Short note on the mass matrix for Gauss-Lobatto grid points

JOURNAL OF COMPUTATIONAL PHYSICS

卷:283

Article

Teukolsky, Saul A.^1,2 

[1] Cornell Univ, Dept Phys, Ithaca, NY 14853 USA

[2] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA

关键词: Mass matrix;    Gauss-Lobatto quadrature;    Spectral methods;    Discontinuous Galerkin methods;    Finite element methods;   

DOI  :  10.1016/j.jcp.2014.12.012

来源: Elsevier

【 摘 要 】

The mass matrix for Gauss-Lobatto grid points is usually approximated by Gauss-Lobatto quadrature because this leads to a diagonal matrix that is easy to invert. The exact mass matrix and its inverse are full. We show that the exact mass matrix and its inverse differ from the approximate diagonal ones by a simple rank-1 update (outer product). They can thus be applied to an arbitrary vector in 0(N) operations instead of 0(N-2). (C) 2014 Elsevier Inc. Allrightsreserved.

【 授权许可】

Free