Open gabrielfougeron opened 1 year ago
PS: I apologize if this is not the right place to ask this kind of questions.
It is ok to ask this question. I wrote the first version of MB04PB 25 years ago. I did have a version for skew-Hamiltonians, that might be a lower-level support function or never made it into SLICOT. I will check my files, but this might take a few days.
Wow this is great, thank you very much!
Currently, SLICOT does not include a routine for computing the PVL form of a skew-Hamiltonian matrix. We do have one for skew-Hamiltonian/Hamiltonian pencils. An appropriate routine for item 1 above could be DSHPVB from HAPACK package. It might be possible to include its adaptation into SLICOT Library in the near future.
I don't know now an answer for item 2.
Sounds great! I had never heard of HAPACK before. A quick google search leads me to believe the project home page is https://www.tu-chemnitz.de/mathematik/industrie_technik/software/hapack.php?lang=en . The download links are all down though :-(
Maybe a project for your next visit?
Best regards,
Peter
On Wed, Feb 08, 2023 at 11:01:27PM -0800, VasileSima4 wrote:
Currently, SLICOT does not include a routine for computing the PVL form of a skew-Hamiltonian matrix. We do have one for skew-Hamiltonian/Hamiltonian pencils. An appropriate routine for item 1 above could be DSHPVB from HAPACK package. It might be possible to include its adaptation into SLICOT Library in the near future.
I don't know now an answer for item 2.-- Reply to this email directly or view it on GitHub: https://github.com/SLICOT/SLICOT-Reference/issues/9#issuecomment-1423725848 You are receiving this because you commented.
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Maybe a project for your next visit? Best regards, Peter … On Wed, Feb 08, 2023 at 11:01:27PM -0800, VasileSima4 wrote: Currently, SLICOT does not include a routine for computing the PVL form of a skew-Hamiltonian matrix. We do have one for skew-Hamiltonian/Hamiltonian pencils. An appropriate routine for item 1 above could be DSHPVB from HAPACK package. It might be possible to include its adaptation into SLICOT Library in the near future. I don't know now an answer for item 2. -- Reply to this email directly or view it on GitHub: #9 (comment) You are receiving this because you commented. Message ID: @.> ____ Upcoming: 25-27 September 2023 / Heidelberg, Germany: European Conference on Computational Optimization (EUCCO) https://scoop.iwr.uni-heidelberg.de/events/2023_eucco/ ____ Prof. Dr. Peter Benner - Director - Max Planck Institute for Dynamics of Complex Technical Systems Sandtorstr. 1, 39106 Magdeburg (Germany) +49 391-6110-450 @. | www.mpi-magdeburg.mpg.de/benner zoom: peterbenner | webex: benner | skype: peter_benner BigBlueButton: bbba.mpi-magdeburg.mpg.de/b/pet-gjq-xek Co-Chair "BiGmax - the Max Planck research network on big-data-driven materials science", https://www.bigmax.mpg.de/ Professor, Research group "Mathematics in Industry and Technology" Fakultät für Mathematik, TU Chemnitz Honorarprofessor, Fakultät für Mathematik Otto-von-Guericke Universität Magdeburg
Sure! Most HAPACK routines are already integrated into SLICOT. From the six routines you sent, two are already there, under the names MB01MD and MB01ND.
Here is my numerical problem: I want to compute a Hamiltonian square root of a given skew-Hamiltonian matrix.
The following article Structure-Preserving Schur Methods for Computing Square Roots of Real Skew-Hamiltonian Matrices by Zhongyun Liu, Yulin Zhang, Carla Ferreira, and Rui Ralha proposes an algorithm involving the following steps:
I think I can use Lapack to deal with 3. and 4. My question is: can I use SLICOT to deal with 1. and/or 2. ? I see in the doc that there is a subroutine for the Paige/Van Loan form of a Hamiltonian matrix MB04PB, but I don't see anything for the skew-Hamiltonian case.
Any tips would be greatly appreciated