from ..base import Property
from ..measures import Measure
from ..types.multihypothesis import MultipleHypothesis
from .base import Gater
""" Distance based gater
Uses a measure to calculate the distance between a hypothesis' measurement prediction and the
hypothised measurement, then removes any hypotheses whose calculated distance exceeds the
specified gate threshold.
measure: Measure = Property(
doc="Measure class used to calculate the distance between the measurement "
"prediction and the hypothesised measurement.")
gate_threshold: float = Property(
doc="The gate threshold. Hypotheses whose calculated distance "
"exceeds this threshold will be filtered out.")
def hypothesise(self, track, detections, *args, **kwargs):
hypotheses = self.hypothesiser.hypothesise(track, detections, *args, **kwargs)
gated_hypotheses = [hypothesis for hypothesis in hypotheses
if (not hypothesis
hypothesis.measurement) < self.gate_threshold)]
return MultipleHypothesis(sorted(gated_hypotheses, reverse=True))