boinor.ephem
============

.. py:module:: boinor.ephem

.. autoapi-nested-parse::

   calculate Ephemerides of objects



Attributes
----------

.. autoapisummary::

   boinor.ephem.EPHEM_FORMAT


Classes
-------

.. autoapisummary::

   boinor.ephem.BaseInterpolator
   boinor.ephem.SincInterpolator
   boinor.ephem.SplineInterpolator
   boinor.ephem.Ephem


Functions
---------

.. autoapisummary::

   boinor.ephem.build_ephem_interpolant


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

.. py:data:: EPHEM_FORMAT
   :value: 'Ephemerides at {num} epochs from {start} ({start_scale}) to {end} ({end_scale})'


.. py:function:: build_ephem_interpolant(body, epochs, attractor=Earth)

   Interpolates ephemerides data.

   :param body: Source body.
   :type body: Body
   :param epochs: Array of time values, can be generated with boinor.util.time_range.
   :type epochs: ~astropy.time.Time
   :param attractor: Attractor, default to Earth.
   :type attractor: ~boinor.bodies.Body, optional

   :returns: **interpolant** -- Interpolant function that receives time increment in seconds
             since the initial epoch.
   :rtype: callable


.. py:class:: BaseInterpolator

   Dummy interpolator, the correct one has to be set


   .. py:method:: interpolate(epochs, reference_epochs, coordinates)
      :abstractmethod:


      Dummy interpolation function, the correct one has to be set



.. py:class:: SincInterpolator

   Whittaker-Shannon interpolator


   .. py:method:: interpolate(epochs, reference_epochs, coordinates)

      Interpolation function of the Whittaker-Shannon interpolator



.. py:class:: SplineInterpolator(kind='cubic')

   spline interpolator, by default a cubic spline is used


   .. py:method:: interpolate(epochs, reference_epochs, coordinates)

      interpolation function of the spline interpolator (by default a cubic spline is used)



.. py:class:: Ephem(coordinates, epochs, plane)

   Time history of position and velocity of some object at particular epochs.

   Instead of creating Ephem objects directly, use the available classmethods.

   :param coordinates: Coordinates with velocities.
   :type coordinates: astropy.coordinates.CartesianRepresentation
   :param epochs: Epochs corresponding to the coordinates.
   :type epochs: astropy.time.Time
   :param plane: Reference plane of the coordinates.
   :type plane: ~boinor.frames.Planes


   .. py:method:: __str__()


   .. py:method:: __repr__()


   .. py:property:: epochs

      Epochs at which the ephemerides was originally sampled.


   .. py:property:: coordinates

      Coordinates with velocitiy.


   .. py:property:: plane

      Reference plane of the ephemerides.


   .. py:method:: from_body(body, epochs, *, attractor=None, plane=Planes.EARTH_EQUATOR)
      :classmethod:


      Return `Ephem` for a `SolarSystemPlanet` at certain epochs.

      :param body: Body.
      :type body: ~boinor.bodies.SolarSystemPlanet
      :param epochs: Epochs to sample the body positions.
      :type epochs: ~astropy.time.Time
      :param attractor: Body to use as central location,
                        if not given the Solar System Barycenter will be used.
      :type attractor: ~boinor.bodies.SolarSystemPlanet, optional
      :param plane: Fundamental plane of the frame, default to Earth Equator.
      :type plane: ~boinor.frames.Planes, optional



   .. py:method:: from_horizons(name, epochs, *, attractor=None, plane=Planes.EARTH_EQUATOR, id_type=None)
      :classmethod:


      Return `Ephem` for an object using JPLHorizons module of Astroquery.

      :param name: Name of the body to query for.
      :type name: str
      :param epochs: Epochs to sample the body positions.
      :type epochs: ~astropy.time.Time
      :param attractor: Body to use as central location,
                        if not given the Solar System Barycenter will be used.
      :type attractor: ~boinor.bodies.SolarSystemPlanet, optional
      :param plane: Fundamental plane of the frame, default to Earth Equator.
      :type plane: ~boinor.frames.Planes, optional
      :param id_type: Use "smallbody" for Asteroids and Comets and None (default) to first
                      search for Planets and Satellites.
      :type id_type: NoneType or str, optional



   .. py:method:: from_orbit(orbit, epochs, plane=Planes.EARTH_EQUATOR)
      :classmethod:


      Return `Ephem` from an `Orbit` at certain epochs.

      :param orbit: Orbit.
      :type orbit: ~boinor.twobody.orbit.Orbit
      :param epochs: Epochs to sample the orbit positions.
      :type epochs: ~astropy.time.Time
      :param plane: Fundamental plane of the frame, default to Earth Equator.
      :type plane: ~boinor.frames.Planes, optional



   .. py:method:: sample(epochs=None, *, interpolator=SplineInterpolator())

      Returns coordinates at specified epochs.

      :param epochs: Epochs to sample the ephemerides,
                     if not given the original one from the object will be used.
      :type epochs: ~astropy.time.Time, optional
      :param interpolator: Interpolation method to use for epochs outside of the original ones,
                           default to splines.
      :type interpolator: ~boinor.ephem.BaseInterpolator, optional

      :returns: Sampled coordinates with velocities.
      :rtype: CartesianRepresentation



   .. py:method:: rv(epochs=None, **kwargs)

      Position and velocity vectors at given epochs.

      :param epochs: Epochs to sample the ephemerides, default to now.
      :type epochs: ~astropy.time.Time, optional
      :param \*\*kwargs: Extra kwargs for interpolation method.