vix.ing · top · new · best · stats · spec

Sparse Approximate Solutions to Linear Systems

1995/04/01 by B. K. Natarajan · 123 citations
Mathematics · Engineering · Computer Science · #Advanced Optimization Algorithms Research #Sparse and Compressive Sensing Techniques #Computational Geometry and Mesh Generation

paper · doi:10.1137/s0097539792240406

Abstract

The following problem is considered: given a matrix A in \bf Rm× n, (m rows and n columns), a vector b in \bf Rm, and ε > 0, compute a vector x satisfying ‖Ax - b‖2 ≤ ε if such exists, such that x has the fewest number of non-zero entries over all such vectors. It is shown that the problem is NP-hard, but that the well-known greedy heuristic is good in that it computes a solution with at most \lceil 18 Opt(ε/2)‖\bf A+22 ln (‖ b ‖2/ε)\rceil non-zero entries, where Opt(ε/2) is the optimum number of nonzero entries at error ε/2, A is the matrix obtained by normalizing each column of A with respect to the L2 norm, and A+ is its pseudo-inverse.

Citations

Cited by

Related