[petsc-users] SLEPc Eigenvalue problem - Zero Pivot

[Jose E. Roman]

El 14/05/2015, a las 19:13, venkatesh g escribió:

> Hi, 
> 1. I am not calling EPSSetFromOptions in source code. I am using the ex7.c given in the SLEPc webpage. 
> 2. A-matrix is not singular. Only B is singular.
> 3. I will try with MUMPS.
> 4. Matrix sizes are same as in Matlab. If B is not singular it is giving same result as Matlab, but if B is singular it gives the zero pivot issue which Matlab doesnt give. 
> So is there a way ?
> 

The ex7.c example calls EPSSetFromOptions(). If it is not called, then command-line options are ignored.

It is strange that you get zero pivots when factoring A-sigma*B for different values of sigma. Try with MUMPS.

Jose