Hi Matt and PETSc.
Thanks again for the advice.
So I think I know what my problem might be. Looking at the comments above
the function
KSPInitialResidual()
in
src/ksp/ksp/interface/itres.c
I see that the initial residual, as passed into VEC_VV(0) is the residual
of the *preconditioned* system (an
On Fri, May 24, 2019 at 8:38 AM Dave Lee wrote:
> Thanks Matt, great suggestion.
>
> I did indeed find a transpose error this way. The SVD as reconstructed via
> U S V^T now matches the input Hessenberg matrix as derived via the
> *HES(row,col) macro, and all the singular values are non-zero. How
