[petsc-users] EPSKrylovSchurSetDetectZeros() not working

[Jose E. Roman]

> El 24 jul 2016, a las 19:50, Hassan Md Mahmudulla <mhassan at miners.utep.edu> escribió:
> 
> Hi,
> I am solving a generalized eigenvalue problem using spectrum slicing. I am using this example (http://slepc.upv.es/documentation/current/src/eps/examples/tutorials/ex25.c.html) as it is. Part of the code is:
> ierr =EPSKrylovSchurSetDetectZeros(eps,PETSC_TRUE);CHKERRQ(ierr);
> 
> But I am getting the following: 
> 
> [0]PETSC ERROR: Mismatch between number of values found and information from inertia, consider using EPSKrylovSchurSetDetectZeros()
> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
> 
> It seems the input PETSC_TRUE is not working for EPSKrylovSchurSetDetectZeros(). Any idea?
> 
> M Hassan

It seems that you are not using MUMPS. Spectrum slicing can be used with PETSc's Cholesky, but for guaranteed robustness it is necessary to use MUMPS.

Jose