Merge pull request #2494 from firedrakeproject/sv/fix-gusto

Sv/fix gusto

Author: JDBetteridge

firedrake/slate/static_condensation/la_utils.py

@@ -46,6 +46,7 @@ def condense_and_forward_eliminate(A, b, elim_fields, prefix, pc):
         raise ValueError("Left-hand operator must be a Slate Tensor")
 
     # Ensures field indices are in increasing order
+    id_0, id_1 = elim_fields[0], elim_fields[-1]
     elim_fields = list(as_tuple(elim_fields))
     elim_fields.sort()
 
@@ -73,8 +74,6 @@ def condense_and_forward_eliminate(A, b, elim_fields, prefix, pc):
     # where subscript `e` denotes the coupling with fields
     # that will be eliminated, and `f` denotes the condensed
     # fields.
-    id_0 = e_idx0
-    id_1 = e_idx1
     outer_id_0 = slice(e_idx0, e_idx1 + 1)
     outer_id_1 = slice(f_idx0, f_idx1 + 1)
     Aff = _A[outer_id_1, outer_id_1]

tests/slate/test_variational_prb.py

@@ -4,8 +4,8 @@
 from itertools import product
 
 
-@pytest.mark.parametrize(('degree', 'nested'), list(product([1, 2], [True, False])))
-def test_lvp_equiv_hdg(degree, nested):
+@pytest.mark.parametrize(('degree', 'nested', 'elimination'), list(product([1, 2], [True, False], ['0,1', '1,0'])))
+def test_lvp_equiv_hdg(degree, nested, elimination):
     """Runs an HDG problem and checks that passing
     a Slate-defined problem into a variational problem
     produces the same result for the traces as solving
@@ -47,7 +47,7 @@ def test_lvp_equiv_hdg(degree, nested):
               'ksp_type': 'preonly',
               'pc_type': 'python',
               'pc_python_type': 'firedrake.SCPC',
-              'pc_sc_eliminate_fields': '0, 1',
+              'pc_sc_eliminate_fields': elimination,
               'condensed_field': {'ksp_type': 'preonly',
                                   'pc_type': 'lu',
                                   'pc_factor_mat_solver_type': 'mumps',