[petsc-users] Solving NON-Diagonally dominant sparse system

[Barry Smith]

   I would suggest using ./configure --download-superlu and then when running the program -pc_type lu -pc_factor_mat_solver_package superlu

   Note that this is SuperLU, it is not SuperLU_DIST.  Superlu uses partial pivoting for numerical stability so should be able to handle the small or zero diagonal entries.

    Barry

> On Apr 10, 2017, at 1:17 PM, Kaushik Kulkarni <kaushikggg at gmail.com> wrote:
> 
> Hello,
> I am trying to solve a 2500x2500 sparse matrix. To get an idea about the matrix structure I have added a file matrix.log which contains the output of MatView() and also the output of Matview_draw in the image file. 
> 
> From the matrix structure it can be seen that Jacobi iteration won't work and some of the diagonal entries being very low(of the order of 1E-16) LU factorization would also fail. 
> 
> C​an someone please suggest what all could I try next, in order to make the solution converge?
> 
> Thanks,
> Kaushik
> ​
> -- 
> Kaushik Kulkarni
> Fourth Year Undergraduate
> Department of Mechanical Engineering
> Indian Institute of Technology Bombay
> Mumbai, India
> https://kaushikcfd.github.io/About/
> +91-9967687150
> <matrix.log><matrix_pattern.png>