Dear Firedrakers,

The attached code runs and gives good convergence for linear and quadratic DG basis.
But when I run the scheme with a constant basis I get the following error:

This integral is missing an integration domain.

Traceback (most recent call last):

File "compressible_acoustic.py", line 98, in <module>

L1 = -div_u(dFdu_vec, dHdrho0)

File "compressible_acoustic.py", line 94, in div_u

return (dot(u, grad(p)))*dx + (jump(p)*dot((u('-')*(1-theta)+u('+')*theta), n('-')))*(dS)

File "/usr/not-backed-up/firedrake/2016-05-11/firedrake/lib/python2.7/site-packages/ufl/measure.py", line 398, in __rmul__

error("This integral is missing an integration domain.")

File "/usr/not-backed-up/firedrake/2016-05-11/firedrake/lib/python2.7/site-packages/ufl/log.py", line 158, in error

raise self._exception_type(self._format_raw(*message))

ufl.log.UFLException: This integral is missing an integration domain.

I've had a working version, including a constant basis, when I had the terms separately instead of being a definition.
So I'm not quite sure where the error is.

Regards,
Will