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[Norman Lang <question164419@xxxxxxxxxxxxxxxxxxxxx>]

New question #164419 on UFL:
https://answers.launchpad.net/ufl/+question/164419



i am really new in working with fenics and the packages around. So i have got a question about ufl. I want to generate an input Matrix for an optimal control problem.
So i am writing down my variational form and want to get the expression

                                    L = c*inner(1,v)*ds(1)

in my matrix (c is only an constant). For that i am assembling L to an Vector B via

                          assemble(B, L, NULL, & sub_domains, NULL);

Now i want to pointwise multiply this vector with another vector, called z.
I am writing my main programm in C++ and the pointwise multiplying doesn't make any problem.

My question is now. How could i get the pointwise multiplication into the ufl-file, such that, i don't have to do the multiplication after assembling my vector.

I tried to use the Coefficient class in ufl and later on i tried it with the Function class via

elem=FiniteElement("Lagrange",tetrahedron,1)

z = Coefficient(elem) or z = Function(elem).

With the Coefficient class the multiplication

                        L = z*c*inner(1,v)*ds(1)

does not create an error but the result isn't correct when i'm comparing it with the pointwise operation

                z.*B,        where B is the assembled Vector from above

in MATLAB. So i'm sure i'm not computing a pointwise multiplication of two vectors.
Could you please help me with this problem. It would really help me.

Regards,

Norman


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