chore: import upstream snapshot with attribution

2026-07-13 12:36:30 +08:00
commit 55ab4e4a73
473 changed files with 72932 additions and 0 deletions
@@ -0,0 +1,72 @@
+import math
+import unittest
+
+import easygraph as eg
+
+from easygraph.utils.exception import EasyGraphError
+
+
+class test_hypergraph_operation(unittest.TestCase):
+    def setUp(self):
+        self.g = eg.get_graph_karateclub()
+        self.edges = [(1, 2), (8, 4)]
+        self.hg = [
+            eg.Hypergraph(num_v=10, e_list=self.edges, e_property=None),
+            eg.Hypergraph(num_v=2, e_list=[(0, 1)]),
+        ]
+        # checked -- num_v cannot be set to negative number
+
+    def test_hypergraph_operation(self):
+        for i in self.hg:
+            print(eg.hypergraph_density(i))
+            i.draw(v_color="#e6928f", e_color="#4e9595")
+
+    def test_basic_density(self):
+        hg = eg.Hypergraph(num_v=3, e_list=[(0, 1), (1, 2)])
+        expected = 2 / (2**3 - 1)
+        self.assertAlmostEqual(eg.hypergraph_density(hg), expected)
+
+    def test_density_ignore_singletons(self):
+        hg = eg.Hypergraph(num_v=3, e_list=[(0,), (1, 2)])
+        expected = 2 / ((2**3 - 1) - 3)
+        self.assertAlmostEqual(
+            eg.hypergraph_density(hg, ignore_singletons=True), expected
+        )
+
+    def test_density_all_singletons(self):
+        hg = eg.Hypergraph(num_v=3, e_list=[(0,), (1,), (2,)])
+        expected = 3 / (2**3 - 1)
+        self.assertAlmostEqual(eg.hypergraph_density(hg), expected)
+        expected_ignoring = 3 / ((2**3 - 1) - 3)
+        self.assertAlmostEqual(
+            eg.hypergraph_density(hg, ignore_singletons=True), expected_ignoring
+        )
+
+    def test_no_edges_returns_zero(self):
+        hg = eg.Hypergraph(num_v=5, e_list=[])
+        self.assertEqual(eg.hypergraph_density(hg), 0.0)
+
+    def test_single_node_single_edge(self):
+        hg = eg.Hypergraph(num_v=1, e_list=[(0,)])
+        self.assertEqual(eg.hypergraph_density(hg), 1.0)
+
+    def test_density_max_possible_edges(self):
+        n = 4
+        from itertools import chain
+        from itertools import combinations
+
+        powerset = list(
+            chain.from_iterable(combinations(range(n), r) for r in range(1, n + 1))
+        )
+        hg = eg.Hypergraph(num_v=n, e_list=powerset)
+        self.assertAlmostEqual(eg.hypergraph_density(hg), 1.0)
+
+    def test_density_zero_division_guard(self):
+        # Singleton ignored in n=1 graph should not divide by zero
+        hg = eg.Hypergraph(num_v=1, e_list=[(0,)])
+        result = eg.hypergraph_density(hg, ignore_singletons=True)
+        self.assertEqual(result, 0.0)
+
+
+if __name__ == "__main__":
+    unittest.main()