Ed, I agree with you that there is a problem with how the interface is
presented and guidelines need to be improved. That's why your feedback is so
valuable - and we appreciate it. I created Table 12 (ref below) to make things
more clear, but based on your and others feedback is definitely not
Karl Lin writes:
> Thanks for the feedback. What about if I build A to have as many rows as A
> and B and then later on use MatGetRow and MatSetValues to add B matrix
> entries to A? Can MatGetRow and MatSetValues be used after MatAssembly is
> called? B is much much smaller than A so the number
Thanks for the feedback. What about if I build A to have as many rows as A
and B and then later on use MatGetRow and MatSetValues to add B matrix
entries to A? Can MatGetRow and MatSetValues be used after MatAssembly is
called? B is much much smaller than A so the number of rows can be added to
Karl Lin writes:
> I guess another way to look at this is if I already build matrix A and
> MatAssembly has been called. Can I populate more rows to matrix A later on?
> With the number of columns and column ownership pattern not changed of
> course. Thank you.
No.
I guess another way to look at this is if I already build matrix A and
MatAssembly has been called. Can I populate more rows to matrix A later on?
With the number of columns and column ownership pattern not changed of
course. Thank you.
On Mon, Aug 31, 2020 at 10:29 PM Jed Brown wrote:
> Karl
Karl Lin writes:
> Thanks for the quick reply. The reason why I want to do this is because I
> would like to build A and B separately first. Then do something with B by
> itself. Then scale B by a constant. Then append B to A to make C and
> continue some other matrix operations. I took a look
Thanks for the quick reply. The reason why I want to do this is because I
would like to build A and B separately first. Then do something with B by
itself. Then scale B by a constant. Then append B to A to make C and
continue some other matrix operations. I took a look at
MatGetLocalSubMatrix()
Karl Lin writes:
> If I have two matrix A and B with the same number of columns, same
> distribution pattern (column ownership pattern) among processes but
> different number of rows, is there a function to append B to A to make a
> new matrix C = [A; B]? Thanks.
Sort of; you can create a
If I have two matrix A and B with the same number of columns, same
distribution pattern (column ownership pattern) among processes but
different number of rows, is there a function to append B to A to make a
new matrix C = [A; B]? Thanks.
Emil --
When I use PETSc on various tasks, so far, I have separated (1) how
I describe the problem structure for use by the PETSc component, and (2)
the choice of solver. For TS I am confused about what is expected by the
design you describe. I would like to describe my ODE system as clearly as
On 8/31/20 12:17 PM, Ed Bueler wrote:
Emil --
Thanks for looking at this.
> Hi Ed, can you please add the following
> TSSetEquationType(ts,TS_EQ_IMPLICIT);
> before calling TSSolve and try again? This is described in Table 12 in the
> pdf doc.
Yep, that fixes it. After setting the
On Mon, Aug 31, 2020 at 4:00 PM Thibault Bridel-Bertomeu <
thibault.bridelberto...@gmail.com> wrote:
>
>
> Le lun. 31 août 2020 à 20:35, Matthew Knepley a
> écrit :
>
>> On Mon, Aug 31, 2020 at 9:45 AM Thibault Bridel-Bertomeu <
>> thibault.bridelberto...@gmail.com> wrote:
>>
>>> Hi Matt,
>>>
Le lun. 31 août 2020 à 20:35, Matthew Knepley a écrit :
> On Mon, Aug 31, 2020 at 9:45 AM Thibault Bridel-Bertomeu <
> thibault.bridelberto...@gmail.com> wrote:
>
>> Hi Matt,
>>
>> OK so I tried to replicate the problem starting from one of the tests in
>> PETSc repo.
>> I found
>>
thanks for the info.
regards,
kun
On Aug 31, 2020 2:20 PM, Matthew Knepley wrote:
On Mon, Aug 31, 2020 at 3:12 PM Barry Smith
mailto:bsm...@petsc.dev>> wrote:
On Aug 31, 2020, at 2:08 PM, Kun Jiao mailto:kj...@slb.com>>
wrote:
If I am correct, to do this, it will double the peak memory
On Mon, Aug 31, 2020 at 3:12 PM Barry Smith wrote:
> On Aug 31, 2020, at 2:08 PM, Kun Jiao wrote:
>
> If I am correct, to do this, it will double the peak memory usage.
>
>
> Yes
>
>
> Is there any way no to double the peak memory usage?
>
>
> The only way would be to destroy the old
> On Aug 31, 2020, at 2:08 PM, Kun Jiao wrote:
>
> If I am correct, to do this, it will double the peak memory usage.
Yes
>
> Is there any way no to double the peak memory usage?
The only way would be to destroy the old matrix, allocate a new one and
recompute the entries.
Barry
If I am correct, to do this, it will double the peak memory usage.
Is there any way no to double the peak memory usage?
Schlumberger-Private
From: Barry Smith
Sent: Monday, August 31, 2020 1:56 PM
To: Kun Jiao
Cc: petsc-users
Subject: [Ext] Re: [petsc-users] change matrix
Kun,
This
Kun,
This is not possible, PETSc matrices have a static size (resizing in
parallel is tricky so we don't support it).
If it is more efficient to reuse the matrix entries than recompute them you
can create a larger matrix and then loop over the old matrix calling
MatGetRow() and then
On Mon, Aug 31, 2020 at 2:51 PM Kun Jiao via petsc-users <
petsc-users@mcs.anl.gov> wrote:
> Hi Petsc Experts,
>
>
>
> Trying to do something like appending some rows (~100 rows) to an already
> created matrix, but could not find any document about it.
>
>
>
> Could anyone provide some
Sophie,
Thanks.
The factor of 4 is lot, the 1.5 not so bad.
You will definitely want to retain the full matrix assembly codes for speed
and to verify a reduced matrix version.
It is worth trying a "reduced matrix version" with matrix-free multiply
based on these numbers. This
Hi Petsc Experts,
Trying to do something like appending some rows (~100 rows) to an already
created matrix, but could not find any document about it.
Could anyone provide some information about it?
Regards,
Kun
Schlumberger-Private
On Mon, Aug 31, 2020 at 9:45 AM Thibault Bridel-Bertomeu <
thibault.bridelberto...@gmail.com> wrote:
> Hi Matt,
>
> OK so I tried to replicate the problem starting from one of the tests in
> PETSc repo.
> I found
> https://gitlab.com/petsc/petsc/-/blob/master/src/dm/impls/plex/tests/ex20.c
>
Hi Barry,
I ran the 2 cases to look at the effect of the Jacobi pre-conditionner:
* 1D with 200 grid points and 7759 DOF per grid point (for the PSI
application), for 20 TS: the factor between SOR and Jacobi is ~4 (976 MatMult
for SOR and 4162 MatMult for Jacobi)
* 2D with 63x63 grid
Oh, cool.
Thanks, Jose,
I will try that.
Fande,
On Mon, Aug 31, 2020 at 11:11 AM Jose E. Roman wrote:
> Call EPSMonitorCancel() before EPSMonitorSet().
> Jose
>
>
> > El 31 ago 2020, a las 18:33, Fande Kong escribió:
> >
> > Hi All,
> >
> > There is a statement on API EPSMonitorSet:
> >
> >
Sure, random definitely is better.
Seems like worth putting in (at least debug mode) since it will catch nearly
all incorrect uses of this functionality.
Barry
> On Aug 31, 2020, at 10:23 AM, Jed Brown wrote:
>
> Ed Bueler writes:
>
> I realize the ARKIMEX page does say
Emil --
Thanks for looking at this.
> Hi Ed, can you please add the following
> TSSetEquationType(ts,TS_EQ_IMPLICIT);
> before calling TSSolve and try again? This is described in Table 12 in
the pdf doc.
Yep, that fixes it. After setting the TS_EQ_IMPLICIT flag programmatically
I get:
$
Call EPSMonitorCancel() before EPSMonitorSet().
Jose
> El 31 ago 2020, a las 18:33, Fande Kong escribió:
>
> Hi All,
>
> There is a statement on API EPSMonitorSet:
>
> "Sets an ADDITIONAL function to be called at every iteration to monitor the
> error estimates for each requested
Hi All,
There is a statement on API EPSMonitorSet:
"Sets an ADDITIONAL function to be called at every iteration to monitor the
error estimates for each requested eigenpair."
I was wondering how to replace SLEPc EPS monitors instead of adding one? I
want to use my monitor only.
Thanks,
Fande,
Ed Bueler writes:
I realize the ARKIMEX page does say "Methods with an explicit stage can
only be used with ODE in which the stiff part G(t,X,Xdot) has the form
> Xdot
+ Ghat(t,X)." So my example does not do that. Is there a way for
ARKIMEX to detect that dG/d(Xdot) = I?
>>
On 8/30/20 6:04 PM, Ed Bueler wrote:
Actually, ARKIMEX is not off the hook. It still gets the wrong answer if told
the whole thing is implicit:
$ ./ex54 -ts_type arkimex -ts_arkimex_fully_implicit# WRONG (AND REALLY
SLOW)
error norm at tf = 1.00 from 224 steps: |u-u_exact| =
Hi Matt,
OK so I tried to replicate the problem starting from one of the tests in
PETSc repo.
I found
https://gitlab.com/petsc/petsc/-/blob/master/src/dm/impls/plex/tests/ex20.c
that
actually uses DMAdaptLabel.
Just add
{
DM
On Mon, Aug 31, 2020 at 5:34 AM Thibault Bridel-Bertomeu <
thibault.bridelberto...@gmail.com> wrote:
> Dear all,
>
> I have recently been playing around with the AMR capabilities embedded in
> PETSc for quad meshes using p4est. Based on the TS tutorial ex11, I was
> able to incorporate the AMR
Dear all,
I have recently been playing around with the AMR capabilities embedded in
PETSc for quad meshes using p4est. Based on the TS tutorial ex11, I was
able to incorporate the AMR into a pre-existing code with different metrics
for the adaptation process.
Now I would like to do something
>>> I realize the ARKIMEX page does say "Methods with an explicit stage can
>>> only be used with ODE in which the stiff part G(t,X,Xdot) has the form
Xdot
>>> + Ghat(t,X)." So my example does not do that. Is there a way for
>>> ARKIMEX to detect that dG/d(Xdot) = I?
>
>> Other than sampling its
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