Kernkonzepte
This work presents a new algorithm that efficiently computes the matrix exponential within a given tolerance by incorporating Taylor, partitioned, and classical Padé methods, and selecting the most suitable scheme based on the matrix norm and the desired tolerance.
Zusammenfassung
The key highlights and insights of the content are:
- The algorithm computes a bound θ on the norm of the input matrix A, and then selects the most efficient scheme among a list of Taylor and Padé methods to approximate the matrix exponential eA within the given tolerance.
- The algorithm avoids computing matrix inverses when possible, making it convenient for some problems. It also has an option to use only diagonal Padé approximants, which preserve the Lie group structure when A belongs to a Lie algebra.
- The authors analyze an extensive set of Taylor and rational Padé methods, obtain error bounds for a set of tolerances, and select the methods that provide the desired accuracy at the lowest computational cost.
- The authors propose efficient ways to compute higher-order superdiagonal Padé approximants at the same cost as the diagonal ones, leading to more efficient schemes.
- Numerical experiments show the superior performance of the proposed algorithm compared to state-of-the-art implementations.