Zobrazeno 1 - 10
of 22
pro vyhledávání: '"Jeannette Van Iseghem"'
Autor:
Jeannette Van Iseghem
Publikováno v:
Journal of Computational and Applied Mathematics. 219(2):537-550
A function f is considered in the form of its formal series expansion @?"k"="0^~f"kP"k where (P"k)"k"="0^~ denotes a given system of orthogonal polynomials with respect to a measure on the real line. We prove that the denominators, numerators and res
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6751173573cdf1fa3a291b5e37d0482c
Autor:
Ana C. Matos, Jeannette Van Iseghem
Publikováno v:
Journal of Computational and Applied Mathematics. 176:231-258
In this paper, we extend to simultaneous approximation the notion of Frobenius–Padé approximants; we then construct rational approximants for vector functions given by their expansion in an orthogonal series. After giving the definitions and notat
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3d45a26c2e8760a0704561c275b43a5a
https://doi.org/10.1016/j.cam.2004.07.012
https://doi.org/10.1016/j.cam.2004.07.012
Autor:
Jeannette Van Iseghem
Publikováno v:
Linear Algebra and its Applications. 384:21-42
The definition, in previous studies, of vector Stieltjes continued fractions in connection with spectral properties of band operators with intermediate zero diagonals, left unsolved the question of a direct definition of their coefficients in terms o
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::80b13b9c52faa6bfbd6c6469d0e0929d
https://doi.org/10.1016/j.laa.2003.12.032
https://doi.org/10.1016/j.laa.2003.12.032
Autor:
Jeannette Van Iseghem
Publikováno v:
Numerical Algorithms. 33:485-498
The definition, in previous studies, of vector Stieltjes continued fractions in connexion with spectral properties of band operators with intermediate zero diagonals, left unsolved the question of a direct definition of their coefficients in terms of
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2c737bb4dbd6dee6c72f62cca5e2fb3d
https://doi.org/10.1023/a:1025565400379
https://doi.org/10.1023/a:1025565400379
Autor:
Jeannette Van Iseghem
Publikováno v:
Numerical Algorithms. 29:267-279
A method for solving a linear system is defined. It is a Lanczos-type method, but it uses formal vector orthogonality instead of scalar orthogonality. Moreover, the dimension of vector orthogonality may vary which gives a large freedom in leading the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::66d963fd77172ad8fdb9b236b6eeab53
https://doi.org/10.1023/a:1014836728675
https://doi.org/10.1023/a:1014836728675
Autor:
Jeannette Van Iseghem
Publikováno v:
Acta Applicandae Mathematicae. 61:351-365
The aim of this paper is the expansion of a matrix function in terms of a matrix-continued fraction as defined by Sorokin and Van Iseghem. The function under study is the Weyl function or resolvent function of an operator, given in the standard basis
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::816a7e59a0c1dc128e726695f71b2d04
https://doi.org/10.1023/a:1006413306541
https://doi.org/10.1023/a:1006413306541
Autor:
V. N. Sorokin, Jeannette Van Iseghem
Publikováno v:
Journal of Approximation Theory. 96(2):237-257
A matrix continued fraction is defined and used for the approximation of a function F known as a power series in 1/zwith matrix coefficientsp×q, or equivalently by a matrix of functions holomorphic at infinity. It is a generalization of P-fractions,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::86bc05568c54c33462380ff4bfe7f7cf
Autor:
Jeannette Van Iseghem, V. N. Sorokin
Publikováno v:
Journal of Approximation Theory. 90:97-116
An algebraic theory of orthogonality for vector polynomials with respect to a matrix of linear forms is presented including recurrence relations, extension of the Shohat?Favard theorem, of the Christoffel?Darboux formula, and its converse. The connec
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2ee2e065df584afb5fc0a7c9f7be0835
https://doi.org/10.1006/jath.1996.3064
https://doi.org/10.1006/jath.1996.3064
Publikováno v:
Numerical Algorithms. 11:339-351
Approximants are defined for a function which is holomorphic in an annulus. They are shown to have good qualitative properties whenf is meromorphic with a fixed number of poles in the annulus. Their denominators are linked to the reverse orthogonal p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2a68f97d4a8821998975a0cf7d0e3663
https://doi.org/10.1007/bf02142506
https://doi.org/10.1007/bf02142506
Autor:
Jeannette van Iseghem
Publikováno v:
Numerische Mathematik. 68:549-562
A transformation of vectorial sequences is given, analogous to the Shank's transform in the scalar case. This is possible because of the link with the Vector Pad\'e approximants defined for a power series, with vectorial coefficients. Algorithms, dif
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e26da7d93ed8fdddb4972df48aefdbd6
https://doi.org/10.1007/s002110050075
https://doi.org/10.1007/s002110050075