Efficient algorithm for the oscillatory matrix functions
Dongping Li, Xue Wang, Xiuying Zhang
TL;DR
The paper addresses efficient computation of general oscillatory $φ$-functions of a matrix, $φ_l(A)$, which arise in second-order IVPs. It introduces a quadruple-angle formula and a scaling/restoring framework, where $s$ and the Taylor degree $m$ are selected via forward error analysis to guarantee a prescribed tolerance. Core contributions include a stable recurrence-based algorithm, an error-bound analysis, and integration with the Paterson–Stockmeyer method for efficient matrix polynomials. Empirical results demonstrate both numerical stability and improved efficiency over a standard ODE solver in various test scenarios, with publicly available code for replication and further exploration.
Abstract
This paper introduces an efficient algorithm for computing the general oscillatory matrix functions. These computations are crucial for solving second-order semi-linear initial value problems. The method is exploited using the scaling and restoring technique based on a quadruple angle formula in conjunction with a truncated Taylor series. The choice of the scaling parameter and the degree of the Taylor polynomial relies on a forward error analysis. Numerical experiments show that the new algorithm behaves in a stable fashion and performs well in both accuracy and efficiency.
