[Nek5000-users] find a point

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

Here you go:

h Š handle to use generated by findpts_setup
stride Š used to increment the pointer to the next grid point (e.g.
proc_stride = 1, x_stride = mdim)
r_base Š stores the coordinates in rst-space (needed for interpolation)

There are no global variables. All MPI_ranks have to call findpts().However
in your case only one MPI_rank (it is your choice and can be completely
arbitrary) will do the call with npt = 1, all others will use npt = 0. It
does not matter if this point is located on that MPI_rank or not!

Cheers,
Stefan

Von:  <nek5000-users at lists.mcs.anl.gov>
Antworten an:  <nek5000-users at lists.mcs.anl.gov>
Datum:  Wednesday, December 2, 2015 at 1:14 AM
An:  <nek5000-users at lists.mcs.anl.gov>
Betreff:  Re: [Nek5000-users] find a point

Thanks for your answers!
I think I found the routine that is right for me:

call findpts(h, code_base,  code_stride,
                  proc_base,  proc_stride,
                    el_base,    el_stride,
                     r_base,     r_stride,
                 dist2_base, dist2_stride,
                     x_base,     x_stride,
                     y_base,     y_stride,
                     z_base,     z_stride, npt)

nevertheless I didn't understand the meaning of some variables. I think that
I can set the *_stride parameters equal to 1 for my case because i should
follow just one point. "code_base" return 0 if is in the element, 1 if it is
on the border and 2 if it is out. "proc_base" the processor that have the
element ("el_base") in which the point is located. "x_base", "y_base" and
"z_base" are the coordinates of the input point. But is not clear for me the
means of "r_base", "dist2_base" and "h". Moreover I should give in input the
"h" value and I saw that "h" is the output of findpts_setup function or
intpts_setup if I use the routine defined in postpro.f that wrap the
findpts_setup routine. However in both cases it is not clear for me what "h"
represents.

Other question, are *_base values global variables or local? namely, does
each processor know that the investigated point is contained in the el_base
element?  

Alessandro


2015-12-01 18:39 GMT+01:00  <nek5000-users at lists.mcs.anl.gov>:
> in postpro.f there is a Fortran routine hpts which acts as a driver to the
> various hpts... routines. I guess from reading that subroutine you can figure
> out how to call the various operations. You can also use these routines to
> find out on what processor and in what element a certain point is located.
> 
> philipp
> 
> On 2015-12-01 17:35, nek5000-users at lists.mcs.anl.gov wrote:
>> Yes, the routines in findpts.c are your friends. Have a look at hpts()
>> to see how it works.
>> 
>> Cheers,
>> Stefan
>> Von: <nek5000-users at lists.mcs.anl.gov
>> <mailto:nek5000-users at lists.mcs.anl.gov>>
>> Antworten an: <nek5000-users at lists.mcs.anl.gov
>> <mailto:nek5000-users at lists.mcs.anl.gov>>
>> Datum: Tuesday, December 1, 2015 at 7:02 PM
>> An: <nek5000-users at lists.mcs.anl.gov
>> <mailto:nek5000-users at lists.mcs.anl.gov>>
>> Betreff: [Nek5000-users] find a point
>> 
>> Hi Neks,
>> 
>> Given a point P(x,y,z) (even not grid point), is there in Nek a fast way
>> to found in which element it is located and also the corresponding
>> processor?
>> 
>> sincerely
>> Alessandro
>> _______________________________________________ Nek5000-users mailing
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