On Min-Max Affine Approximants of Convex or Concave Real-Valued Functions from $$\mathbb R^k$$ , Chebyshev Equioscillation and Graphics

Autor: Steven B. Damelin, David L. Ragozin, Michael Werman
Rok vydání: 2021
Předmět:
Zdroj: Applied and Numerical Harmonic Analysis ISBN: 9783030696368
DOI: 10.1007/978-3-030-69637-5_19
Popis: We study min-max affine approximants of a continuous convex or concave function \(f:\Delta \subseteq \mathbb R^k\xrightarrow {} \mathbb R\), where Δ is a convex compact subset of \(\mathbb R^k\). In the case when Δ is a simplex, we prove that there is a vertical translate of the supporting hyperplane in \(\mathbb R^{k+1}\) of the graph of f at the vertices which is the unique best affine approximant to f on Δ. For k = 1, this result provides an extension of the Chebyshev equioscillation theorem for linear approximants. Our result has interesting connections to the computer graphics problem of rapid rendering of projective transformations.
Databáze: OpenAIRE