[docs]
class PushEtaPC(Propagator):
r"""For each marker :math:`p`, solves
.. math::
\frac{\textnormal d \mathbf x_p(t)}{\textnormal d t} = \mathbf v_p + \mathbf U (\mathbf x_p(t))\,,
for constant :math:`\mathbf v_p` and :math:`\mathbf U` in logical space given by :math:`\mathbf x = F(\boldsymbol \eta)`:
.. math::
\frac{\textnormal d \boldsymbol \eta_p(t)}{\textnormal d t} = DF^{-1}(\boldsymbol \eta_p(t)) \,\mathbf v_p + \textnormal{vec}(\hat{\mathbf U}) \,,
where
.. math::
\textnormal{vec}( \hat{\mathbf U}^{1}) = G^{-1}\hat{\mathbf U}^{1}\,,\qquad \textnormal{vec}( \hat{\mathbf U}^{2}) = \frac{\hat{\mathbf U}^{2}}{\sqrt g}\,, \qquad \textnormal{vec}( \hat{\mathbf U}) = \hat{\mathbf U}\,.
Available algorithms:
* ``rk4`` (4th order, default)
* ``forward_euler`` (1st order)
* ``heun2`` (2nd order)
* ``rk2`` (2nd order)
* ``heun3`` (3rd order)
"""
[docs]
class Variables:
"""Container for variables advanced by :class:`PushEtaPC`.
Attributes
----------
var : PICVariable or SPHVariable
Particle variable whose marker positions are advanced.
"""
def __init__(self):
self._var: PICVariable | SPHVariable = None
@property
def var(self) -> PICVariable | SPHVariable:
return self._var
@var.setter
def var(self, new):
assert isinstance(new, PICVariable | SPHVariable)
self._var = new
def __init__(self, u_tilde: FEECVariable = None):
"""
Parameters
----------
u_tilde : FEECVariable, default=None
Background fluid velocity field used to push particles.
The FEEC space is controlled by ``Options.u_space``.
"""
self.variables = self.Variables()
self.u_tilde = u_tilde
[docs]
@dataclass(repr=False)
class Options(OptionsBase):
"""Configuration options for :class:`PushEtaPC`.
Parameters
----------
butcher : ButcherTableau, default=None
Butcher tableau used for explicit Runge-Kutta marker pushing.
If ``None``, defaults to ``ButcherTableau()``.
use_perp_model : bool, default=True
Flag forwarded to the particle kernel to select the perpendicular
model formulation.
u_space : LiteralOptions.OptsVecSpace, default="Hdiv"
FEEC space used to interpret ``u_tilde`` in the pusher kernel.
"""
butcher: ButcherTableau = None
use_perp_model: bool = True
u_space: LiteralOptions.OptsVecSpace = "Hdiv"
def __post_init__(self):
# checks
check_option(self.u_space, LiteralOptions.OptsVecSpace)
# defaults
if self.butcher is None:
self.butcher = ButcherTableau()
@property
def options(self) -> Options:
if not hasattr(self, "_options"):
self._options = self.Options()
return self._options
@options.setter
def options(self, new):
assert isinstance(new, self.Options)
self._options = new
logger.info(f"\nNew options for propagator '{self.__class__.__name__}':\n{self._options}")
@profile
def allocate(self):
self._u_tilde = self.u_tilde.spline.vector
# get kernell:
if self.options.u_space == "Hcurl":
kernel = Pyccelkernel(pusher_kernels.push_pc_eta_stage_Hcurl)
elif self.options.u_space == "Hdiv":
kernel = Pyccelkernel(pusher_kernels.push_pc_eta_stage_Hdiv)
elif self.options.u_space == "H1vec":
kernel = Pyccelkernel(pusher_kernels.push_pc_eta_stage_H1vec)
else:
raise ValueError(
f'{self.options.u_space =} not valid, choose from "Hcurl", "Hdiv" or "H1vec.',
)
# define algorithm
butcher = self.options.butcher
# temp fix due to refactoring of ButcherTableau:
args_kernel = (
self.derham.args_derham,
self._u_tilde[0]._data,
self._u_tilde[1]._data,
self._u_tilde[2]._data,
self.options.use_perp_model,
butcher.a_stage,
butcher.b,
butcher.c,
)
self._pusher = Pusher(
self.variables.var.particles,
kernel,
args_kernel,
self.domain.args_domain,
alpha_in_kernel=1.0,
n_stages=butcher.n_stages,
mpi_sort="each",
)
def __call__(self, dt):
self._u_tilde.update_ghost_regions()
self._pusher(dt)
# update_weights
if self.variables.var.particles.control_variate:
self.variables.var.particles.update_weights()
