Hi Animesh, Although in that code-gallery example the system is assembled into a BlockSparseMatrix<double>, the system actually has only one block. So you can retrieve the underlying SparseMatrix<double> (and Vector<double> for the RHS) via tangent_matrix.block(u_dof, u_dof); system_rhs.block(u_dof); and use them with one of the standard eigensolvers (maybe ArpackSolver <https://dealii.org/developer/doxygen/deal.II/classArpackSolver.html>, since you want both the eigenvalues and eigenvectors).
I hope that this helps you! Best, Jean-Paul > On 23 Sep 2020, at 20:53, Animesh Rastogi IIT Gandhinagar > <animesh.rast...@alumni.iitgn.ac.in> wrote: > > Hi All, > > I am trying to play with the code of Quassi Static Finite Strain > Compressibility > <https://dealii.org/developer/doxygen/deal.II/code_gallery_Quasi_static_Finite_strain_Compressible_Elasticity.html>. > I want to calculate the eigenvalues and eigenvectors of the System Tangent > Matrix (BlockSparseMatrix<double> > <https://dealii.org/developer/doxygen/deal.II/classBlockSparseMatrix.html> > tangent_matrix) that we get at every time step after the Newton method has > converged. However, I could not find any function to calculate the > eigenvalues and eigenvectors of the BlockSparse Matrix. Could someone please > help me with this? > > Thanks! > > AR > > -- > The deal.II project is located at http://www.dealii.org/ > <http://www.dealii.org/> > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > <https://groups.google.com/d/forum/dealii?hl=en> > --- > You received this message because you are subscribed to the Google Groups > "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to dealii+unsubscr...@googlegroups.com > <mailto:dealii+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/dealii/987eb63a-333e-43b3-a9e0-fbcbae2d567en%40googlegroups.com > > <https://groups.google.com/d/msgid/dealii/987eb63a-333e-43b3-a9e0-fbcbae2d567en%40googlegroups.com?utm_medium=email&utm_source=footer>. -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/EC116463-277A-46D1-8193-462769D8EA5D%40gmail.com.
