English

Normalized Information Distance is Not Semicomputable

Computational Complexity 2010-06-17 v1 Computer Vision and Pattern Recognition Data Analysis, Statistics and Probability

Abstract

Normalized information distance (NID) uses the theoretical notion of Kolmogorov complexity, which for practical purposes is approximated by the length of the compressed version of the file involved, using a real-world compression program. This practical application is called 'normalized compression distance' and it is trivially computable. It is a parameter-free similarity measure based on compression, and is used in pattern recognition, data mining, phylogeny, clustering, and classification. The complexity properties of its theoretical precursor, the NID, have been open. We show that the NID is neither upper semicomputable nor lower semicomputable.

Keywords

Cite

@article{arxiv.1006.3275,
  title  = {Normalized Information Distance is Not Semicomputable},
  author = {Sebastiaan A. Terwijn and Leen Torenvliet and Paul M. B. Vitanyi},
  journal= {arXiv preprint arXiv:1006.3275},
  year   = {2010}
}

Comments

9 pages, LaTeX, No figures, To appear in J. Comput. Syst. Sci

R2 v1 2026-06-21T15:37:16.520Z