def main():
N=1024
N2 = 0
x = 1.25
#convert_nbody = nbody_system.nbody_to_si(1.0*N | units.MSun, 149.5e3 | units.AU)
radius = 0.0 | nbody_system.length
#radius = convert_nbody.to_si(radius)
eta=1/32. | nbody_system.time
#eta = convert_nbody.to_si(eta)
eps=0.001 | nbody_system.length
#eps = convert_nbody.to_si(eps)
dt=0.5 | nbody_system.time
#dt = convert_nbody.to_si(dt)
tmax=350 | nbody_system.time
#tmax = convert_nbody.to_si(tmax)
parts=MakePlummerModel(N).result
parts.radius=radius
#Mass segregation
if N2 >0:
N1 = N-N2
m1 = 1/(N1+x*N2)
m2 = x*m1
M1 = numpy.zeros((N1,1)) + (m1)
M2 = numpy.zeros((N2,1)) + (m2)
M = numpy.concatenate((M1,M2))
parts.mass = nbody_system.mass.new_quantity(numpy.hstack(M))
#gravity = Fi(convert_nbody)
gravity = Fi()
gravity.initialize_code()
gravity.parameters.epsilon_squared = eps**2
gravity.parameters.timestep = eta
gravity.legacy_interface.set_gdgtol(0.001)
gravity.legacy_interface.set_gdgop(0)
gravity.legacy_interface.set_usequad(0)
gravity.legacy_interface.set_acc_tstp(0)
gravity.legacy_interface.set_bh_tol(0.5)
gravity.legacy_interface.set_tstpcr2(0.025)
gravity.legacy_interface.set_sqrttstp(0)
gravity.legacy_interface.set_tstepcrit(0.25)
#gravity.parameters.initial_timestep_parameter=etas
gravity.commit_parameters()
gravity.particles.add_particles(parts)
time=0 | nbody_system.time
#time = convert_nbody.to_si(time)
gravity.synchronize_model()
#e0=gravity.particles.kinetic_energy() + \
# gravity.particles.potential_energy()
# e0=gravity.particles.kinetic_energy() + \ gravity.particles.potential_energy(smoothing_length_squared=eps**2,G=nbody_system.G)
e0=gravity.kinetic_energy + \
gravity.potential_energy
output_file = "Fi.hdf5"
if os.path.exists(output_file):
os.remove(output_file)
storage = store.StoreHDF(output_file)
#from_gravity_to_model = gravity.particles.new_channel_to(parts)
#L = []
#output = open('data.pkl', 'wb')
parts = gravity.particles.copy()
# ek = gravity.kinetic_energy
# ep = gravity.potential_energy
# e0 = ek + ep
while time < tmax:
ek = gravity.kinetic_energy
ep = gravity.potential_energy
print "time,T/V,err_E:", time,(ek/ep).number, ((ep+ek-e0)/e0).number
#print "time,T/V,err_E:", time, ep
# L.append(LagrangianRadii(parts)[-1])
gravity.particles.new_channel_to(parts).copy()
#parts = gravity.particles.copy()
#parts = gravity.particles.copy()
parts.savepoint(time)
storage.store(parts.previous_state())
time=time+dt
gravity.evolve_model(time)
gravity.synchronize_model()
# write_set_to_file(parts,'cc_nb/cc_nb_'+str(time.number/dt.number)+'.txt')
#parts_temp = gravity.particles.copy()
#print parts_temp
# pickle.dump(adaas,output)
# parts.savepoint(time)
# storage.store(parts.previous_state())
storage.close()
#output.close()
del gravity
del parts
with_units = len(sys.argv) > 2
if not with_units :
mass_unit = nbody_system.mass
length_unit = nbody_system.length
else :
mass_unit = units.MSun
length_unit = units.parsec
m_min = 0.1 | mass_unit
m_max = 100 | mass_unit
alpha = -2.35
r_vir = 1 | length_unit
initial_mass_function = SalpeterIMF(m_min, m_max, alpha)
m_tot, masses = initial_mass_function.next_set(nstars)
if not with_units :
convert_nbody = None
masses /= m_tot.value_in(nbody_system.mass) # scale to unit mass
m_tot = 1 | nbody_system.mass
else :
convert_nbody = nbody_system.nbody_to_si(m_tot, r_vir)
convert_nbody.set_as_default()
print m_tot
stars = MakePlummerModel(nstars, convert_nbody, random_state = seed).result;
stars.mass = masses
LagrangianRadii(stars, verbose=1)
eps=0.001 | nbody_system.length
dt=0.5 | nbody_system.time
tmax=500 | nbody_system.time
parts=MakePlummerModel(N).result
#Mass segregation
N2 = 82
x = 1.25
N1 = N-N2
m1 = 1/(N1+x*N2)
m2 = x*m1
M1 = numpy.zeros((N1,1)) + (m1)
M2 = numpy.zeros((N2,1)) + (m2)
M = numpy.concatenate((M1,M2))
parts.mass = nbody_system.mass.new_quantity(numpy.hstack(M))
parts.radius=radius
gravity=PhiGRAPE()#(mode="gpu")
gravity.parameters.epsilon_squared = eps**2
gravity.particles.add_particles(parts)
gravity.parameters.timestep_parameter=eta
gravity.parameters.initial_timestep_parameter=etas
time=0 | nbody_system.time
e0=gravity.particles.kinetic_energy() + \
gravity.particles.potential_energy(smoothing_length_squared=eps**2,G=nbody_system.G)
MassFraction = [0.005, 0.01, 0.02, 0.05, 0.1, 0.25, 0.5, 0.75, 0.9, 1.0] \
| units.none
def distance_sq(stars) :
return stars.x**2 + stars.y**2 +stars.z**2