Hi Bruno, I would like to use this patch <https://github.com/ORNL-CEES/mfmg/blob/master/scripts/0001-Enable-ARPACK-in-regular-mode.patch> to compute the smallest eigenvalues in my case. Could you please let me know how should I update my source code in the arpack.h header file to accommodate these changes in the patch. I understand that I would need to reinstall dealii after updating the source code, which I am fine with.
When I am using the shift-inverse mode, I am not getting the results similar to what I would get using the eigenvalue solver in MATLAB or Python for the same matrix. There is a difference of about 15 to 20 in the eigenvalues (even when comparing it with the ARPACK solver in Python). This is the reason that I would want to try calculating the eigenvalues using the patch you created in regular mode. Thanks! Animesh On Sunday, November 8, 2020 at 6:00:58 PM UTC+5:30 Animesh Rastogi IIT Gandhinagar wrote: > Thank you Bruno, I was able to change the source code accordingly. I > reinstalled dealii and it worked fine! > > Thanks again! > > Animesh > > On Friday, November 6, 2020 at 3:55:29 AM UTC+5:30 bruno.t...@gmail.com > wrote: > >> Animesh, >> >> On Thursday, November 5, 2020 at 1:11:33 PM UTC-5 >> animesh...@alumni.iitgn.ac.in wrote: >> >>> However, I have no way of passing it as a parameter to the solver >>> <https://www.dealii.org/current/doxygen/deal.II/classArpackSolver.html#afdc3aa9d761c43b5b4132e731c6191a5> >>> >>> function. I was planning to edit the header file *arpack.h* >>> <https://www.dealii.org/current/doxygen/deal.II/arpack__solver_8h_source.html> >>> >>> accordingly which is inside the */usr/local/include/deal.II/lac* to >>> have that functionality. I was actually thinking of passing the flag "rvec" >>> as an argument to the function solve >>> <https://www.dealii.org/current/doxygen/deal.II/classArpackSolver.html#afdc3aa9d761c43b5b4132e731c6191a5>. >>> >>> I was wondering if I change the permission of the file to write mode, edit >>> it and save it, would I be able to run my code inside the examples folder. >>> Or do I need to take care of something else while and after editing that >>> headerfile? >>> >> You should change the source code and reinstall deal.II. I would do what >> you propose only if you cannot compile deal.II on that machine. It might >> work in this particular case but I really advise you against it. >> >> Best, >> >> Bruno >> >> > -- 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/81e7a0d4-4ab9-4323-8beb-aa7897feb4c2n%40googlegroups.com.
