Abstract
The order of positive and copositive spline approximation in the Lp-norm, 1 ≤ p < ∞, is studied; the main results are 1. (1) the error of positive approximation by splines is bounded by Cω2(f, 1 n)p if f has a nonnegative extension; 2. (2) the order deteriorates to ω1 if f does not have such an extension; 3. (3) the error of copositive spline approximation is bounded by Cω(f, 1 n)p; 4. (4) if f is also continuous, the error in (3) can be estimated in terms of the third τ-modulus τ3(f, 1 n)p. All constants in the error bounds are absolute.
Original language | English |
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Pages (from-to) | 137-146 |
Number of pages | 10 |
Journal | Computers and Mathematics with Applications |
Volume | 30 |
Issue number | 3-6 |
DOIs | |
State | Published - Sep 1995 |
Keywords
- Constrained approximation in L space
- Degree of copositive approximation
- Polynomial approximation
- Spline approximation