On the existence of Optimal Subspace Clustering Models

التفاصيل البيبلوغرافية
العنوان: On the existence of Optimal Subspace Clustering Models
المؤلفون: Aldroubi, Akram, Tessera, Romain
سنة النشر: 2010
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Functional Analysis, Mathematics - Operator Algebras, 68Q32, 46N10, 47N10
الوصف: Given a set of vectors $\F=\{f_1,\dots,f_m\}$ in a Hilbert space $\HH$, and given a family $\CC$ of closed subspaces of $\HH$, the {\it subspace clustering problem} consists in finding a union of subspaces in $\CC$ that best approximates (models) the data $\F$. This problem has applications and connections to many areas of mathematics, computer science and engineering such as the Generalized Principle Component Analysis (GPCA), learning theory, compressed sensing, and sampling with finite rate of innovation. In this paper, we characterize families of subspaces $\CC$ for which such a best approximation exists. In finite dimensions the characterization is in terms of the convex hull of an augmented set $\CC^+$. In infinite dimensions however, the characterization is in terms of a new but related notion of contact hull. As an application, the existence of best approximations from $\pi(G)$-invariant families $\CC$ of unitary representations of abelian groups is derived.
Comment: 13 pages
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/1008.4811
رقم الأكسشن: edsarx.1008.4811
قاعدة البيانات: arXiv