[petsc-users] Spectrum Slicing with MATMPISBAIJ

[Fischer, Franz]

Dear all,

I am dealing with large, sparse symmetric (and hermitian) matrices (N ~ 1e5) and I am using slepc in order to solve them.
For now, I was using the matrix type MATMPISBAIJ to fill my matrix in parallel and I was solving the EVP for the EPS_SMALLEST_REAL eigenvalues just fine.

Now I am dealing with spectra, where I am not desired in knowing the small real part of the eigenvalue spectrum, but rather in some energy interval - thus, making me want to use spectrum slicing.

For that I have browsed your documentation and now I am a little concerned on what to do.
I saw that my matrix type is not supported for LU decomposition, so I have converted my matrix to type MATMPIAIJ.
There is this table here (https://urldefense.us/v3/__https://petsc.org/release/overview/linear_solve_table/__;!!G_uCfscf7eWS!e_EQDlcM6bSB8ayYFeVL6q8O-g91z5wOtB-pL91VevkcE-S7h_vfKV-Tx7PRpJRVsRJuYkvple6k1IZvvAPGGWPJsYRnSAPKf3SZ$ ), where I found which solvers are available for which matrix type.

What I can not fully understand are the columns Parallel and Complex. What does it mean to have an X in there, does it mean it is possible or not?

Do I need to compile Petsc with external LU-solver packages or not?

Thanks in advance for your reply!

Best,
Franz

---------------------------------------------------------
MSc. Franz Fischer
Universität Hamburg
HARBOR, Geb. 610
Luruper Chaussee 149
D-22761 Hamburg
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