On Jan 24, 2013, at 2:29 PM, Peter Zajac <[email protected]> wrote:
> According to the PETSC documentation zero pivot does not always mean the > matrix is singular and since I am getting the correct results I am ignoring > the error. Could my ignorance in this case cause a serious problem in the > future I should be aware of? > > thank you again Previously Roy mentioned penalty vs Dirichlet boundary conditions? Penalty boundary conditions sometimes can cause an issue like this, as can disparate scaling in variables. What happens if you pass '-pc_factor_zeropivot 0 -sub_pc_factor_zeropivot 0' to your application? Do you still get that message? PETSc has a default tolerance that it considers '0' during the factorization, these options override that default. -Ben ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
