Re: [Libmesh-users] Performance: FEMSystem vs scalar-valued FE

[Roy S. <roy...@ic...>]

On Thu, 14 Aug 2014, walter kou wrote:

> I am currently using scalar-valued FE in libmesh (like the example in 3D
> Linear Elastic Cantilever). It seems libmesh-0.9.3 gives more features on
> FEMsystem: vector-valued FE.

You can use vector-valued elements without FEMSystem and vice-versa.

> 1) What is the advantage of the way based on FEMSystem over the way based
> on scalar-valued FE? especially about the performance for the large-scale
> systems.

I doubt there's currently any performance advantage to using
vector-valued elements.  We might be able to optimize their assembly
slightly in the future.

The big advantage of using vector-valued elements is that you can then
choose vector-valued approximation spaces (right now just Nedelec,
although we'll probably add more later) which aren't tensor products
of scalar-valued approximation spaces.  This can be important
depending on your PDE and formulation.
---
Roy