Eigenvalue Solver Problems

Asked by Houdong Hu on 2013-03-13

Hi,

I try to solve an eigenvalue problem with the format " a = inner(nabla_grad(u), nabla_grad(v))*dx + u*v_ext*v*dx "

1. I don't know how to use other eigenvalue solvers except the default one
    What I know right now is to do as "eigensolver = SLEPcEigenSolver(A); eigensolver.solve()", but what eigenvalue solver is using here? how could we use other eigenvalue solvers?

2. When I set v_ext as 1/r (r is the distance from the point to the mesh center), it takes forever to get the results; and if I set v_ext as some other more common funtions (such as r, constant), it is pretty fast to solve.
I have changed the center a little bit to avoid the infinity, but it still takes very long, why?

thanks,
Houdong

Question information

Language:
English Edit question
Status:
Solved
For:
DOLFIN Edit question
Assignee:
No assignee Edit question
Solved by:
Houdong Hu
Solved:
2013-03-16
Last query:
2013-03-16
Last reply:
2013-03-13
Marie Rognes (meg-simula) said : #1

1. Read the documentation for the eigensolver (for instance for v 1.1.0):

http://fenicsproject.org/documentation/dolfin/1.1.0/cpp/programmers-reference/la/SLEPcEigenSolver.html#SLEPcEigenSolver

2. This is not really a DOLFIN related question.

Houdong Hu (vincehouhou) said : #2

Thanks,