<div dir="ltr">Yes ex13 works for me. Could you let me know where can I download the program and how can I add options at the runtime? Thank you so much.<div><br></div><div>Jifeng</div></div><div class="gmail_extra"><br><br>
<div class="gmail_quote">On Thu, Jul 3, 2014 at 12:13 PM, murat keçeli <span dir="ltr"><<a href="mailto:keceli@gmail.com" target="_blank">keceli@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">Hi Jifeng,<div><br></div><div>You can start with ex13 in SLEPc to see how it works for your case. You would need MUMPS as a direct solver. Section 3.4.5 is the relevant section in SLEPc manual (Campos and Roman 2012 paper would be very helpful if you need more details). Let me know if it works for you and we can continue from there.</div>
<div><br></div><div>Thanks,</div><div>Murat</div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Jul 3, 2014 at 12:18 AM, jifeng zhao <span dir="ltr"><<a href="mailto:jifengzhao2015@u.northwestern.edu" target="_blank">jifengzhao2015@u.northwestern.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Murat, <div><br></div><div>Yes, that sounds great. I would like to have a try. Would you let me know how to use it on top of SLEPC and PETSC in more details? </div>
<div><br></div><div>Cheers,</div><div>Jifeng Zhao</div>
</div><div><div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Jul 2, 2014 at 9:41 PM, murat keçeli <span dir="ltr"><<a href="mailto:keceli@gmail.com" target="_blank">keceli@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div style="font-family:arial,sans-serif;font-size:13px">Hi Jifeng,</div><div style="font-family:arial,sans-serif;font-size:13px">
<br></div><div style="font-family:arial,sans-serif;font-size:13px">I think your application is suitable for the SIPs method, see attached paper. We have improved it recently, so that it can handle very large (500k by 500k with more than 3.e7 nonzeros) sparse matrices.Current version of SIPs is basically adding a second layer of parallelism on top of SLEPc's shift and invert method. Let me or Hong Zhang (cc, the developer of SIPs) know, if you would like to give it a try. </div>
<div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">Murat Keceli</div><div><div>
<div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Jul 2, 2014 at 4:46 PM, jifeng zhao <span dir="ltr"><<a href="mailto:jifengzhao2015@u.northwestern.edu" target="_blank">jifengzhao2015@u.northwestern.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hello all,<div><br></div><div>I am working on solving a generalized eigenvalue problem with SLEPC and PETSC. </div>
<div><div><br></div><div><b>K</b> x = lamda <b>M</b> x</div><div><br></div><div>I attached the sparsity pattern of matrix <b>M</b> (<b>K</b> is the same). It is a FEM model. It is so sparse is because of constraints. </div>
<div><br></div><div>I have tried two things:</div><div><br></div><div>1. <span style="font-family:arial,sans-serif;font-size:13px">Krylov-Schur and exact shift-and-invert (I will try MUMPS in future). It works. But I am worrying that it is less parrallelable, when the problem contains millions of degree of freedom. </span></div>
<div><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div><div><span style="font-family:arial,sans-serif;font-size:13px">2. JD with Jacobi preconditioner. It could work, but a lot of tuning needs to be done in terms of RTOL, max_iteration_number. And sometimes I suffer from a stagnated solution, and can't obtain accurate result. </span></div>
<div><br></div><div>Does anybody know that for my specific case of matrix sparsity, is there any thing I can do to speed up my direct solver (<span style="font-family:arial,sans-serif;font-size:13px">Krylov-Schur</span>)? </div>
<div><br></div><div>Is there any recommended preconditioners I could try on, for the case of JD? There are a lot of preconditioners in HYPRE library. </div><div><br></div><div>Thank you in advance!</div><div><img src="cid:ii_146f901b60ba150d" alt="Inline image 1" width="506" height="379.5"></div>
<span><font color="#888888">
-- <br><div dir="ltr">Jifeng Zhao<div>PhD candidate at Northwestern University, US</div><div>Theoretical and Applied Mechanics Program</div></div>
</font></span></div></div>
</blockquote></div><br></div></div></div></div>
</blockquote></div><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Jifeng Zhao<div>PhD candidate at Northwestern University, US</div><div>Theoretical and Applied Mechanics Program</div></div>
</div>
</div></div></blockquote></div><br></div>
</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Jifeng Zhao<div>PhD candidate at Northwestern University, US</div><div>Theoretical and Applied Mechanics Program</div></div>
</div>