A Local Fourier Extension Method for Function Approximation

Abstract: This paper presents a novel localized Fourier extension method for approximating non-periodic functions through domain segmentation. By subdividing the computational domain into subregions and employing uniform discretization scales, the method achieves spectral accuracy with $\mathcal{O}(M)$ computational complexity. Theoretical error bounds and parameter dependency analyses validate the robustness of the proposed method. The relationship among the key parameters involved is analytically established, accompanied by an optimized parameter selection strategy. Numerical experiments further verify the effectiveness of the proposed method.