Dear all, I wrote the attached simple code to solve a shallow water problem with a nonlinear solver, but I get the following error (note that the linear problem works fine). Can someone help me and see what I am doing wrong? Thanks you very much! Kind regards, Anna Kalogirou. =================================== Traceback (most recent call last): File "nonlinear_swe.py", line 43, in <module> phi_solver = NonlinearVariationalSolver(phi_problem) File "/opt/firedrake/2.0/lib/python2.7/site-packages/firedrake/solving.py", line 123, in __init__ self._jac_tensor = assemble(self._problem.J_ufl, bcs=self._problem.bcs) File "/opt/firedrake/2.0/lib/python2.7/site-packages/firedrake/solving.py", line 420, in assemble return _assemble(f, tensor=tensor, bcs=_extract_bcs(bcs)) File "/opt/firedrake/2.0/lib/python2.7/site-packages/firedrake/solving.py", line 439, in _assemble kernels = ffc_interface.compile_form(f, "form") File "/opt/firedrake/2.0/lib/python2.7/site-packages/firedrake/ffc_interface.py", line 235, in compile_form FFCKernel(form, name).kernels)] File "/opt/firedrake/2.0/lib/python2.7/site-packages/PyOP2-0.11.0_117_gcfe592d-py2.7-linux-x86_64.egg/pyop2/caching.py", line 202, in __new__ obj = make_obj() File "/opt/firedrake/2.0/lib/python2.7/site-packages/PyOP2-0.11.0_117_gcfe592d-py2.7-linux-x86_64.egg/pyop2/caching.py", line 192, in make_obj obj.__init__(*args, **kwargs) File "/opt/firedrake/2.0/lib/python2.7/site-packages/firedrake/ffc_interface.py", line 181, in __init__ ffc_tree = ffc_compile_form(form, prefix=name, parameters=parameters["form_compiler"]) File "/opt/firedrake/2.0/lib/python2.7/site-packages/ffc/compiler.py", line 151, in compile_form analysis = analyze_forms(forms, parameters) File "/opt/firedrake/2.0/lib/python2.7/site-packages/ffc/analysis.py", line 57, in analyze_forms parameters) for form in forms) File "/opt/firedrake/2.0/lib/python2.7/site-packages/ffc/analysis.py", line 57, in <genexpr> parameters) for form in forms) File "/opt/firedrake/2.0/lib/python2.7/site-packages/ffc/analysis.py", line 136, in _analyze_form _attach_integral_metadata(form_data, parameters) File "/opt/firedrake/2.0/lib/python2.7/site-packages/ffc/analysis.py", line 266, in _attach_integral_metadata scheme = quad_schemes[0] IndexError: list index out of range =================================== -- Dr Anna Kalogirou Research Fellow School of Mathematics University of Leeds