K functionals and best polynomial approximation in weighted Lp(R)
نویسندگان
چکیده
منابع مشابه
Best Approximation in TVS
In this paper we give newresults on the best approximation in the Hausdorff topological vectorspace and consider relationship with orthogonality. Also we determined under what conditions the map $P_{K,f}$ is upper semicontinous.
متن کاملWeighted Polynomial Approximation in the Complex Plane
Given a pair (G,W ) of an open bounded set G in the complex plane and a weight function W (z) which is analytic and different from zero in G, we consider the problem of the locally uniform approximation of any function f(z), which is analytic in G, by weighted polynomials of the form {Wn(z)Pn(z)}n=0, where deg Pn ≤ n. The main result of this paper is a necessary and sufficient condition for suc...
متن کاملWeighted Extremal Domains and Best Rational Approximation
Let f be holomorphically continuable over the complex plane except for finitely many branch points contained in the unit disk. We prove that best rational approximants to f of degree n, in the L2-sense on the unit circle, have poles that asymptotically distribute according to the equilibrium measure on the compact set outside of which f is single-valued and which has minimal Green capacity in t...
متن کاملConstrained polynomial degree reduction in the L2-norm equals best weighted Euclidean approximation of Bézier coefficients
In this paper we show that the best constrained degree reduction of a given Bézier curve f of degree from n to m with Cα−1-continuity at the boundary in L2-norm is equivalent to the best weighted Euclidean approximation of the vector of Bernstein–Bézier (BB) coefficients of f from the vector of degree raised BB coefficients of polynomials of degree m with Cα−1-continuity at the boundary. 2003...
متن کاملCOMPRESSED SENSING AND BEST k-TERM APPROXIMATION
The typical paradigm for obtaining a compressed version of a discrete signal represented by a vector x ∈ R is to choose an appropriate basis, compute the coefficients of x in this basis, and then retain only the k largest of these with k < N . If we are interested in a bit stream representation, we also need in addition to quantize these k coefficients. Assuming, without loss of generality, tha...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Approximation Theory
سال: 1986
ISSN: 0021-9045
DOI: 10.1016/0021-9045(86)90084-5