def evolve_disk_flyby(bodies, gravity, t_end, n_steps, converter, snap_dir,
file_out):
bodies = ParticlesSuperset([stars, planetesimals])
channel_from_gr_to_framework = gravity.particles.new_channel_to(bodies)
rm_file(file_out)
Etot_init = gravity.kinetic_energy + gravity.potential_energy
Etot = Etot_init
dt = t_end / float(n_steps)
time = 0.0 | units.yr
stdout = (file_out.split('.'))[0]
stdout += '.txt'
f = open(snap_dir + "/" + stdout, 'a')
print " ** evolving: t_end = ", t_end, ", dt = ", dt.in_(units.yr)
print " \t\t", "time", "\t\t", "dE"
while time <= t_end:
gravity.evolve_model(time)
channel_from_gr_to_framework.copy()
bodies.collection_attributes.timestamp = time
Ekin = gravity.kinetic_energy
Epot = gravity.potential_energy
Etot = Ekin + Epot
dE = Etot_init - Etot
nb_E = converter.to_nbody(Etot)
#nb_J = converter.nbody_length ** 2 * units.nbody_mass * units.nbody_time ** -2 # not supposed to work
# A formatted string would work better than tabs. (Tabs never work)
line = " \t" + str(time.value_in(
units.yr)) + "\t" + str(nb_E) + "\t" + str(dE / Etot_init)
print line
f.write(line + "\n")
# Write coordinates in Center of Mass frame
# Move Stars to CoM (initially in CoM)
#### The stars are already in CoM coordinates ####
# Move planetesimals to CoM (initially in CoM)
#### The stars are already in CoM coordinates #### (Does this mean the other method is wrong?)
write_set_to_file(bodies, snap_dir + "/" + file_out, "hdf5")
time += dt
gravity.stop()
return
def evolve_disk_flyby(bodies, gravity,
t_end, n_steps, converter, snap_dir, file_out):
bodies = ParticlesSuperset([stars, planetesimals])
channel_from_gr_to_framework = gravity.particles.new_channel_to(bodies)
rm_file(file_out)
Etot_init = gravity.kinetic_energy + gravity.potential_energy
Etot = Etot_init
dt = t_end / float(n_steps)
time = 0.0 | units.yr
stdout = (file_out.split('.'))[0]
stdout += '.txt'
f = open(snap_dir + "/" + stdout, 'a')
print " ** evolving: t_end = ", t_end, ", dt = ", dt.in_(units.yr)
print " \t\t", "time", "\t\t", "dE"
while time<=t_end:
gravity.evolve_model(time)
channel_from_gr_to_framework.copy()
bodies.collection_attributes.timestamp = time
Ekin = gravity.kinetic_energy
Epot = gravity.potential_energy
Etot = Ekin + Epot
dE = Etot_init-Etot
nb_E = converter.to_nbody(Etot)
#nb_J = converter.nbody_length ** 2 * units.nbody_mass * units.nbody_time ** -2 # not supposed to work
# A formatted string would work better than tabs. (Tabs never work)
line = " \t" + str(time.value_in(units.yr)) + "\t" + str(nb_E) + "\t" + str(dE/Etot_init)
print line
f.write(line + "\n")
# Write coordinates in Center of Mass frame
# Move Stars to CoM (initially in CoM)
#### The stars are already in CoM coordinates ####
# Move planetesimals to CoM (initially in CoM)
#### The stars are already in CoM coordinates #### (Does this mean the other method is wrong?)
write_set_to_file(bodies, snap_dir + "/" + file_out, "hdf5")
time += dt
gravity.stop()
return
def update_plot(self, time, code):
time = time.value_in(nbody_system.time),
sum_energy = code.kinetic_energy + code.potential_energy - self.code.multiples_energy_correction
energy = sum_energy.value_in(nbody_system.energy)
coreradius = self.star_code.particles.virial_radius().value_in(self.rscale.to_unit())
if self.line is None:
pylab.ion()
pylab.subplot(1,2,1)
self.line = pylab.plot([time], [energy])[0]
pylab.xlim(0, self.endtime.value_in(nbody_system.time))
pylab.ylim(energy * 0.8, energy * 1.2)
pylab.subplot(1,2,2)
self.line2 = pylab.plot([time], [coreradius])[0]
#self.line2 = pylab.plot([time], [kicke])[0]
pylab.xlim(0, self.endtime.value_in(nbody_system.time))
pylab.ylim(0,3)
#pylab.ylim(-0.1, 0.1)
else:
xdata = self.line.get_xdata()
ydata = self.line.get_ydata()
xdata = numpy.concatenate( (xdata, time) )
ydata = numpy.concatenate( (ydata, [energy]) )
self.line.set_xdata(xdata)
self.line.set_ydata(ydata)
xdata = self.line2.get_xdata()
ydata = self.line2.get_ydata()
xdata = numpy.concatenate( (xdata, time) )
#ydata = numpy.concatenate( (ydata, [kicke]) )
ydata = numpy.concatenate( (ydata, [coreradius]) )
self.line2.set_xdata(xdata)
self.line2.set_ydata(ydata)
pylab.draw()
def evolve_double_star(Mprim, Msec, a, e, end_time, n_steps):
q = Msec/Mprim
double_star, stars = create_double_star(Mprim, Msec, a, e)
time = 0|units.Myr
time_step = end_time/n_steps
code = SeBa()
code.particles.add_particles(stars)
code.binaries.add_particles(double_star)
channel_from_code_to_model_for_binaries = code.binaries.new_channel_to(double_star)
channel_from_code_to_model_for_stars = code.particles.new_channel_to(stars)
t = []
a = []
e = []
while time < end_time:
time += time_step
code.evolve_model(time)
channel_from_code_to_model_for_stars.copy()
channel_from_code_to_model_for_binaries.copy()
t.append(time.value_in(units.Myr))
a.append(double_star[0].semi_major_axis.value_in(units.RSun))
e.append(double_star[0].eccentricity)
code.stop()
fig = pyplot.figure(figsize = (8,8))
fta = fig.add_subplot(2,1,1)
# fte = fig.add_subplot(2,2,1)
pyplot.title('Binary evolution', fontsize=12)
fta.plot(t, a)
pyplot.xlabel('time [Myr]')
pyplot.ylabel('semi major axis (AU)')
# fta.plot(t, e)
#pyplot.ylabel('eccentricity')
pyplot.show()
def evolve_double_star(Mprim, Msec, a, e, end_time, n_steps):
q = Msec / Mprim
double_star, stars = create_double_star(Mprim, Msec, a, e)
time = 0 | units.Myr
time_step = end_time / n_steps
code = SeBa()
code.particles.add_particles(stars)
code.binaries.add_particles(double_star)
channel_from_code_to_model_for_binaries = code.binaries.new_channel_to(double_star)
channel_from_code_to_model_for_stars = code.particles.new_channel_to(stars)
t = []
a = []
e = []
while time < end_time:
time += time_step
code.evolve_model(time)
channel_from_code_to_model_for_stars.copy()
channel_from_code_to_model_for_binaries.copy()
t.append(time.value_in(units.Myr))
a.append(double_star[0].semi_major_axis.value_in(units.RSun))
e.append(double_star[0].eccentricity)
code.stop()
fig = pyplot.figure(figsize=(8, 8))
fta = fig.add_subplot(2, 1, 1)
# fte = fig.add_subplot(2,2,1)
pyplot.title("Binary evolution", fontsize=12)
fta.plot(t, a)
pyplot.xlabel("time [Myr]")
pyplot.ylabel("semi major axis (AU)")
# fta.plot(t, e)
# pyplot.ylabel('eccentricity')
pyplot.show()
def evolve_galaxy(
end_time,
time_step,
gal_fraction=1e-6,
binfraction=1.0,
Mmin=0.125,
Mmax=125.,
a_min=0.01,
a_max=1e6,
e_min=0,
e_max=1.,
ce=0.5,
Mmax_NS=2.1,
plot = True
):
#initialize some variables for monitoring
date = str(datetime.datetime.now())
stellar_galaxy_mass = 0.0
number_of_binaries = 0
number_of_systems = 0
number_of_stars = 0
time = 0.0 * end_time
try:
session_id = session.query(Simulation.id).all()[-1][0] + 1
except:
session_id = 0
code = SeBa() #link code
#code = BSE()
#configure parameters
code.parameters.common_envelope_efficiency = ce
code.parameters.maximum_neutron_star_mass = Mmax_NS | units.MSun
pyplot.ion()
pyplot.show()
while time < end_time:
time += time_step
mass_in_timestep = star_formation(15,7e9,time.value_in(units.yr)) - star_formation(15,7e9,(time-time_step).value_in(units.yr))
mass_in_timestep = mass_in_timestep*gal_fraction
N = stars_for_given_Mtot(mass_in_timestep,Mmin,Mmax)
#N = 4 #for de-bugging
number_of_stars += N
number_of_binaries = np.int(number_of_stars*binfraction/2)
number_of_systems = np.int(number_of_stars*(1-binfraction) + number_of_binaries)
stellar_galaxy_mass += mass_in_timestep
print
print
print
print "Total stellar mass of the Galaxy [in 1e10 Msun]:", stellar_galaxy_mass/gal_fraction/1e10
print "Age of the disk:",time.value_in(units.Gyr), "Gyr"
print "Number of stellar systems:", number_of_systems, "of which", number_of_binaries ,"are binaries"
print "Injected", N, "stars in the last timestep. Total number of stars:", number_of_stars
print
print
print
if (time == time_step):
binaries, stars = generate_initial_population_grid(Mmin, Mmax, N, gal_fraction, binfraction, a_min, a_max, e_min , e_max,binfraction)
code.particles.add_particles(stars)
code.binaries.add_particles(binaries)
else:
binaries2, stars2 = generate_initial_population_grid(0.125, 125,N, 1e-5, 1, 0.1, 1e6, 0.0 , 1.0, binfraction)
stars.add_particles(stars2)
binaries.add_particles(binaries2)
code.particles.add_particles(stars2)
code.binaries.add_particles(binaries2)
channel_from_code_to_model_for_binaries = code.binaries.new_channel_to(binaries)
channel_from_code_to_model_for_stars = code.particles.new_channel_to(stars)
code.evolve_model(time)
channel_from_code_to_model_for_stars.copy()
channel_from_code_to_model_for_binaries.copy()
if plot:
if (time > time_step):
make_hr_diagram3(stars)
pyplot.clf()
#add_sim_info_to_database(end_time=end_time,time_step=time_step,
# gal_fraction=gal_fraction,binfraction=binfraction,Mmin=Mmin,
# Mmax=Mmax,a_min=a_min,a_max=a_max,date=date,code='BSE',ce=ce,MNSmax = Mmax_NS)
#add_stars_to_database(binaries,sim_id = session_id)
write_set_to_file(code.particles,'stellar_properties.bse.hdf5',format='hdf5')
write_set_to_file(binaries,'binary_properties.bse.hdf5',format='hdf5')