Fast hierarchical clustering from the Baire distance

Abstract

The Baire or longest common prefix ultrametric allows a hierarchy, a multiway tree, or ultrametric topology embedding, to be constructed very efficiently. The Baire distance is a 1-bounded ultrametric. For high dimensional data, one approach for the use of the Baire distance is to base the hierarchy construction on random projections. In this paper we use the Baire distance on the Sloan Digital Sky Survey (SDSS, http://www.sdss.org) archive. We are addressing the regression of (high quality, more costly to collect) spectroscopic and (lower quality, more readily available) photometric redshifts. Nonlinear regression is used for mapping photometric and astrometric redshifts. © Springer-Verlag Berlin Heidelberg 2010.