On 11/7/07, Barry Smith bsmith at mcs.anl.gov wrote:
Go ahead add and add the features you'd like.
Well, I was thinking about all this. As I take very seriously all your
concerns, I've decided to implement anyway a full features 'python
shell' SNES. I was far more easier than I thought.
On Nov 8, 2007, at 3:00 PM, Lisandro Dalcin wrote:
On 11/7/07, Barry Smith bsmith at mcs.anl.gov wrote:
Go ahead add and add the features you'd like.
Well, I was thinking about all this. As I take very seriously all your
concerns, I've decided to implement anyway a full features
On 11/1/07, Barry Smith bsmith at mcs.anl.gov wrote:
On Nov 1, 2007 9:24 AM, Lisandro Dalcin dalcinl at gmail.com For
example, I would love to have SNESSetPresolve/SNESSetPostSolve
and
SNESSetPreStep/SNESSetPostStep, and perhaps a
SNESSetPreLinearSolve/SNESSetPostLinearSolve. Of
Lisandro,
Go ahead add and add the features you'd like.
Barry
On Nov 7, 2007, at 10:01 AM, Lisandro Dalcin wrote:
On 11/1/07, Barry Smith bsmith at mcs.anl.gov wrote:
On Nov 1, 2007 9:24 AM, Lisandro Dalcin dalcinl at gmail.com
For example, I would love to have
Actually, making the regularization parameter independent for each
process is much more efficient. Gene Golub had a poster on this at
the last SIAM CSE meeting.
Matt
On Nov 1, 2007 9:24 AM, Lisandro Dalcin dalcinl at gmail.com wrote:
On 10/31/07, Barry Smith bsmith at mcs.anl.gov wrote:
On Nov 1, 2007, at 10:16 AM, Matthew Knepley wrote:
Actually, making the regularization parameter independent for each
process is much more efficient. Gene Golub had a poster on this at
the last SIAM CSE meeting.
Matt
On Nov 1, 2007 9:24 AM, Lisandro Dalcin dalcinl at gmail.com wrote:
On 10/31/07, Barry Smith bsmith at mcs.anl.gov wrote:
Lisandro,
A followup to our previous discussion. It sounds to me like you
are actually solving an n+1 unknown nonlinear problem where the
special unknown is kept secret from SNES and managed somehow by the
application code?
That's
Lisandro,
A followup to our previous discussion. It sounds to me like you
are actually solving an n+1 unknown nonlinear problem where the
special unknown is kept secret from SNES and managed somehow by the
application code?
You can guess how I feel about this :-). PETSc/SNES is suppose
You might want to investigate FeasNewt from Todd Munson, which is
a very elegant solution of this problem.
Matt
On 10/29/07, Lisandro Dalcin dalcinl at gmail.com wrote:
Some time ago I made a request for adding SNESSetLinearSolve(), in
order to let users set a custom linear solve routine
)
KSPGetPC(
PCSetType(pc,PCSHELL);
PCShellSetApply(pc,YourSolver);
On Mon, 29 Oct 2007, Lisandro Dalcin wrote:
Some time ago I made a request for adding SNESSetLinearSolve(), in
order to let users set a custom linear solve routine to SNES. I was
not clear to me if this idea
ago I made a request for adding SNESSetLinearSolve(), in
order to let users set a custom linear solve routine to SNES. I was
not clear to me if this idea was finally accepted, so I want to ask
again.
I really needs this feature in the near future, I I would like this to
go
for adding SNESSetLinearSolve(), in
order to let users set a custom linear solve routine to SNES. I was
not clear to me if this idea was finally accepted, so I want to ask
again.
I really needs this feature in the near future, I I would like this to
go in the next petsc release. My
On 10/29/07, Lisandro Dalcin dalcinl at gmail.com wrote:
In practice, the only way to wrap any solver package is
KSPPREONLY+PCSHELL. And you actually implement the linear solve in PC,
not KSP.
I disagree here. See below.
If PETSc internals were implemented in C++, I would simply do:
MyKSP:
On Mon, 29 Oct 2007, Lisandro Dalcin wrote:
On 10/29/07, Barry Smith bsmith at mcs.anl.gov wrote:
I strongly resist this. Back in the bad old days, 1995?, there was
some pressure to allow SNES to use any linear solver package, not just
PETSc's. WELL, the whole idea then and now is
Barry,
That accomplishes essentially the same thing as Lisandro's proposed
SNESSetLinearSolve() but is more consistent with the existing framework of
PETSc. In fact, it seems *inconsistent* right now that there is a way to use
a shell PC but not a way to use a shell KSP. Since it is not
On 10/29/07, Barry Smith bsmith at mcs.anl.gov wrote:
This may be an error in our design, we may need a shell KSP. It would be
nice not to need it, but ...
You seem to be saying you want something much like a KSP shell?
Indeed. Perhaps we need one in the end, but I would prefer to avoid
So SNES is actually only seeing a system of size n? And you are
NOT using Newton's method on that nonlinear system of size n? Instead
you are solving some other linear system (defined by your solution
process) and pretending it is the Newton solution?
Barry
On Mon, 29 Oct 2007, Lisandro
On 10/29/07, Richard Tran Mills rmills at ornl.gov wrote:
Barry,
That accomplishes essentially the same thing as Lisandro's proposed
SNESSetLinearSolve() but is more consistent with the existing framework of
PETSc.
it seems like there ought to be a KSP shell option. But what might
this
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