On Tue, Jul 15, 2025 at 10:44 AM SCOTTO Alexandre <
alexandre.sco...@irt-saintexupery.com> wrote:
> The place where the problem is quite deep in a large code, I will try to
> isolate the problematic behaviour but this may take some time.
>
>
>
> @Matthew, is there a way in the Python API to check
The place where the problem is quite deep in a large code, I will try to
isolate the problematic behaviour but this may take some time.
@Matthew, is there a way in the Python API to check whether a vector is
assembled?
Regards,
Alexandre.
De : Matthew Knepley
Envoyé : mardi 15 juillet 2025 16
We check that the x argument is assembled in MatMultTranspose(), but not y.
It seems possible that y could have stashed values that get communicated
when the operation is performed. Why do we not check that y is assembled?
Thanks,
Matt
On Tue, Jul 15, 2025 at 9:36 AM Jose E. Roman wrote:
It is better if you can provide a full python script that we can run to
reproduce the problem.
Jose
> El 15 jul 2025, a las 14:49, SCOTTO Alexandre
> escribió:
>
> Ok I get it, Vec.assemble() is mandatory whenever MPI communications are
> required to get the values to appropriate processes.
A.multTranspose(x, y) produces y = A^t * x
If it is not the case, you are doing something wrong
I minimal working example will help us debug your approach.
You can take a look at the test folder
https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/tree/main/src/binding/petsc4py/test__;!!G_u
Ok I get it, Vec.assemble() is mandatory whenever MPI communications are
required to get the values to appropriate processes.
To provide more information, I am in a situation where I perform a
A.multTranspose(x, y), where y is a vector that has been filled in with values
earlier in the process.
On Tue, Jul 15, 2025 at 8:13 AM SCOTTO Alexandre via petsc-users <
petsc-users@mcs.anl.gov> wrote:
> Hello Jose,
>
> Thanks for your answer. Then it seems that I have under the hood usages of
> setValues() in my code since I do not explicitly make use of it but still
> has problems when not assemb
> On Jul 15, 2025, at 8:13 AM, SCOTTO Alexandre via petsc-users
> wrote:
>
> Hello Jose,
>
> Thanks for your answer. Then it seems that I have under the hood usages of
> setValues() in my code since I do not explicitly make use of it but still has
> problems when not assembling my vector.
Hello Jose,
Thanks for your answer. Then it seems that I have under the hood usages of
setValues() in my code since I do not explicitly make use of it but still has
problems when not assembling my vector. Do I need to assemble vectors after
Mat.mult or Scatter.scatter?
By the way, I did not kn
Assembly is needed after a call to x.setValues() or any of its variants.
https://urldefense.us/v3/__https://petsc.org/main/petsc4py/reference/petsc4py.PETSc.Vec.html*petsc4py.PETSc.Vec.setValue__;Iw!!G_uCfscf7eWS!cvSh6J_ggyBtDLAEXjAIxkYQUbKkTTiA-QPyYNKZh3E_iJjftgP4afSVeUnPwdIE84eDB6to38b3rFjJg9yRB1
Dear PETSc community,
As a beginner in the MPI world and with the PETSc library, I come with a
possibly very naive question.
I know from the documentation that assembling vectors must be done, but it is
not clear to me when to perform this operation.
Is there a simple way to know when a vector n
11 matches
Mail list logo
