<div class="gmail_quote">On Fri, Oct 14, 2011 at 09:09, behzad baghapour <span dir="ltr"><<a href="mailto:behzad.baghapour@gmail.com">behzad.baghapour@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":p0">1- If I set BAIJ for Mat, then the ILU preconditoner automatically recognize to use Block-version of ILU preconditioners? (like VBILUM developed by Saad and coworkers) or I should do more for Block preconditioning?<br>
</div></blockquote><div><br></div><div>Yes, block ILU, block SOR, etc.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div id=":p0">
<br>2- "the block size is the same the matrix block size" means that there is no way to combine the matrix elements to build blocks of possible maximum size like Hash method or something like this?</div></blockquote>
</div><br><div>For AIJ, there are "Inodes" which automatically detect identical rows where blocking can be used. This helps more or less, depending on the hardware. There is no such thing for BAIJ, but it wouldn't offer much improvement in memory performance anyway. BAIJ performance approaches dense mat-vec as long as the ordering is such that the vector can be reused.</div>