Comparison of 2nd and 4th Order Discretizations
for Multigrid Poisson Solvers

Murli M. Gupta, Jules Kouatchou, and Jun Zhang
Department of Mathematics
The George Washington University
Washington, DC 20052, USA


We combine a compact high-order difference approximation with multigrid V-cycle algorithm to solve the two dimensional Poisson equation with Dirichlet boundary conditions. This scheme, along with several different orderings of grid space and projection operators, is compared with the five-point formula to show the dramatic improvement in computed accuracy, on serial and vector machines.

Contributed December 22, 1995.