Ok, I don't understand the logic behind this but if you use
PetscFunctionBeginUser (not PetscFunctionBegin) the check on the exit to the
function is not done.
PetscCheckAbort(!stack__.check || stack__.petscroutine[stack__.currentsize] !=
1 || stack__.function[stack__.currentsize] == (const
> On 12 Jul 2023, at 6:04 PM, TARDIEU Nicolas via petsc-users
> wrote:
>
> Dear PETSc team,
>
> In the attached example, I set up a block pc for a saddle-point problem in
> petsc4py. The IS define the unknowns, namely some physical quantity (phys)
> and a Lagrange multiplier (lags).
> I wou
I created a small toy example (attached) that suggests that the verification of
matching PetscFunctionBeginUser() and PetscFunctionReturn() fails when
PetscFunctionReturn() is missing or in some cases when different functions are
missing PetscFunctionBeginUser() or PetscFunctionReturn(). The cas
By default, it is solving the problem as B^{-1}*A*x=lambda*x (see chapter on
Spectral Transformation). That is why A can be a shell matrix without problem.
But B needs to be an explicit matrix in order to compute an LU factorization.
If B is also a shell matrix then you should set an iterative s
Hello PETSc Users,
I have a generalised eigenvalue problem : Ax= lambda Bx
I used to have only A as a matrix-free method, I used mumps and an LU
preconditioner, everything worked fine.
Now B is matrix-free as well, and my solver is returning an error :
"MatSolverType mumps does not support matrix
Dear PETSc team,
In the attached example, I set up a block pc for a saddle-point problem in
petsc4py. The IS define the unknowns, namely some physical quantity (phys) and
a Lagrange multiplier (lags).
I would like to attach a near null space to the physical block, in order to get
the best perfo
The computed eigenvalue has 7 matching digits, which agrees with the used
tolerance. If you want more matching digits you have to reduce the tolerance.
The performance seems reasonable for up to 64 processes, so yes the problem may
be too small for more processes. But performance depends also a
Hi,
When I try to increase the number of processors to solve the same
matrix(to acquire the smallest eigenvalue) , I find all the results differ
from each other within the 1e-5 scope (Though the ||Ax-kx||/||kx|| are all
achieve 1e-8) . And the solve time are first decreasing then increasing.
my
