Merge branch 'optimisation/last_state_change_bisection' into 'master'

Use bisection method to compute the last state change for improved performance

See merge request cara/cara!239
This commit is contained in:
Nicolas Mounet 2021-08-06 13:25:16 +00:00
commit c745823768
2 changed files with 42 additions and 36 deletions

View file

@ -762,26 +762,34 @@ class ConcentrationModel:
return (self.infected.emission_rate(time)) / (IVRR * V)
@method_cache
def state_change_times(self) -> typing.List[float]:
"""
All time dependent entities on this model must provide information about
the times at which their state changes.
"""
state_change_times = set()
state_change_times = {0.}
state_change_times.update(self.infected.presence.transition_times())
state_change_times.update(self.ventilation.transition_times())
return sorted(state_change_times)
def last_state_change(self, time: float) -> float:
"""
Find the most recent state change.
Find the most recent/previous state change.
Find the nearest time less than the given one. If there is a state
change exactly at ``time`` the previous state change is returned
(except at ``time == 0``).
"""
for change_time in self.state_change_times()[::-1]:
if change_time < time:
return change_time
return 0.
times = self.state_change_times()
t_index: int = np.searchsorted(times, time) # type: ignore
# Search sorted gives us the index to insert the given time. Instead we
# want to get the index of the most recent time, so reduce the index by
# one unless we are already at 0.
t_index = max([t_index - 1, 0])
return times[t_index]
def _next_state_change(self, time: float) -> float:
"""
@ -796,14 +804,6 @@ class ConcentrationModel:
f"state change time ({change_time})"
)
def _is_interval_between_state_changes(self, start: float, stop: float) -> bool:
"""
Check that the times start and stop are in-between two state
changes of the concentration model (to ensure sure that all
model parameters stay constant between start and stop).
"""
return (self.last_state_change(stop) <= start)
@method_cache
def _concentration_cached(self, time: float) -> _VectorisedFloat:
# A cached version of the concentration method. Use this method if you

View file

@ -53,7 +53,7 @@ def test_concentration_model_vectorisation(override_params):
@pytest.fixture
def simple_conc_model():
interesting_times = models.SpecificInterval(([0., 1.], [1.1, 1.999], [2., 3.]), )
interesting_times = models.SpecificInterval(([0.5, 1.], [1.1, 2], [2., 3.]), )
return models.ConcentrationModel(
models.Room(75),
models.AirChange(interesting_times, 100),
@ -68,14 +68,38 @@ def simple_conc_model():
)
@pytest.mark.parametrize(
"time, expected_last_state_change", [
[-15., 0.], # Out of range goes to the first state.
[0., 0.],
[0.5, 0.0],
[0.51, 0.5],
[1., 0.5],
[1.05, 1.],
[1.1, 1.],
[1.11, 1.1],
[2., 1.1],
[2.1, 2],
[3., 2],
[15., 3.], # Out of range goes to the last state.
]
)
def test_last_state_change_time(
simple_conc_model: models.ConcentrationModel,
time,
expected_last_state_change,
):
assert simple_conc_model.last_state_change(float(time)) == expected_last_state_change
@pytest.mark.parametrize(
"time, expected_next_state_change", [
[0, 0],
[0.0, 0.0],
[0.5, 0.5],
[1, 1],
[1.05, 1.1],
[1.1, 1.1],
[1.11, 1.999],
[1.9991, 2],
[1.11, 2],
[2, 2],
[2.1, 3],
[3, 3],
@ -97,24 +121,6 @@ def test_next_state_change_time_out_of_range(simple_conc_model: models.Concentra
simple_conc_model._next_state_change(3.1)
@pytest.mark.parametrize(
"start, stop, is_valid", [
[0, 1.05, False],
[0.99, 1.1, False],
[0.5, 1.01, False],
[0, 1, True],
[1.01, 1.1, True],
[0.01, 1, True],
[1.11, 1.99, True],
]
)
def test_valid_interval(
start, stop, is_valid,
simple_conc_model: models.ConcentrationModel
):
assert simple_conc_model._is_interval_between_state_changes(start, stop) == is_valid
def test_integrated_concentration(simple_conc_model):
c1 = simple_conc_model.integrated_concentration(0, 2)
c2 = simple_conc_model.integrated_concentration(0, 1)