The conference "approximation and extrapolation of convergent and divergentsequences and series" discusses some very old problems of mathematical analysis and modern approaches for their solution based on s...
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The conference "approximation and extrapolation of convergent and divergentsequences and series" discusses some very old problems of mathematical analysis and modern approaches for their solution based on so-called nonlinear sequence transformations. In spite of all the advances in computer hard and software, slowly convergent or divergentsequences and series are still annoying obstacles not only in mathematics, but in particular also in other mathematically oriented disciplines. This articles tries to give a highly condensed survey of the topics treated at this conference. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.
The conference "approximation and extrapolation of convergent and divergentsequences and series" discusses some very old problems of mathematical analysis and modern approaches for their solution based on s...
详细信息
The conference "approximation and extrapolation of convergent and divergentsequences and series" discusses some very old problems of mathematical analysis and modern approaches for their solution based on so-called nonlinear sequence transformations. In spite of all the advances in computer hard and software, slowly convergent or divergentsequences and series are still annoying obstacles not only in mathematics, but in particular also in other mathematically oriented disciplines. This articles tries to give a highly condensed survey of the topics treated at this conference. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.
The purpose of this paper is to tell how continued fraction expansions of functions are derived, how they relate to Pade approximation, and how they can improve Pade approximants. (C) 2010 IMACS. Published by Elsevier...
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The purpose of this paper is to tell how continued fraction expansions of functions are derived, how they relate to Pade approximation, and how they can improve Pade approximants. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.
The paper reviews the relation between Pade-type approximants of a power series and interpolatory quadrature formulae with free nodes, and between Pade approximants and Gaussian quadrature methods. Then, it is shown h...
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The paper reviews the relation between Pade-type approximants of a power series and interpolatory quadrature formulae with free nodes, and between Pade approximants and Gaussian quadrature methods. Then, it is shown how the Kronrod procedure and the anti-Gaussian quadrature methods could be used for estimating the error in Pade approximation. The epsilon-algorithm for accelerating the convergence of sequences, and computing recursively Parte approximants is evoked, and its error estimated by the same procedures. Finally, the case of series of functions is considered. Considerations on further research topics end the paper. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.
The purpose of this paper is to tell how continued fraction expansions of functions are derived, how they relate to Pade approximation, and how they can improve Pade approximants. (C) 2010 IMACS. Published by Elsevier...
详细信息
The purpose of this paper is to tell how continued fraction expansions of functions are derived, how they relate to Pade approximation, and how they can improve Pade approximants. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.
Factorial series played a major role in Stirling's classic book Methodus Differentialis (1730), but now only a few specialists still use them. This article wants to show that this neglect is unjustified, and that ...
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Factorial series played a major role in Stirling's classic book Methodus Differentialis (1730), but now only a few specialists still use them. This article wants to show that this neglect is unjustified, and that factorial series are useful numerical tools for the summation of divergent (inverse) power series. This is documented by summing the divergent asymptotic expansion for the exponential integral E-1 (z) and the factorially divergent Rayleigh-Schrodinger perturbation expansion for the quartic anharmonic oscillator. Stirling numbers play a key role since they occur as coefficients in expansions of an inverse power in terms of inverse Pochhammer symbols and vice versa. It is shown that the relationships involving Stirling numbers are special cases of more general orthogonal and triangular transformations. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.
The paper reviews the relation between Pade-type approximants of a power series and interpolatory quadrature formulae with free nodes, and between Pade approximants and Gaussian quadrature methods. Then, it is shown h...
详细信息
The paper reviews the relation between Pade-type approximants of a power series and interpolatory quadrature formulae with free nodes, and between Pade approximants and Gaussian quadrature methods. Then, it is shown how the Kronrod procedure and the anti-Gaussian quadrature methods could be used for estimating the error in Pade approximation. The epsilon-algorithm for accelerating the convergence of sequences, and computing recursively Parte approximants is evoked, and its error estimated by the same procedures. Finally, the case of series of functions is considered. Considerations on further research topics end the paper. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.
The 2 transformation, introduced recently by Wozny and Nowak, may serve as a good tool for summation of slowly convergence series. This approach can be easily applied to the case of generalized or basic hypergeometric...
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The 2 transformation, introduced recently by Wozny and Nowak, may serve as a good tool for summation of slowly convergence series. This approach can be easily applied to the case of generalized or basic hypergeometric series, as well as some orthogonal polynomial expansions. It is closely related to the famous Wynn's epsilon algorithm. Weniger's or Homeier's transformations, and the method introduced by Cizek, Zamastil and Skala. However, it is difficult to use the algorithm proposed by Woiny and Nowak in the general case, because of its high complexity, and some other restrictions. We propose another realization of the 2 transformation, which results in obtaining a simpler and faster algorithm. Four illustrative numerical examples are given. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.
Sequence transformations are important tools for the convergence acceleration of slowly convergent scalar sequences or series and for the summation of divergentseries. The basic idea is to construct from a given sequ...
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Sequence transformations are important tools for the convergence acceleration of slowly convergent scalar sequences or series and for the summation of divergentseries. The basic idea is to construct from a given sequence {{s(n)}} a new sequence {{s(n)'}} = T({{s(n)}}) where each s(n)' depends on a finite number of elements s(n1), ..., s(nm). Often, the s(n) are the partial sums of an infinite series. The aim is to find transformations such that {{s(n)'}} converges faster than (or sums) {{s(n)}}. Transformations T{{s(n)}}, {{w(n)}}) that depend not only on the sequence elements or partial sums s(n) but also on an auxiliary sequence of the so-called remainder estimates w(n) are of Levin-type if they are linear in the s(n), and nonlinear in the w(n). Such remainder estimates provide an easy-to-use possibility to use asymptotic information on the problem sequence for the construction of highly efficient sequence transformations. As shown first by Levin, it is possible to obtain such asymptotic information easily for large classes of sequences in such a way that the w(n) are simple functions of a few sequence elements s(n). Then, nonlinear sequence transformations are obtained. Special cases of such Levin-type transformations belong to the most powerful currently known extrapolation methods for scalar sequences and series. Here, we review known Levin-type sequence transformations and put them in a common theoretical framework. It is discussed how such transformations may be constructed by either a model sequence approach or by iteration of simple transformations. As illustration, two new sequence transformations are derived. Common properties and results on convergence acceleration and stability are given. For important special cases, extensions of the general results are presented. Also, guidelines for the application of Levin-type sequence transformations are discussed, and a few numerical examples are given. (C) 2000 Elsevier Science B.V. All rights reserved. MSC: 65
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