allow overrides of the restored data (OK for delta_t, NOT
# recommended for timestep_parameter or softening_length). Note
# that reading the state also commits the particles, and hence
# calculates the initial time steps. Probably should reinitialize
# if timestep_parameter or softening_length are changed. TODO
if input_delta_t.number > 0:
if input_delta_t != delta_t:
print 'modifying delta_t from stored', delta_t, \
'to input', input_delta_t
delta_t = input_delta_t
else:
print "using stored delta_t =", delta_t
print input_timestep_parameter
print gravity.parameters.timestep_parameter
if input_timestep_parameter > 0:
if input_timestep_parameter != gravity.parameters.timestep_parameter:
print 'modifying timestep_parameter from stored', \
gravity.parameters.timestep_parameter, \
'to input', input_timestep_parameter
gravity.parameters.timestep_parameter \
= input_timestep_parameter
else:
print 'timestep_parameter =', gravity.parameters.timestep_parameter
if input_softening_length.number >= 0:
if input_softening_length*input_softening_length \
!= gravity.parameters.epsilon_squared:
print 'modifying softening_length from stored', \
gravity.parameters.epsilon_squared.sqrt(), \
'to input', input_softening_length
gravity.parameters.epsilon_squared \
= softening_length*softening_length
else:
print 'softening length =', gravity.parameters.epsilon_squared.sqrt()
gravity.parameters.use_gpu = use_gpu
gravity.parameters.begin_time = time
if 0:
print ''
print gravity.parameters.begin_time
print stars.mass
#print stars.position
for s in stars:
print '%.18e %.18e %.18e' % (s.x.number, s.y.number, s.z.number)
print stars.velocity
channel = gravity.particles.new_channel_to(stars)
if use_multiples:
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
gravity.parameters.force_sync = 1 # end exactly at the specified time
pre = "%%% "
print_log(pre, time, multiples_code, E0, cpu0)
tsave = time + Delta_t
save_file = ''
while time < end_time:
time += delta_t
multiples_code.evolve_model(time) #, callback=handle_callback)
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
# Write log information.
print_log(pre, time, multiples_code, E0, cpu0)
sys.stdout.flush()
# Optionally create a restart file.
if save_restart and time >= tsave:
#save_file = 't='+'{:07.2f}'.format(time.number) # not in Python 2.6
save_file = 't=%07.2f' % time.number
write_state_to_file(time, stars, gravity, multiples_code,
save_file, delta_t, E0, cpu0)
sys.stdout.flush()
tsave += Delta_t
if strict_restart: break
gravity.stop()
kep.stop()
stop_smalln()
return time, save_file
def make_nbody(number_of_stars = 100, time = 0.0,
n_workers = 1, use_gpu = 1, gpu_worker = 1,
salpeter = 0,
delta_t = 1.0 | nbody_system.time,
timestep_parameter = 0.1,
softening_length = 0.0 | nbody_system.length,
random_seed = 1234):
# Make an N-body system, print out some statistics on it, and save
# it in a restart file. The restart file name is of the form
# 't=nnnn.n.xxx', where the default time is 0.0.
if random_seed <= 0:
numpy.random.seed()
random_seed = numpy.random.randint(1, pow(2,31)-1)
numpy.random.seed(random_seed)
print "random seed =", random_seed
init_smalln()
# Note that there are actually three GPU options:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
if gpu_worker == 1:
try:
gravity = grav(number_of_workers = n_workers,
redirection = "none", mode = "gpu")
except Exception as ex:
gravity = grav(number_of_workers = n_workers,
redirection = "none")
else:
gravity = grav(number_of_workers = n_workers,
redirection = "none")
gravity.initialize_code()
gravity.parameters.set_defaults()
#-----------------------------------------------------------------
# Make a standard N-body system.
print "making a Plummer model"
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id+1
print "setting particle masses and radii"
if salpeter == 0:
print 'equal masses'
total_mass = 1.0 | nbody_system.mass
scaled_mass = total_mass / number_of_stars
else:
print 'salpeter mass function'
mmin = 0.5 | nbody_system.mass
mmax = 10.0 | nbody_system.mass
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars,
mass_min = mmin,
mass_max = mmax)
stars.mass = scaled_mass
print "centering stars"
stars.move_to_center()
print "scaling stars to virial equilibrium"
stars.scale_to_standard(smoothing_length_squared
= gravity.parameters.epsilon_squared)
# Set dynamical radii (assuming virial equilibrium and standard
# units). Note that this choice should be refined, and updated
# as the system evolves. Probably the choice of radius should be
# made entirely in the multiples module. TODO. In these units,
# M = 1 and <v^2> = 0.5, so the mean 90-degree turnaround impact
# parameter is
#
# b_90 = G (m_1+m_2) / vrel^2
# = 2 <m> / 2<v^2>
# = 2 / N for equal masses
#
# Taking r_i = m_i / 2<v^2> = m_i in virial equilibrium means
# that, approximately, "contact" means a 90-degree deflection (r_1
# + r_2 = b_90). A more conservative choice with r_i less than
# this value will isolate encounters better, but also place more
# load on the large-N dynamical module.
stars.radius = 0.5*stars.mass.number | nbody_system.length
time = 0.0 | nbody_system.time
# print "IDs:", stars.id.number
print "recentering stars"
stars.move_to_center()
sys.stdout.flush()
#-----------------------------------------------------------------
if softening_length < 0.0 | nbody_system.length:
# Use ~interparticle spacing. Assuming standard units here. TODO
softening_length = 0.5*float(number_of_stars)**(-0.3333333) \
| nbody_system.length
print 'softening length =', softening_length
gravity.parameters.timestep_parameter = timestep_parameter
gravity.parameters.epsilon_squared = softening_length*softening_length
gravity.parameters.use_gpu = use_gpu
print ''
print "adding particles"
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print ''
print "number_of_stars =", number_of_stars
sys.stdout.flush()
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
# -----------------------------------------------------------------
# Create the coupled code and integrate the system to the desired
# time, managing interactions internally.
kep = init_kepler(stars[0], stars[1])
multiples_code = multiples.Multiples(gravity, new_smalln, kep)
multiples_code.neighbor_perturbation_limit = 0.1
multiples_code.neighbor_veto = True
print ''
print 'multiples_code.initial_scale_factor =', \
multiples_code.initial_scale_factor
print 'multiples_code.neighbor_perturbation_limit =', \
multiples_code.neighbor_perturbation_limit
print 'multiples_code.neighbor_veto =', \
multiples_code.neighbor_veto
print 'multiples_code.final_scale_factor =', \
multiples_code.final_scale_factor
print 'multiples_code.initial_scatter_factor =', \
multiples_code.initial_scatter_factor
print 'multiples_code.final_scatter_factor =', \
multiples_code.final_scatter_factor
print 'multiples_code.retain_binary_apocenter =', \
multiples_code.retain_binary_apocenter
print 'multiples_code.wide_perturbation_limit =', \
multiples_code.wide_perturbation_limit
# Take a dummy step, just in case...
multiples_code.evolve_model(time)
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
pre = "%%% "
E0,cpu0 = print_log(pre, time, multiples_code)
sys.stdout.flush()
# file = 't='+'{:07.2f}'.format(time.number) # fails in Python 2.6
file = 't=%07.2f'%time.number
write_state_to_file(time, stars, gravity, multiples_code,
file, delta_t, E0, cpu0)
tree_copy = multiples_code.root_to_tree.copy()
del multiples_code
sys.stdout.flush()
gravity.stop()
kep.stop()
stop_smalln()
print ''
def run_ph4(infile = None, number_of_stars = 40,
end_time = 10 | nbody_system.time,
delta_t = 1 | nbody_system.time,
n_workers = 1, use_gpu = 1, gpu_worker = 1, gpu_id = -1,
accuracy_parameter = 0.1,
softening_length = -1 | nbody_system.length,
manage_encounters = 1):
if infile != None: print "input file =", infile
print "end_time =", end_time.number
print "delta_t =", delta_t.number
print "n_workers =", n_workers
print "use_gpu =", use_gpu
print "manage_encounters =", manage_encounters
print "initializing the gravity module"
sys.stdout.flush()
# Note that there are actually really three GPU options to test:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
#print "1"; sys.stdout.flush()
gpu = 0
if gpu_worker == 1:
try:
gravity = grav(number_of_workers = n_workers,
redirection = "none", mode = "gpu")
# debugger='valgrind')
gpu = 1
except Exception as ex:
print \
'*** GPU worker code not found. Reverting to non-GPU code. ***'
gpu = 0
if gpu == 0:
gravity = grav(number_of_workers = n_workers,
redirection = "none")
# debugger='valgrind')
#print "2"; sys.stdout.flush()
gravity.initialize_code()
#print "3"; sys.stdout.flush()
gravity.parameters.set_defaults()
gravity.parameters.gpu_id = gpu_id
#-----------------------------------------------------------------
#print "4"; sys.stdout.flush()
print "making a Plummer model"
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id+1
print "setting particle masses and radii"
stars.mass = (1.0 / number_of_stars) | nbody_system.mass
if 0:
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars)
stars.mass = scaled_mass
stars.radius = 0.0 | nbody_system.length
print "centering stars"
stars.move_to_center()
if 0:
print "scaling stars to virial equilibrium"
stars.scale_to_standard(smoothing_length_squared
= gravity.parameters.epsilon_squared)
time = 0.0 | nbody_system.time
sys.stdout.flush()
#-----------------------------------------------------------------
#print "5"; sys.stdout.flush()
if softening_length == -1 | nbody_system.length:
eps2 = 0.25*(float(number_of_stars))**(-0.666667) \
| nbody_system.length**2
else:
eps2 = softening_length*softening_length
#print "6"; sys.stdout.flush()
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.epsilon_squared = eps2
gravity.parameters.use_gpu = use_gpu
gravity.parameters.manage_encounters = manage_encounters
print "adding particles"
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print ''
print "number_of_stars =", number_of_stars
sys.stdout.flush()
E0,cpu0,wall0 = print_log('', time, gravity)
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
#-----------------------------------------------------------------
cpu0 = cputime()
t0 = 0.
pi = math.pi
times = [1., 2., pi, 4*pi/3, 5., 2*pi, 2*pi + pi/100,
2*pi + pi/5, 7., 8., 3*pi, 10.]
gravity.parameters.force_sync = 1 # stays set until explicitly unset
for t in times:
time = t|nbody_system.time
print "\nEvolving to time", time
sys.stdout.flush()
gravity.parameters.block_steps = 0
gravity.parameters.total_steps = 0
gravity.evolve_model(time)
dt = t - t0
t0 = t
cpu = cputime()
dcpu = cpu - cpu0
cpu0 = cpu
# Ensure that the stars list is consistent with the internal
# data in the module.
ls = len(stars)
# Update the bookkeeping: synchronize stars with the module data.
try:
gravity.update_particle_set()
gravity.particles.synchronize_to(stars)
except:
pass
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
if stopping_condition.is_set():
star1 = stopping_condition.particles(0)[0]
star2 = stopping_condition.particles(1)[0]
print '\nstopping condition set at time', \
gravity.get_time().number,'for:\n'
print star1
print ''
print star2
print ''
raise Exception("no encounter handling")
if len(stars) != ls:
if 0:
print "stars:"
for s in stars:
print " ", s.id.number, s.mass.number, \
s.x.number, s.y.number, s.z.number
else:
print "number of stars =", len(stars)
sys.stdout.flush()
print_log('', time, gravity, E0, cpu0, wall0)
print '@@@'
print '@@@ t =', time.number, ' dt =', dt
print '@@@ sync_time =', gravity.parameters.sync_time.number
print '@@@ dcpu/dt =', dcpu/dt
nb = gravity.parameters.block_steps
ns = gravity.parameters.total_steps
print '@@@ d(block_steps) =', nb, ' #/dt =', nb/dt
print '@@@ d(total steps) =', ns, ' #/dt =', ns/dt
#print stars
sys.stdout.flush()
#-----------------------------------------------------------------
print ''
gravity.stop()
def run_ph4(infile = None, number_of_stars = 40,
end_time = 10 | nbody_system.time,
delta_t = 1 | nbody_system.time,
n_workers = 1, use_gpu = 1, gpu_worker = 1,
accuracy_parameter = 0.1,
softening_length = -1 | nbody_system.length,
manage_encounters = 1, random_seed = 1234):
if random_seed <= 0:
numpy.random.seed()
random_seed = numpy.random.randint(1, pow(2,31)-1)
numpy.random.seed(random_seed)
print "random seed =", random_seed
if infile != None: print "input file =", infile
print "end_time =", end_time.number
print "delta_t =", delta_t.number
print "n_workers =", n_workers
print "use_gpu =", use_gpu
print "manage_encounters =", manage_encounters
print "\ninitializing the gravity module"
sys.stdout.flush()
# Note that there are actually three GPU options to test:
#
# 1. use the GPU code and allow GPU use (default)
# 2. use the GPU code but disable GPU use (-g)
# 3. use the non-GPU code (-G)
if gpu_worker == 1:
try:
gravity = grav(number_of_workers = n_workers,
redirection = "none", mode = "gpu")
except Exception as ex:
gravity = grav(number_of_workers = n_workers, redirection = "none")
else:
gravity = grav(number_of_workers = n_workers, redirection = "none")
gravity.initialize_code()
gravity.parameters.set_defaults()
#-----------------------------------------------------------------
if infile == None:
print "making a Plummer model"
stars = new_plummer_model(number_of_stars)
id = numpy.arange(number_of_stars)
stars.id = id+1
print "setting particle masses and radii"
#stars.mass = (1.0 / number_of_stars) | nbody_system.mass
scaled_mass = new_salpeter_mass_distribution_nbody(number_of_stars)
stars.mass = scaled_mass
stars.radius = 0.02 | nbody_system.length
print "centering stars"
stars.move_to_center()
print "scaling stars to virial equilibrium"
stars.scale_to_standard(smoothing_length_squared
= gravity.parameters.epsilon_squared)
time = 0.0 | nbody_system.time
sys.stdout.flush()
else:
# Read the input data. Units are dynamical.
print "reading file", infile
id = []
mass = []
pos = []
vel = []
f = open(infile, 'r')
count = 0
for line in f:
if len(line) > 0:
count += 1
cols = line.split()
if count == 1: snap = int(cols[0])
elif count == 2: number_of_stars = int(cols[0])
elif count == 3: time = float(cols[0]) | nbody_system.time
else:
if len(cols) >= 8:
id.append(int(cols[0]))
mass.append(float(cols[1]))
pos.append((float(cols[2]),
float(cols[3]), float(cols[4])))
vel.append((float(cols[5]),
float(cols[6]), float(cols[7])))
f.close()
stars = datamodel.Particles(number_of_stars)
stars.id = id
stars.mass = mass | nbody_system.mass
stars.position = pos | nbody_system.length
stars.velocity = vel | nbody_system.speed
stars.radius = 0. | nbody_system.length
# print "IDs:", stars.id.number
sys.stdout.flush()
#-----------------------------------------------------------------
if softening_length == -1 | nbody_system.length:
eps2 = 0.25*(float(number_of_stars))**(-0.666667) \
| nbody_system.length**2
else:
eps2 = softening_length*softening_length
gravity.parameters.timestep_parameter = accuracy_parameter
gravity.parameters.epsilon_squared = eps2
gravity.parameters.use_gpu = use_gpu
# gravity.parameters.manage_encounters = manage_encounters
print "adding particles"
# print stars
sys.stdout.flush()
gravity.particles.add_particles(stars)
gravity.commit_particles()
print ''
print "number_of_stars =", number_of_stars
print "evolving to time =", end_time.number, \
"in steps of", delta_t.number
sys.stdout.flush()
E0 = print_log(time, gravity)
# Channel to copy values from the code to the set in memory.
channel = gravity.particles.new_channel_to(stars)
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
kep = Kepler(redirection = "none")
kep.initialize_code()
multiples_code = multiples.Multiples(gravity, new_smalln, kep)
while time < end_time:
time += delta_t
multiples_code.evolve_model(time)
# Copy values from the module to the set in memory.
channel.copy()
# Copy the index (ID) as used in the module to the id field in
# memory. The index is not copied by default, as different
# codes may have different indices for the same particle and
# we don't want to overwrite silently.
channel.copy_attribute("index_in_code", "id")
print_log(time, gravity, E0)
sys.stdout.flush()
print ''
gravity.stop()
def GetValues(cluster_name,
num_workers=1,
use_gpu=1,
gpu_ID=0,
eps2=0.0 | nbody_system.length**2,
delta_t=0.05 | nbody_system.time):
# This function uses calls upon the restart fuction to reload the multiples from the simulation to use
# the multiples function to get the Energy and it correction, num_files can probably be replaced if we
# can measure how many files are in a cluster, maybe glob.glob can do that.
# This function returns the arrays below:
Energy = []
UncorrectedEnergy = []
Time = []
Kinetic = []
Potential = []
L = []
P = []
i = 0
# You will need to change the File Path varibale to run this on anyone else's account
file_path = "/home/draco/jthornton/Tycho/Restart/"
file_loc = file_path + cluster_name
search = glob.glob(file_loc + "*.hdf5")
for key in search:
if i % 2 == 0:
# This loop will go through the restart files of the cluster and append energy and momentum values to the corresponding arrays
# First get the restart naming correct
restart_file = key[:-11]
# Second retrieve the timestep from the file and convert it to a float
time_grab = []
time_grab = key.split("_")
time = float(time_grab[2]) | nbody_system.time
if use_gpu == 1:
gravity = ph4(number_of_workers=num_workers,
redirection="none",
mode="gpu")
else:
gravity = grav(number_of_workers=num_workers,
redirection="none")
# Initializing PH4 with Initial Conditions
print "Initializing gravity"
gravity.initialize_code()
gravity.parameters.set_defaults()
gravity.parameters.begin_time = time
gravity.parameters.epsilon_squared = eps2
gravity.parameters.timestep_parameter = delta_t.number
# Setting up the Code to Run with GPUs Provided by Command Line
gravity.parameters.use_gpu = use_gpu
gravity.parameters.gpu_id = gpu_ID
# Initializing Kepler and SmallN
print "Initializing Kepler"
kep = Kepler(None, redirection="none")
kep.initialize_code()
print "Initializing SmallN"
util.init_smalln()
MasterSet = []
print "Retrieving data"
MasterSet, multiples_code = read.read_state_from_file(
restart_file, gravity, kep, util.new_smalln())
# Setting Up the Stopping Conditions in PH4
stopping_condition = gravity.stopping_conditions.collision_detection
stopping_condition.enable()
sys.stdout.flush()
# Starting the AMUSE Channel for PH4
grav_channel = gravity.particles.new_channel_to(MasterSet)
print "Reload Successful"
U = multiples_code.potential_energy
T = multiples_code.kinetic_energy
Etop = T + U
print "T: "
print T
print "U: "
print U
angular_momentum = MasterSet.total_angular_momentum()
momentum = MasterSet.total_momentum()
Nmul, Nbin, Emul = multiples_code.get_total_multiple_energy()
tmp1, tmp2, Emul2 = multiples_code.get_total_multiple_energy2()
Etot = Etop + Emul
Eext = multiples_code.multiples_external_tidal_correction
Eint = multiples_code.multiples_internal_tidal_correction
Eerr = multiples_code.multiples_integration_energy_error
Edel = multiples_code.multiples_external_tidal_correction \
+ multiples_code.multiples_internal_tidal_correction \
+ multiples_code.multiples_integration_energy_error
Ecor = Etot - Edel
print "Ecor: "
print Ecor
gravity.stop()
kep.stop()
util.stop_smalln()
Energy.append(Ecor.number)
UncorrectedEnergy.append(Etop.number)
Time.append(time.number)
Kinetic.append(T.number)
Potential.append(U.number)
L.append(angular_momentum.number)
P.append(momentum.number)
i += 1
return Energy, UncorrectedEnergy, Time, Kinetic, Potential, L, P
add_planets(objects, number_of_planets, kc_converter, cluster_name, Neptune=True, Double=False)
# Defining Initial Conditions for PH4
time = 0.0 | nbody_system.time
delta_t = options.dt | nbody_system.time
number_of_steps = options.num_steps
end_time = number_of_steps*delta_t
num_workers = 1
eps2 = 0.0 | nbody_system.length**2
use_gpu = options.use_gpu
gpu_ID = options.gpu_ID
# Setting PH4 as the Top-Level Gravity Code
if use_gpu == 1:
try:
gravity = grav(number_of_workers = num_workers, redirection = "none", mode = "gpu")
except Exception as ex:
gravity = grav(number_of_workers = num_workers, redirection = "none")
print "*** GPU worker code not found. Reverting to non-GPU code. ***"
else:
gravity = grav(number_of_workers = num_workers, redirection = "none")
# Initializing PH4 with Initial Conditions
gravity.initialize_code()
gravity.parameters.set_defaults()
gravity.parameters.begin_time = time
gravity.parameters.epsilon_squared = eps2
gravity.parameters.timestep_parameter = delta_t.number
# Setting up the Code to Run with GPUs Provided by Command Line
gravity.parameters.use_gpu = use_gpu