demo/twist/fishy.py crashes

[Patrick Farrell]

With the latest trunk (r751), the fishy.py example in demo/twist/ doesn't work.

[pef@caoimhe:/data/pfarrell/src/cbc.solve/trunk/demo/twist]$ python fishy.py
A hyperelastic fish being pushed by a flow to the right :)
Using HHT time-stepping.
Creating 0 Dirichlet boundary condition(s).
Converting given numerical parameter to DOLFIN Constant.
Converting given numerical parameter to DOLFIN Constant.
Converting given numerical parameter to DOLFIN Constant.
Converting given numerical parameter to DOLFIN Constant.
Applying Neumann boundary condition.
on_boundary
Solving the problem at time t = 0
Calling FFC just-in-time (JIT) compiler, this may take some time.
All terms in form must have same rank.
Traceback (most recent call last):
  File "fishy.py", line 42, in <module>
    problem.solve()
  File "/data/pfarrell/src/cbc.solve/trunk/cbc/twist/problem_definitions.py", line 114, in solve
    return self.solver.solve()
  File "/data/pfarrell/src/cbc.solve/trunk/cbc/twist/solution_algorithms.py", line 325, in solve
    self.step(self.dt)
  File "/data/pfarrell/src/cbc.solve/trunk/cbc/twist/solution_algorithms.py", line 341, in step
    problem = NonlinearVariationalProblem(self.L, self.u1, self.bcu, self.a)
  File "/usr/lib/python2.6/dist-packages/dolfin/fem/solving.py", line 116, in __init__
    F = Form(F, form_compiler_parameters=form_compiler_parameters)
  File "/usr/lib/python2.6/dist-packages/dolfin/fem/form.py", line 54, in __init__
    common_cell)
  File "/usr/lib/python2.6/dist-packages/dolfin/compilemodules/jit.py", line 66, in mpi_jit
    return local_jit(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/dolfin/compilemodules/jit.py", line 154, in jit
    return jit_compile(form, parameters=p, common_cell=common_cell)
  File "/usr/lib/python2.6/dist-packages/ffc/jitcompiler.py", line 73, in jit
    return jit_form(ufl_object, parameters, common_cell)
  File "/usr/lib/python2.6/dist-packages/ffc/jitcompiler.py", line 130, in jit_form
    common_cell=common_cell)
  File "/usr/lib/python2.6/dist-packages/ffc/compiler.py", line 150, in compile_form
    analysis = analyze_forms(forms, object_names, parameters, common_cell)
  File "/usr/lib/python2.6/dist-packages/ffc/analysis.py", line 64, in analyze_forms
    common_cell) for form in forms)
  File "/usr/lib/python2.6/dist-packages/ffc/analysis.py", line 64, in <genexpr>
    common_cell) for form in forms)
  File "/usr/lib/python2.6/dist-packages/ffc/analysis.py", line 152, in _analyze_form
    "All terms in form must have same rank.")
  File "/usr/lib/python2.6/dist-packages/ffc/log.py", line 46, in ffc_assert
    condition or error(*message)
  File "<string>", line 1, in <lambda>
  File "/usr/lib/python2.6/dist-packages/ufl/log.py", line 148, in error
    raise self._exception_type(self._format_raw(*message))
Exception: All terms in form must have same rank.

[Patrick Farrell (pefarrell)]

This also applies to uniaxial-tension.py.

[Anders E. Johansen (andersej)]

I think the HHT time stepping scheme is broken, and has been for a while.

def time_stepping(self):
    return "CG1"

will make the programs run until the problem with HHT is solved.

Anders

[Patrick Farrell (pefarrell)]

Great, thanks.

[Anders Logg (logg)]

I tried reverting back, but couldn't find a version that worked. I went all the way back to the point where I started getting errors related to things introduced in DOLFIN 1.0 (setting default values for Expression parameters). So it looks like it's not related to the recent changes I made to the Twist solver.