Persistent cohomology and circular coordinates

  • Authors:
  • Vin de Silva;Mikael Vejdemo-Johansson

  • Affiliations:
  • Pomona College, Claremont, CA, USA;Stanford University, Stanford, CA, USA

  • Venue:
  • Proceedings of the twenty-fifth annual symposium on Computational geometry
  • Year:
  • 2009

Quantified Score

Hi-index 0.00

Visualization

Abstract

Nonlinear dimensionality reduction (NLDR) algorithms such as Isomap, LLE and Laplacian Eigenmaps address the problem of representing high-dimensional nonlinear data in terms of low-dimensional coordinates which represent the intrinsic structure of the data. This paradigm incorporates the assumption that real-valued coordinates provide a rich enough class of functions to represent the data faithfully and efficiently. On the other hand, there are simple structures which challenge this assumption: the circle, for example, is one-dimensional but its faithful representation requires two real coordinates. In this work, we present a strategy for constructing circle-valued functions on a statistical data set. We develop a machinery of persistent cohomology to identify candidates for significant circle-structures in the data, and we use harmonic smoothing and integration to obtain the circle-valued coordinate functions themselves. We suggest that this enriched class of coordinate functions permits a precise NLDR analysis of a broader range of realistic data sets.