<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt"><div><span>Jed,</span></div><div><span></span> </div><div><span>It seems there is a deflated GMRES solver in PETSc (KSPDGMRES), but PETSc manual does not give any details how to use it. A doc I found online is "parallel implementation of the deflated GMRES in the PETSc package", which mentioned to set number of eigenvalues to deflate by --ksp_dgmres_eigen, etc. Can I set these parameters by function calls (rather than using .petscrc)? </span></div><div><span></span> </div><div><span>Suppose the number of unknowns is 10,000, what would be the good number of number of eigenvalues to deflate? Or I may just use the default values (if they exist) for this solver?</span></div><div><span></span> </div><div><span>Thanks,</span></div><div><span>Qin</span></div><div style="display: block;"
class="yahoo_quoted"> <br> <br> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div dir="ltr"> <font size="2" face="Arial"> On Thursday, February 13, 2014 1:07 PM, Jed Brown <jed@jedbrown.org> wrote:<br> </font> </div> <div class="y_msg_container">Qin Lu <<a href="mailto:lu_qin_2000@yahoo.com" shape="rect" ymailto="mailto:lu_qin_2000@yahoo.com">lu_qin_2000@yahoo.com</a>> writes:<br clear="none"><br clear="none">> Hello,<br clear="none">><br clear="none">> Is there a deflated Krylov solver available in PETSc? <br clear="none"><br clear="none">See the discussion here:<br clear="none"><br clear="none"><a href="http://lists.mcs.anl.gov/pipermail/petsc-dev/2013-March/011393.html" shape="rect"
target="_blank">http://lists.mcs.anl.gov/pipermail/petsc-dev/2013-March/011393.html</a><br clear="none"><br clear="none">Let us know if you have any follow-up questions.<div id="yqtfd77736" class="yqt0293551451"><br clear="none"><br clear="none">> If yes, what is the corresponding solver name when calling KSPSetType?<br clear="none">> Does it work with any existing preconditioners?<br clear="none">><br clear="none">> Many thanks for your info!<br clear="none">><br clear="none">> Regards, Qin </div><br><br></div> </div> </div> </div> </div></body></html>