<div class="gmail_quote">On Sun, May 1, 2011 at 18:57, Li, Zhisong (lizs) <span dir="ltr"><<a href="mailto:lizs@mail.uc.edu">lizs@mail.uc.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":1dj">For those elliptic Poisson-style equations, the matrix is often non-symmetrical and costly to solve. And it's often mentioned that the incomplete Cholesky conjugate gradient (ICCG) method will be the best choice for handling these problems.<br>
</div></blockquote><div><br></div><div>Hardly. Multigrid is much better for "Poisson-style equations".</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":1dj">
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In Petsc, the ICC preconditioner is only implemented in serial processing. And parallel ICC is not available in other packages such as Hypre.</div></blockquote><div><br></div><div>You can use ILU. It is normally the same, but uses more memory. Note that incomplete factorization tends not to scale very well, so you may want to consider multilevel or domain decomposition methods.</div>
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