Angelus.Ephemeris (Angelus v0.0.2)

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Public v0.1 API for geocentric ephemeris positions.

Summary

Functions

position(body, datetime, opts \\ [])

Returns the geocentric position of a single celestial body at a UTC datetime.

positions(bodies, datetime, opts \\ [])

Returns geocentric positions for a list of celestial bodies at a UTC datetime.

Functions

position(body, datetime, opts \\ [])

@spec position(atom(), DateTime.t(), keyword()) ::
  {:ok, Angelus.Ephemeris.BodyPosition.t()} | {:error, term()}

Returns the geocentric position of a single celestial body at a UTC datetime.

body must be one of the atoms supported by the v0.1 ephemeris body catalog. datetime must be a %DateTime{} in the UTC timezone.

Options

Returns

  • {:ok, %Angelus.Ephemeris.BodyPosition{}} on success.
  • {:error, :invalid_body} when body is not an atom.
  • {:error, :invalid_datetime} / {:error, :datetime_must_be_utc} for bad datetimes.
  • {:error, {:unsupported_body, body}} for unrecognised bodies.
  • {:error, {:datetime_out_of_range, %{from: Date.t(), to: Date.t()}}} outside the supported range.

Examples

iex> {:ok, pos} = Angelus.Ephemeris.position(:sun, ~U[2000-01-01 12:00:00Z])
iex> pos.body
:sun

positions(bodies, datetime, opts \\ [])

@spec positions([atom(), ...], DateTime.t(), keyword()) ::
  {:ok, %{required(atom()) => Angelus.Ephemeris.BodyPosition.t()}}
  | {:error, term()}

Returns geocentric positions for a list of celestial bodies at a UTC datetime.

All entries in bodies must be atoms supported by the v0.1 ephemeris body catalog. The list must be non-empty and contain no duplicates. datetime must be a %DateTime{} in the UTC timezone.

Options

Returns

  • {:ok, %{atom() => %Angelus.Ephemeris.BodyPosition{}}} — a map keyed by body atom.
  • {:error, :empty_body_list} when bodies is [].
  • {:error, :invalid_body_list} when bodies is not a list of atoms.
  • {:error, {:duplicate_body, atom()}} when the same body appears more than once.
  • {:error, {:unsupported_body, atom()}} for unrecognised bodies.
  • {:error, :invalid_datetime} / {:error, :datetime_must_be_utc} for bad datetimes.
  • {:error, {:datetime_out_of_range, %{from: Date.t(), to: Date.t()}}} outside the supported range.
  • {:error, {:unsupported_option, term()}} for unknown options.

Examples

iex> {:ok, positions} = Angelus.Ephemeris.positions([:sun, :moon], ~U[2000-01-01 12:00:00Z])
iex> Map.keys(positions)
[:sun, :moon]