class SimulationLoopFourier(SimulationLoop):
"""This class acts as the main simulation loop. It owns a propagator that
propagates a set of initial values during a time evolution.
"""
def __init__(self, parameters):
"""Create a new simulation loop instance for a simulation
using the Fourier propagation method.
:param parameters: The simulation parameters.
:type parameters: A :py:class:`ParameterProvider` instance.
"""
# Keep a reference to the simulation parameters
self.parameters = parameters
# The time propagator instance driving the simulation.
self.propagator = None
# An `IOManager` instance for saving simulation results.
self.IOManager = None
# Which data do we want to save
self._tm = self.parameters.get_timemanager()
# Set up serialization of simulation data
self.IOManager = IOManager()
self.IOManager.create_file()
self.IOManager.create_block()
# Save the simulation parameters
self.IOManager.add_parameters()
self.IOManager.save_parameters(parameters)
def prepare_simulation(self):
r"""Set up a Fourier propagator for the simulation loop. Set the
potential and initial values according to the configuration.
:raise: :py:class:`ValueError` For invalid or missing input data.
"""
# The potential instance
potential = BlockFactory().create_potential(self.parameters)
# Compute the position space grid points
grid = BlockFactory().create_grid(self.parameters)
# Construct initial values
I = Initializer(self.parameters)
initialvalues = I.initialize_for_fourier(grid)
# Transform the initial values to the canonical basis
BT = BasisTransformationWF(potential)
BT.set_grid(grid)
BT.transform_to_canonical(initialvalues)
# Finally create and initialize the propagator instance
self.propagator = FourierPropagator(potential, initialvalues, self.parameters)
# Write some initial values to disk
slots = self._tm.compute_number_saves()
self.IOManager.add_grid(self.parameters, blockid="global")
self.IOManager.add_fourieroperators(self.parameters)
self.IOManager.add_wavefunction(self.parameters, timeslots=slots)
self.IOManager.save_grid(grid.get_nodes(flat=True), blockid="global")
self.IOManager.save_fourieroperators(self.propagator.get_operators())
self.IOManager.save_wavefunction(initialvalues.get_values(), timestep=0)
def run_simulation(self):
r"""Run the simulation loop for a number of time steps.
"""
# The number of time steps we will perform.
nsteps = self._tm.compute_number_timesteps()
# Run the prepropagate step
self.propagator.pre_propagate()
# Note: We do not save any data here
# Run the simulation for a given number of timesteps
for i in xrange(1, nsteps+1):
print(" doing timestep "+str(i))
self.propagator.propagate()
# Save some simulation data
if self._tm.must_save(i):
# Run the postpropagate step
self.propagator.post_propagate()
self.IOManager.save_wavefunction(self.propagator.get_wavefunction().get_values(), timestep=i)
# Run the prepropagate step
self.propagator.pre_propagate()
# Run the postpropagate step
self.propagator.post_propagate()
# Note: We do not save any data here
def end_simulation(self):
"""Do the necessary cleanup after a simulation. For example request the
:py:class:`IOManager` to write the data and close the output files.
"""
self.IOManager.finalize()
