Dear Johan, > i need to perform a modal analysis on my solver, would like to avoid > poweriterate and use levelshift. Anyone implemented an efficient jacobi > solver?
I don't know about an efficient implementation of a Jacobi eigensolver - you want to get the matrix eigenvalues and eigenvectors, don't you? Or is it enough to repeatedly use a Jacobi preconditioner? Regarding eigenvalues: One thing you could try instead (and that is probably even more efficient than the Jacobi transformation method) is to find a viable method for your problem in the eigensolver package Anasazi of the software Trilinos. You can find a tutorial of it at http://trilinos.sandia.gov/Trilinos9.0Tutorial.pdf and the doxygen documentation here: http://trilinos.sandia.gov/packages/docs/r9.0/packages/anasazi/doc/html/group__anasazi__solver__framework.html). A more general paper that discusses software for eigenanalysis can be found at http://trilinos.sandia.gov/packages/anasazi/anasazi-toms.pdf Anasazi implements a few efficient (and even parallel) algorithms for matrix eigenvalues. So you could use the Trilinos wrappers in the latest subversion of deal.II to generate your matrix (or just copy over a deal.II matrix into that format) and then call the Anasazi algorithm of your choice... And probably PETSc also has some eigenvalue algorithms... Best, Martin _______________________________________________
