A monotone block coordinate descent method for solving absolute value equations
Tingting Luo, Jiayu Liu, Cairong Chen, Qun Wang
TL;DR
The paper tackles solving the absolute value equation $A x - |x| = b$, a problem linked to generalized AVEs and known to be challenging. It introduces a monotone block coordinate descent algorithm (BCDA) that minimizes the auxiliary function $f(x)=x^T A x - |x|^T x - 2 b^T x$ along pairs of coordinate directions, providing closed-form step updates and ensuring monotone descent. With $A-I \succ 0$, BCDA is proven to converge to the AVE solution via level-set compactness and descent arguments, improving upon prior nonmonotone methods. Numerical experiments show BCDA's monotone convergence and superior performance against MGSM in SPD and certain non-SPD scenarios, highlighting its practical efficacy for AVE solving in numerical optimization.
Abstract
In this paper, we proposed a monotone block coordinate descent method for solving absolute value equation (AVE). Under appropriate conditions, we analyzed the global convergence of the algorithm and conduct numerical experiments to demonstrate its feasibility and effectiveness.
