D4 zig-zag (D4Z) is a new renumbering scheme for producing a reduced matrix to be solved by an incomplete LU preconditioned, restarted conjugate-gradient iterative solver. By renumbering alternate diagonals in a zig-zag fashion, a very low sensitivity of convergence rate to renumbering direction is obtained. For two demonstration problems involving groundwater flow and solute transport, iteration counts are related to condition numbers and spectra of the reduced matrices.
Additional publication details
D4Z - a new renumbering for iterative solution of ground-water flow and solute- transport equations
Publ by Computational Mechanics Publ
Southampton, United Kingdom
Larger Work Title:
Finite Elements in Water Resources, Proceedings of the International Conference
Proceedings of the 9th International Conference on Computational Methods in Water Resources