creators_name: Elliott, D
creators_name: Johnston, PR
creators_id: David.Elliott@utas.edu.au
creators_id: 
type: article
datestamp: 2008-04-07 14:06:23
lastmod: 2008-07-18 10:45:58
metadata_visibility: show
title: Error analysis for a sinh transformation used in evaluating nearly singular boundary element integrals
ispublished: pub
subjects: 230107
full_text_status: restricted
keywords: Numerical integration; Boundary element method; Nearly singular integrals; Nonlinear coordinate transformation; Sinh function
abstract: In the two-dimensional boundary element method, one often needs to evaluate numerically integrals of the form  where j2 is a quadratic, g is a polynomial and f is a rational, logarithmic or algebraic function with a singularity at zero. The constants a and b are such that -1a1 and 0<b1 so that the singularities of f will be close to the interval of integration. In this case the direct application of Gauss–Legendre quadrature can give large truncation errors. By making the transformation x=a+bsinh(μu-η), where the constants μ and η are chosen so that the interval of integration is again [-1,1], it is found that the truncation errors arising, when the same Gauss–Legendre quadrature is applied to the transformed integral, are much reduced. The asymptotic error analysis for Gauss–Legendre quadrature, as given by Donaldson and Elliott [A unified approach to quadrature rules with asymptotic estimates of their remainders, SIAM J. Numer. Anal. 9 (1972) 573–602], is then used to explain this phenomenon and justify the transformation.
date: 2007
date_type: published
publication: Journal of Computational and Applied Mathematics
volume: 203
number: 1
publisher: Elsevier Science BV
pagerange: 103-124
id_number: 10.1016/j.cam.2006.03.012
refereed: TRUE
issn: 0377-0427
official_url: http://dx.doi.org/10.1016/j.cam.2006.03.012
citation: Elliott, D and Johnston, PR (2007) Error analysis for a sinh transformation used in evaluating nearly singular boundary element integrals. Journal of Computational and Applied Mathematics, 203 (1). pp. 103-124. ISSN 0377-0427
document_url: http://eprints.utas.edu.au/3780/1/52999.pdf