Zero Pivot Row in LU Factorization

Tim Stitt timothy.stitt at
Sun Nov 25 12:54:54 CST 2007

Hi all,

Can anyone suggest ways of overcoming the following pivot error I keep 
receiving in my PETSc code during a KSPSolve().

[1]PETSC ERROR: Detected zero pivot in LU factorization
[1]PETSC ERROR: Zero pivot row 1801 value 0.00102826 tolerance 
0.00165189 * rowsum 1.65189e+09!

 From checking the documentation....the error is in row 1801, which 
means it is most likely not a matrix assembly issue?

I tried the following prior to the solve with no luck either.....

call KSPGetPC(ksp,pc,error)
call PCFactorSetShiftNonzero(pc,PETSC_DECIDE,error)

Is there anything else I can try?



Dr. Timothy Stitt <>
HPC Application Consultant - ICHEC (

Dublin Institute for Advanced Studies
5 Merrion Square - Dublin 2 - Ireland

+353-1-6621333 (tel) / +353-1-6621477 (fax)

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