[Nek5000-users] Average in arbitrary direction

[nek5000-users at lists.mcs.anl.gov]

Hello Aleks,

I see the three routines I need, and I think I understand the basics
of the functions (although I think it would still be nice to see an
example if you are still working on updating it).

I had some quick questions about the routine intpts_setup...it defines
some variables npt_max, nxf, nyf, nzf.  Could you give a quick
definition of the meaning of these 4 variables to the findpts_setup
routine?

Particularly, at least in the repo I have, npt_max is set to 256.  Do
I need to change this if I'll be needing to interpolate onto more than
256 points (or does this mean something else)?

Thanks,

Josh

On Thu, May 19, 2011 at 3:06 PM,  <nek5000-users at lists.mcs.anl.gov> wrote:
> Hi Josh,
>
> yes, there are 3 intpts* routines from postpro.f that you can use. I have an example but I need to update it for the current repo version of this routines -- I'll send it to you once I modify and test it.
>
> Best,
> Aleks
>
>
> ----- Original Message -----
> From: nek5000-users at lists.mcs.anl.gov
> To: nek5000-users at lists.mcs.anl.gov
> Sent: Thursday, May 19, 2011 9:21:03 AM
> Subject: Re: [Nek5000-users] Average in arbitrary direction
>
> Hello Paul,
>
> This sound like exactly what I need.  I didn't find anything like
> interp() while using grep in the repo--are you referring to the
> routines found in postpro.f ??
>
> Thanks,
>
> Josh
>
> On Wed, May 18, 2011 at 3:59 PM,  <nek5000-users at lists.mcs.anl.gov> wrote:
>>
>> Hi Josh,
>>
>> You can use the interp() routines --- let me check if we have
>> examples in the repo.
>>
>> These are somewhat expensive, so if you're also integrating in
>> time (even over just 10 steps), it would pay to only interpolate
>> the time-averaged data, rather than interpolating every timestep
>> and then averaging the profiles.   However, I can understand that
>> there are times you'd want the full time signal.
>>
>> The best integration formulae for periodic signals (e.g., in your theta
>> direction and perhaps in z, if you have periodicity)
>> is to simply sum the values, sampled uniformly in space (z or
>> theta), and dived by n, the number of samples.   You do need
>> to sample with sufficient density to capture all the wiggles ---
>> another reason that time averaging has value.
>>
>> Paul
>>
>>
>>
>> On Wed, 18 May 2011, nek5000-users at lists.mcs.anl.gov wrote:
>>
>>> Hello Neks,
>>>
>>> I have looked at the turbChannel example for an example on planar
>>> averaging.
>>>
>>> However, I was wondering if there was any advice  on how to do this if
>>> the elements aren't exactly "nice"... (i.e., the elements may have
>>> arbitrary rotations)
>>>
>>> Specifically, I have a pipe flow, and I am wanting to do an average in
>>> the z (axial) direction.  My initial thoughts were to interpolate my
>>> values to set R, theta components, and then average this along z.  I'm
>>> stuck on the best way to do either one of these operations, however
>>> (especially because I would like to use an integration rule to compute
>>> the average in the z direction).
>>>
>>> If anyone could point me in the right direction, that would be a big
>>> help.  Thanks!
>>>
>>> --
>>> Josh Camp
>>>
>>> "All that is necessary for the triumph of evil is that good men do
>>> nothing" -- Edmund Burke
>>> _______________________________________________
>>> Nek5000-users mailing list
>>> Nek5000-users at lists.mcs.anl.gov
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>
>
>
> --
> Josh Camp
>
> "All that is necessary for the triumph of evil is that good men do
> nothing" -- Edmund Burke
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-- 
Josh Camp

"All that is necessary for the triumph of evil is that good men do
nothing" -- Edmund Burke