Hi Tomasz,
On 24 May 2016, at 08:47, David Ham <david.ham@imperial.ac.uk> wrote:
Hi Tomasz,
There are two things here. The first one is cell subdomains. There is a pull request in at PETSc right now which will make this work to some extent. We'll let you know once the PETSc people accept that pull.
This is now incorporated in Firedrake. If your Gmsh file has physical region ids then you can use those numbers in the dx measure to restrict integration to the given region. e.g. mesh = Mesh("...") assemble(Constant(1)*dx(1, domain=mesh)) assembles a Constant over the region of the mesh tagged with the marker "1". Using this information to construct the appropriate indicator functions is a little more work, but we can help with getting this right. Lawrence