Hi,
I updated petsc from 3.2 to 3.4. However, I found that the nonlinear solver
previously worked well now failed with massage DIVERGED_LINE_SEARCH.
My problem is extremely nonlinear, cubic line search may fail but Newton method
works.
With petsc 3.2, I only use basic Newton by calling
Hi Jed,
I added a third specie to my problem (step by step :-)).
Now my system is the following:
u_t - alpha u_xx +(k.u.v - q.w) = 0
v_t - beta v_xx +(k.u.v - q.w) = 0
w_t -(k.u.v - q.w) = 0
So I have 2 PDEs and 1 ODE. I put everything under IFunction and IJacobian.
For the PDEs I defined
On Tue, Oct 22, 2013 at 3:57 AM, Juha Jäykkä ju...@iki.fi wrote:
Barry,
I seem to have touched a topic which goes way past my knowledge of PETSc
internals, but it's very nice to see a thorough response nevertheless.
Thank
you. And Matthew, too.
After reading your suspicions about number
On Tuesday 22 October 2013 05:06:02 Matthew Knepley wrote:
On Tue, Oct 22, 2013 at 3:57 AM, Juha Jäykkä ju...@iki.fi wrote:
Barry,
I seem to have touched a topic which goes way past my knowledge of PETSc
internals, but it's very nice to see a thorough response nevertheless.
Thank
On Tue, Oct 22, 2013 at 5:12 AM, Juha Jäykkä ju...@iki.fi wrote:
On Tuesday 22 October 2013 05:06:02 Matthew Knepley wrote:
On Tue, Oct 22, 2013 at 3:57 AM, Juha Jäykkä ju...@iki.fi wrote:
Barry,
I seem to have touched a topic which goes way past my knowledge of
PETSc
internals,
On Tue, Oct 22, 2013 at 2:18 AM, Gong Ding gd...@ustc.edu wrote:
Hi,
I updated petsc from 3.2 to 3.4. However, I found that the nonlinear
solver previously worked well now failed with massage DIVERGED_LINE_SEARCH.
My problem is extremely nonlinear, cubic line search may fail but Newton
Add -snes_monitor -snes_converged_reason -ksp_monitor -ksp_converged_reason
-pc_type lu (send the output)
Does it now get stuck at the same time step or does it get past it? The
most common cause of this problem is an incorrect Jacobian
Matthew Knepley knep...@gmail.com writes:
We sometimes allocate temporary memory that we free afterwards (like 2
vectors which we use to setup the scatters). It will not be allocated
at the same time as other vectors, but if the OS does not reclaim the
memory, it will show up on RSS.
That
Hi, I'm trying to solve a vibration generalized eigenvalue problem like
this:
| KC | = lambda* | M 0 |
| C^t 0 || 0 0 |
I have try a lot of convinations eigensolvers, KSP and PC, but I can't make
that it works.
I use the ST shift-and-invert to get the firsts 5
El 22/10/2013, a las 14:39, Ricardo Marquez escribió:
Hi, I'm trying to solve a vibration generalized eigenvalue problem like this:
| KC | = lambda* | M 0 |
| C^t 0 || 0 0 |
I have try a lot of convinations eigensolvers, KSP and PC, but I can't make
that
Hi Barry,
Thanks for suggestions. Here is the output.
Before using the options you suggest I get:
TSAdapt 'basic': step 182 accepted t=0.341561 + 3.416e-02 wlte=1.1e-09
family='arkimex' scheme=0:'3' dt=3.757e-02
TSAdapt 'basic': step 183 accepted t=0.375717 + 3.757e-02
wlte=9.05e-14
On Tue, Oct 22, 2013 at 8:29 AM, Christophe Ortiz
christophe.or...@ciemat.es wrote:
Hi Barry,
Thanks for suggestions. Here is the output.
Before using the options you suggest I get:
TSAdapt 'basic': step 182 accepted t=0.341561 + 3.416e-02 wlte=1.1e-09
family='arkimex' scheme=0:'3'
On Tue, Oct 22, 2013 at 3:37 PM, Matthew Knepley knep...@gmail.com wrote:
On Tue, Oct 22, 2013 at 8:29 AM, Christophe Ortiz
christophe.or...@ciemat.es wrote:
Hi Barry,
Thanks for suggestions. Here is the output.
Before using the options you suggest I get:
TSAdapt 'basic': step 182
Hi,
I have a linear system with about 161^3=4,173,281 unknowns. I used the default
KSP solver(to my understand it is GMRES) to solve it. The relative tolerance is
set as 1.266e-9. The number of iterations is 5373 and the computing time
problem is about 23.65 mins with 128 processes. With
On Tue, Oct 22, 2013 at 1:58 PM, Roc Wang pengxw...@hotmail.com wrote:
Hi,
I have a linear system with about 161^3=4,173,281 unknowns. I used the
default KSP solver(to my understand it is GMRES) to solve it. The relative
tolerance is set as 1.266e-9. The number of iterations is 5373 and the
On 10/22/2013 09:16 PM, Matthew Knepley wrote:
There are no blackbox preconditioners. You must find one that matches
your system. The right thing to do
is to lookup the literature on your problem and see what other people
have done. It should be easy to
replicate in PETSc.
+ The first thing
Thanks for the answer. It makes sense.However, in my case, matrix A is huge and rather sparse, which also owns a pretty good diagonal structure although there are some other elements are nonzero. I have to look for a better way to solve the system more efficiently. If in parallel, it is even
On Tue, Oct 22, 2013 at 3:04 PM, huaibao zhang paulhuaizh...@gmail.comwrote:
Thanks for the answer. It makes sense.
However, in my case, matrix A is huge and rather sparse, which also owns a
pretty good diagonal structure although there are some other elements are
nonzero. I have to look
-- Forwarded message --
From: paul zhang paulhuaizh...@gmail.com
Date: Tue, Oct 22, 2013 at 4:12 PM
Subject: Re: [petsc-users] Fwd: How PETSc solves Ax=b in parallel
To: Matthew Knepley knep...@gmail.com
One more question, can I solve the system in parallel?
On Tue, Oct 22,
On Tue, Oct 22, 2013 at 3:12 PM, paul zhang paulhuaizh...@gmail.com wrote:
One more question, can I solve the system in parallel?
Yes, or you would be using ETSC :)
Matt
On Tue, Oct 22, 2013 at 4:08 PM, Matthew Knepley knep...@gmail.comwrote:
On Tue, Oct 22, 2013 at 3:04 PM, huaibao
That is a good one. I mean for my case. which method can I try?
On Tue, Oct 22, 2013 at 4:14 PM, Matthew Knepley knep...@gmail.com wrote:
On Tue, Oct 22, 2013 at 3:12 PM, paul zhang paulhuaizh...@gmail.comwrote:
One more question, can I solve the system in parallel?
Yes, or you would be
On Tue, Oct 22, 2013 at 3:16 PM, paul zhang paulhuaizh...@gmail.com wrote:
That is a good one. I mean for my case. which method can I try?
Both those direct methods are parallel (SuperLU_dist and MUMPS).
Matt
On Tue, Oct 22, 2013 at 4:14 PM, Matthew Knepley knep...@gmail.comwrote:
On
Appreciate it.
Paul
On Tue, Oct 22, 2013 at 4:25 PM, Matthew Knepley knep...@gmail.com wrote:
On Tue, Oct 22, 2013 at 3:16 PM, paul zhang paulhuaizh...@gmail.comwrote:
That is a good one. I mean for my case. which method can I try?
Both those direct methods are parallel (SuperLU_dist and
Hi all,
The problem is solved.
I previously use
ierr = SNESSetType(snes,SNESNEWTONLS);
ierr = SNESLineSearchCreate(PETSC_COMM_WORLD, snesls);
ierr = SNESLineSearchSetType(snesls, SNESLINESEARCHBASIC);
This method create a new snesls, but not work.
Barry told me that I should use
ierr =
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