Mark Adams via petsc-users writes:
> On Thu, Apr 4, 2019 at 7:35 AM Dave Lee wrote:
>
>> I already have the Navier Stokes solver. My issue is wrapping it in a JFNK
>> solver to find the periodic solutions. I will keep reading up on SVD
>> approaches, there may be some capability for something li
On Thu, Apr 4, 2019 at 7:36 AM Dave Lee via petsc-users <
petsc-users@mcs.anl.gov> wrote:
> Thanks Mark,
>
> I already have the Navier Stokes solver. My issue is wrapping it in a JFNK
> solver to find the periodic solutions. I will keep reading up on SVD
> approaches, there may be some capability
On Thu, Apr 4, 2019 at 7:35 AM Dave Lee wrote:
> Thanks Mark,
>
> I already have the Navier Stokes solver. My issue is wrapping it in a JFNK
> solver to find the periodic solutions. I will keep reading up on SVD
> approaches, there may be some capability for something like this in SLEPc.
>
Yes,
[keep on list]
On Thu, Apr 4, 2019 at 7:08 AM Dave Lee wrote:
> Hi Mark,
>
> Thanks for responding. My brief scan of the literature suggested that
> there are some methods out there to approximate the null space using SVD
> methods, but I wasn't sure how mature these methods were, or if PETSc ha
The Krylov space can not see the null space (by definition) and so getting
a useful near null space from it is not likely.
Getting a null space is a hard problem and bootstrap AMG methods, for
instance, are developed to try to do that. This is an advanced research
topic.
You really want to know y
Hello PETSc,
I'm attempting to solve a JFNK problem for a system where I only have a
function to compute the residual, but no matrix.
I wanted to know if there exists functionality in PETSc to do the following:
1) approximate a null space from a set of Krylov vectors
2) remove such a null space
