So why is it not 162x162? step-17 claims to solve same problem as step-8. If one produces symmetry matrix and the other does not or both do not -- this is suspicious. Anyway, I recommend you creating an issue on github and put short description with the link to this thread. People who created step-17 will more likely see it there than go into details of this thread.
Best, Alexander Am Mittwoch, 27. Juli 2016 20:10:09 UTC+2 schrieb shanglong zhang: > > Alexander, > > I run step-8 and the system matrix is symmetry at least for the first > cycle. I attach the output txt of the system matrix in this reply. Thanks. > > Best, > Shanglong > > 在 2016年7月27日星期三 UTC-4上午10:53:46，Alexander写道： >> >> Shanglong, >> I'm not an expert in this field, but I assume it should be. >> >> Can you please check if system matrix in step-8 (which was used to >> implement step-17) is symmetric? >> >> Alexander >> >> Am Mittwoch, 27. Juli 2016 15:58:42 UTC+2 schrieb shanglong zhang: >>> >>> Hi Alexander, >>> >>> Thank you for your explanation. I should have checked the symmetricity >>> first. >>> However, since the step-17 is isotropic linear elasticity problem, >>> should the system matrix be symmetry? >>> >>> Thank you very much for your help and patience. >>> >>> Regards, >>> Shanglong >>> >>> 在 2016年7月27日星期三 UTC-4上午4:49:53，Alexander写道： >>>> >>>> Shanglong, >>>> I can reproduce this behaviour, but this isn't a bug. I output the >>>> 162x162 system matrix at first cycle and as far as I can see it fails >>>> symmetry check. You can see this already from first few non-zero entries: >>>> >>>> (0,0) 1.33333 >>>> (1,1) 1.33333 >>>> (2,2) 1.33333 >>>> (3,3) 1.33333 >>>> (4,4) 1.33333 >>>> (5,5) 1.33333 >>>> (6,0) -0.666667 >>>> >>>> See, there is no (0, 6) and symmetry is violated. >>>> >>>> The matrix is still positive-definite, that is probably why CG still >>>> gets something out of it. >>>> >>>> Alexander >>>> >>>> -- 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 dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
