Sparse coding via a Delaunay triangulation

Abstract: Sparse coding is a technique of representing data as a sparse linear combination of a set of vectors. This representation facilitates computation and analysis of high-dimensional data that is prevalent in many applications. We study sparse coding in the setting where the set of vectors define a unique Delaunay triangulation. We propose a weighted l1 regularizer and show that it provably yields a sparse solution. Further, we show stability of sparse codes using the Cayley-Menger determinant. We make connections to dictionary learning, manifold learning and computational geometry. We discuss an optimization algorithm to learn the sparse codes and optimal set of vectors given a set of data points. Finally, we show numerical experiments to show that the resulting sparse representations give competitive performance in the problem of clustering.  
Date
Location
Carnegie 113
Speaker: Dr. Abiy Tasissa from Tufts University
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