Setup AMUSE Bridge with external kicker codes

setup_bridge_detailed.py

"""
Example of combining gas and stars via Bridge with a dedicated kicker code.
"""

from amuse.units import nbody_system, units
from amuse.couple.bridge import Bridge, CalculateFieldForCodes
from amuse.community.bhtree import Bhtree
from amuse.community.fastkick import Fastkick
from amuse.community.ph4 import Ph4
from amuse.community.gadget2 import Gadget2


TIME_STEP = 0.01 | units.Myr
CONVERTER = nbody_system.nbody_to_si(TIME_STEP, 0.1 | units.pc)
EPSILON = 0.01 | units.pc
FIELD_CODE_TYPE = "tree"


def new_field_tree_gravity_code(
        code=Bhtree,
):
    "Create a new field tree code"
    result = code(
        CONVERTER,
        # redirection="none",
    )
    result.parameters.epsilon_squared = EPSILON**2
    return result


def new_field_direct_gravity_code(
        code=Fastkick,
):
    "Create a new field direct code"
    print("Creating field direct code")
    result = code(
        CONVERTER,
        # redirection="none",
        number_of_workers=8,
    )
    result.parameters.epsilon_squared = EPSILON**2
    return result


def new_field_code(
        code,
        mode="direct",
):
    " something"
    if mode == "tree":
        new_field_gravity_code = new_field_tree_gravity_code
    elif mode == "direct":
        new_field_gravity_code = new_field_direct_gravity_code
    else:
        new_field_gravity_code = new_field_direct_gravity_code
    result = CalculateFieldForCodes(
        new_field_gravity_code,
        [code],
    )
    return result


INTEGRATOR_STARS = Ph4(CONVERTER)
INTEGRATOR_GAS = Gadget2(CONVERTER)

to_gas_kickers = []
to_stars_kickers = []

to_gas_kickers.append(
    new_field_code(
        INTEGRATOR_STARS,
        mode=FIELD_CODE_TYPE,
    )
)

to_stars_kickers.append(
    new_field_code(
        INTEGRATOR_GAS,
        mode=FIELD_CODE_TYPE,
    )
)

system = Bridge(
    timestep=TIME_STEP,
    use_threading=False,
)
system.add_system(
    INTEGRATOR_STARS,
    partners=to_stars_kickers,
    do_sync=True,
)
system.add_system(
    INTEGRATOR_GAS,
    partners=to_gas_kickers,
    do_sync=True,
    h_smooth_is_eps=True,
)