Some ideas Basic Principles 1. Multigrid is an iterative method a good initial guess will reduce the number of iterations to solve An Wh= fn by iteration, we could take un w2h, Where Azh W2h= f2h but the number of iterations needed to solve An uh= fn still O(n2) SMA-HPC⊙2003MT Iterative Methods: Multigrid Techniques 2