api: fix symbolic indices with stagger

devitocodes · Mar 10, 2024 · 5f4bc51 · 5f4bc51
1 parent 17c53c1
commit 5f4bc51
Show file tree

Hide file tree

Showing 3 changed files with 7 additions and 3 deletions.
diff --git a/devito/finite_differences/tools.py b/devito/finite_differences/tools.py
@@ -374,14 +374,18 @@ def generate_indices_staggered(expr, dim, order, side=None, x0=None):
             indices = [start, start - diff]
             indices = IndexSet(dim, indices)
         else:
-            if start is dim:
+            if x0 is None or order % 2 == 0:
+                o_min = -order//2
+                o_max = order//2
+            elif start is dim:
                 o_min = -order//2 + 1
                 o_max = order//2
                 start = dim + diff/2
             else:
                 o_min = -order//2
                 o_max = order//2 - 1
                 start = dim
+
             d = make_stencil_dimension(expr, o_min, o_max)
             iexpr = ind0 + d * diff
             indices = IndexSet(dim, expr=iexpr)

diff --git a/examples/seismic/elastic/elastic_example.py b/examples/seismic/elastic/elastic_example.py
@@ -37,7 +37,7 @@ def run(shape=(50, 50), spacing=(20.0, 20.0), tn=1000.0,
 def test_elastic(dtype):
     _, _, _, [rec1, rec2, v, tau] = run(dtype=dtype)
     assert np.isclose(norm(rec1), 19.25636, atol=1e-3, rtol=0)
-    assert np.isclose(norm(rec2), 0.644412, atol=1e-3, rtol=0)
+    assert np.isclose(norm(rec2), 0.6276, atol=1e-3, rtol=0)
 
 
 @pytest.mark.parametrize('shape', [(51, 51), (16, 16, 16)])

diff --git a/examples/seismic/viscoelastic/viscoelastic_example.py b/examples/seismic/viscoelastic/viscoelastic_example.py
@@ -39,7 +39,7 @@ def run(shape=(50, 50), spacing=(20.0, 20.0), tn=1000.0,
 def test_viscoelastic(dtype):
     _, _, _, [rec1, rec2, v, tau] = run(dtype=dtype)
     assert np.isclose(norm(rec1), 12.28040, atol=1e-3, rtol=0)
-    assert np.isclose(norm(rec2), 0.320738, atol=1e-3, rtol=0)
+    assert np.isclose(norm(rec2), 0.312462, atol=1e-3, rtol=0)
 
 
 @pytest.mark.parametrize('shape', [(51, 51), (16, 16, 16)])