[petsc-users] SLEPc Eigenvalue problem - Zero Pivot

[Jose E. Roman]

El 13/05/2015, a las 17:28, venkatesh g escribió:

> Dear All,
> 
> I am having a block matrix Eigenvalue problem AX = lambda BX
> 
> My B is singular, it is a block matrix and only one block has non-zero values. 
> 
> Matlab Eigs is giving the result. 
> 
> I am using option: "./ex7 -f1 A1 -f2 B1 -st_type sinvert"  
> 
> Result is: Detected zero pivot in LU factorization.
> 
> The ex7 is an example from SLEPc. 
> 
> Pls advice what to do ? 
> 
> cheers,
> Venkatesh
> 
> 

If you know where your wanted eigenvalues are, set the target value, for instance:
./ex7 -f1 A1 -f2 B1 -st_type sinvert -eps_target 0.5

Jose