ANN_1.1.2(Newest-Vision-2010-1-27)-

代码说明：

  ANN是一个构造数据索引结果的程序，可以实现最近邻、KD树等功能。ANN is designed for data sets that are small enough that the search structure can be stored in main memory (in contrast to approaches from databases that assume that the data resides in secondary storage). Points are assumed to be represented as coordinate vectors of reals (or integers). The distance between two points can be defi ned in many ways. ANN assumes that distances are measured using any class of distance functions called Minkowski metrics. These include the well known Euclidean distance, Manhattan distance, and max distance.(One diffi culty with exact nearest neighbor searching is that for virtually all methods other than brute-force search, the running time or space grows exponentially as a function of dimension. Consequently these methods are often not signifi cantly better than brute-force search, except in fairly small dimensions. )