[petsc-users] PETScFE Point Source

[Matthew Knepley]

On Fri, Apr 13, 2018 at 1:51 PM, Robert Walker <rlwalker at usc.edu> wrote:

> Ok, let me rephrase that...something like way FEniCS (if i remember
> correctly) handles this ... between two values with a very small difference
> between them on each axis? Is there an example of something like that to
> use as a security blanket from which to expand?
>

I would start with a Gaussian source at some point, and then push it toward
the limit. That way you know
all the correct normalization, and its smooth.

  Matt


> Robert
>
> Robert L. Walker
> MS Petroleum Engineering
> Mork Family Department of Chemicals and Materials Sciences
> University of Southern California
> ----------------------------------------------
> Mobile US: +1 (213) - 290 -7101
> Mobile EU: +34 62 274 66 40
> rlwalker at usc.edu
>
> On Fri, Apr 13, 2018 at 10:46 AM, Matthew Knepley <knepley at gmail.com>
> wrote:
>
>> On Fri, Apr 13, 2018 at 1:40 PM, Robert Walker <rlwalker at usc.edu> wrote:
>>
>>> Hello,
>>>
>>> Is there an example of application of a point source in one of the
>>> tutorial  PETScFE style examples? Ideally this would be some point on the
>>> interior, and not necessarily on a boundary.
>>>
>>> Thanks, and apologies in advance if this is a stupid question,
>>>
>>
>> No, good question. You would have to decide what that meant in FEM terms.
>> All the internal integrals are done
>> with quadrature. So putting the source at a quadrature point would work,
>> although its a little difficult to know where
>> they will be. You could smooth it out a little, and check coordinates in
>> the forcing function. Last, you could check
>> for a "close enough" quadrature point and put it there. I think making a
>> slightly extended source is usually best.
>>
>>   Thanks,
>>
>>      Matt
>>
>>
>>> Robert
>>>
>>>
>>> Robert L. Walker
>>> MS Petroleum Engineering
>>> Mork Family Department of Chemicals and Materials Sciences
>>> University of Southern California
>>> ----------------------------------------------
>>> Mobile US: +1 (213) - 290 -7101
>>> Mobile EU: +34 62 274 66 40
>>> rlwalker at usc.edu
>>>
>>
>>
>>
>> --
>> 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
>>
>> https://www.cse.buffalo.edu/~knepley/
>> <https://urldefense.proofpoint.com/v2/url?u=http-3A__www.caam.rice.edu_-7Emk51_&d=DwMFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=BWOpUsAp5dvI5cUiP4uZxQ&m=NhwycEffStNWdPC1pT8qnGZOOnaReNM_T0V8yU1UKHE&s=qwCDj6rCWjIJ1T-NmL3j1bZCdrFx5cOVzTA-l0e0W0o&e=>
>>
>
>


-- 
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

https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/>
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