gradient descent meet shift-and-invert preconditioning
Gradient Descent Meets Shift-and-Invert Preconditioning for Eigenvector Computation
Shift-and-invert preconditioning, as a classic acceleration technique for the leading eigenvector computation, has received much attention again recently, owing to fast least-squares solvers for efficiently approximating matrix inversions in power iterations. In this work, we adopt an inexact Riemannian gradient descent perspective to investigate this technique on the effect of the step-size scheme. The shift-and-inverted power method is included as a special case with adaptive step-sizes. Particularly, two other step-size settings, i.e., constant step-sizes and Barzilai-Borwein (BB) step-sizes, are examined theoretically and/or empirically.
Reviews: Gradient Descent Meets Shift-and-Invert Preconditioning for Eigenvector Computation
The main idea is incorporating Nesterov's accelerated gradient descent (AGD) in eigenvalue problem. The approach relies on shift-and-invert preconditioning method that reduces the non-convex objective of Rayleigh quotient to a sequence of convex programs. Shift-and-invert preconditioning improves the convergence dependency of the gradient method to the eigengap of the given matrix. The focus of this paper is using AGD method to approximately solve the convex programs and reaching an accelerated convergence rate for the convex part. Exploiting the accelerated convergence of AGD, they reach an accelerated convergence for the first-order optimization of the eigenvalue problem.
Gradient Descent Meets Shift-and-Invert Preconditioning for Eigenvector Computation
Shift-and-invert preconditioning, as a classic acceleration technique for the leading eigenvector computation, has received much attention again recently, owing to fast least-squares solvers for efficiently approximating matrix inversions in power iterations. In this work, we adopt an inexact Riemannian gradient descent perspective to investigate this technique on the effect of the step-size scheme. The shift-and-inverted power method is included as a special case with adaptive step-sizes. Particularly, two other step-size settings, i.e., constant step-sizes and Barzilai-Borwein (BB) step-sizes, are examined theoretically and/or empirically. Our experimental studies show that the proposed algorithm can be significantly faster than the shift-and-inverted power method in practice.