For w=1/2, one has |
x(k+1) =1/2[x(k) + x(k+1 ) ] where J denotes Pure Jacobi |
and subscript JOR stands for Jacobi Over Relaxation again |
This has "update" matrix in two dimensions |
xpoint = 1/2 xpoint + 1/8 times x of four neighbors |
We now "couple" even and odd grid points which were decoupled in original Jacobi |
Corresponding eigenvalue of most rapidly varying eigenfunction is |
now lJOR|min ~ 0 |
not lJOR|min ~ -1 as before |