<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="">Ok, so here’s some behavior I don’t understand. I am working with a DMComposite structure, and I do the following,<div class=""><br class=""></div><div class=""><div class=""> SNESComputeFunction(snes,U_refine,r);</div><div class=""> SNESGetDM(snes, &dm_refine);</div><div class=""><br class=""></div><div class=""> DMCompositeGetLocalVectors(dm_refine, &rp, &rQ);</div><div class=""> DMCompositeScatter(dm_refine, r, rp, rQ);</div><div class=""> </div><div class=""> VecNorm(r, NORM_2, &r_norm);</div><div class=""> VecNorm(rp, NORM_2, &rp_norm);</div><div class=""> VecNorm(rQ, NORM_2, &rQ_norm);</div><div class=""><br class=""></div><div class=""> VecGetSize(r,&r_size);</div><div class=""> VecGetSize(rp, &rp_size);</div><div class=""> VecGetSize(rQ, &rQ_size);</div><div class=""><br class=""></div><div class=""> DMCompositeRestoreLocalVectors(dm_refine, &rp, &rQ);</div><div class=""> VecDestroy(&r);</div><div class=""><br class=""></div><div class=""> PetscPrintf(PETSC_COMM_WORLD," ||r|| = %g, %i entries\n",r_norm,r_size);</div><div class=""> PetscPrintf(PETSC_COMM_WORLD," ||rp|| = %g, %i entries\n",rp_norm,rp_size);</div><div class=""> PetscPrintf(PETSC_COMM_WORLD," ||rQ|| = %g, %i entries\n",rQ_norm,rQ_size);</div></div><div class=""><br class=""></div><div class="">and my output is:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-family: Menlo;" class=""><span style="font-size: 12px;" class=""> ||r|| = 225.31, 7999 entries</span></div><div style="margin: 0px; font-family: Menlo;" class=""><span style="font-size: 12px;" class=""> ||rp|| = 140.021, 3 entries</span></div><div style="margin: 0px; font-family: Menlo;" class=""><span style="font-size: 12px;" class=""> ||rQ|| = 176.56, 8004 entries</span></div></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">The arithmetic, is off, no?</div><div class=""><br class=""><div class="">
<span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px;">-gideon</span>
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<br class=""><div><blockquote type="cite" class=""><div class="">On Sep 10, 2015, at 5:28 PM, Barry Smith <<a href="mailto:bsmith@mcs.anl.gov" class="">bsmith@mcs.anl.gov</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><br class=""> SNESGetDM() this will return not the original DM you set but the refined one.<br class=""><br class=""><blockquote type="cite" class="">On Sep 10, 2015, at 3:47 PM, Gideon Simpson <<a href="mailto:gideon.simpson@gmail.com" class="">gideon.simpson@gmail.com</a>> wrote:<br class=""><br class="">I’m using a DMCompsosite along with grid sequencing and here’s what I’m trying to accomplish. After running the SNES solve, I’d like to evaluate the residual on the refined grid, on each piece of the DMComposite. How do I get a DM for the refined grid which I can then use with DMCompositeGetLocalVectors in order to get each piece of the problem? Or is there a better way?<br class=""><br class="">-gideon<br class=""><br class=""></blockquote><br class=""></div></blockquote></div><br class=""></div></body></html>