Eigenframe (ligo.skymap.coordinates.eigenframe)

Astropy coordinate frame for eigendecomposition of a cloud of points or a 3D sky map.

class ligo.skymap.coordinates.eigenframe.EigenFrame(*args, copy=True, representation_type=None, differential_type=None, **kwargs)

Bases: BaseCoordinateFrame

A coordinate frame that has its axes aligned with the principal components of a cloud of points.

property default_differential

Default representation for differential data (e.g., velocity)

property default_representation

Default representation for position data

e_x

A frame attribute

Default: (1., 0., 0.)

e_y

A frame attribute

Default: (0., 1., 0.)

e_z

A frame attribute

Default: (0., 0., 1.)

classmethod for_coords(coords)

Create a coordinate frame that has its axes aligned with the principal components of a cloud of points.

Parameters:

coordsastropy.coordinates.SkyCoord

A cloud of points

Returns:

frameEigenFrame

A new coordinate frame

classmethod for_skymap(prob, distmu, distsigma, nest=False)

Create a coordinate frame that has its axes aligned with the principal components of a 3D sky map.

Parameters:

probnumpy.ndarray

Marginal probability (pix^-2)

distmunumpy.ndarray

Distance location parameter (Mpc)

distsigmanumpy.ndarray

Distance scale parameter (Mpc)

distnormnumpy.ndarray

Distance normalization factor (Mpc^-2)

nestbool, default=False

Indicates whether the input sky map is in nested rather than ring-indexed HEALPix coordinates (default: ring).

Returns:

frameEigenFrame

A new coordinate frame

property frame_specific_representation_info

Mapping for frame-specific component names