Results 281 to 290 of about 57,073,214 (327)

On approximation of functions by p–Faber-Laurent rational functions

open access: yes, 2015
Let G be a doubly connected domain bounded by regular curves. In this work, the approximation of the functions by p–Faber-Laurent rational functions in Smirnov classes (Formula presented.) are studied.
S. Jafarov
semanticscholar   +2 more sources

Approximation by Rational Functions

Journal of the London Mathematical Society, 1977
This paper contains eight theorems on the rational approximation of \(e^{-x}\) . We cite one of them by way of an example: ''Let \(p(x)\) and \(q(x)\) be any polynomials of degress at most \(n-1\) where \(n\geq 2\). Then we have \[ \left\|e^{-x}-\frac{p(x)}{q(x)}\right\|_{l_{\infty}(N)}\geq\frac{(e-1)^ne^{-4n}2^{-7n}}{n(3+2\sqrt2)^{n-1}}.'', \] (\(N ...
Erdős, Paul   +2 more
openaire   +1 more source

Multivariate rational approximation of functions with curves of singularities

arXiv.org, 2023
Functions with singularities are notoriously difficult to approximate with conventional approximation schemes. In computational applications, they are often resolved with low-order piecewise polynomials, multilevel schemes, or other types of grading ...
Nicolas Boulle   +2 more
semanticscholar   +1 more source

Rational functional network for function approximation

2008 3rd International Conference on Intelligent System and Knowledge Engineering, 2008
This paper presents a new functional network which is based on rational function. A learning algorithm of rational functional network is proposed, the learning of functional network parameters use Lagrange multipliers by means of auxiliary function and solving a system of linear equations obtain parameters.
Yongquan Zhou   +3 more
openaire   +1 more source

Matrix Padé Approximation of rational functions

Numerical Algorithms, 1997
This paper on rectangular matrix valued Padé approximation discusses existence and uniqueness issues of left and right approximants as well as certain minimality conditions on the degrees in numerator and denominator matrix polynomials of the approximants.
Celina Pestano-Gabino   +1 more
openaire   +1 more source

ON RATIONAL APPROXIMATION OF ANALYTIC FUNCTIONS

Mathematics of the USSR-Sbornik, 1973
Let E be a regular compact set, and D an arbitrary domain containing E. A constructive characterization is given of the class of functions analytic in D, using best approximation on E by rational functions with a specially chosen sequence of poles. Bibliography: 4 items.
openaire   +2 more sources

Best approximations by rational functions

Mathematical Notes of the Academy of Sciences of the USSR, 1971
Description of a general class of real continuous functions cn a segment Δ of the real line for which a best rational approximation with complex coefficients is not unique.
openaire   +3 more sources

The Rational Approximation of Real Functions

American Journal of Mathematics, 1978
Publisher Summary This chapter discusses the rational approximation of real functions. The chapter is closely related to the classical theory of best uniform approximation of continuous functions by quotients of polynomials. The chapter illustrates that if the function being approximated is the real function f, then its best approximation in P n ( ℭ
openaire   +2 more sources

RATIONAL APPROXIMATION OF ANALYTIC FUNCTIONS

Russian Academy of Sciences. Sbornik Mathematics, 1994
Let \(E\) be an arbitrary compact set in the extended complex plane \(\overline \mathbb{C}\), \(f\) analytic on \(E\), and for any nonnegative integer \(n\) let \(\rho_ n\) denote the uniformly best error of the rational approximation of \(f\) on \(E\), i.e.
openaire   +2 more sources

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