def resolve(self, subproblemcontext, existingStepper):
# Return a new AdaptiveDriver object (not a Basic one)
# appropriate for the given subproblem. If the
# existingStepper is still appropriate, return it instead.
from ooflib.engine import twostep
from ooflib.SWIG.engine import steperrorscaling
if subproblemcontext.second_order_fields():
from ooflib.engine import ss22
if (isinstance(existingStepper, AdaptiveDriver)
and isinstance(existingStepper.stepper, twostep.TwoStep)
and isinstance(existingStepper.stepper.singlestep,
ss22.SS22)):
return existingStepper
singlestep = ss22.SS22(theta1=0.5, theta2=0.5)
else: # no second order fields
from ooflib.engine import euler
if (isinstance(existingStepper, AdaptiveDriver)
and isinstance(existingStepper.stepper, twostep.TwoStep)
and isinstance(existingStepper.stepper.singlestep,
euler.CrankNicolson)):
return existingStepper
singlestep = euler.CrankNicolson()
return AdaptiveDriver(
stepper=twostep.TwoStep(singlestep),
tolerance=self.tolerance,
errorscaling=steperrorscaling.AbsoluteErrorScaling(),
initialstep=0.0,
minstep=self.minstep)
'Adaptive',
StepDriver,
AdaptiveDriver,
ordering=1,
params=[
parameter.FloatParameter('tolerance',
1.e-4,
tip="Maximum permissable error."),
parameter.FloatParameter("initialstep", 0.1, tip="Initial step size."),
parameter.FloatParameter('minstep',
1.e-5,
tip="Minimum time step size."),
parameter.RegisteredParameter(
'errorscaling',
steperrorscaling.StepErrorScaling,
value=steperrorscaling.AbsoluteErrorScaling(),
tip="How to compute the error for each degree of freedom."),
parameter.RegisteredParameter('stepper',
QCTimeStepper,
tip="Time stepping method.")
],
tip="Take variable sized timesteps.",
discussion=xmlmenudump.loadFile(
'DISCUSSIONS/engine/reg/adaptivedriver.xml'))
############
class UniformDriver(StepDriver):
def __init__(self, stepper, stepsize):
self.stepsize = stepsize