Neighbors.BallTree

constructor(
    X: number[][] = [],
    leafSize: number = 40,
    metric: Distance.IDistanceType = 'euclidiean',
    p: number = 2
)

Parameters

• X (number[][]): training data used to build the tree. Can be provided at construction time or via fit.
• leafSize (number): maximum number of points stored in a leaf. Default is 40.
• metric (Distance.IDistanceType): distance function for search. Defaults to 'euclidiean'.
• p (number): norm order for Minkowski distance when applicable. Default is 2.

Algorithm

Ball tree organizes points in hyperspheres. Each node stores a centroid and radius covering its children. During queries the tree is traversed to prune branches that are farther than the currently found neighbors, leading to faster neighbor search than a brute-force approach.

query(X: number[][], k: number = 1) returns distances and indices of nearest neighbors.

queryRadius(X: number[][], r: number, returnDistance = false) finds neighbors within given radius.

Example

const tree = new BallTree(X, 2);
const result = tree.query(X.slice(0, 1), 3);