I think what happens on the 1st version is that the input list has
len(3), and since the DMDA only has 1 dimension petsc4py throws the
first ValueError.

As far as I can tell, the code is expecting a list of lists: ie for
each dimension it gets ranges[i] (where i is the index for the
dimension) and casts it into an array. So I tried the 2nd version,
which fails regardless of whether I use lists or tuples, and I don't
understand why.

-Chris

On Thu, Apr 7, 2016 at 9:00 PM, Matthew Knepley <[email protected]> wrote:
> On Thu, Apr 7, 2016 at 1:52 PM, Chris Eldred <[email protected]> wrote:
>>
>> Hey All,
>>
>> (I sent this to petsc-users a few days ago and didn't get any replies,
>> figured I would try here as well...)
>>
>> Does anyone know the correct syntax for setting ownership ranges for
>> DMDAs in petsc4py? For example, if I have a 1D DMDA with 20 vertices
>> and 3 processes, and I want to distribute the vertices as [8,8,4],
>> should the correct create call be:
>>
>> da =
>> PETSc.DMDA().create(dim=1,dof=1,sizes=[20,],proc_sizes=[3,],boundary_type=[PETSc.DM.BoundaryType.PERIODIC,],
>> stencil_type= PETSc.DMDA.StencilType.BOX,
>> stencil_width=1,ownership_ranges=[8,8,4])
>>
>> or
>>
>> da =
>> PETSc.DMDA().create(dim=1,dof=1,sizes=[20,],proc_sizes=[3,],boundary_type=[PETSc.DM.BoundaryType.PERIODIC,],
>> stencil_type= PETSc.DMDA.StencilType.BOX,
>> stencil_width=1,ownership_ranges=[[8,8,4],])
>>
>> For me, the 1st version fails with
>> ValueError: number of dimensions 1 and number ownership ranges 3
>> (which I expected)
>> but the 2nd version also fails with
>> TypeError: Expected tuple, got list
>>
>> I have tried using tuples instead of lists and nothing changes.
>> Creating without the ownership_ranges argument works fine as well. Is
>> there something else I am missing?
>
>
> Here is the code:
>
>
> https://bitbucket.org/petsc/petsc4py/src/b234a50085607b793fce93d5dc46307c0d9b57c4/src/PETSc/petscdmda.pxi?at=master&fileviewer=file-view-default#petscdmda.pxi-150
>
> I do not understand why the 1st version fails.
>
>    Matt
>
>>
>> Thanks in advance for any assistance!
>>
>> Regards,
>> -Chris
>>
>>
>> --
>> Chris Eldred
>> Postdoctoral Fellow, LAGA, University of Paris 13
>> PhD, Atmospheric Science, Colorado State University, 2015
>> DOE Computational Science Graduate Fellow (Alumni)
>> B.S. Applied Computational Physics, Carnegie Mellon University, 2009
>> [email protected]
>
>
>
>
> --
> What most experimenters take for granted before they begin their experiments
> is infinitely more interesting than any results to which their experiments
> lead.
> -- Norbert Wiener



-- 
Chris Eldred
Postdoctoral Fellow, LAGA, University of Paris 13
PhD, Atmospheric Science, Colorado State University, 2015
DOE Computational Science Graduate Fellow (Alumni)
B.S. Applied Computational Physics, Carnegie Mellon University, 2009
[email protected]

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