最近邻搜索（Nearest Neighbor Search）
Name of the problem: nearest neighbors, k nearest neighbors (kNN, k-NN), nearset neighbor search, proximity search, similarity search, approximate nearest neighbors (ANN), range queries, maximal intersection queries, post-office problem, partial match, best match file searching, best match retrieval, sequence nearest neighbors (SNN).
Solution concepts: locality-sensitive hashing (LSH), low-distortion embeddings, k-d trees, kd-trees, metric trees, M-trees, R*-trees, vp-trees, vantage point trees, vantage point forest, multi-vantage point tree, bisector trees, Orchard‘s algorithm, random projections, fixed queries tree, Voronoi tree, BBD-tree, min-wise independent permutations, Burkhard-Keller tree, generalized hyperplane tree, geometric near-neighbor access tree (GNAT), approximating eliminating search algorithm (AESA), inverted index, spatial approximation tree (SAT).
Applications: k-nearest neighbor classification algorithm, image similarity identification, audio similarity identification, fingerprint search, audio/video compression (MPEG), optical character recognition, coding theory, function approximation, recommendation systems, near-duplicate detection, targeting on-line ads, distributional similarity computation, spelling correction, nearest neighbor interpolation.
1.K近邻搜索、近似近邻搜索
2.k-d树
3.R树
参考文献：
1. http://www.cnblogs.com/breakinen/archive/2012/03/31/bigdata_nearest_neighbor_search.html?utm_source=tuicool&utm_medium=referral
2. http://www.cnblogs.com/v-July-v/archive/2012/11/20/3125419.html
3. http://blog.sina.com.cn/s/blog_72e1c7550101dsc3.html
https://en.wikipedia.org/wiki/Nearest_neighbor_search#Approximate_nearest_neighbor