two version of R2R are hereHEADmaster

1 files changed, 63 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/networkx/utils/tests/test_rcm.py b/.venv/lib/python3.12/site-packages/networkx/utils/tests/test_rcm.py
new file mode 100644
index 00000000..88702b36
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/networkx/utils/tests/test_rcm.py
@@ -0,0 +1,63 @@
+import networkx as nx
+from networkx.utils import reverse_cuthill_mckee_ordering
+
+
+def test_reverse_cuthill_mckee():
+    # example graph from
+    # http://www.boost.org/doc/libs/1_37_0/libs/graph/example/cuthill_mckee_ordering.cpp
+    G = nx.Graph(
+        [
+            (0, 3),
+            (0, 5),
+            (1, 2),
+            (1, 4),
+            (1, 6),
+            (1, 9),
+            (2, 3),
+            (2, 4),
+            (3, 5),
+            (3, 8),
+            (4, 6),
+            (5, 6),
+            (5, 7),
+            (6, 7),
+        ]
+    )
+    rcm = list(reverse_cuthill_mckee_ordering(G))
+    assert rcm in [[0, 8, 5, 7, 3, 6, 2, 4, 1, 9], [0, 8, 5, 7, 3, 6, 4, 2, 1, 9]]
+
+
+def test_rcm_alternate_heuristic():
+    # example from
+    G = nx.Graph(
+        [
+            (0, 0),
+            (0, 4),
+            (1, 1),
+            (1, 2),
+            (1, 5),
+            (1, 7),
+            (2, 2),
+            (2, 4),
+            (3, 3),
+            (3, 6),
+            (4, 4),
+            (5, 5),
+            (5, 7),
+            (6, 6),
+            (7, 7),
+        ]
+    )
+
+    answers = [
+        [6, 3, 5, 7, 1, 2, 4, 0],
+        [6, 3, 7, 5, 1, 2, 4, 0],
+        [7, 5, 1, 2, 4, 0, 6, 3],
+    ]
+
+    def smallest_degree(G):
+        deg, node = min((d, n) for n, d in G.degree())
+        return node
+
+    rcm = list(reverse_cuthill_mckee_ordering(G, heuristic=smallest_degree))
+    assert rcm in answers