<html><head></head><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:16px"><div id="yui_3_16_0_1_1468944869609_64897"><span id="yui_3_16_0_1_1468944869609_64995">Thank you for sharing the additional insight.</span></div><div id="yui_3_16_0_1_1468944869609_64961"><span><br></span></div><div id="yui_3_16_0_1_1468944869609_64962"><span id="yui_3_16_0_1_1468944869609_64994">The separate Galerkin coarsening of A and M will be part of the overall algorithm only. <br></span></div><div id="yui_3_16_0_1_1468944869609_65006"><span id="yui_3_16_0_1_1468944869609_64994"><br></span></div><div id="yui_3_16_0_1_1468944869609_65019"><span id="yui_3_16_0_1_1468944869609_64994">I think it is wise to implement in two stages: first a fragile implementation and later <br></span></div><div dir="ltr" id="yui_3_16_0_1_1468944869609_67222"><span id="yui_3_16_0_1_1468944869609_64994">a more stable one. <br></span></div><div id="yui_3_16_0_1_1468944869609_67236" dir="ltr"><span id="yui_3_16_0_1_1468944869609_64994"><br></span></div><div id="yui_3_16_0_1_1468944869609_67248" dir="ltr"><span id="yui_3_16_0_1_1468944869609_64994">Kind wishes, Domenico. <br> </span></div><div id="yui_3_16_0_1_1468944869609_64895" class="qtdSeparateBR"><br></div><div style="display: block;" id="yui_3_16_0_1_1468944869609_64908" class="yahoo_quoted"> <div id="yui_3_16_0_1_1468944869609_64907" style="font-family: times new roman, new york, times, serif; font-size: 16px;"> <div id="yui_3_16_0_1_1468944869609_64906" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1468944869609_64905" dir="ltr"> <font id="yui_3_16_0_1_1468944869609_64904" face="Arial" size="2"> <hr id="yui_3_16_0_1_1468944869609_64960" size="1"> <b><span style="font-weight:bold;">From:</span></b> Lawrence Mitchell <lawrence.mitchell@imperial.ac.uk><br> <b id="yui_3_16_0_1_1468944869609_64903"><span id="yui_3_16_0_1_1468944869609_64902" style="font-weight: bold;">To:</span></b> domenico lahaye <domenico_lahaye@yahoo.com> <br><b id="yui_3_16_0_1_1468944869609_65018"><span id="yui_3_16_0_1_1468944869609_65017" style="font-weight: bold;">Cc:</span></b> PETSc Users List <petsc-users@mcs.anl.gov><br> <b id="yui_3_16_0_1_1468944869609_67253"><span id="yui_3_16_0_1_1468944869609_67252" style="font-weight: bold;">Sent:</span></b> Thursday, July 21, 2016 1:09 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [petsc-users] Regarding ksp ex42 - Citations<br> </font> </div> <div id="yui_3_16_0_1_1468944869609_64956" class="y_msg_container"><br><br clear="none">> On 21 Jul 2016, at 10:55, domenico lahaye <<a id="yui_3_16_0_1_1468944869609_64957" shape="rect" ymailto="mailto:domenico_lahaye@yahoo.com" href="mailto:domenico_lahaye@yahoo.com">domenico_lahaye@yahoo.com</a>> wrote:<br clear="none">> <br clear="none">> Apologies for being not sufficient clear in my previous message.<br clear="none">> <br clear="none">> I would like to be able to Galerkin coarsen A^h to obtain A^H<br clear="none">> and to separately Galerkin coarsen M^h to obtain M^H.<br clear="none">> <br clear="none">> So, yes, the way in which I currently (partially) understand your<br clear="none">> description of the new DMCreateMatrices would do the job.<br clear="none"><br clear="none">If you want to separately coarsen A and M via Galerkin, I think it will be easier to just change the code in PCSetUp_MG to handle the case where A and M are different on the coarse levels. Effectively you just need to replicate the code that computes the coarse grid "B" matrix to separately compute coarse grid A and B matrices and pass them in to KSPSetOperators.<br clear="none"><br clear="none">Cheers,<div class="yqt6537581038" id="yqtfd26731"><br clear="none"><br clear="none">Lawrence<br clear="none"></div><br><br></div> </div> </div> </div></div></body></html>