class OphiuchusPriceWhelan16(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the Ophiuchus stream, as described in
Price-Whelan et al. 2016 (see: `<https://arxiv.org/abs/1601.06790>`_).
For more information about this class, see the Astropy documentation
on coordinate frames in :mod:`~astropy.coordinates`.
Parameters
----------
representation : :class:`~astropy.coordinates.BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
phi1 : angle_like, optional, must be keyword
The longitude-like angle corresponding to Ophiuchus's orbit.
phi2 : angle_like, optional, must be keyword
The latitude-like angle corresponding to Ophiuchus's orbit.
distance : :class:`~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_phi1_cosphi2 : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in the longitude-like direction corresponding to
the Ophiuchus stream's orbit.
pm_phi2 : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in the latitude-like direction perpendicular to the
Ophiuchus stream's orbit.
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2'),
coord.RepresentationMapping('distance', 'distance')
]
}
_default_wrap_angle = 180 * u.deg
def __init__(self, *args, **kwargs):
wrap = kwargs.pop('wrap_longitude', True)
super().__init__(*args, **kwargs)
if wrap and isinstance(self._data, (coord.UnitSphericalRepresentation,
coord.SphericalRepresentation)):
self._data.lon.wrap_angle = self._default_wrap_angle
# TODO: remove this. This is a hack required as of astropy v3.1 in order
# to have the longitude components wrap at the desired angle
def represent_as(self, base, s='base', in_frame_units=False):
r = super().represent_as(base, s=s, in_frame_units=in_frame_units)
if hasattr(r, "lon"):
r.lon.wrap_angle = self._default_wrap_angle
return r
represent_as.__doc__ = coord.BaseCoordinateFrame.represent_as.__doc__
class Sagittarius(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the Sagittarius dwarf galaxy, as described in
http://adsabs.harvard.edu/abs/2003ApJ...599.1082M
and further explained in
http://www.stsci.edu/~dlaw/Sgr/.
Parameters
----------
representation : `BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
Lambda : `Angle`, optional, must be keyword
The longitude-like angle corresponding to Sagittarius' orbit.
Beta : `Angle`, optional, must be keyword
The latitude-like angle corresponding to Sagittarius' orbit.
distance : `Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
"""
default_representation = coord.SphericalRepresentation
frame_specific_representation_info = {
'spherical': [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta'),
coord.RepresentationMapping('distance', 'distance')
],
'unitspherical': [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta')
]
}
class GD1(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the GD1 stream, as described in
Koposov et al. 2010 (see: `<http://arxiv.org/abs/0907.1085>`_).
For more information about this class, see the Astropy documentation
on coordinate frames in :mod:`~astropy.coordinates`.
Parameters
----------
representation : :class:`~astropy.coordinates.BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
phi1 : angle_like, optional, must be keyword
The longitude-like angle corresponding to Orphan's orbit.
phi2 : angle_like, optional, must be keyword
The latitude-like angle corresponding to Orphan's orbit.
distance : :class:`~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
"""
default_representation = coord.SphericalRepresentation
frame_specific_representation_info = {
'spherical': [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2'),
coord.RepresentationMapping('distance', 'distance')
],
'unitspherical': [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2')
]
}
class SagittariusLaw10(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the Sagittarius dwarf galaxy, as described in
http://adsabs.harvard.edu/abs/2003ApJ...599.1082M
and further explained in http://www.stsci.edu/~dlaw/Sgr/.
Parameters
----------
representation : `BaseRepresentation` or None
A representation object or None to have no data (or use the other
keywords).
Lambda : `Angle`, optional, must be keyword
The longitude-like angle corresponding to Sagittarius' orbit.
Beta : `Angle`, optional, must be keyword
The latitude-like angle corresponding to Sagittarius' orbit.
distance : `Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_Lambda_cosBeta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion along the stream in ``Lambda`` (including the
``cos(Beta)`` factor) for this object (``pm_Beta`` must also be given).
pm_Beta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in Declination for this object (``pm_ra_cosdec`` must
also be given).
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The radial velocity of this object.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta'),
coord.RepresentationMapping('distance', 'distance')
]
}
_default_wrap_angle = 180 * u.deg
def __init__(self, *args, **kwargs):
wrap = kwargs.pop('wrap_longitude', True)
super().__init__(*args, **kwargs)
if wrap and isinstance(self._data, (coord.UnitSphericalRepresentation,
coord.SphericalRepresentation)):
self._data.lon.wrap_angle = self._default_wrap_angle
# TODO: remove this. This is a hack required as of astropy v3.1 in order
# to have the longitude components wrap at the desired angle
def represent_as(self, base, s='base', in_frame_units=False):
r = super().represent_as(base, s=s, in_frame_units=in_frame_units)
if hasattr(r, "lon"):
r.lon.wrap_angle = self._default_wrap_angle
return r
represent_as.__doc__ = coord.BaseCoordinateFrame.represent_as.__doc__
class Sagittarius(coord.BaseCoordinateFrame):
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta'),
coord.RepresentationMapping('distance', 'distance')]
}
class ArbitraryPoleFrame(coord.BaseCoordinateFrame):
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2'),
coord.RepresentationMapping('distance', 'distance')
],
coord.SphericalCosLatDifferential: [
coord.RepresentationMapping('d_lon_coslat', 'pm_phi1_cosphi2'),
coord.RepresentationMapping('d_lat', 'pm_phi2'),
coord.RepresentationMapping('d_distance', 'radial_velocity')
],
coord.SphericalDifferential: [
coord.RepresentationMapping('d_lon', 'pm_phi1'),
coord.RepresentationMapping('d_lat', 'pm_phi2'),
coord.RepresentationMapping('d_distance', 'radial_velocity')
]
}
pole = coord.CoordinateAttribute(frame=coord.ICRS)
roll = coord.QuantityAttribute(default=0 * u.degree)
class GD1(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the GD1 stream, as described in
Koposov et al. 2010 (see: `<http://arxiv.org/abs/0907.1085>`_).
For more information about this class, see the Astropy documentation
on coordinate frames in :mod:`~astropy.coordinates`.
Parameters
----------
representation : :class:`~astropy.coordinates.BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
phi1 : angle_like, optional, must be keyword
The longitude-like angle corresponding to Orphan's orbit.
phi2 : angle_like, optional, must be keyword
The latitude-like angle corresponding to Orphan's orbit.
distance : :class:`~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_phi1_cosphi2 : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in the longitude-like direction corresponding to
the Orphan stream's orbit.
pm_phi2 : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in the latitude-like direction perpendicular to the
Orphan stream's orbit.
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2'),
coord.RepresentationMapping('distance', 'distance')
],
coord.SphericalCosLatDifferential: [
coord.RepresentationMapping('d_lon_coslat', 'pm_phi1_cosphi2'),
coord.RepresentationMapping('d_lat', 'pm_phi2'),
coord.RepresentationMapping('d_distance', 'radial_velocity')
],
coord.SphericalDifferential: [
coord.RepresentationMapping('d_lon', 'pm_phi1'),
coord.RepresentationMapping('d_lat', 'pm_phi2'),
coord.RepresentationMapping('d_distance', 'radial_velocity')
]
}
frame_specific_representation_info[coord.UnitSphericalRepresentation] = \
frame_specific_representation_info[coord.SphericalRepresentation]
frame_specific_representation_info[coord.UnitSphericalCosLatDifferential] = \
frame_specific_representation_info[coord.SphericalCosLatDifferential]
frame_specific_representation_info[coord.UnitSphericalDifferential] = \
frame_specific_representation_info[coord.SphericalDifferential]
class NewbergOrphan(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the Orphan stream, as described in
Newberg et al. 2010 (see: `<http://arxiv.org/abs/1001.0576>`_).
Note: to be consistent with other stream classes, we refer to the longitude
and latitude as ``phi1`` and ``phi2`` instead of ``Lambda`` and ``Beta``.
For more information about this class, see the Astropy documentation
on coordinate frames in :mod:`~astropy.coordinates`.
Parameters
----------
representation : :class:`~astropy.coordinates.BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
phi1 : angle_like, optional, must be keyword
The longitude-like angle corresponding to Orphan's orbit.
phi2 : angle_like, optional, must be keyword
The latitude-like angle corresponding to Orphan's orbit.
distance : :class:`~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_phi1_cosphi2 : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in the longitude-like direction corresponding to
the Orphan stream's orbit.
pm_phi2 : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in the latitude-like direction perpendicular to the
Orphan stream's orbit.
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2'),
coord.RepresentationMapping('distance', 'distance')
]
}
_default_wrap_angle = 180 * u.deg
def __init__(self, *args, **kwargs):
wrap = kwargs.pop('wrap_longitude', True)
super().__init__(*args, **kwargs)
if wrap and isinstance(self._data, (coord.UnitSphericalRepresentation,
coord.SphericalRepresentation)):
self._data.lon.wrap_angle = self._default_wrap_angle
class Sagittarius(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the Sagittarius dwarf galaxy, as described in
http://adsabs.harvard.edu/abs/2003ApJ...599.1082M
and further explained in
http://www.stsci.edu/~dlaw/Sgr/.
Parameters
----------
representation : `BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
Lambda : `Angle`, optional, must be keyword
The longitude-like angle corresponding to Sagittarius' orbit.
Beta : `Angle`, optional, must be keyword
The latitude-like angle corresponding to Sagittarius' orbit.
distance : `Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_Lambda_cosBeta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion along the stream in ``Lambda`` (including the
``cos(Beta)`` factor) for this object (``pm_Beta`` must also be given).
pm_Beta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in Declination for this object (``pm_ra_cosdec`` must
also be given).
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The radial velocity of this object.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta'),
coord.RepresentationMapping('distance', 'distance')
],
coord.SphericalCosLatDifferential: [
coord.RepresentationMapping('d_lon_coslat', 'pm_Lambda_cosBeta'),
coord.RepresentationMapping('d_lat', 'pm_Beta'),
coord.RepresentationMapping('d_distance', 'radial_velocity')
],
coord.SphericalDifferential: [
coord.RepresentationMapping('d_lon', 'pm_Lambda'),
coord.RepresentationMapping('d_lat', 'pm_Beta'),
coord.RepresentationMapping('d_distance', 'radial_velocity')
]
}
frame_specific_representation_info[coord.UnitSphericalRepresentation] = \
frame_specific_representation_info[coord.SphericalRepresentation]
frame_specific_representation_info[coord.UnitSphericalCosLatDifferential] = \
frame_specific_representation_info[coord.SphericalCosLatDifferential]
frame_specific_representation_info[coord.UnitSphericalDifferential] = \
frame_specific_representation_info[coord.SphericalDifferential]
class RotatedFrame(coord.BaseCoordinateFrame):
"""Example Rotated frame.
Implemented from an Astropy [astropy]_ SkyOffset Frame.
Parameters
----------
representation : `~astropy.coordinates.BaseRepresentation` or None
A representation object or None to have no data
(or use the other keywords)
phi1 : `~astropy.coordinates.Angle`, optional, must be keyword
The longitude-like angle corresponding to Sagittarius' orbit.
phi2 : `~astropy.coordinates.Angle`, optional, must be keyword
The latitude-like angle corresponding to Sagittarius' orbit.
distance : `Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_phi1_cosphi2 : :class:`~astropy.units.Quantity`, optional, keyword
The proper motion along the stream in ``Lambda`` (including the
``cos(Beta)`` factor) for this object (``pm_Beta`` must also be given).
pm_phi2 : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in Declination for this object (``pm_ra_cosdec`` must
also be given).
radial_velocity : :class:`~astropy.units.Quantity`, optional, keyword
The radial velocity of this object.
References
----------
.. [astropy] Astropy Collaboration, Robitaille, T., Tollerud, E.,
Greenfield, P., Droettboom, M., Bray, E., Aldcroft, T., Davis,
M., Ginsburg, A., Price-Whelan, A., Kerzendorf, W., Conley, A.,
Crighton, N., Barbary, K., Muna, D., Ferguson, H., Grollier, F.,
Parikh, M., Nair, P., Unther, H., Deil, C., Woillez, J.,
Conseil, S., Kramer, R., Turner, J., Singer, L., Fox, R.,
Weaver, B., Zabalza, V., Edwards, Z., Azalee Bostroem, K.,
Burke, D., Casey, A., Crawford, S., Dencheva, N., Ely, J.,
Jenness, T., Labrie, K., Lim, P., Pierfederici, F., Pontzen, A.,
Ptak, A., Refsdal, B., Servillat, M., & Streicher, O. (2013).
Astropy: A community Python package for astronomy.
Astronomy and Astrophysics, 558, A33.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping("lon", "phi1"),
coord.RepresentationMapping("lat", "phi2"),
coord.RepresentationMapping("distance", "distance"),
],
}
class GreatCircleICRSFrame(coord.BaseCoordinateFrame):
"""A frame rotated into great circle coordinates with the pole and longitude
specified as frame attributes.
``GreatCircleICRSFrame``s always have component names for spherical
coordinates of ``phi1``/``phi2``.
"""
pole = CoordinateAttribute(default=None, frame=coord.ICRS)
ra0 = QuantityAttribute(default=np.nan * u.deg, unit=u.deg)
rotation = QuantityAttribute(default=0, unit=u.deg)
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2'),
coord.RepresentationMapping('distance', 'distance')
]
}
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
_default_wrap_angle = 180 * u.deg
def __init__(self, *args, **kwargs):
wrap = kwargs.pop('wrap_longitude', True)
super().__init__(*args, **kwargs)
if wrap and isinstance(self._data, (coord.UnitSphericalRepresentation,
coord.SphericalRepresentation)):
self._data.lon.wrap_angle = self._default_wrap_angle
@classmethod
def from_endpoints(cls, coord1, coord2, ra0=None, rotation=None):
"""TODO
"""
pole = pole_from_endpoints(coord1, coord2)
kw = dict(pole=pole)
if ra0 is not None:
kw['ra0'] = ra0
if rotation is not None:
kw['rotation'] = rotation
if ra0 is None and rotation is None:
midpt = sph_midpoint(coord1, coord2)
kw['ra0'] = midpt.ra
return cls(**kw)
class LocalSheet(coord.BaseCoordinateFrame):
"""
Local Sheet Coordinates
(see McCall 2014, <http://adsabs.harvard.edu/abs/2014MNRAS.440..405M>,
and references therein).
"""
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'lsl'),
coord.RepresentationMapping('lat', 'lsb')
],
coord.CartesianRepresentation: [
coord.RepresentationMapping('x', 'lsx'),
coord.RepresentationMapping('y', 'lsy'),
coord.RepresentationMapping('z', 'lsz')
],
coord.CartesianDifferential: [
coord.RepresentationMapping('d_x', 'v_x', u.km/u.s),
coord.RepresentationMapping('d_y', 'v_y', u.km/u.s),
coord.RepresentationMapping('d_z', 'v_z', u.km/u.s)
],
}
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
# North supergalactic pole in Galactic coordinates.
# Needed for transformations to/from Galactic coordinates.
n_sgal = coord.SkyCoord(sgl=241.74*u.degree, sgb=82.05*u.degree, frame="supergalactic")
_nlsp_gal = n_sgal.galactic
class SDSSMuNu(ac.BaseCoordinateFrame):
"""SDSS Great Circle Coordinates
Attributes
----------
stripe
SDSS `Stripe Number`_ .
node
Node of the great circle with respect to the celestial equator.
In SDSS, this is almost always RA = 95.0 degrees.
incl
Inclination of the great circle with respect to the celestial
equator.
phi
Counter-clockwise position angle w.r.t. north for an arc
in the +nu direction.
Parameters
----------
mu : :class:`~astropy.coordinates.Angle`
Angle corresponding to longitude measured along a stripe.
nu : :class:`~astropy.coordinates.Angle`
Angle corresponding to latitude measured perpendicular to a stripe.
Notes
-----
https://www.sdss.org/dr14/algorithms/surveycoords/
.. _`Stripe Number`: https://www.sdss.org/dr14/help/glossary/#stripe
"""
default_representation = ac.SphericalRepresentation
frame_specific_representation_info = {
'spherical': [
ac.RepresentationMapping(reprname='lon',
framename='mu',
defaultunit=u.deg),
ac.RepresentationMapping(reprname='lat',
framename='nu',
defaultunit=u.deg)
]
}
frame_specific_representation_info['unitspherical'] = (
frame_specific_representation_info['spherical'])
stripe = ac.Attribute(default=0)
node = ac.QuantityAttribute(default=ac.Angle(95.0, unit=u.deg), unit=u.deg)
# phi = ac.QuantityFrameAttribute(default=None, unit=u.deg)
@property
def incl(self):
return ac.Angle(stripe_to_incl(self.stripe), unit=u.deg)
class stream_coord(coord.BaseCoordinateFrame):
"""
Based on the Sgr example in the Astropy docs, this creates a new
coordinate system for the stream model
Parameters
----------
representation : `~astropy.coordinates.BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
Lambda : `~astropy.coordinates.Angle`, optional, must be keyword
The longitude-like angle corresponding to the direction along Phoenix.
Beta : `~astropy.coordinates.Angle`, optional, must be keyword
The latitude-like angle corresponding to the direction perpendicular to Phoenix.
distance : `Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_Lambda_cosBeta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion along the stream in ``Lambda`` (including the
``cos(Beta)`` factor) for this object (``pm_Beta`` must also be given).
pm_Beta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in Declination for this object (``pm_ra_cosdec`` must
also be given).
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The radial velocity of this object.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta'),
coord.RepresentationMapping('distance', 'distance')]
}
_default_wrap_angle = 180*u.deg
def __init__(self, *args, **kwargs):
wrap = kwargs.pop('wrap_longitude', True)
super().__init__(*args, **kwargs)
if wrap and isinstance(self._data, (coord.UnitSphericalRepresentation,
coord.SphericalRepresentation)):
self._data.lon.wrap_angle = self._default_wrap_angle
def represent_as(self, base, s='base', in_frame_units=False):
r = super().represent_as(base, s=s, in_frame_units=in_frame_units)
r.lon.wrap_angle = self._default_wrap_angle
return r
class OrphanKoposov19(coord.BaseCoordinateFrame):
"""A coordinate frame for the Orphan stream defined by Sergey Koposov.
Parameters
----------
phi1 : `~astropy.units.Quantity`
Longitude component.
phi2 : `~astropy.units.Quantity`
Latitude component.
distance : `~astropy.units.Quantity`
Distance.
pm_phi1_cosphi2 : `~astropy.units.Quantity`
Proper motion in longitude.
pm_phi2 : `~astropy.units.Quantity`
Proper motion in latitude.
radial_velocity : `~astropy.units.Quantity`
Line-of-sight or radial velocity.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2'),
coord.RepresentationMapping('distance', 'distance')
]
}
_default_wrap_angle = 180 * u.deg
def __init__(self, *args, **kwargs):
wrap = kwargs.pop('wrap_longitude', True)
super().__init__(*args, **kwargs)
if wrap and isinstance(self._data, (coord.UnitSphericalRepresentation,
coord.SphericalRepresentation)):
self._data.lon.wrap_angle = self._default_wrap_angle
# TODO: remove this. This is a hack required as of astropy v3.1 in order
# to have the longitude components wrap at the desired angle
def represent_as(self, base, s='base', in_frame_units=False):
r = super().represent_as(base, s=s, in_frame_units=in_frame_units)
r.lon.wrap_angle = self._default_wrap_angle
return r
represent_as.__doc__ = coord.BaseCoordinateFrame.represent_as.__doc__
class MagellanicStream(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the Magellanic Stream
Parameters
----------
representation : `BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
MSLongitude : `Angle`, optional, must be keyword
The longitude-like angle corresponding to the Magellanic Stream.
MSLatitude : `Angle`, optional, must be keyword
The latitude-like angle corresponding to the Magellanic Stream.
distance : `Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_Lambda_cosBeta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion along the Stream in ``Lambda`` (including the
``cos(Beta)`` factor) for this object (``pm_Beta`` must also be given).
pm_Beta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in Declination for this object (``pm_ra_cosdec`` must
also be given).
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The radial velocity of this object.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'MSLongitude'),
coord.RepresentationMapping('lat', 'MSLatitude'),
coord.RepresentationMapping('distance', 'distance')
],
coord.SphericalCosLatDifferential: [
coord.RepresentationMapping('d_lon_coslat', 'pm_lon_coslat'),
coord.RepresentationMapping('d_lat', 'pm_lat'),
coord.RepresentationMapping('d_distance', 'radial_velocity')
],
coord.SphericalDifferential: [
coord.RepresentationMapping('d_lon', 'pm_lon'),
coord.RepresentationMapping('d_lat', 'pm_lat'),
coord.RepresentationMapping('d_distance', 'radial_velocity')
]
}
frame_specific_representation_info[coord.UnitSphericalRepresentation] = \
frame_specific_representation_info[coord.SphericalRepresentation]
frame_specific_representation_info[coord.UnitSphericalCosLatDifferential] = \
frame_specific_representation_info[coord.SphericalCosLatDifferential]
frame_specific_representation_info[coord.UnitSphericalDifferential] = \
frame_specific_representation_info[coord.SphericalDifferential]
class RotY45(coord.BaseCoordinateFrame):
'''
This class rotates a vector 45 degrees around the y-axis.
(0,0,1) in (x,y,z) or (0,90) in long, lat should yield
(-0.707, 0, 0.707) or (180, 45)
Parameters:
longitude-like angle
latitude-like angle
'''
default_representation = UnitSphericalRepresentation
frame_specific_representation_info = {
UnitSphericalRepresentation: [
coord.RepresentationMapping('lon', 'lon'),
coord.RepresentationMapping('lat', 'lat')]
}
class StreamFrame(coord.BaseCoordinateFrame):
"""StreamFrame.
A Heliocentric spherical coordinate system defined to linearize
a stream about a point, using the angular momentum at that point.
http://docs.astropy.org/en/stable/generated/examples/coordinates/
plot_sgr-coordinate-frame.html
#sphx-glr-generated-examples-coordinates-plot-sgr-coordinate-frame-py
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping("lon", "phi1"),
coord.RepresentationMapping("lat", "phi2"),
coord.RepresentationMapping("distance", "distance"),
],
coord.SphericalCosLatDifferential: [
coord.RepresentationMapping("d_lon_coslat", "pm_phi1_cosphi2"),
coord.RepresentationMapping("d_lat", "pm_phi2"),
coord.RepresentationMapping("d_distance", "radial_velocity"),
],
coord.SphericalDifferential: [
coord.RepresentationMapping("d_lon", "pm_phi1"),
coord.RepresentationMapping("d_lat", "pm_phi2"),
coord.RepresentationMapping("d_distance", "radial_velocity"),
],
}
frame_specific_representation_info[
coord.
UnitSphericalRepresentation] = frame_specific_representation_info[
coord.SphericalRepresentation]
frame_specific_representation_info[
coord.
UnitSphericalCosLatDifferential] = frame_specific_representation_info[
coord.SphericalCosLatDifferential]
frame_specific_representation_info[
coord.UnitSphericalDifferential] = frame_specific_representation_info[
coord.SphericalDifferential]
class MarsNAlign(coord.BaseCoordinateFrame):
'''
A unit spherical representation frame that aligns J2000 (RA,DEC) frame to
Mars's rotation frame: Mars's rotational axis in J2000 should point
due north (0,0,1) in Cartesian or (0,90) in long, lat.
Note:
This new frame is a simple realignment or rotation of the J2000 frame
to match that of Mars's rotations axis.
This doesn't take into consideration the location of Mars's prime meridian.
To fix this, an additional perimeter for the longitude needs
to be addressed.
Parameters:
longitude-like angle using ra-like as label to maintain consistency
latitude-like angle using dec-like label to maintain consistency
'''
default_representation = UnitSphericalRepresentation
frame_specific_representation_info = {
UnitSphericalRepresentation: [
coord.RepresentationMapping('lon', 'ra'), # ('lon', 'lon')
coord.RepresentationMapping('lat', 'dec')] # ('lon', 'lon')
}
class Phoenix(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the Phoenix stream, as described in
Balbinot et al. 2016
Parameters
----------
representation : `~astropy.coordinates.BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
Lambda : `~astropy.coordinates.Angle`, optional, must be keyword
The longitude-like angle corresponding to the direction along Phoenix.
Beta : `~astropy.coordinates.Angle`, optional, must be keyword
The latitude-like angle corresponding to the direction perpendicular to Phoenix.
distance : `Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
pm_Lambda_cosBeta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion along the stream in ``Lambda`` (including the
``cos(Beta)`` factor) for this object (``pm_Beta`` must also be given).
pm_Beta : :class:`~astropy.units.Quantity`, optional, must be keyword
The proper motion in Declination for this object (``pm_ra_cosdec`` must
also be given).
radial_velocity : :class:`~astropy.units.Quantity`, optional, must be keyword
The radial velocity of this object.
"""
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta'),
coord.RepresentationMapping('distance', 'distance')
]
}
class Sagittarius(coord.BaseCoordinateFrame):
"""
A Heliocentric spherical coordinate system defined by the orbit
of the Sagittarius dwarf galaxy, as described in
Majewski et al. 2003 (see: `<http://adsabs.harvard.edu/abs/2003ApJ...599.1082M>`_)
and further explained at
`this website <http://www.astro.virginia.edu/~srm4n/Sgr/>`_.
For more information about this class, see the Astropy documentation
on `Coordinate Frames <http://docs.astropy.org/en/latest/coordinates/frames.html>`_.
Parameters
----------
representation : :class:`~astropy.coordinates.BaseRepresentation` or None
A representation object or None to have no data (or use the other keywords)
Lambda : angle_like, optional, must be keyword
The longitude-like angle corresponding to Sagittarius' orbit.
Beta : angle_like, optional, must be keyword
The latitude-like angle corresponding to Sagittarius' orbit.
distance : :class:`~astropy.units.Quantity`, optional, must be keyword
The Distance for this object along the line-of-sight.
"""
default_representation = coord.SphericalRepresentation
frame_specific_representation_info = {
'spherical': [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta'),
coord.RepresentationMapping('distance', 'distance')
],
'unitspherical': [
coord.RepresentationMapping('lon', 'Lambda'),
coord.RepresentationMapping('lat', 'Beta')
]
}
class GreatCircleICRSFrame(coord.BaseCoordinateFrame):
"""A frame rotated into great circle coordinates with the pole and longitude
specified as frame attributes.
``GreatCircleICRSFrame``s always have component names for spherical
coordinates of ``phi1``/``phi2``.
"""
pole = CoordinateAttribute(default=None, frame=coord.ICRS)
center = CoordinateAttribute(default=None, frame=coord.ICRS)
ra0 = QuantityAttribute(default=np.nan * u.deg, unit=u.deg)
rotation = QuantityAttribute(default=0, unit=u.deg)
frame_specific_representation_info = {
coord.SphericalRepresentation: [
coord.RepresentationMapping('lon', 'phi1'),
coord.RepresentationMapping('lat', 'phi2'),
coord.RepresentationMapping('distance', 'distance')
]
}
default_representation = coord.SphericalRepresentation
default_differential = coord.SphericalCosLatDifferential
_default_wrap_angle = 180 * u.deg
def __init__(self, *args, **kwargs):
wrap = kwargs.pop('wrap_longitude', True)
super().__init__(*args, **kwargs)
if wrap and isinstance(self._data, (coord.UnitSphericalRepresentation,
coord.SphericalRepresentation)):
self._data.lon.wrap_angle = self._default_wrap_angle
if self.center is not None and np.isfinite(self.ra0):
raise ValueError(
"Both `center` and `ra0` were specified for this "
"{} object: you can only specify one or the other.".format(
self.__class__.__name__))
# TODO: remove this. This is a hack required as of astropy v3.1 in order
# to have the longitude components wrap at the desired angle
def represent_as(self, base, s='base', in_frame_units=False):
r = super().represent_as(base, s=s, in_frame_units=in_frame_units)
r.lon.wrap_angle = self._default_wrap_angle
return r
represent_as.__doc__ = coord.BaseCoordinateFrame.represent_as.__doc__
@classmethod
def from_endpoints(cls, coord1, coord2, ra0=None, rotation=None):
"""Compute the great circle frame from two endpoints of an arc on the
unit sphere.
Parameters
----------
coord1 : `~astropy.coordinates.SkyCoord`
One endpoint of the great circle arc.
coord2 : `~astropy.coordinates.SkyCoord`
The other endpoint of the great circle arc.
ra0 : `~astropy.units.Quantity`, `~astropy.coordinates.Angle` (optional)
If specified, an additional transformation will be applied to make
this right ascension the longitude zero-point of the resulting
coordinate frame.
rotation : `~astropy.units.Quantity`, `~astropy.coordinates.Angle` (optional)
If specified, a final rotation about the pole (i.e. the resulting z
axis) applied.
"""
pole = pole_from_endpoints(coord1, coord2)
kw = dict(pole=pole)
if ra0 is not None:
kw['ra0'] = ra0
if rotation is not None:
kw['rotation'] = rotation
if ra0 is None and rotation is None:
midpt = sph_midpoint(coord1, coord2)
kw['ra0'] = midpt.ra
return cls(**kw)
@classmethod
def from_xyz(cls, xnew=None, ynew=None, znew=None):
"""Compute the great circle frame from a specification of the coordinate
axes in the new system.
Parameters
----------
xnew : astropy ``Representation`` object
The x-axis in the new system.
ynew : astropy ``Representation`` object
The y-axis in the new system.
znew : astropy ``Representation`` object
The z-axis in the new system.
"""
is_none = [xnew is None, ynew is None, znew is None]
if np.sum(is_none) > 1:
raise ValueError("At least 2 axes must be specified.")
if xnew is not None:
xnew = xnew.to_cartesian()
if ynew is not None:
ynew = ynew.to_cartesian()
if znew is not None:
znew = znew.to_cartesian()
if znew is None:
znew = xnew.cross(ynew)
if ynew is None:
ynew = -xnew.cross(znew)
if xnew is None:
xnew = ynew.cross(znew)
pole = coord.SkyCoord(znew, frame='icrs')
center = coord.SkyCoord(xnew, frame='icrs')
return cls(pole=pole, center=center)
