httk.atomistic.models.trajectory.trajectory
===========================================

.. py:module:: httk.atomistic.models.trajectory.trajectory

.. autoapi-nested-parse::

   Store the native immutable trajectory representation.



Classes
-------

.. autoapisummary::

   httk.atomistic.models.trajectory.trajectory.Trajectory


Module Contents
---------------

.. py:class:: Trajectory(frames, observables = None, reference_frames = None)

   Bases: :py:obj:`httk.atomistic.models.trajectory.backend.TrajectoryBackend`


   Store an immutable trajectory in the native backend.

   A trajectory requires at least one frame and keeps one constant composition
   across all frames.

   :param frames: Unit-cell structures to coerce and store.
   :param observables: Optional per-frame observable values.
   :param reference_frames: Optional indexes of bounded reference frames.


   .. py:attribute:: kind
      :type:  ClassVar[str]
      :value: 'native'



   .. py:property:: nframes
      :type: int


      Return the number of stored frames.


   .. py:method:: frame(i)

      Return one stored frame by index.

      :param i: Frame index.
      :return: The requested unit-cell structure.
      :raises IndexError: If the index is out of range.



   .. py:method:: frames()

      Iterate over the stored frames.

      :return: An iterator of unit-cell structures.



   .. py:property:: reference_frames
      :type: tuple[int, ...] | None


      Return the bounded reference-frame indexes, or ``None``.


   .. py:property:: species
      :type: tuple[httk.atomistic.models.species.species.Species, ...]


      Return the constant distinct species.


   .. py:property:: species_at_sites
      :type: tuple[str, ...]


      Return the constant species name at each site.


   .. py:property:: observable_names
      :type: tuple[str, ...]


      Return the names of stored observables.


   .. py:method:: observable(name)

      Return one observable's values in frame order.

      :param name: Observable name.
      :return: The observable values.
      :raises KeyError: If the observable is unavailable.