[petsc-users] FPE when trying to find the condition number

[baikadi pranay]

Hello,

I am trying to find the condition number of the A matrix for a linear
system I am solving. I have used the following commands.

*./a.out -ksp_monitor_singular_value -ksp_type gmres -ksp_gmres_restart
1000 -pc_type none*However, the execution comes to a halt after a few
iterations with the following error.
[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] LAPACKgesvd line 40
/packages/7x/petsc/3.11.1/petsc-3.11.1/src/ksp/ksp/impls/gmres/gmreig.c
[0]PETSC ERROR: [0] KSPComputeExtremeSingularValues_GMRES line 22
/packages/7x/petsc/3.11.1/petsc-3.11.1/src/ksp/ksp/impls/gmres/gmreig.c
[0]PETSC ERROR: [0] KSPComputeExtremeSingularValues line 59
/packages/7x/petsc/3.11.1/petsc-3.11.1/src/ksp/ksp/interface/itfunc.c
[0]PETSC ERROR: [0] KSPMonitorSingularValue line 130
/packages/7x/petsc/3.11.1/petsc-3.11.1/src/ksp/ksp/interface/iterativ.c
[0]PETSC ERROR: [0] KSPMonitor line 1765
/packages/7x/petsc/3.11.1/petsc-3.11.1/src/ksp/ksp/interface/itfunc.c
[0]PETSC ERROR: [0] KSPGMRESCycle line 122
/packages/7x/petsc/3.11.1/petsc-3.11.1/src/ksp/ksp/impls/gmres/gmres.c
[0]PETSC ERROR: [0] KSPSolve_GMRES line 225
/packages/7x/petsc/3.11.1/petsc-3.11.1/src/ksp/ksp/impls/gmres/gmres.c
[0]PETSC ERROR: [0] KSPSolve line 678
/packages/7x/petsc/3.11.1/petsc-3.11.1/src/ksp/ksp/interface/itfunc.c
[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR: Signal received
[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for
trouble shooting.
[0]PETSC ERROR: Petsc Release Version 3.11.1, Apr, 12, 2019
[0]PETSC ERROR: ./a.out on a linux-gnu-c-debug named cg17-9.agave.rc.asu.edu
by pbaikadi Thu Oct 22 12:07:11 2020
[0]PETSC ERROR: Configure options
[0]PETSC ERROR: #1 User provided function() line 0 in  unknown file
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD
with errorcode 59.

NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.
--------------------------------------------------------------------------
Is the error because the A matrix is singular (causing the max/min to be
undefined)? Please let me know.

Thank you,
Sincerely,
Pranay.
ᐧ
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20201022/8767c75f/attachment.html>