A note on rational Lp approximation
نویسندگان
چکیده
منابع مشابه
Discrete Rational Lp Approximation
In this paper, the problem of approximating a function defined on a finite subset of the real line by a family of generalized rational functions whose numerator and denominator spaces satisfy the Haar conditions on some closed interval [a, b] containing the finite set is considered. The pointwise closure of the family restricted to the finite set is explicitly determined. The representation obt...
متن کاملA Note on Approximation by Rational Functions
The theory of the approximation by rational functions on point sets E of the js-plane (z = x+iy) has been summarized by J. L. Walsh who himself has proved a great number of important theorems some of which are fundamental. The results concern both the case when E is bounded and when E extends to infinity. In the present note a Z^-theory (0<p< oo) will be given for the following point sets exten...
متن کاملA Note on Complexity of Lp Minimization
We show that the Lp (0 ≤ p < 1) minimization problem arising from sparse solution construction and compressed sensing is both hard and easy. More precisely, for any fixed 0 < p < 1, we prove that checking the global minimal value of the problem is NP-Hard; but computing a local minimizer of the problem is polynomialtime doable. We also develop an interior-point algorithm with a provable complex...
متن کاملA Note on Belief Structures and S-approximation Spaces
We study relations between evidence theory and S-approximation spaces. Both theories have their roots in the analysis of Dempsterchr('39')s multivalued mappings and lower and upper probabilities, and have close relations to rough sets. We show that an S-approximation space, satisfying a monotonicity condition, can induce a natural belief structure which is a fundamental block in evidence theory...
متن کاملA note on Diophantine approximation
Given a set of nonnegative real numbers Λ= {λi}i=0, a Λ-polynomial (or Müntz polynomial) is a function of the form p(x)=ni=0 aizi (n∈N). We denote byΠ(Λ) the space of Λ-polynomials and byΠZ(Λ) := {p(x)=ni=0 aizi ∈Π(λ) : ai ∈ Z for all i≥ 0} the set of integral Λ-polynomials. Clearly, the sets ΠZ(Λ) are subgroups of infinite rank of Z[x] wheneverΛ⊂N, #Λ=∞ (by infinite rank, wemean that the real ...
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: 1978
ISSN: 0021-9045
DOI: 10.1016/0021-9045(78)90108-9