[Trilinos-Users] Matrix-Free Method

[Matt McGurn]

Hi,

I’m trying to implement the matrix free solver, but my solution has a very hard time converging.  I’ve been going though some debugging and I was able to get the GMRES solver to tell me: 
	***************************************************************

	Warning: the GMRES Hessenberg matrix is ill-conditioned.  This may 
	indicate that the application matrix is singular. In this case, GMRES
	may have a least-squares solution.

	***************************************************************

I tried to output the linear the system however I does not seem to be capable because it is matrix free:
	Error: NOX::Epetra::LinearSystemAztecOO::applyJacobianInverse() - Could not cast the Jacobian operator to an Epetra_RowMatrix!Please set the "Write Linear System" parameter to false.

Does anybody have any advice on further debugging, is there a way I can see the linear system?  Or is there a better approach for near singular systems?

Thanks,
Matt