<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><br class=""></div> Randy,<div class=""><br class=""></div><div class=""> Please take a look at <a href="https://gitlab.com/petsc/petsc/-/merge_requests/4543/" class="">https://gitlab.com/petsc/petsc/-/merge_requests/4543/</a> and try its branch. It has more features and may provide more of what you need.</div><div class=""><br class=""></div><div class=""> Barry</div><div class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On May 23, 2022, at 1:59 PM, Randall Mackie <<a href="mailto:rlmackie862@gmail.com" class="">rlmackie862@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Dear PETSc team:<div class=""><br class=""></div><div class="">I am trying to use Strumpack in ILU mode, which is suppose to activate it’s low rank approximation as described on the man page:</div><div class=""><br class=""></div><div class=""><a href="https://petsc.org/release/docs/manualpages/Mat/MATSOLVERSSTRUMPACK.html" class="">https://petsc.org/release/docs/manualpages/Mat/MATSOLVERSSTRUMPACK.html</a></div><div class=""><br class=""></div><div class="">and in this exchange a few years ago:</div><div class=""><br class=""></div><div class=""><a href="https://lists.mcs.anl.gov/pipermail/petsc-users/2017-October/033560.html" class="">https://lists.mcs.anl.gov/pipermail/petsc-users/2017-October/033560.html</a></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">However, regardless of whether I specify ILU or LU, the behavior is the same, and the solution is in 1 step, meaning (to me) it’s doing the LU direct solve.</div><div class="">Furthermore, when I set verbose mode, it doesn’t seem to be activating low rank mode (that is, there are HSS or BLR frontal matrices created).</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">I’m running this example:</div><div class=""><br class=""></div><div class=""><a href="https://petsc.org/release/src/ksp/ksp/tutorials/ex2.c.html" class="">https://petsc.org/release/src/ksp/ksp/tutorials/ex2.c.html</a></div><div class=""><br class=""></div><div class="">using options:</div><div class=""><br class=""></div><div class=""><pre class="">mpiexec -n 4 ./ex2 -pc_type ilu -pc_factor_mat_solver_package strumpack</pre><div class=""><br class=""></div></div><div class="">I’m likely doing something wrong, but I can’t figure out what, and would appreciate advice on how to use the strumpack ILU mode.</div><div class=""><br class=""></div><div class="">Thanks, Randy M.</div><div class=""><br class=""></div><div class=""><br class=""></div></div></div></blockquote></div><br class=""></div></body></html>