bounding.py 文件源码

def _friends_leaveoneout_radius(points, ftype):
    """Internal method used to compute the radius (half-side-length) for each
    ball (cube) used in :class:`RadFriends` (:class:`SupFriends`) using
    leave-one-out (LOO) cross-validation."""

    # Construct KDTree to enable quick nearest-neighbor lookup for
    # our resampled objects.
    kdtree = spatial.KDTree(points)

    if ftype == 'balls':
        # Compute radius to two nearest neighbors (self + neighbor).
        dists, ids = kdtree.query(points, k=2, eps=0, p=2)
    elif ftype == 'cubes':
        # Compute half-side-length to two nearest neighbors (self + neighbor).
        dists, ids = kdtree.query(points, k=2, eps=0, p=np.inf)

    dist = dists[:, 1]  # distances to LOO nearest neighbor

    return dist