lsdb.core.crossmatch.kdtree_utils

lsdb.core.crossmatch.kdtree_utils#

Functions#

_find_crossmatch_indices(...)

_query_min_max_neighbors(→ tuple[numpy.ndarray, ...)

Finds n_neighbors within a distance range for all points in a pair of partitions

_lon_lat_to_xyz(→ numpy.typing.NDArray[numpy.float64])

Converts longitude and latitude to cartesian coordinates on the unit sphere

_get_chord_distance(→ float)

Calculates the distance between two points on the surface of the unit sphere,

Module Contents#

_find_crossmatch_indices(left_xyz: numpy.typing.NDArray[numpy.float64], right_xyz: numpy.typing.NDArray[numpy.float64], n_neighbors: int, max_distance: float, min_distance: float = 0) → tuple[numpy.typing.NDArray[numpy.float64], numpy.typing.NDArray[numpy.int64], numpy.typing.NDArray[numpy.int64]][source]#
_query_min_max_neighbors(tree: scipy.spatial.KDTree, left_xyz: numpy.typing.NDArray[numpy.float64], right_xyz: numpy.typing.NDArray[numpy.float64], n_neighbors: int, min_distance: float, max_distance: float) → tuple[numpy.ndarray, numpy.ndarray][source]#

Finds n_neighbors within a distance range for all points in a pair of partitions

_lon_lat_to_xyz(lon: numpy.typing.NDArray[numpy.float64], lat: numpy.typing.NDArray[numpy.float64]) → numpy.typing.NDArray[numpy.float64][source]#

Converts longitude and latitude to cartesian coordinates on the unit sphere

Parameters:

  • lon (np.ndarray[np.float64]) – longitude in radians

  • lat (np.ndarray[np.float64]) – latitude in radians

_get_chord_distance(radius_arcsec: float) → float[source]#

Calculates the distance between two points on the surface of the unit sphere, for a given radius, in arcseconds

Parameters:

radius_arcsec (float) – Tbe radius, in arcseconds

Returns:

The chord distance between the two points on the unit sphere.

Contents