5 research outputs found
On the use of rational-function fitting methods for the solution of 2D Laplace boundary-value problems
A computational scheme for solving 2D Laplace boundary-value problems using
rational functions as the basis functions is described. The scheme belongs to
the class of desingularized methods, for which the location of singularities
and testing points is a major issue that is addressed by the proposed scheme,
in the context of the 2D Laplace equation. Well-established rational-function
fitting techniques are used to set the poles, while residues are determined by
enforcing the boundary conditions in the least-squares sense at the nodes of
rational Gauss-Chebyshev quadrature rules. Numerical results show that errors
approaching the machine epsilon can be obtained for sharp and almost sharp
corners, nearly-touching boundaries, and almost-singular boundary data. We show
various examples of these cases in which the method yields compact solutions,
requiring fewer basis functions than the Nystr\"{o}m method, for the same
accuracy. A scheme for solving fairly large-scale problems is also presented