def iteration(self, k, t0, dt, **kw):
"""Perform one PFASST iteration."""
rank = self.mpi.rank
state = self.state
levels = self.levels
T = levels[0] # finest/top level
B = levels[-1] # coarsest/bottom level
state.set(iteration=k, cycle=0)
T.call_hooks("pre-iteration", **kw)
# post receive requests
for F in levels[:-1]:
F.post_receive((F.level + 1) * 100 + k)
# down
for F, G in self.fine_to_coarse:
state.increment_cycle()
for s in range(F.sweeps):
F.sdc.sweep(t0, dt, F, **kw)
F.send((F.level + 1) * 100 + k, blocking=False)
restrict_time_space(t0, dt, F, G, **kw)
# bottom
state.increment_cycle()
B.receive((B.level + 1) * 100 + k, blocking=True)
for s in range(B.sweeps):
B.sdc.sweep(t0, dt, B, **kw)
B.send((B.level + 1) * 100 + k, blocking=True)
# up
for F, G in self.coarse_to_fine:
state.increment_cycle()
interpolate_time_space(t0, F, G, **kw)
F.receive((F.level + 1) * 100 + k, **kw)
if rank > 0:
interpolate(F.q0, G.q0, F, G, **kw)
if F.level != 0:
for s in range(F.sweeps):
F.sdc.sweep(t0, dt, F, **kw)
# done
state.set(cycle=0)
T.call_hooks("post-iteration", **kw)
def predictor(self, t0, dt, **kwargs):
"""Perform the PFASST predictor."""
B = self.levels[-1]
rank = self.mpi.rank
ntime = self.mpi.ntime
B.q0[...] = B.qSDC[0]
self.state.cycle = -1
self.state.iteration = -1
self.state.predictor = True
B.call_hooks('pre-predictor', **kwargs)
pred_iters = optdb.predictor_iterations or 1
for k in range(1, rank+pred_iters+1):
self.state.iteration = k
# get new initial value (skip on first iteration)
if k > 1 and rank > 0:
B.receive(k-1, blocking=True)
# coarse sdc sweep
B.call_hooks('pre-sweep', **kwargs)
B.bSDC[0] = B.q0
for s in range(B.sweeps):
B.sdc.sweep(B.bSDC, t0, dt, B.qSDC, B.fSDC, B.feval, **kwargs)
B.qend[...] = B.qSDC[-1]
B.call_hooks('post-sweep', **kwargs)
# send result forward
if rank < ntime-1:
B.send(k, blocking=True)
self.state.iteration = -1
B.call_hooks('post-predictor', **kwargs)
# interpolate coarest to finest and set initial conditions
for F, G in self.coarse_to_fine:
interpolate_time_space(F.qSDC, G.qSDC, F, G, **kwargs)
eval_at_sdc_nodes(t0, dt, F.qSDC, F.fSDC, F, **kwargs)
for F in self.levels:
F.q0[...] = F.qSDC[0]
for F in self.levels:
F.call_hooks('predictor', **kwargs)
def predictor(self, t0, dt, **kw):
"""Perform the PFASST predictor."""
B = self.levels[-1]
rank = self.mpi.rank
state = self.state
self.state.set(cycle=-1, iteration=-1, predictor=True)
B.call_hooks("pre-predictor", **kw)
B.q0[...] = B.qSDC[0]
# predictor loop
for k in range(1, rank + 2):
state.set(iteration=k)
if k > 1:
B.receive(k - 1, blocking=True)
for s in range(B.sweeps):
B.sdc.sweep(t0, dt, B, **kw)
B.send(k, blocking=True)
state.set(iteration=-1)
B.call_hooks("post-predictor", **kw)
# interpolate
for F, G in self.coarse_to_fine:
# XXX: sweep in middle levels?
interpolate_time_space(t0, F, G, **kw)
# done
for F in self.levels:
F.call_hooks("end-predictor", **kw)
state.set(predictor=False)
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)