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Local Communication

Example: Jacobi finite difference method
for t = 0 to T-1
  send X(t)(i,j) to each neighbor
  receive from neighbors 
    X(t)(i-1,j), X(t)(i+1,j), 
    X(t)(i,j-1), X(t)(i,j+1)
  compute X(t+1)(i,j)
Easy parallelization, but many iterations.

Improvement: Gauss-Seidel strategy

Elements are updated in a particular order.

(See Foster, Figures 2.4 and 2.5)

Author: Wolfgang Schreiner
Last modification: November 15, 1996