I solved a heat diffusion problem and get a temperature distribution.

I calculate the heat flux at each node and save it to a pvd file with:

```
n = FacetNormal(mesh)
V = VectorFunctionSpace(mesh, 'P', 1)
qw = project(k*grad(T), V)
vtkfile_q << qw
```

However the in Paraview I do not have access to the x, y and z components of the heat flux. How can I get them?

Also, I get the local heat flux on one boundary with

```
qb = dot(n, qw) * ds_bc(association_table["base"])
```

and I would like to get the numerical values of qb in an array for further processing.

However, the dot product has neither vector() or get_local() methods.

How could I achieve this?