{ "id": "1611.02785", "version": "v1", "published": "2016-11-09T00:48:19.000Z", "updated": "2016-11-09T00:48:19.000Z", "title": "Numerical Integration over the Unit Sphere by using spherical t-design", "authors": [ "Congpei An", "Siyong Chen" ], "categories": [ "math.NA" ], "abstract": "This paper studies numerical integration over the unit sphere $ \\mathbb{S}^2 \\subset \\mathbb{R}^{3} $ by using spherical $t$-design, which is an equal positive weights quadrature rule with polynomial precision $t$. We investigate two kinds of spherical $t$-designs with $t$ up to 160. One is well conditioned spherical $t$-design(WSTD), which was proposed by [1] with $ N=(t+1)^{2} $. The other is efficient spherical $t$-design(ESTD), given by Womersley [2], which is made of roughly of half cardinality of WSTD. Consequently, a series of persuasive numerical evidences indicates that WSTD is better than ESTD in the sense of worst-case error in Sobolev space $ \\mathbb{H}^{s}(\\mathbb{S}^2) $. Furthermore, WSTD is employed to approximate integrals of various of functions, especially including integrand has a point singularity over the unit sphere and a given ellipsoid. In particular, to deal with singularity of integrand, Atkinson's transformation [3] and Sidi's transformation [4] are implemented with the choices of `grading parameters' to obtain new integrand which is much smoother. Finally, the paper presents numerical results on uniform errors for approximating representive integrals over sphere with three quadrature rules: Bivariate trapezoidal rule, Equal area points and WSTD.", "revisions": [ { "version": "v1", "updated": "2016-11-09T00:48:19.000Z" } ], "analyses": { "subjects": [ "65D30" ], "keywords": [ "unit sphere", "spherical t-design", "equal positive weights quadrature rule", "bivariate trapezoidal rule", "paper studies numerical integration" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }