Source code for stonesoup.types.track

# -*- coding: utf-8 -*-
import uuid
from typing import MutableSequence, MutableMapping

from .multihypothesis import MultipleHypothesis
from .state import State, StateMutableSequence
from .update import Update
from ..base import Property

[docs]class Track(StateMutableSequence): """Track type A :class:`~.StateMutableSequence` representing a track. Notes: Any manual modifications to :attr:`metadata` or :attr:`metadatas` will be overwritten if a state is inserted at a point prior to where the modifications are made. For example, inserting a state at the start of :attr:`states` will result in a :attr:`metadatas` update that will update all subsequent metadata values, resulting in manual metadata modifications being lost. """ states: MutableSequence[State] = Property( default=None, doc="The initial states of the track. Default `None` which initialises with empty list.") id: str = Property(default=None, doc="The unique track ID") init_metadata: MutableMapping = Property( default={}, doc="Initial dictionary of metadata items for track. Default `None` which " "initialises track metadata as an empty dictionary.") def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.metadatas = list() for state in self.states: self._update_metadata_from_state(state) if is None: = str(uuid.uuid4()) def __setitem__(self, index, value): super().__setitem__(index, value) if index < 0: index = len(self.states) + index self._update_metadatas(index)
[docs] def insert(self, index, value): """Insert value at index of :attr:`states`. Parameters ---------- index: int Index of :attr:`states` to insert value at. value: State A state object to be inserted at the specified index of :attr:`states`. """ super().insert(index, value) if index < 0: if index < -len(self.states): index = 0 else: index += len(self.states) - 1 elif index >= len(self.states): index = len(self.states) - 1 self._update_metadatas(index)
[docs] def append(self, value): """Add value at end of :attr:`states`. Parameters ---------- value: State A state object to be added at the end of :attr:`states`. """ # Update metadata self._update_metadata_from_state(value) return self.states.append(value)
@property def metadata(self): """Current metadata dictionary of track. If track contains no states, this is the initial metadata dictionary :attr:`init_metadata`.""" if self.metadatas: return self.metadatas[-1] else: return self.init_metadata def _update_metadatas(self, index): """Update track :attr:`metadatas` property, starting at specified index. Parameters ---------- index: Int Index of :attr:`metadatas` to update from. """ # Plus one for 0th initial track meta data self.metadatas = self.metadatas[:index] for future_state in self.states[index:]: self._update_metadata_from_state(future_state) def _update_metadata_from_state(self, state): """Update :attr:`metadatas` with an updated metadata entry, accounting for extracted metadata from state. Parameters ---------- state: State A state object from which to extract metadata. Metadata can only be extracted from Update (or subclassed) objects. Calling this method with a non-Update (subclass) object will NOT raise an error, but will have no effect on the metadata. """ self.metadatas.append(self.metadata.copy()) if isinstance(state, Update): if isinstance(state.hypothesis, MultipleHypothesis): # Sort and iterate through multiple hypotheses such that most # likely hypothesis comes last. This ensures that metadata # from all hypotheses are retained, but more likely # hypotheses will over-write the metadata set by less likely # ones. for hypothesis in sorted(state.hypothesis, reverse=True): if hypothesis \ and hypothesis.measurement.metadata is not None: self.metadata.update(hypothesis.measurement.metadata) else: hypothesis = state.hypothesis if hypothesis and hypothesis.measurement.metadata is not None: self.metadata.update(hypothesis.measurement.metadata)