How to get the first order derivative of the solution and store it in a numpy array

I/O
20

Hi again,

I wonder if interpolating the derivative function (DG -0) back into a function from the primary function space (Lagrange,1) makes any sense?

I have something like this:

Q = functionspace(domain, ("DG",0))
m1_dx = fem.Function(Q)

m1_dx.interpolate(fem.Expression(ufl.grad(m1)[0], Q.element.interpolation_points()))
##We then try to interpolate back into the Lagrange 1 function space
m1_dx_l1 = fem.Function(V)

m1_dx_l1.interpolate(m1_dx)

In this case V is a Lagrange-1 function space and m1 is a function from this function space.

Would this approach make sense? Can I trust the results from interpolating back from the DG-0 to the Lagrange-1 function space?