2012/03/30 by Christos Boutsidis, Boutsidis, Christos, Alex Gittens +1 · 5 citations
Engineering · Computer Science · #Sparse and Compressive Sensing Techniques #Stochastic Gradient Optimization Techniques #Matrix Theory and Algorithms
paper · pdf · doi:10.48550/arxiv.1204.0062
Several recent randomized linear algebra algorithms rely upon fast dimension\nreduction methods. A popular choice is the Subsampled Randomized Hadamard\nTransform (SRHT). In this article, we address the efficacy, in the Frobenius\nand spectral norms, of an SRHT-based low-rank matrix approximation technique\nintroduced by Woolfe, Liberty, Rohklin, and Tygert. We establish a slightly\nbetter Frobenius norm error bound than currently available, and a much sharper\nspectral norm error bound (in the presence of reasonable decay of the singular\nvalues). Along the way, we produce several results on matrix operations with\nSRHTs (such as approximate matrix multiplication) that may be of independent\ninterest. Our approach builds upon Tropp's in "Improved analysis of the\nSubsampled Randomized Hadamard Transform".\n