Analyzing Jacobi Iteration
config var n : integer = 512;
direction N = [-1, 0]; S = [ 1, 0];
E = [ 0, 1]; W = [ 0,-1];
[N of R] A := 0.0; [W of R] A := 0.0;
[E of R] A := 0.0; [S of R] A := 1.0;
Temp := (A@N + A@E + A@W + A@S)/4.0;
err := max<< abs(Temp - A);