[petsc-users] Recommended solver and preconditioner to solve Poisson eqn on win7

Sat Sep 15 09:32:55 CDT 2012

This is in GMRES, I would check for a zero on the diagonal.

On Sep 15, 2012, at 3:16 AM, TAY wee-beng <zonexo at gmail.com> wrote:

> On 14/9/2012 4:38 PM, Mark F. Adams wrote:
>> 
>> On Sep 14, 2012, at 8:47 AM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
>> 
>>> On Fri, Sep 14, 2012 at 3:47 AM, TAY wee-beng <zonexo at gmail.com> wrote:
>>> Hi,
>>> 
>>> I need to solve the Poisson eqn on my win7 machine. I'm currently using BCGS without preconditioner. I can't use HYPRE since I'm using Fortran and win7. It's rather slow.
>>> 
>>> Is there a recommended solver and preconditioner to solve the Poisson eqn to get me started?
>>> 
>>> What discretization?
>>> 
>>> Run with -pc_type gamg to start.
>> 
>> and 
>> 
>> -pc_gamg_agg_nsmooths 1
> 
> I am using non-uniform Cartesian grid to solve. What do you mean by the discretization? I 'm using finite volume method to obtain a system of linear eqns.
> 
> I tried both -pc_type gamg and -pc_gamg_agg_nsmooths 1 but the solver breaks down. The error msg is:
> 
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: Caught signal number 8 FPE: Floating Point Exception,probably divide by zero
> [0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
> [0]PETSC ERROR: or see http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind[0]PETSC ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS X to find memory corruption errors
> [0]PETSC ERROR: likely location of problem given in stack below
> [0]PETSC ERROR: ---------------------  Stack Frames ------------------------------------
> [0]PETSC ERROR: Note: The EXACT line numbers in the stack are not available,
> [0]PETSC ERROR:       INSTEAD the line number of the start of the function
> [0]PETSC ERROR:       is given.
> [0]PETSC ERROR: [0] KSPComputeExtremeSingularValues_GMRES line 24 src/ksp/ksp/impls/gmres/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\impls\gmres\gmreig.c
> [0]PETSC ERROR: [0] KSPComputeExtremeSingularValues line 40 src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c
> [0]PETSC ERROR: [0] PCGAMGOptprol_AGG line 1294 src/ksp/pc/impls/gamg/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\impls\gamg\agg.c
> [0]PETSC ERROR: [0] PCSetUp_GAMG line 559 src/ksp/pc/impls/gamg/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\impls\gamg\gamg.c
> [0]PETSC ERROR: [0] PCSetUp line 810 src/ksp/pc/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\INTERF~1\precon.c
> [0]PETSC ERROR: [0] KSPSetUp line 182 src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c
> [0]PETSC ERROR: [0] KSPSolve line 351 src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c
> [0]PETSC ERROR: --------------------- Error Message ------------------------------------
> [0]PETSC ERROR: Signal received!
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: Petsc Development HG revision: d560f272ff1b6e7f4e28667ab8b55f0c7408979e  HG Date: Wed Jul 25 14:42:03 2012 -0500
> [0]PETSC ERROR: See docs/changes/index.html for recent updates.
> [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
> [0]PETSC ERROR: See docs/index.html for manual pages.
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: C:\Obj_tmp\ibm3d_high_Re_staggered_AB2\Debug\ibm3d_high_Re_staggered_AB2.exe on a petsc-3.3 named USER-PC by User Sat Sep 15 09:12:58 2012
> [0]PETSC ERROR: Libraries linked from /cygdrive/d/wtay/Lib/petsc-3.3-dev_win32_vs2008/lib
> [0]PETSC ERROR: Configure run at Thu Jul 26 11:01:27 2012
> [0]PETSC ERROR: Configure options --with-cc="win32fe cl" --with-fc="win32fe ifort" --with-cxx="win32fe cl" --with-mpi-dir=/cygdrive/c/MPICH2/ --download-f-blas-lapack=1 --prefix=/cygdrive/d/wtay/Lib/petsc-3.3-dev_win32_vs2008 --with-debugging=1 --useThreads=0
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: User provided function() line 0 in unknown directory unknown file
> application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0
> 
> Btw, I've used both GMRES and BCGS as the ksp. What other options can I try?
> 
> Thanks
>> 
>> (I should make this the default)
>> 
>> Mark
>> 
> 

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