Hello, I‘m kind of lost in the nature of laplace operator. Poisson equations are easy to solve numerically, and it has <grad, grad> type weak form. However, in step-22 <https://www.dealii.org/current/doxygen/deal.II/step_22.html#:~:text=Consequently,%20the%20matrix%20is%20badly%20conditioned%20for%20small%20mesh%20sizes%20and%20we%20had%20to%20come%20up%20with%20an%20elaborate%20preconditioning%20scheme%20for%20the%20Schur%20complement> it says laplace operator is ill-conditioned and expensive to invert with iterative method.
This question might be silly. Is laplcae operator a positive definite system and easy to solve? Does it become ill-conditioned when mesh size and mesh quality reduce? -- 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 on the web visit https://groups.google.com/d/msgid/dealii/17cdeaa8-bab3-4e81-ba22-c7392dd6840en%40googlegroups.com.
