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DAcreate2d process layout order
- To: petsc-users@xxxxxxxxxxx
- Subject: DAcreate2d process layout order
- From: Sean Dettrick <sean@xxxxxxxxxxxxxxxxxx>
- Date: Mon, 15 May 2006 22:14:31 -0400
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Hi,
I'm trying to use DACreate2d and KSP in my existing MPI application. I
already have a Cartesian communicator established, and I set
PETSC_COMM_WORLD equal to it and then call PetscInitialize.
This works fine on a prime number of CPUs, because there is only one
possible ordered MPI layout in one dimension. But with a non-prime
number there are two possible ordered layouts and it just happens that
my 2D CPU layout (determined by MPI_Cart_create) is the transpose of the
PETSc 2D CPU layout.
Is there a way to organize the DA layout more explicitly than with
DACreate2d? Or to tell PETSc to transpose its CPU order? I also
wonder about the 3D case.
thanks
Sean