astro py:docs

- Index
- Modules

### Navigation

- Astropy v1.1.1 »
- Module code »

# Source code for astropy.coordinates.builtin_frames.supergalactic

    # -*- coding: utf-8 -*-
    # Licensed under a 3-clause BSD style license - see LICENSE.rst
    from __future__ import (absolute_import, unicode_literals, division,
                            print_function)

    from ... import units as u
    from ..angles import Angle
    from ..representation import SphericalRepresentation
    from ..baseframe import BaseCoordinateFrame, RepresentationMapping
    from .galactic import Galactic

    class Supergalactic(BaseCoordinateFrame):
        """
        Supergalactic Coordinates
        (see Lahav et al. 2000, <http://adsabs.harvard.edu/abs/2000MNRAS.312..166L>,
        and references therein).

        Parameters
        ----------
        representation : `BaseRepresentation` or None
            A representation object or None to have no data (or use the other keywords)
        sgl : `Angle`, optional, must be keyword
            The supergalactic longitude for this object (``sgb`` must also be given and
            ``representation`` must be None).
        sgb : `Angle`, optional, must be keyword
            The supergalactic latitude for this object (``sgl`` must also be given and
            ``representation`` must be None).
        distance : `~astropy.units.Quantity`, optional, must be keyword
            The Distance for this object along the line-of-sight.
        """

        frame_specific_representation_info = {
            'spherical': [RepresentationMapping('lon', 'sgl'),
                          RepresentationMapping('lat', 'sgb')],
            'cartesian': [RepresentationMapping('x', 'sgx'),
                          RepresentationMapping('y', 'sgy'),
                          RepresentationMapping('z', 'sgz')]
        }
        frame_specific_representation_info['unitspherical'] = \
            frame_specific_representation_info['spherical']

        default_representation = SphericalRepresentation

        # North supergalactic pole in Galactic coordinates.
        # Needed for transformations to/from Galactic coordinates.
        _nsgp_gal = Galactic(l=47.37*u.degree, b=+6.32*u.degree)