Dear all,

An additional note regarding the problem described below (please also see attached):

the problem is essentially that I have one equation (1c) with two test functions, v3 and the integral of v3 which is basically a real number. I tried writing

v_int = assemble(v3*step_b*dx)
Flambda = ( v3*step_b*((eta1-Z0)/dt - W0) + rho/Mass*v_int*step_b*mu0_5 )*dx


but UFL complains that

ufl.log.UFLException: Can't add expressions with different shapes.


In a matrix form, this is just the product of two vectors (as you can see from equation (2) in the attached document). Thank you in advance for your help.

Best, Anna.


P.S. Based on people's availability, I could potentially visit you in London and discuss this in person (e.g. 17-18 Aug?).


On 03/08/16 17:47, Onno Bokhove wrote:

I think it is easier to formulate this case for the global case with mu included (so no Theta/Heaviside functions needed)

and it may be useful to also give the matrix form along side with the integral weak form, especially for the last equation.


--Onno

From: firedrake-bounces@imperial.ac.uk <firedrake-bounces@imperial.ac.uk> on behalf of Anna Kalogirou <a.kalogirou@leeds.ac.uk>
Sent: Wednesday, July 27, 2016 11:01:18 AM
To: firedrake@imperial.ac.uk
Subject: [firedrake] Mixed system
 
Dear all,

I am trying to solve the system found in the attached pdf as a mixed system. I want to solve the same
problem as the one found here, but with the use of Schur complements and not linear algebra.

In a previous discussion about this problem, Lawrence mentioned that the test function for integral(lambda*Theta(x-Lp)dx) needs to be considered as coming from the real space of constant functions. Could you please elaborate on this?

Regards,

Anna.
-- 


 Dr Anna Kalogirou
 Research Fellow
 School of Mathematics
 University of Leeds

 http://www1.maths.leeds.ac.uk/~matak/




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