# Package org.apache.ignite.ml.knn.utils.indices

- Interface Summary
  Interface | Description
  --- | ---
  SpatialIndex<L> | An index that works with spatial data and allows to quickly find `k` closest element.

- Class Summary
  Class | Description
  --- | ---
  ArraySpatialIndex<L> | Array based implementation of `SpatialIndex`.
  BallTreeSpatialIndex<L> | Ball tree based implementation of `SpatialIndex`.
  KDTreeSpatialIndex<L> | KD tree based implementation of `SpatialIndex`.

- Enum Summary
  Enum | Description
  --- | ---
  SpatialIndexType | Spatial index type.

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Ignite Database and Caching Platform | : ver. 2.9.1
Release Date | : December 9 2020