Abstract

. We present a new data structure, called the fixed-queries tree, for the problem of finding all elements of a fixed set that are close, under some distance function, to a query element. Fixedqueries trees can be used for any distance function, not necessarily even a metric, as long as it satisfies the triangle inequality. We give an analysis of several performance parameters of fixed-queries trees and experimental results that support the analysis. Fixed-queries trees are particularly efficient for applications in which comparing two elements is expensive. 1 Introduction Search structures such as hashing and trees are at the basis of many efficient computer science applications. But they usually support only exact queries. Finding things approximately, that is, allowing some errors in the query specifications, is much harder. The first question that a prominent biologist once asked one of the authors when finding that he is a computer scientist is whether it is possible to adapt bina...

Citations