Hello,
I’ve been using the default newton line search nonlinear solver in petsc. I
recently discovered that the default line search method is bt – backtracking. I
have two questions.
1. How exactly does the backtracking line search use the L2 norm of the
function to modify the newton step?
What is the default maxstep value?
How do I find where this default value is set?
From: Barry Smith
Date: Tuesday, March 7, 2023 at 8:52 AM
To: "Angus, Justin Ray"
Cc: "petsc-dev@mcs.anl.gov"
Subject: Re: [petsc-dev] SNESNEWTONLS
On Mar 7, 2023, at 11:36 AM, Angus,
ject: Re: [petsc-dev] SNESNEWTONLS
On Tue, Mar 7, 2023 at 12:03 PM Angus, Justin Ray via petsc-dev
mailto:petsc-dev@mcs.anl.gov>> wrote:
Hi Barry,
Very helpful.
I’m still having some trouble with reconciling your answer to question number 2
based on some recent observations I have had. I’ve
y, March 7, 2023 at 9:16 AM
To: "Angus, Justin Ray" mailto:ang...@llnl.gov>>
Cc: Barry Smith mailto:bsm...@petsc.dev>>,
"petsc-dev@mcs.anl.gov<mailto:petsc-dev@mcs.anl.gov>"
mailto:petsc-dev@mcs.anl.gov>>
Subject: Re: [petsc-dev] SNESNEWTONLS
On Tue, Mar
Hello,
I’ve been able to successfully use -log_view in a cpp code using PETSc when
setting it through a .petscrc file. I get lots of information about the SNES
and KS solvers at the end of my simulation as expected.
However, if I instead try to turn on log_view from inside my cpp code, using
s
Hello,
A project I work on uses GMRES via PETSc. In particular, we have had good
successes using the Additive Schwarz Method + ILU preconditioner setup using a
CPU-based code. I found online where it is stated that “Parts of most
preconditioners run directly on the GPU”
(https://urldefense.us/
host for device matrix types.
You can try to see if it works for your case.
--Junchao Zhang
On Mon, Apr 14, 2025 at 4:39 PM Angus, Justin Ray via petsc-dev
mailto:petsc-dev@mcs.anl.gov>> wrote:
Hello,
A project I work on uses GMRES via PETSc. In particular, we have had good
successes usi
