Hi, i'm trying to solve a generalized eigenvalue problem which is the stokes equations discretized by finite elements (with fenics) and producing a banded matrix (reordered structure) of the well known block form
[N Q] [QT 0] The domain is the unit square with dirichlet boundary condition evaluating to zero at all boundary nodes. A is the block matrix in banded reordered structure and M is the mass matrix. I'm using slepc4py for the eigenvalue calculation. E = SLEPc.EPS().create() E.setOperators(A, M) E.setDimensions(NEV, PETSc.DECIDE) E.setFromOptions() I always get the error [0] Zero pivot row 1 value 0 tolerance 2.22045e-14 I cannot find a combination which solves the eigenvalues for this problem. The system itself solves fine with a KSP solver object from PETSc using tfmqr with the icc PC. I can assemble the matrix with a penalty term for the pressure and calculate the eigenvalues with a direct solver, but i try to avoid that.
