[Nektar-users] 回复： ARPACK is not set-up for parallel execution

15 May 2024

      Dear nektar++ users and developers,

Sorry to bother you again. Maybe I didn't express my question clearly. I want to use MPI to run the solver in parallel to improve computational speed. When I enter the command $/IncNavierStokesSolver Cylinder.xml Cylinder_Adjoint.xml, the error "ARPACK is not set-up for parallel execution" pops up. 

I have selected "use MPI" during the cmake process, and in the file build/CMakeCache.tst have a line saying: NEKTAR-USE-MPI: BOOL=ON.

I would like to know how to use mpi to run IncNavierStokesSolver in parallel to solve stability_Adjoint. As you said,to replace "Arpack" in condition.xml with "ModifiedArnoldi" instead?

Hongtao Cheng

------------------ 原始邮件 ------------------
发件人:                                                                                                                        "Sherwin, Spencer J"                                                                                    <s.sherwin@imperial.ac.uk>;
发送时间: 2024年5月10日(星期五) 晚上7:54
收件人: "🌸那慢慢🌸"<2644878715@qq.com>;"nektar-users"<nektar-users@imperial.ac.uk>;

主题: Re: [Nektar-users] ARPACK is not set-up for parallel execution

HI Hongtao,

You can compile Nektar++ without the NEKTAR_USE_MPI flag, or go into ccmake from  your builds directory and toggle off NEKTAR_USE_MPI, reconfigure and this should then generate a  configuration wtihouth mpi.

Alternatively you can try running “ModifiedArnoldi” instead of Arpack. I think that does run in parallel.

Cheers,

Spencer.

From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of 🌸那慢慢🌸 <2644878715@qq.com>
 Date: Friday, 10 May 2024 at 12:37
 To: nektar-users <nektar-users@imperial.ac.uk>
 Subject: [Nektar-users] ARPACK is not set-up for parallel execution

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Dear nektar++ users and developers,

I get the error "ARPACK is not set-up for parallel execution" when running the incompressbile flow solver in parallel with MPI，but in the file build/CMakeCache.tst have a line saying:NEKTAR_USE_MPI:BOOL=ON.How  do I fix this?

Hongtao Cheng