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</o:shapelayout></xml><![endif]--></head><body lang=DE link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>for help, I have read both algorithms in Saad. My main problem in understanding of the procedure is how the decompose the domain. At the moment I decompose with jacobi block method(without overlapping) and I run on each block LIU(0) in parallel after that I put each solution together for an CG solver. With that my iteration number raises instead of break down, so there must be something wrong </span><span lang=EN-US style='font-size:11.0pt;font-family:Wingdings;color:#1F497D'>J</span><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Perhaps you know the order of the methods? First Jacobi-block then additive-Schwarz then ILU(0) and at least cg loop, or is it another order?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kind regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Jürgen Dürrwang<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Von:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> petsc-users-bounces@mcs.anl.gov [mailto:petsc-users-bounces@mcs.anl.gov] <b>Im Auftrag von </b>Matthew Knepley<br><b>Gesendet:</b> Montag, 6. Juni 2011 09:39<br><b>An:</b> PETSc users list<br><b>Betreff:</b> Re: [petsc-users] Some papers for additive schwarz and blocked jacobi?<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>2011/6/6 Dürrwang, Jürgen <<a href="mailto:Juergen.Duerrwang@iosb.fraunhofer.de">Juergen.Duerrwang@iosb.fraunhofer.de</a>><o:p></o:p></p><div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Hi,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>I am working on a NVIDIA CUDA improved cg solver, with fast preconditioning. Since I have tested PETSC PCJACOBI with ILU(0) on each block I have some nice results. Unfortunately the pc is on CPU, so I try to port them on GPU. Now my question is, has body some material about this PETSC implementation?</span><o:p></o:p></p></div></div></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>The ILU(0) algorithm is described in Yousef Saad's book on Iterative Methods. It is notoriously hard to parallelize.<o:p></o:p></p></div><div><p class=MsoNormal>ASM and Block-Jacobi jsut decompose the system into blocks. They are also described in the book.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal> Matt<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Kind regards,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Jürgen Dürrwang<o:p></o:p></p></div></div></blockquote></div><p class=MsoNormal><br><br clear=all><br>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener<o:p></o:p></p></div></body></html>