Optimized connectivity: Simultaneous face_edges and edge_nodes

benchmarks/bench_connectivity.py

@@ -54,6 +54,9 @@ def teardown(self, resolution, *args, **kwargs):
 
 class Connectivity(GridBenchmark):
 
+    def time_n_nodes_per_face(self, resolution):
+        _ = self.uxgrid.n_nodes_per_face
+
     def time_face_node(self, resolution):
         _ = self.uxgrid.face_node_connectivity
 

test/grid/geometry/test_centroids.py

@@ -63,13 +63,16 @@ def test_edge_centroids_from_triangle():
     grid = ux.open_grid(test_triangle, latlon=False)
     _populate_edge_centroids(grid)
 
-    centroid_x = np.mean(grid.node_x[grid.edge_node_connectivity[0][0:]])
-    centroid_y = np.mean(grid.node_y[grid.edge_node_connectivity[0][0:]])
-    centroid_z = np.mean(grid.node_z[grid.edge_node_connectivity[0][0:]])
+    edge_nodes = grid.edge_node_connectivity.values
 
-    assert centroid_x == grid.edge_x[0]
-    assert centroid_y == grid.edge_y[0]
-    assert centroid_z == grid.edge_z[0]
+    centroid_x = grid.node_x.values[edge_nodes].mean(axis=1)
+    centroid_y = grid.node_y.values[edge_nodes].mean(axis=1)
+    centroid_z = grid.node_z.values[edge_nodes].mean(axis=1)
+    centroid_x, centroid_y, centroid_z = _normalize_xyz(centroid_x, centroid_y, centroid_z)
+
+    nt.assert_array_almost_equal(grid.edge_x.values, centroid_x)
+    nt.assert_array_almost_equal(grid.edge_y.values, centroid_y)
+    nt.assert_array_almost_equal(grid.edge_z.values, centroid_z)
 
 def test_edge_centroids_from_mpas(gridpath):
     """Test computed centroid values compared to values from a MPAS dataset."""

test/grid/grid/test_connectivity.py

@@ -3,10 +3,12 @@
 import pytest
 
 import uxarray as ux
-from uxarray.constants import INT_FILL_VALUE, ERROR_TOLERANCE
+from uxarray.constants import INT_DTYPE, INT_FILL_VALUE, ERROR_TOLERANCE
 from uxarray.grid.connectivity import (_populate_face_edge_connectivity, _build_edge_face_connectivity,
                                       _build_edge_node_connectivity, _build_face_face_connectivity,
                                       _populate_face_face_connectivity)
+from uxarray.grid.utils import (_adaptive_sort_bucket, _insertion_sort_bucket,
+                                MIN_ADAPTIVE_SORT_SIZE)
 
 
 def test_connectivity_build_n_nodes_per_face(gridpath):
@@ -63,6 +65,83 @@ def test_connectivity_build_face_edges_connectivity(gridpath):
     assert np.all(valid_edges >= 0)
     assert np.all(valid_edges < uxgrid.n_edge)
 
+@pytest.mark.parametrize("grid_parts", [("ugrid", "outCSne30", "outCSne30.ug"),
+                                        ("ugrid", "quad-hexagon", "grid.nc"),
+                                        ("ugrid", "geoflow-small", "grid.nc")])
+def test_connectivity_edge_node_canonical_order(gridpath, grid_parts):
+    """Test that constructed edges are numbered in lexicographic node order."""
+    uxgrid = ux.open_grid(gridpath(*grid_parts))
+    edge_nodes = uxgrid.edge_node_connectivity.values
+
+    # Each edge is stored as an ascending node pair
+    assert np.all(edge_nodes[:, 0] < edge_nodes[:, 1])
+
+    # Edges are numbered lexicographically by that pair, with no duplicates
+    lexicographic_order = np.lexsort((edge_nodes[:, 1], edge_nodes[:, 0]))
+    nt.assert_array_equal(lexicographic_order, np.arange(uxgrid.n_edge))
+    assert len(np.unique(edge_nodes, axis=0)) == uxgrid.n_edge
+
+@pytest.mark.parametrize("sort", [_insertion_sort_bucket, _adaptive_sort_bucket],
+                         ids=["insertion", "adaptive"])
+def test_connectivity_bucket_sort(sort):
+    """Test that each bucket sort orders its own slice and nothing else.
+
+    The bucket sizes straddle ``MIN_ADAPTIVE_SORT_SIZE``: the small ones cannot accumulate
+    enough shifts to exhaust the budget, so the metered sort stays on its insertion path,
+    while the 500 element bucket is shuffled far past the budget and falls back to the heap
+    sort. Keys repeat, since an interior edge reaches its bucket once per adjacent face.
+    """
+    rng = np.random.default_rng(0)
+
+    sizes = [5, MIN_ADAPTIVE_SORT_SIZE, MIN_ADAPTIVE_SORT_SIZE + 1, 500]
+    bounds = np.cumsum([0] + sizes)
+    n_half_edge = int(bounds[-1])
+    buckets = list(zip(bounds[:-1], bounds[1:]))
+
+    keys = rng.integers(0, 40, n_half_edge).astype(INT_DTYPE)
+    order = rng.permutation(n_half_edge).astype(INT_DTYPE)
+
+    # the key each half edge must still be paired with once the permutation has moved it
+    key_for = np.empty(n_half_edge, dtype=INT_DTYPE)
+    key_for[order] = keys
+
+    expected_keys = np.concatenate([np.sort(keys[start:end]) for start, end in buckets])
+
+    got_keys, got_order = keys.copy(), order.copy()
+    for start, end in buckets:
+        shuffle = rng.permutation(end - start)
+        got_keys[start:end] = got_keys[start:end][shuffle]
+        got_order[start:end] = got_order[start:end][shuffle]
+
+        sort(got_keys, got_order, start, end - start)
+
+    nt.assert_array_equal(got_keys, expected_keys)
+
+    # sorted keys alone would pass even if the permutation had been scrambled independently
+    nt.assert_array_equal(key_for[got_order], got_keys)
+    nt.assert_array_equal(np.sort(got_order), np.arange(n_half_edge))
+
+
+def test_connectivity_face_edge_positional_alignment(gridpath):
+    """Test that face_edge_connectivity[i, j] is the edge between face nodes j and j+1."""
+    uxgrid = ux.open_grid(gridpath("ugrid", "outCSne30", "outCSne30.ug"))
+
+    face_nodes = uxgrid.face_node_connectivity.values
+    face_edges = uxgrid.face_edge_connectivity.values
+    edge_nodes = uxgrid.edge_node_connectivity.values
+
+    for face_idx, n_edges in enumerate(uxgrid.n_nodes_per_face.values):
+        for cur in range(n_edges):
+            start_node = face_nodes[face_idx, cur]
+            end_node = face_nodes[face_idx, (cur + 1) % n_edges]
+
+            expected = sorted((start_node, end_node))
+            actual = sorted(edge_nodes[face_edges[face_idx, cur]])
+            assert actual == expected
+
+        # Remaining slots stay padded
+        assert np.all(face_edges[face_idx, n_edges:] == INT_FILL_VALUE)
+
 def test_connectivity_build_face_edges_connectivity_fillvalues():
     """Test face-edge connectivity with fill values."""
     # Create a simple grid with mixed face types