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Best L 1 approximation of Heaviside-type functions from Chebyshev and weak-Chebyshev spaces

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Abstract

In this article, we study the problem of best L 1 approximation of Heaviside-type functions from Chebyshev and weak-Chebyshev spaces. We extend the Hobby-Rice theorem (Proc. Am. Math. Soc., 16, 665–670, 1965) into an appropriate framework and prove the unicity of best L 1 approximation of Heaviside-type functions from an even-dimensional Chebyshev space under some assumptions on the dimension of the subspaces composed of the odd and even functions. We also apply the results to compute best L 1 approximations of Heaviside-type functions by polynomials and Hermite polynomial splines with fixed knots.

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Gajny, L., Gibaru, O., Nyiri, E. et al. Best L 1 approximation of Heaviside-type functions from Chebyshev and weak-Chebyshev spaces. Numer Algor 75, 827–843 (2017). https://doi.org/10.1007/s11075-016-0222-8

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  • DOI: https://doi.org/10.1007/s11075-016-0222-8

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