Separate HTML for Scripted Foil 31 Decoupling of Even and Odd Grid Point Updates in Basic Jacobi Iteration

Basic HTML version of Foils prepared 8 November 1995

Foil 31 Decoupling of Even and Odd Grid Point Updates in Basic Jacobi Iteration

From CPS615 Module on Iterative PDE Solvers CPS615 Basic Simulation Track for Computational Science -- Fall Semester 95. by Geoffrey C. Fox

There is a minor confusion as shortest wavelength eigensolutions with n = (N-1) has a large eigenvalue whose modulus |lN-1| = l1 (lN-1 = -l1) is equal to that of "difficult" long wavelength case

One would expect it to be damped strongly. This is an artifact of this iteration scheme as even (l = 0, 2, 4 ....) and odd grid points are decoupled

Update of even l points only involves odd l

Update of odd l points only involves even l

We will return to this when we discuss relaxation