Error-functions in double-sided Taylor's approximations

One-sided Band-limited Approximations of Some Radial Functions

We construct majorants and minorants of a Gaussian function in Euclidean space that have Fourier transforms supported in a box. The majorants that we construct are shown to be extremal and our minorants are shown to be asymptotically extremal as the sides of the box become uniformly large. We then adapt the Distribution and Gaussian Subordination methods of [12] to the multidimensional setting ...

One - sided Versus Two - sided Error in

Asymptotic error expansion of wavelet approximations of smooth functions II

We generalize earlier results concerning an asymptotic error expansion of wavelet approximations. The properties of the monowavelets, which are the building blocks for the error expansion, are studied in more detail, and connections between spline wavelets and Euler and Bernoulli polynomials are pointed out. The expansion is used to compare the error for different wavelet families. We prove tha...

Error bounds for GMLS derivatives approximations of Sobolev functions

This paper provides the error estimates for generalized moving least squares (GMLS) derivatives approximations of a Sobolev function in L norms and extends them for local weak forms of DMLPG methods. Sometimes they are called diffuse or uncertain derivatives, but precisely they are direct approximants of exact derivatives which possess the optimal rates of convergence. GMLS derivatives approxim...

Error Bounds for Lanczos Approximations of Rational Functions of Matrices

Having good estimates or even bounds for the error in computing approximations to expressions of the form f(A)v is very important in practical applications. In this paper we consider the case that A is Hermitian and that f is a rational function. We assume that the Lanczos method is used to compute approximations for f(A)v and we show how to obtain a posteriori upper and lower bounds on the `2-...