ffc team mailing list archive

[Fredrik Bengzon <fredrik.bengzon@xxxxxxxxxxx>]

Hello
I'm wondering if there is some simple way (i.e., other than component 
wise) of writing the term

integral ( [ outer(n, v) ] : < grad u > ) dS

where the test and trial functions u, and v are BDM functions. Here 
outer(n,v) is the outer product of the normal n and v, [] is the jump, 
and <> the average operator. Can you use some sort of python arrays to 
do the outer product, for instance? Also is there a way of imposing 
constraints using FFC; I'm thinking of the pressure in the Stokes 
equations for instance which sometimes is required to have a zero integral?

Regards

Fredrik Bengzon