[petsc-users] Trying to modify petrbf to use custom text file

Matthew Knepley knepley at gmail.com
Tue Mar 26 23:20:24 CDT 2013


On Wed, Mar 27, 2013 at 3:13 PM, Anil . <dasans at gmail.com> wrote:

> Matt,
>
> Petsc Options I use to run are....
> mpirun -np 4 ./reader -pc_type asm -sub_pc_type lu -sub_mat_type dense
> -ksp_monitor -ksp_rtol 1e-13 -ksp_max_it 100 -vecscatter_alltoall
> -log_summary
>

1) Always run with -ksp_view.

2) The relative tolerance is probably too tight, but that is secondary

3) Something is really wrong here. I am guessing something in the input not
what you want. If the interaction is
    truly short range, you would see significant drop in the residual on
the first iteration. First, take a look at the
    matrix using -mat_view draw:: -draw_pause -1. It should be banded.

    Matt

Attached is the output..It also contains my petsc configuration
>
>
>
> On Wed, Mar 27, 2013 at 7:59 AM, Matthew Knepley <knepley at gmail.com>wrote:
>
>> On Wed, Mar 27, 2013 at 11:58 AM, Anil . <dasans at gmail.com> wrote:
>>
>>> Matt,
>>>
>>> I am having around 3481 particles that are placed in an unstructured
>>> manner.
>>> Attached is the image showing the distribution.
>>>
>>
>>  Show me your PETSc options, and try playing with the number of blocks.
>> If you look
>> at the PetRBF paper, we give guidance for choosing the sizes.
>>
>>    Matt
>>
>>
>>>
>>> On Tue, Mar 26, 2013 at 11:45 PM, Matthew Knepley <knepley at gmail.com>wrote:
>>>
>>>> On Mon, Mar 25, 2013 at 10:38 PM, Anil . <dasans at gmail.com> wrote:
>>>>
>>>>> 1) Could not find the petrbf mailing list
>>>>> 2) Petrbf runs perfectly
>>>>> 3) Attached is the output with -ksp_view -ksp_monitor
>>>>>
>>>>> Just point me in the right direction. Issues might be very basic as I
>>>>> am starting to use Petsc
>>>>>
>>>>
>>>> This output is a little strange. Some partitions have 0 entries. I am
>>>> guessing this problem is very
>>>> small. For PeRBF, it does turn out to be optimal to use small blocks,
>>>> but the block size depends
>>>> on your interaction scale. Right now you have 75 blocks, which might be
>>>> too many for your small
>>>> problem.
>>>>
>>>>    Matt
>>>>
>>>>
>>>>> On Sat, Mar 23, 2013 at 2:18 AM, Matthew Knepley <knepley at gmail.com>wrote:
>>>>>
>>>>>> On Fri, Mar 22, 2013 at 10:58 PM, Anil . <dasans at gmail.com> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> I have a text file containing N rows.
>>>>>>> Each row with x,y,omega values.
>>>>>>> I am trying to interpolate this data onto a regular grid using petrbf
>>>>>>> But the KSP does not converge and am not able to find the reason.
>>>>>>>
>>>>>>> The code is available with the text files at
>>>>>>> https://www.dropbox.com/s/cypuwugbxo07kx0/rbf-interpolation.tar.gz
>>>>>>>
>>>>>>> I am very new to petsc and any direction how o proceed would be
>>>>>>> helpful.
>>>>>>>
>>>>>>
>>>>>> 1) Did you mail the petrbf list?
>>>>>>
>>>>>> 2) Could you run the petrbf examples?
>>>>>>
>>>>>> 3) We cannot tell anything about convergence without the output of
>>>>>> -ksp_view -ksp_monitor.
>>>>>>
>>>>>>    Matt
>>>>>>
>>>>>>
>>>>>>> --
>>>>>>> Sincerely
>>>>>>> Anil Das P V
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> 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
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Sincerely
>>>>> Anil Das P V
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> 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
>>>>
>>>
>>>
>>>
>>> --
>>> Sincerely
>>> Anil Das P V
>>>
>>
>>
>>
>> --
>> 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
>>
>
>
>
> --
> Sincerely
> Anil Das P V
>



-- 
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
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