English

Efficient Computation of the Bergsma-Dassios Sign Covariance

Computation 2015-12-31 v2

Abstract

In an extension of Kendall's τ\tau, Bergsma and Dassios (2014) introduced a covariance measure τ\tau^* for two ordinal random variables that vanishes if and only if the two variables are independent. For a sample of size nn, a direct computation of tt^*, the empirical version of τ\tau^*, requires O(n4)O(n^4) operations. We derive an algorithm that computes the statistic using only O(n2log(n))O(n^2\log(n)) operations.

Keywords

Cite

@article{arxiv.1504.00964,
  title  = {Efficient Computation of the Bergsma-Dassios Sign Covariance},
  author = {Luca Weihs and Mathias Drton and Dennis Leung},
  journal= {arXiv preprint arXiv:1504.00964},
  year   = {2015}
}

Comments

Improved formatting, added reference to R package implementing the algorithm, and added additional experiments