Hello 
(A question arose from the error obtained while using dot product of my edited code in the dolfinx environment.)
I want to express the vector coordinates defined as coefficients in the dolfinx environment, but I do not know how to express it, so I leave a question.
For example,
When expressing a vector element with (0, -3) dimension in the existing dolfin environment,
It could be expressed as
Constant((0.0, -3.0))
If I check the code result using jupyter notebook, the code is expressed as follows.
The calculation was made when the
v = TestFunction(U)
and dot product defined as
U = VectorFunctionSpace(mesh, ("CG", 1))
were applied to the above coefficient such that
Unlike the dolfin environment, ‘Constant’ in dolfinx was essential to declare the domain.
In the dolfin environment, the coefficient came out, whereas in the dolfinx environment, it was declared as Constant.
As a result of that, an error occurred when dot product was performed.
I think it is because of ‘Constant’ declared in the dolfinx environment. As written in bold in the first paragraph of writing, is there a way to declare a vector element as a constant coefficient in the dolfinx environment?