I used
omega = UnitCubeMesh(4, 4, 4)
But I need to make a cube $\Omega = [-1,1]\times [-2,2] \times [-1,3]$
Which is the function that does this?
Try
omega = BoxMesh(-1, -2, -1, 1, 2, 3, 4, 4, 4)
Mikael
in python:
NameError: name 'BoxMesh' is not defined
That means your FEniCS version is older and you should simply use Box.