def groundtruth_paths_gen(self, random_state=None):
groundtruth_paths = OrderedSet()
time = self.initial_state.timestamp or datetime.datetime.now()
random_state = random_state if random_state is not None else self.random_state
for _ in range(self.number_steps):
# Random drop tracks
groundtruth_paths.difference_update(
gttrack for gttrack in groundtruth_paths.copy()
if random_state.rand() <= self.death_probability)
# Move tracks forward
for gttrack in groundtruth_paths:
self.index = gttrack[-1].metadata.get("index")
trans_state_vector = self.transition_model.function(
gttrack[-1], noise=True, time_interval=self.timestep)
gttrack.append(
GroundTruthState(trans_state_vector,
timestamp=time,
metadata={"index": self.index}))
# Random create
for _ in range(random_state.poisson(self.birth_rate)):
self.index = 0
gttrack = GroundTruthPath()
gttrack.append(
GroundTruthState(
self.initial_state.state_vector +
self.initial_state.covar @ random_state.randn(
self.initial_state.ndim, 1),
timestamp=time,
metadata={"index": self.index}))
groundtruth_paths.add(gttrack)
yield time, groundtruth_paths
time += self.timestep
