DOLFIN

Generalized eigenvalue problem

Asked by Alexander

Hello

I'm trying to solve the generalized eigenvalue problem.
A * u = lambda * M * u.

I have a system of equations, two-group neutron dif
usion equations:

-div(k1 * grad(u1)) + (r11 + r12) * u1 = lambda * (r13 * u1 + r14* u2)
-div(k2 * grad(u2)) + r21 * u1 - r22 * u2 = 0
where r11,r12,r13,r14,r21,r22 are coefficients

can anyone knows how to implement it?

Alexander.

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Garth Wells
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Best Garth Wells (garth-wells) said : 		#1

Look at

    http://fenicsproject.org/documentation/dolfin/1.0.0/python/demo/la/eigenvalue/python/documentation.html

for an eigenvalue example. For a generalised problem (copy-pasted from dolfin/la/SLEPcEigenSolver.h)

    /// Create eigenvalue solver Ax = \lambda Bx
    SLEPcEigenSolver(const PETScMatrix& A, const PETScMatrix& B);

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Alexander (haska87) said : 		#3

Thanks Garth Wells, that solved my question.