def __init__(self,
name=None,
do_demag=True,
id="Generic Simulation class"):
self.class_id = id # String identifying the kind of Simulation
# class
self.units = None # Simulation units used by this class
self.do_demag = do_demag # Whether we should include the demag field
# List of all the materials used by the Simulation object
self.materials = None
# Dictionary used by the hysteresis method to find abbreviations for
# frequently used things to save or do.
# Example: for ``sim.hysteresis(..., save=[('averages', at(...))])``
# the string 'averages' needs to be a key in this dictionary.
# The corresponding value is the function to call.
self.action_abbreviations = {}
# Every quantity the user may want to save needs to be listed here
self.known_quantities = known_quantities
self.known_quantities_by_name = known_quantities_by_name
self.known_field_quantities = known_field_quantities
### Set the simulation name
if name == None:
self.name = features.get('etc', 'runid')
else:
self.name = name
log.info("Simulation(name=%s) object created" % self.name)
### Check whether the files we are going to write do already exist.
# if this is the case we should stop, unless the --clean option was
# given: we do not want to overwrite data as a default!
self._restarting = False
data_filenames = [
self._ndtfilename(),
self._h5filename(),
self._tolfilename()
]
if features.get('nmag', 'clean', raw=True):
# Existing data files should be deleted
nsim.snippets.rename_old_files(data_filenames)
elif features.get('nmag', 'restart', raw=True):
log.info("Starting simulation in restart mode...")
self._restarting = True
else:
# Check that no data files exist
for filename in data_filenames:
if os.path.exists(filename):
msg = ("Error: Found old file %s -- cannot proceed. "
"To start a simulation script with old data "
"files present you either need to use '--clean' "
"(and then the old files will be deleted), "
"or use '--restart' in which case the run "
"will be continued." % filename)
raise NmagUserError(msg)
# See documentation for SimulationClock object
self.clock = SimulationClock()
# The advance_time method does not allow to carry on the simulation
# up to t = infinite. Sometimes we want to simulate for n steps,
# without any time limits. However we must give a time limit.
# This is then how we approximate t = infinite.
# For now, we do not provide any function to set or change it.
# The user should just use:
# sim = Simulation()
# sim.max_time_reached = SI(1000, "s")
self.max_time_reached = SI(1, "s")
# Add abbreviations so that things can be saved just by giving
# corresponding ID strings.
# Example: hysteresis(..., save=[('averages', ...)])
self.add_save_abbrev('save_averages',
lambda sim: sim.save_data(avoid_same_step=True))
self.add_save_abbrev(
'save_fields',
lambda sim: sim.save_data(fields='all', avoid_same_step=True))
self.add_save_abbrev(
'save_field_m',
lambda sim: sim.save_data(fields=['m'], avoid_same_step=True))
self.add_save_abbrev('save_restart',
lambda sim: sim.save_restart_file())
self.add_do_abbrev('do_next_stage',
SimulationCore.hysteresis_next_stage)
self.add_do_abbrev('do_exit', SimulationCore.hysteresis_exit)
# Used to write the ndt file
self._ndt_writer = ColWriter(out=self._ndtfilename())
self._ndt_writer.set_formats([('float', '% 25.13g'), ('int', '% 25d'),
('date', '% 25s'),
('pfield', '% 25.13g'),
('field', '% 25.13g')])
# The following list contains a description of the physics components
# which are included in the physical model For example,
# ["exch", "demag"] indicates that exchange and demag are included.
# In this case, spin transfer torque is not. This information
# is used to understand which fields are relevant and which are not
# (so that we do not save empty fields). Following the previous
# example, dm_dcurrent, current_density won't be saved.
self._components = None
