Hi Saikat, Nek provides routines to interpolate from its own spectral element mesh to any other grid. Going from any other grid to (x,y,z) [ given by entries in xm1(),ym1(),zm1()], requires an interpolator designed for that grid. You could, say, use some sort of piecewise polynomial or piecewise linear interpolant --- it would be a routine that you could develop and test as a stand-alone code on your own before putting into your usr file. hth, Paul ________________________________ From: Nek5000-users <[email protected]> on behalf of [email protected] <[email protected]> Sent: Monday, June 4, 2018 10:44:10 AM To: nek5000-users Subject: Re: [Nek5000-users] Using Cartesian grid lookup table in Nekton Thanks Paul, I will try this. Regarding the interpolation, do we have a subroutine that interpolates from uniform grid to GLL grid in nek5000? Thanks, Saikat Saikat Mukherjee, PhD Student, Paul Research Group - http://www.me.vt.edu/mpaul/ Engineering Science and Mechanics, Virginia Tech. On Mon, Jun 4, 2018 at 7:32 AM, <[email protected]<mailto:[email protected]>> wrote: Hi Saikat, If it's not too big for loading onto each rank, I would do the following, which is not very parallel, but is quite effective up to modest array sizes: subroutine usrdat2 include 'SIZE' include 'TOTAL' parameter (my_array_size=10000) real my_array(my_array_size), work(my_array_size) n = my_array_size call rzero(my_array,n) call rzero(work. ,n) if (nid.eq.0) then open (unit=49,file='myfile') read(49,*) (my_array(k),k=1,n) close(49) endif call gop(my_array,work,'+ ',n) ! Sum over all processors return end I've not tested this code... just wrote it here but it should work as is. Paul ________________________________ From: Nek5000-users <[email protected]<mailto:[email protected]>> on behalf of [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> Sent: Sunday, June 3, 2018 11:11:29 PM To: nek5000-users Subject: Re: [Nek5000-users] Using Cartesian grid lookup table in Nekton Hey Paul, Thanks for the reply. I have never really used the mpi architecture of Nek5000. I am thinking this should be a separate subroutine on the .usr file where I have to copy it onto each mpi rank? My finite difference grid is not that big. So the interpolation into SEM points should be easy. I would like to know how to copy it onto each MPI rank. Thanks, Saikat Saikat Mukherjee, PhD Student, Paul Research Group - http://www.me.vt.edu/mpaul/ Engineering Science and Mechanics, Virginia Tech. On Thu, May 31, 2018 at 7:58 AM, <[email protected]<mailto:[email protected]>> wrote: Hi Saikat, How large is your finite-difference look up table? (1 million points? 1 billion? 1000?) If it's not too large you can just copy it onto each mpi rank and then call your own serial interpolation routine for each SEM point, x,y,z, and store the results into an array in a common block that you can then reference in users Presumably you'd have to do this interpolation only one time and then de-reference the values from the common block on each time step with fairly low overhead. Paul ________________________________ From: Nek5000-users <[email protected]<mailto:[email protected]>> on behalf of [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> Sent: Wednesday, May 30, 2018 2:42:14 PM To: [email protected]<mailto:[email protected]> Subject: Re: [Nek5000-users] Using Cartesian grid lookup table in Nekton There is nothing spectral element specific here. You could do e.g. a trilinear interpolation but that's something you have to code yourself. -----Original message-----
From:[email protected]<mailto:From%[email protected]> <[email protected]<mailto:[email protected]>> Sent: Wednesday 30th May 2018 21:26 To: nek5000-users <[email protected]<mailto:[email protected]>> Subject: Re: [Nek5000-users] Using Cartesian grid lookup table in Nekton
The question is how to read in a discrete data set defined in a finite difference grid in ffx or forcing in the .usr file. It seems like there will be some sort of interpolation to the spectral element grid. So yes, that is my question.
Thank you, Saikat <br clear="all" />Saikat Mukherjee, PhD Student, Paul Research Group - http://www.me.vt.edu/mpaul/ <http://www.me.vt.edu/mpaul/> Engineering Science and Mechanics, Virginia Tech.
On Wed, May 30, 2018 at 2:48 PM, <[email protected]<mailto:[email protected]> <mailto:[email protected]>> wrote: What’s your question? How to do the interpolation in your function f?
On 30 May 2018, at 20:17, "[email protected]<mailto:[email protected]> <mailto:[email protected]>" <[email protected]<mailto:[email protected]> <mailto:[email protected]>> wrote:
Hi,
Thanks for the reply. My problem is f is given as a discrete data set described in finite difference grid. I want to interpolate this to ffx like you said in my .usr file. Would like to know how to proceed.
Thanks, Saikat <br clear="all" />Saikat Mukherjee, PhD Student, Paul Research Group - http://www.me.vt.edu/mpaul/ <http://www.me.vt.edu/mpaul/> Engineering Science and Mechanics, Virginia Tech.
On Wed, May 30, 2018 at 1:36 PM, <[email protected]<mailto:[email protected]> <mailto:[email protected]>> wrote: Lets consider
ffx = f(x,y,z)
here f is an user function (something you have to provide) which get evaluated at x,y,z (your grid points). Interpolation is required if f is given by a discrete data set.
hth
-----Original message-----
From:[email protected]<mailto:From%[email protected]> <mailto:From%[email protected]> <[email protected]<mailto:[email protected]> <mailto:[email protected]>> Sent: Wednesday 30th May 2018 19:19 To: nek5000-users <[email protected]<mailto:[email protected]> <mailto:[email protected]>> Subject: Re: [Nek5000-users] Using Cartesian grid lookup table in Nekton
Hi,
Thanks for the reply. The look up table is in a finite difference grid. Are you saying I can still feed it to the .usr file and it should be fine?
Thanks, Saikat <br clear="all" />Saikat Mukherjee, PhD Student, Paul Research Group - http://www.me.vt.edu/mpaul/ <http://www.me.vt.edu/mpaul/> <http://www.me.vt.edu/mpaul/ <http://www.me.vt.edu/mpaul/>> Engineering Science and Mechanics, Virginia Tech.
On Sat, May 26, 2018 at 10:54 PM, <[email protected]<mailto:[email protected]> <mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]> <mailto:[email protected]>>> wrote: Hi Saikat,
You can always do the reading from the look up table from .usr file, at once then feed the data to your ffx ffy and ffz through a common block.
On Thu, May 24, 2018 at 10:55 PM, <[email protected]<mailto:[email protected]> <mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]> <mailto:[email protected]>>> wrote: Hey all,
Just following up on the query. Would appreciate any input.
Thanks, Saikat <br clear="all" />Saikat Mukherjee, PhD Student, Paul Research Group - http://www.me.vt.edu/mpaul/ <http://www.me.vt.edu/mpaul/> <http://www.me.vt.edu/mpaul/ <http://www.me.vt.edu/mpaul/>> Engineering Science and Mechanics, Virginia Tech.
On Tue, May 22, 2018 at 4:47 PM, Saikat Mukherjee <[email protected]<mailto:[email protected]> <mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]> <mailto:[email protected]>>> wrote: Hey Neks,
I have a forcing function which is in the form of a look up table in X-Y cartesian grid. I would like to use this forcing function in the 2-D fluid momentum equation that Nekton solves. Is there a way to do this in the .usr file or elsewhere?
Thanks, Saikat
<br clear="all" />Saikat Mukherjee, PhD Student, Paul Research Group - http://www.me.vt.edu/mpaul/ <http://www.me.vt.edu/mpaul/> <http://www.me.vt.edu/mpaul/ <http://www.me.vt.edu/mpaul/>> Engineering Science and Mechanics, Virginia Tech.
_______________________________________________ Nek5000-users mailing list [email protected]<mailto:[email protected]> <mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]> <mailto:[email protected]>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users> <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users>>
_______________________________________________ Nek5000-users mailing list [email protected]<mailto:[email protected]> <mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]> <mailto:[email protected]>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users> <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users>>
_______________________________________________ Nek5000-users mailing list [email protected]<mailto:[email protected]> <mailto:[email protected]> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users>
Nek5000-users mailing list [email protected]<mailto:[email protected]> <mailto:[email protected]> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users>
_______________________________________________ Nek5000-users mailing list [email protected]<mailto:[email protected]> <mailto:[email protected]> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users>
_______________________________________________ Nek5000-users mailing list [email protected]<mailto:[email protected]> <mailto:[email protected]> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users>
_______________________________________________ Nek5000-users mailing list [email protected]<mailto:[email protected]> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
Nek5000-users mailing list [email protected]<mailto:[email protected]> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users _______________________________________________ Nek5000-users mailing list [email protected]<mailto:[email protected]> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users _______________________________________________ Nek5000-users mailing list [email protected]<mailto:[email protected]> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users