[Nek5000-users] Element connectivity information

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

Hi Neks,

I am using Nek5000 coupled to an Arnoldi algorithm for hydrodynamic  
stability computations. In these, I form a vector of the velocities,  
which I regularly pass to the Arnoldi solver. Then, a new velocity  
vector is formed which is passed back to Nek5000.

Now, the code works as it is, but in addition to the physical modes it  
produces some spurious modes, which I think originate from the fact  
that the velocities at the element-common boundaries are accounted for  
twice. To fix this, I need to access the element connectivity  
information. Can you please guide me to in which variable this is  
stored?

In particular, this is what I would like to do:
-  add the element-common points to the local vector only for one of  
two adjacent elements (and for a corner point, only one of the four  
elements adjacent to it).
- for the vector that Arnoldi returns, make sure that the new values  
of the velocity are inserted also for the other adjacent element(s).

Thanks a lot in advance!
Outi