Fast Poisson solvers
15.1 TST matrices and the Hockney method
This chapter is concerned with yet another approach to the solution of the linear equations that occur when the Poisson equation is discretized by finite differences. This approach is an alternative to the direct methods of Chapter 11 and to the iterative schemes of Chapters 12–14. We intend to present two techniques for the very fast approximation of ∇2u = f, one in a rectangle and the other in a disc. These techniques share two features. Firstly, they originate in numerical solution ...