Reconstruction of Piecewise Smooth Functions Based on Fourier Extension

This paper proposes a hierarchical Fourier extension framework for the accurate reconstruction of piecewise smooth functions with mixed-order singularities. To address key challenges in spectral approximation–namely boundary-induced artifacts, instability in edge detection, and loss of accuracy near...

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Main Authors: Xusheng Li, Zhenyu Zhao, Xianzheng Jia
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Axioms
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Online Access:https://www.mdpi.com/2075-1680/14/7/489
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author Xusheng Li
Zhenyu Zhao
Xianzheng Jia
author_facet Xusheng Li
Zhenyu Zhao
Xianzheng Jia
author_sort Xusheng Li
collection DOAJ
description This paper proposes a hierarchical Fourier extension framework for the accurate reconstruction of piecewise smooth functions with mixed-order singularities. To address key challenges in spectral approximation–namely boundary-induced artifacts, instability in edge detection, and loss of accuracy near discontinuities–the method integrates three main components: (1) boundary-focused Fourier extensions that isolate endpoint effects while preserving internal structures; (2) a multi-stage edge detection strategy combining spectral mollifiers and coordinate transformations to identify discontinuities in function values and their derivatives; (3) adaptive domain partitioning followed by localized Fourier extensions to retain spectral accuracy on smooth segments. Numerical results demonstrate near machine-precision accuracy (∼10<sup>−14</sup>–10<sup>−15</sup>) with significantly improved stability and performance over traditional global methods.
format Article
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institution DOAJ
issn 2075-1680
language English
publishDate 2025-06-01
publisher MDPI AG
record_format Article
series Axioms
spelling doaj-art-614e89586acc40e683ddb3518eef09e12025-08-20T02:45:33ZengMDPI AGAxioms2075-16802025-06-0114748910.3390/axioms14070489Reconstruction of Piecewise Smooth Functions Based on Fourier ExtensionXusheng Li0Zhenyu Zhao1Xianzheng Jia2School of Mathematics and Statistics, Shandong University of Technology, Zibo 255049, ChinaSchool of Mathematics and Statistics, Shandong University of Technology, Zibo 255049, ChinaSchool of Mathematics and Statistics, Shandong University of Technology, Zibo 255049, ChinaThis paper proposes a hierarchical Fourier extension framework for the accurate reconstruction of piecewise smooth functions with mixed-order singularities. To address key challenges in spectral approximation–namely boundary-induced artifacts, instability in edge detection, and loss of accuracy near discontinuities–the method integrates three main components: (1) boundary-focused Fourier extensions that isolate endpoint effects while preserving internal structures; (2) a multi-stage edge detection strategy combining spectral mollifiers and coordinate transformations to identify discontinuities in function values and their derivatives; (3) adaptive domain partitioning followed by localized Fourier extensions to retain spectral accuracy on smooth segments. Numerical results demonstrate near machine-precision accuracy (∼10<sup>−14</sup>–10<sup>−15</sup>) with significantly improved stability and performance over traditional global methods.https://www.mdpi.com/2075-1680/14/7/489Fourier seriesFourier extensionGibbs phenomenonpiecewise smooth functions
spellingShingle Xusheng Li
Zhenyu Zhao
Xianzheng Jia
Reconstruction of Piecewise Smooth Functions Based on Fourier Extension
Axioms
Fourier series
Fourier extension
Gibbs phenomenon
piecewise smooth functions
title Reconstruction of Piecewise Smooth Functions Based on Fourier Extension
title_full Reconstruction of Piecewise Smooth Functions Based on Fourier Extension
title_fullStr Reconstruction of Piecewise Smooth Functions Based on Fourier Extension
title_full_unstemmed Reconstruction of Piecewise Smooth Functions Based on Fourier Extension
title_short Reconstruction of Piecewise Smooth Functions Based on Fourier Extension
title_sort reconstruction of piecewise smooth functions based on fourier extension
topic Fourier series
Fourier extension
Gibbs phenomenon
piecewise smooth functions
url https://www.mdpi.com/2075-1680/14/7/489
work_keys_str_mv AT xushengli reconstructionofpiecewisesmoothfunctionsbasedonfourierextension
AT zhenyuzhao reconstructionofpiecewisesmoothfunctionsbasedonfourierextension
AT xianzhengjia reconstructionofpiecewisesmoothfunctionsbasedonfourierextension