Abstract
It is known that iff∈Wkp, thenωm(f,t)p≤tω m-1(f′,t)p≤.... Its inverse with any constants independent offis not true in general. Hu and Yu proved that the inverse holds true for splinesSwith equally spaced knots, thusωm(S,t)p~tωm-1(S′,t) p~t2ωm-2(S″,t)p.... In this paper, we extend their results to splines with any given knot sequence, and further to principal shift-invariant spaces and wavelets under certain conditions. Applications are given at the end of the paper.
Original language | English |
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Pages (from-to) | 282-293 |
Number of pages | 12 |
Journal | Journal of Approximation Theory |
Volume | 97 |
Issue number | 2 |
DOIs | |
State | Published - Apr 1999 |
Scopus Subject Areas
- Analysis
- Numerical Analysis
- General Mathematics
- Applied Mathematics
Keywords
- Modulus of smoothness; splines; shift-invariant spaces; wavelets; degree of approximation; convex approximation