def set_initial_conditions(self, u0, t0, dt, **kwargs):
"""Set initial conditions."""
levels = self.levels
T = levels[0]
try:
levels[0].q0[...] = u0
except ValueError:
raise ValueError, 'initial condition shape mismatch'
# set initial condtion and evaluate at finest level
T.qSDC[0] = T.q0
T.feval.evaluate(T.q0, t0, T.fSDC[:,0])
# spread to remaining nodes at finest level
for n in range(1, T.sdc.nnodes):
T.qSDC[n] = T.qSDC[0]
T.fSDC[:,n] = T.fSDC[:,0]
# restrict finest level to coarser levels
for F, G in self.fine_to_coarse:
restrict_time_space(F.qSDC, G.qSDC, F, G, **kwargs)
restrict_space_sum_time(F.bSDC, G.bSDC, F, G, **kwargs)
eval_at_sdc_nodes(t0, dt, G.qSDC, G.fSDC, G, **kwargs)
G.bSDC[1:] += fas(dt, F.fSDC, G.fSDC, F, G, **kwargs)
def iteration(self, k, t0, dt, cycles, **kwargs):
"""Perform one PFASST iteration."""
levels = self.levels
nlevels = len(levels)
rank = self.mpi.rank
ntime = self.mpi.ntime
T = levels[0] # finest/top level
B = levels[nlevels-1] # coarsest/bottom level
self.state.cycle = 0
T.call_hooks('pre-iteration', **kwargs)
# post receive requests
if rank > 0:
for iF in range(len(self.levels)-1):
F = self.levels[iF]
F.post_receive((F.level+1)*100+k)
#### cycle
for down, up in cycles:
#### down
for iF in down:
self.state.cycle += 1
finest = iF == 0
coarsest = iF == nlevels - 1
F = levels[iF]
if not coarsest:
G = levels[iF+1]
# get new initial value on coarsest level
if coarsest:
if rank > 0:
F.receive((F.level+1)*100+k, blocking=coarsest)
# sdc sweep
F.call_hooks('pre-sweep', **kwargs)
F.bSDC[0] = F.q0
for s in range(F.sweeps):
F.sdc.sweep(F.bSDC, t0, dt, F.qSDC, F.fSDC, F.feval, **kwargs)
F.qend[...] = F.qSDC[-1]
F.call_hooks('post-sweep', **kwargs)
# send new value forward
if rank < ntime-1:
F.send((F.level+1)*100+k, blocking=coarsest)
# restrict
if not coarsest:
G.call_hooks('pre-restrict', **kwargs)
restrict_time_space(F.qSDC, G.qSDC, F, G, **kwargs)
restrict_space_sum_time(F.bSDC, G.bSDC, F, G, **kwargs)
eval_at_sdc_nodes(t0, dt, G.qSDC, G.fSDC, G, **kwargs)
G.bSDC[1:,:] += fas(dt, F.fSDC, G.fSDC, F, G, **kwargs)
G.call_hooks('post-restrict', **kwargs)
#### up
for iF in up:
self.state.cycle += 1
finest = iF == 0
F = levels[iF]
G = levels[iF+1]
# interpolate
G.call_hooks('pre-interpolate', **kwargs)
interpolate_time_space(F.qSDC, G.qSDC, F, G, **kwargs)
eval_at_sdc_nodes(t0, dt, F.qSDC, F.fSDC, F, **kwargs)
G.call_hooks('post-interpolate', **kwargs)
# get new initial value
if rank > 0:
F.receive((F.level+1)*100+k)
interpolate(F.q0, G.q0, F, G, **kwargs)
# sdc sweep
if not finest:
F.call_hooks('pre-sweep', **kwargs)
F.bSDC[0] = F.q0
for s in range(F.sweeps):
F.sdc.sweep(F.bSDC, t0, dt, F.qSDC, F.fSDC, F.feval, **kwargs)
F.qend[...] = F.qSDC[-1]
F.call_hooks('post-sweep', **kwargs)
#### done
self.state.cycle = 0
T.call_hooks('post-iteration', **kwargs)