Oh okay I get it now. I also realised I wasn't reading the matrix correctly. I made my system super small, and got non small values of the eigen values and determinant so it should be smooth sailing at this point.
Thanks Abbas On Wednesday, October 30, 2024 at 6:02:45 PM UTC+1 Wolfgang Bangerth wrote: > > > On 10/30/24 08:25, Abbas Ballout wrote: > > > > Yeah I was aiming to compute the smallest eigenvalue. > > I guess my tittle was off. I was just trying to aim to the fact that the > > stiffness matrix > > I wrote to an output file and then I read was singular. > > Abbas: > what I wanted to point out is that it's hard to establish what > "singular" actually means. *Mathematically*, singular means (or is > equivalent to) that the matrix has zero determinant. *In practice*, this > is not a criterion that can be tested numerically because floating point > numbers cannot distinguish whether the determinant is (0.1)^1000 or in > fact zero. > > Best > W. > -- 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. To view this discussion visit https://groups.google.com/d/msgid/dealii/3860c211-ed80-44ce-baad-719ee9e635a9n%40googlegroups.com.
