def new_gas_to_star_interaction_codes_bhtree(self, gas_code):
def new_bhtree():
result = BHTree(self.converter)
result.parameters.epsilon_squared = self.star_epsilon**2
return result
return [bridge.CalculateFieldForCodes(new_bhtree, [gas_code])]\
def new_gas_to_star_interaction_codes_octgrav(self, gas_code):
def new_octgrav():
result = Octgrav(self.converter)
result.parameters.epsilon_squared = self.gas_epsilon**2
return result
return [bridge.CalculateFieldForCodes(new_octgrav, [gas_code])]
def create_codes(self):
self.star_code = self.new_star_code_hermite()
self.gas_code = self.new_gas_code_gadget()
def new_code_to_calculate_gravity_of_gas_particles():
result = BHTree(self.converter)
return result
calculate_gravity_code=bridge.CalculateFieldForCodes(
new_code_to_calculate_gravity_of_gas_particles, # the code that calculates the acceleration field
input_codes = [self.gas_code] # the codes to calculate the acceleration field of
)
self.gas_to_star_codes = [calculate_gravity_code]
self.star_to_gas_codes = [self.star_code]
def run_mc(N=5000, Mcloud=10000. | units.MSun, Rcloud=1. | units.parsec):
conv = nbody_system.nbody_to_si(Mcloud, Rcloud)
interaction_timestep = 0.01 | units.Myr
time_end = 0.36 | units.Myr
parts = molecular_cloud(targetN=N,
convert_nbody=conv,
base_grid=body_centered_grid_unit_cube).result
sph = Fi(conv)
# need to turn off self gravity, the bridge will calculate this
sph.parameters.self_gravity_flag = False
# some typical Fi flags (just for reference, most are default values)
sph.parameters.use_hydro_flag = True
sph.parameters.isothermal_flag = True
sph.parameters.integrate_entropy_flag = False
sph.parameters.gamma = 1
sph.parameters.verbosity = 0
# setting the hydro timestep is important
# the sph code will take 2 timesteps every interaction timestep
sph.parameters.timestep = interaction_timestep / 2
sph.gas_particles.add_particles(parts)
def new_code_to_calculate_gravity_of_gas_particles():
result = BHTree(conv)
return result
calculate_gravity_code = bridge.CalculateFieldForCodes(
new_code_to_calculate_gravity_of_gas_particles, # the code that calculates the acceleration field
input_codes=[sph] # the codes to calculate the acceleration field of
)
bridged_system = bridge.Bridge()
bridged_system.timestep = interaction_timestep
bridged_system.add_system(
sph, # the code to move the particles of
[calculate_gravity_code
] # the codes that provide the acceleration field
)
fig = pyplot.figure(figsize=(12, 12))
ncolumn = 2
nrow = 2
nplot = ncolumn * nrow
grid_size = 3 | units.parsec
extent = (grid_size * (-0.5, 0.5, -0.5, 0.5)).value_in(units.parsec)
if nplot > 1:
plot_timestep = time_end / (nplot - 1)
else:
plot_timestep = time_end
for i in range(nplot):
ttarget = i * plot_timestep
print("evolving to time:", ttarget.as_quantity_in(units.Myr))
bridged_system.evolve_model(ttarget)
rho = make_map(sph, N=200, grid_size=grid_size)
subplot = fig.add_subplot(ncolumn, nrow, i + 1)
subplot.imshow(numpy.log10(1.e-5 +
rho.value_in(units.amu / units.cm**3)),
extent=extent,
vmin=1,
vmax=5)
subplot.set_title(ttarget.as_quantity_in(units.Myr))
sph.stop()
pyplot.show()