Dear David, for debugging your code you should start with simplifying your code as much as possible to see what is going wrong. In particular, you should try with not refining your mesh and confirm that the assembled matrices look as they should. Can you modify the parameters in such a way that you would expect to reproduce the results of step-36?
Best, Daniel Am Montag, 16. Mai 2016 11:28:39 UTC+2 schrieb David: > > Hi, Tobi: > > Thank you so much for your suggestions. I have followed your direction and > checked my code again and again for all day long, but still > could not resolve this problem. If you (or someone else) wouldn't mind, > could you please take a look at my code attached below? > > It is a really short code, of which most parts are exactly the same with > step-36, except some details I changed for learning purposes (I changed > this problem to a simple dynamical elasticity problem on a rectangular > domain). I know this might cause some unconveniences, but I really > need somesone's help. Since nobody around me uses dealii, this is the only > place I can turn to. > > Thanks in advance for any help! > > Best regards, > David. > > > > On Monday, May 16, 2016 at 1:03:30 AM UTC+8, Tobi Young wrote: >> >> > Could anyone please take a look, it says: >> > >> > [0]PETSC ERROR: Object is in wrong state >> > [0]PETSC ERROR: Matrix is missing diagonal entry 8 >> > >> >> >The above tells us that the matrix is singular (missing a diagonal >> entry). >> > > > > >I can recommend you check first, if your matrix should be singular - >> >ie. if you are assembling him correctly; and second, check that the >> >SLEPc solver you are using is capable of solving a singular matrix >> >(not all are). You can get some information from the solver pages of >> >the SLEPc manual. >> >Hope that helps a little. >> > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
