<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Perfect,<div class=""><br class=""></div><div class="">Thank you a lot,</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Sonia<br class=""><div class="">
<div style="letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);">Ph.D. Student</font></div><div class="" style="margin: 0px;"><font color="#6f6f6f" class="">Group of Prof. Rolf Krause</font></div><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);"><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);">Institute of Computational Science</font></div><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);">Università della Svizzera italiana</font></div></font></div><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);">Center for Computation Medicine in Cardiology</font></div><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><span style="color: rgb(111, 111, 111);" class="">Via Giuseppe Buffi, 13</span></div><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);">CH-6900 Lugano</font></div><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);">Switzerland</font></div><div class="" style="color: rgb(111, 111, 111); margin: 0px; line-height: normal; min-height: 12px;"><br class=""></div><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);">Email:<span class="Apple-converted-space"> </span><a href="mailto:pozzis@usi.ch" class="">pozzis@usi.ch</a> </font></div><div class="" style="color: rgb(0, 0, 0); margin: 0px;"><font face="Helvetica" color="#6f6f6f" class="" style="line-height: normal; color: rgb(111, 111, 111);">Phone: </font><span style="color: rgb(111, 111, 111);" class="">+41 58 666 4972</span></div></div></div>
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<br class=""><div style=""><blockquote type="cite" class=""><div class="">On 14 Mar 2018, at 16:00, Matthew Knepley <<a href="mailto:knepley@gmail.com" class="">knepley@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><div class="gmail_extra"><div class="gmail_quote">On Wed, Mar 14, 2018 at 11:21 PM, Sonia Pozzi<span class="Apple-converted-space"> </span><span dir="ltr" class=""><<a href="mailto:sonia.pozzi@usi.ch" target="_blank" class="">sonia.pozzi@usi.ch</a>></span><span class="Apple-converted-space"> </span>wrote:<br class=""><blockquote class="gmail_quote" style="margin: 0px 0px 0px 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex;"><div style="word-wrap: break-word;" class="">Dear Barry,<div class=""><br class=""></div><div class="">thank you for the answer. That helped a lot. Just a second curiosity. </div><div class="">I’m setting A00 to be solved with preonly+lu. I obtain the following</div><div class=""><div style="margin: 0px; font-size: 13px; line-height: normal; font-family: 'Andale Mono'; color: rgb(41, 249, 20); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures;" class="">ksp_0 KSPGetTotalIterations: 26</span></div><div style="margin: 0px; font-size: 13px; line-height: normal; font-family: 'Andale Mono'; color: rgb(41, 249, 20); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures;" class="">ksp_1 KSPGetTotalIterations: 22</span></div><div style="margin: 0px; font-size: 13px; line-height: normal; font-family: 'Andale Mono'; color: rgb(41, 249, 20); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures;" class="">Residual ksp_0: 0 Reason ksp_0: 4</span></div><div style="margin: 0px; font-size: 13px; line-height: normal; font-family: 'Andale Mono'; color: rgb(41, 249, 20); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures;" class="">Solution ksp_0 : Convergence in 1 iterations.</span></div><div style="margin: 0px; font-size: 13px; line-height: normal; font-family: 'Andale Mono'; color: rgb(41, 249, 20); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures;" class="">Residual ksp_1: 5.23074e-14 Reason ksp_1: 2</span></div><div style="margin: 0px; font-size: 13px; line-height: normal; font-family: 'Andale Mono'; color: rgb(41, 249, 20); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures;" class="">Solution ksp_1 : Convergence in 11 iterations.</span></div><div style="margin: 0px; font-size: 13px; line-height: normal; font-family: 'Andale Mono'; color: rgb(41, 249, 20); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures;" class="">Initial system linear residual: 9.904804e-09 </span></div></div><div class=""><br class=""></div><div class="">To me is clear that kps_0 iterations number is equal to 22*1+2*2. </div><div class="">But why is the iterations number for the schur complement multiplied by two?</div><div class="">I’m giving the mass matrix as a preconditioner for the schur complement.</div></div></blockquote><div class=""><br class=""></div><div class="">Possible cause:</div><div class=""><br class=""></div><div class=""> The preconditioner is applied once before the solve happens in order to compute the preconditioned initial residual. Then</div><div class=""> if you do just one iterate in the solve, you would have two applications of the preconditioner.</div><div class=""><br class=""></div><div class=""> Thanks,</div><div class=""><br class=""></div><div class=""> Matt</div><div class=""> </div><blockquote class="gmail_quote" style="margin: 0px 0px 0px 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex;"><div style="word-wrap: break-word;" class=""><div class="">Sonia</div><div class=""><span class=""><br class=""><div class=""><div style="letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; word-wrap: break-word;" class=""><div style="letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; word-wrap: break-word;" class=""><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class="">Ph.D. Student</font></div><div style="margin: 0px;" class=""><font color="#6f6f6f" class="">Group of Prof. Rolf Krause</font></div><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class=""><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class="">Institute of Computational Science</font></div><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class="">Università della Svizzera italiana</font></div></font></div><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class="">Center for Computation Medicine in Cardiology</font></div><div style="margin: 0px;" class=""><span style="color: rgb(111, 111, 111);" class=""><a href="https://maps.google.com/?q=Via+Giuseppe+Buffi,+13+CH-6900+Lugano+Switzerland&entry=gmail&source=g" class="">Via Giuseppe Buffi, 13</a></span></div><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class=""><a href="https://maps.google.com/?q=Via+Giuseppe+Buffi,+13+CH-6900+Lugano+Switzerland&entry=gmail&source=g" class="">CH-6900 Lugano</a></font></div><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class=""><a href="https://maps.google.com/?q=Via+Giuseppe+Buffi,+13+CH-6900+Lugano+Switzerland&entry=gmail&source=g" class="">Switzerland</a></font></div><div style="color: rgb(111, 111, 111); margin: 0px; line-height: normal; min-height: 12px;" class=""><br class=""></div><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class="">Email:<span class="m_-3896794662654634086Apple-converted-space"> </span><a href="mailto:pozzis@usi.ch" target="_blank" class="">pozzis@usi.ch</a> </font></div><div style="margin: 0px;" class=""><font face="Helvetica" color="#6f6f6f" style="line-height: normal; color: rgb(111, 111, 111);" class="">Phone: </font><span style="color: rgb(111, 111, 111);" class=""><a href="tel:+41%2058%20666%2049%2072" value="+41586664972" target="_blank" class="">+41 58 666 4972</a></span></div></div></div></div><br class=""></span><div class=""><blockquote type="cite" class=""><div class="">On 14 Mar 2018, at 14:52, Smith, Barry F. <<a href="mailto:bsmith@mcs.anl.gov" target="_blank" class="">bsmith@mcs.anl.gov</a>> wrote:</div><br class="m_-3896794662654634086Apple-interchange-newline"><div class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; float: none; display: inline !important;" class="">KSPGetIterationNumber</span></div></blockquote></div><br class=""></div></div></blockquote></div><br class=""><br clear="all" class=""><div class=""><br class=""></div>--<span class="Apple-converted-space"> </span><br class=""><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class="">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br class="">-- Norbert Wiener</div><div class=""><br class=""></div><div class=""><a href="http://www.caam.rice.edu/~mk51/" target="_blank" class="">https://www.cse.buffalo.edu/~knepley/</a></div></div></div></div></div></div></div></div></blockquote></div><br class=""></div></body></html>