two version of R2R are hereHEADmaster

1 files changed, 309 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/networkx/generators/tests/test_line.py b/.venv/lib/python3.12/site-packages/networkx/generators/tests/test_line.py
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+++ b/.venv/lib/python3.12/site-packages/networkx/generators/tests/test_line.py
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+import pytest
+
+import networkx as nx
+from networkx.generators import line
+from networkx.utils import edges_equal
+
+
+class TestGeneratorLine:
+    def test_star(self):
+        G = nx.star_graph(5)
+        L = nx.line_graph(G)
+        assert nx.is_isomorphic(L, nx.complete_graph(5))
+
+    def test_path(self):
+        G = nx.path_graph(5)
+        L = nx.line_graph(G)
+        assert nx.is_isomorphic(L, nx.path_graph(4))
+
+    def test_cycle(self):
+        G = nx.cycle_graph(5)
+        L = nx.line_graph(G)
+        assert nx.is_isomorphic(L, G)
+
+    def test_digraph1(self):
+        G = nx.DiGraph([(0, 1), (0, 2), (0, 3)])
+        L = nx.line_graph(G)
+        # no edge graph, but with nodes
+        assert L.adj == {(0, 1): {}, (0, 2): {}, (0, 3): {}}
+
+    def test_multigraph1(self):
+        G = nx.MultiGraph([(0, 1), (0, 1), (1, 0), (0, 2), (2, 0), (0, 3)])
+        L = nx.line_graph(G)
+        # no edge graph, but with nodes
+        assert edges_equal(
+            L.edges(),
+            [
+                ((0, 3, 0), (0, 1, 0)),
+                ((0, 3, 0), (0, 2, 0)),
+                ((0, 3, 0), (0, 2, 1)),
+                ((0, 3, 0), (0, 1, 1)),
+                ((0, 3, 0), (0, 1, 2)),
+                ((0, 1, 0), (0, 1, 1)),
+                ((0, 1, 0), (0, 2, 0)),
+                ((0, 1, 0), (0, 1, 2)),
+                ((0, 1, 0), (0, 2, 1)),
+                ((0, 1, 1), (0, 1, 2)),
+                ((0, 1, 1), (0, 2, 0)),
+                ((0, 1, 1), (0, 2, 1)),
+                ((0, 1, 2), (0, 2, 0)),
+                ((0, 1, 2), (0, 2, 1)),
+                ((0, 2, 0), (0, 2, 1)),
+            ],
+        )
+
+    def test_multigraph2(self):
+        G = nx.MultiGraph([(1, 2), (2, 1)])
+        L = nx.line_graph(G)
+        assert edges_equal(L.edges(), [((1, 2, 0), (1, 2, 1))])
+
+    def test_multidigraph1(self):
+        G = nx.MultiDiGraph([(1, 2), (2, 1)])
+        L = nx.line_graph(G)
+        assert edges_equal(L.edges(), [((1, 2, 0), (2, 1, 0)), ((2, 1, 0), (1, 2, 0))])
+
+    def test_multidigraph2(self):
+        G = nx.MultiDiGraph([(0, 1), (0, 1), (0, 1), (1, 2)])
+        L = nx.line_graph(G)
+        assert edges_equal(
+            L.edges(),
+            [((0, 1, 0), (1, 2, 0)), ((0, 1, 1), (1, 2, 0)), ((0, 1, 2), (1, 2, 0))],
+        )
+
+    def test_digraph2(self):
+        G = nx.DiGraph([(0, 1), (1, 2), (2, 3)])
+        L = nx.line_graph(G)
+        assert edges_equal(L.edges(), [((0, 1), (1, 2)), ((1, 2), (2, 3))])
+
+    def test_create1(self):
+        G = nx.DiGraph([(0, 1), (1, 2), (2, 3)])
+        L = nx.line_graph(G, create_using=nx.Graph())
+        assert edges_equal(L.edges(), [((0, 1), (1, 2)), ((1, 2), (2, 3))])
+
+    def test_create2(self):
+        G = nx.Graph([(0, 1), (1, 2), (2, 3)])
+        L = nx.line_graph(G, create_using=nx.DiGraph())
+        assert edges_equal(L.edges(), [((0, 1), (1, 2)), ((1, 2), (2, 3))])
+
+
+class TestGeneratorInverseLine:
+    def test_example(self):
+        G = nx.Graph()
+        G_edges = [
+            [1, 2],
+            [1, 3],
+            [1, 4],
+            [1, 5],
+            [2, 3],
+            [2, 5],
+            [2, 6],
+            [2, 7],
+            [3, 4],
+            [3, 5],
+            [6, 7],
+            [6, 8],
+            [7, 8],
+        ]
+        G.add_edges_from(G_edges)
+        H = nx.inverse_line_graph(G)
+        solution = nx.Graph()
+        solution_edges = [
+            ("a", "b"),
+            ("a", "c"),
+            ("a", "d"),
+            ("a", "e"),
+            ("c", "d"),
+            ("e", "f"),
+            ("e", "g"),
+            ("f", "g"),
+        ]
+        solution.add_edges_from(solution_edges)
+        assert nx.is_isomorphic(H, solution)
+
+    def test_example_2(self):
+        G = nx.Graph()
+        G_edges = [[1, 2], [1, 3], [2, 3], [3, 4], [3, 5], [4, 5]]
+        G.add_edges_from(G_edges)
+        H = nx.inverse_line_graph(G)
+        solution = nx.Graph()
+        solution_edges = [("a", "c"), ("b", "c"), ("c", "d"), ("d", "e"), ("d", "f")]
+        solution.add_edges_from(solution_edges)
+        assert nx.is_isomorphic(H, solution)
+
+    def test_pair(self):
+        G = nx.path_graph(2)
+        H = nx.inverse_line_graph(G)
+        solution = nx.path_graph(3)
+        assert nx.is_isomorphic(H, solution)
+
+    def test_line(self):
+        G = nx.path_graph(5)
+        solution = nx.path_graph(6)
+        H = nx.inverse_line_graph(G)
+        assert nx.is_isomorphic(H, solution)
+
+    def test_triangle_graph(self):
+        G = nx.complete_graph(3)
+        H = nx.inverse_line_graph(G)
+        alternative_solution = nx.Graph()
+        alternative_solution.add_edges_from([[0, 1], [0, 2], [0, 3]])
+        # there are two alternative inverse line graphs for this case
+        # so long as we get one of them the test should pass
+        assert nx.is_isomorphic(H, G) or nx.is_isomorphic(H, alternative_solution)
+
+    def test_cycle(self):
+        G = nx.cycle_graph(5)
+        H = nx.inverse_line_graph(G)
+        assert nx.is_isomorphic(H, G)
+
+    def test_empty(self):
+        G = nx.Graph()
+        H = nx.inverse_line_graph(G)
+        assert nx.is_isomorphic(H, nx.complete_graph(1))
+
+    def test_K1(self):
+        G = nx.complete_graph(1)
+        H = nx.inverse_line_graph(G)
+        solution = nx.path_graph(2)
+        assert nx.is_isomorphic(H, solution)
+
+    def test_edgeless_graph(self):
+        G = nx.empty_graph(5)
+        with pytest.raises(nx.NetworkXError, match="edgeless graph"):
+            nx.inverse_line_graph(G)
+
+    def test_selfloops_error(self):
+        G = nx.cycle_graph(4)
+        G.add_edge(0, 0)
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
+
+    def test_non_line_graphs(self):
+        # Tests several known non-line graphs for impossibility
+        # Adapted from L.W.Beineke, "Characterizations of derived graphs"
+
+        # claw graph
+        claw = nx.star_graph(3)
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, claw)
+
+        # wheel graph with 6 nodes
+        wheel = nx.wheel_graph(6)
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, wheel)
+
+        # K5 with one edge remove
+        K5m = nx.complete_graph(5)
+        K5m.remove_edge(0, 1)
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, K5m)
+
+        # graph without any odd triangles (contains claw as induced subgraph)
+        G = nx.compose(nx.path_graph(2), nx.complete_bipartite_graph(2, 3))
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
+
+        ## Variations on a diamond graph
+
+        # Diamond + 2 edges (+ "roof")
+        G = nx.diamond_graph()
+        G.add_edges_from([(4, 0), (5, 3)])
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
+        G.add_edge(4, 5)
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
+
+        # Diamond + 2 connected edges
+        G = nx.diamond_graph()
+        G.add_edges_from([(4, 0), (4, 3)])
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
+
+        # Diamond + K3 + one edge (+ 2*K3)
+        G = nx.diamond_graph()
+        G.add_edges_from([(4, 0), (4, 1), (4, 2), (5, 3)])
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
+        G.add_edges_from([(5, 1), (5, 2)])
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
+
+        # 4 triangles
+        G = nx.diamond_graph()
+        G.add_edges_from([(4, 0), (4, 1), (5, 2), (5, 3)])
+        pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
+
+    def test_wrong_graph_type(self):
+        G = nx.DiGraph()
+        G_edges = [[0, 1], [0, 2], [0, 3]]
+        G.add_edges_from(G_edges)
+        pytest.raises(nx.NetworkXNotImplemented, nx.inverse_line_graph, G)
+
+        G = nx.MultiGraph()
+        G_edges = [[0, 1], [0, 2], [0, 3]]
+        G.add_edges_from(G_edges)
+        pytest.raises(nx.NetworkXNotImplemented, nx.inverse_line_graph, G)
+
+    def test_line_inverse_line_complete(self):
+        G = nx.complete_graph(10)
+        H = nx.line_graph(G)
+        J = nx.inverse_line_graph(H)
+        assert nx.is_isomorphic(G, J)
+
+    def test_line_inverse_line_path(self):
+        G = nx.path_graph(10)
+        H = nx.line_graph(G)
+        J = nx.inverse_line_graph(H)
+        assert nx.is_isomorphic(G, J)
+
+    def test_line_inverse_line_hypercube(self):
+        G = nx.hypercube_graph(5)
+        H = nx.line_graph(G)
+        J = nx.inverse_line_graph(H)
+        assert nx.is_isomorphic(G, J)
+
+    def test_line_inverse_line_cycle(self):
+        G = nx.cycle_graph(10)
+        H = nx.line_graph(G)
+        J = nx.inverse_line_graph(H)
+        assert nx.is_isomorphic(G, J)
+
+    def test_line_inverse_line_star(self):
+        G = nx.star_graph(20)
+        H = nx.line_graph(G)
+        J = nx.inverse_line_graph(H)
+        assert nx.is_isomorphic(G, J)
+
+    def test_line_inverse_line_multipartite(self):
+        G = nx.complete_multipartite_graph(3, 4, 5)
+        H = nx.line_graph(G)
+        J = nx.inverse_line_graph(H)
+        assert nx.is_isomorphic(G, J)
+
+    def test_line_inverse_line_dgm(self):
+        G = nx.dorogovtsev_goltsev_mendes_graph(4)
+        H = nx.line_graph(G)
+        J = nx.inverse_line_graph(H)
+        assert nx.is_isomorphic(G, J)
+
+    def test_line_different_node_types(self):
+        G = nx.path_graph([1, 2, 3, "a", "b", "c"])
+        H = nx.line_graph(G)
+        J = nx.inverse_line_graph(H)
+        assert nx.is_isomorphic(G, J)
+
+
+class TestGeneratorPrivateFunctions:
+    def test_triangles_error(self):
+        G = nx.diamond_graph()
+        pytest.raises(nx.NetworkXError, line._triangles, G, (4, 0))
+        pytest.raises(nx.NetworkXError, line._triangles, G, (0, 3))
+
+    def test_odd_triangles_error(self):
+        G = nx.diamond_graph()
+        pytest.raises(nx.NetworkXError, line._odd_triangle, G, (0, 1, 4))
+        pytest.raises(nx.NetworkXError, line._odd_triangle, G, (0, 1, 3))
+
+    def test_select_starting_cell_error(self):
+        G = nx.diamond_graph()
+        pytest.raises(nx.NetworkXError, line._select_starting_cell, G, (4, 0))
+        pytest.raises(nx.NetworkXError, line._select_starting_cell, G, (0, 3))
+
+    def test_diamond_graph(self):
+        G = nx.diamond_graph()
+        for edge in G.edges:
+            cell = line._select_starting_cell(G, starting_edge=edge)
+            # Starting cell should always be one of the two triangles
+            assert len(cell) == 3
+            assert all(v in G[u] for u in cell for v in cell if u != v)