diff env/lib/python3.9/site-packages/networkx/algorithms/tests/test_cuts.py @ 0:4f3585e2f14b draft default tip

"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.9/site-packages/networkx/algorithms/tests/test_cuts.py	Mon Mar 22 18:12:50 2021 +0000
@@ -0,0 +1,165 @@
+"""Unit tests for the :mod:`networkx.algorithms.cuts` module."""
+
+
+import networkx as nx
+
+
+class TestCutSize:
+    """Unit tests for the :func:`~networkx.cut_size` function."""
+
+    def test_symmetric(self):
+        """Tests that the cut size is symmetric."""
+        G = nx.barbell_graph(3, 0)
+        S = {0, 1, 4}
+        T = {2, 3, 5}
+        assert nx.cut_size(G, S, T) == 4
+        assert nx.cut_size(G, T, S) == 4
+
+    def test_single_edge(self):
+        """Tests for a cut of a single edge."""
+        G = nx.barbell_graph(3, 0)
+        S = {0, 1, 2}
+        T = {3, 4, 5}
+        assert nx.cut_size(G, S, T) == 1
+        assert nx.cut_size(G, T, S) == 1
+
+    def test_directed(self):
+        """Tests that each directed edge is counted once in the cut."""
+        G = nx.barbell_graph(3, 0).to_directed()
+        S = {0, 1, 2}
+        T = {3, 4, 5}
+        assert nx.cut_size(G, S, T) == 2
+        assert nx.cut_size(G, T, S) == 2
+
+    def test_directed_symmetric(self):
+        """Tests that a cut in a directed graph is symmetric."""
+        G = nx.barbell_graph(3, 0).to_directed()
+        S = {0, 1, 4}
+        T = {2, 3, 5}
+        assert nx.cut_size(G, S, T) == 8
+        assert nx.cut_size(G, T, S) == 8
+
+    def test_multigraph(self):
+        """Tests that parallel edges are each counted for a cut."""
+        G = nx.MultiGraph(["ab", "ab"])
+        assert nx.cut_size(G, {"a"}, {"b"}) == 2
+
+
+class TestVolume:
+    """Unit tests for the :func:`~networkx.volume` function."""
+
+    def test_graph(self):
+        G = nx.cycle_graph(4)
+        assert nx.volume(G, {0, 1}) == 4
+
+    def test_digraph(self):
+        G = nx.DiGraph([(0, 1), (1, 2), (2, 3), (3, 0)])
+        assert nx.volume(G, {0, 1}) == 2
+
+    def test_multigraph(self):
+        edges = list(nx.cycle_graph(4).edges())
+        G = nx.MultiGraph(edges * 2)
+        assert nx.volume(G, {0, 1}) == 8
+
+    def test_multidigraph(self):
+        edges = [(0, 1), (1, 2), (2, 3), (3, 0)]
+        G = nx.MultiDiGraph(edges * 2)
+        assert nx.volume(G, {0, 1}) == 4
+
+
+class TestNormalizedCutSize:
+    """Unit tests for the :func:`~networkx.normalized_cut_size`
+    function.
+
+    """
+
+    def test_graph(self):
+        G = nx.path_graph(4)
+        S = {1, 2}
+        T = set(G) - S
+        size = nx.normalized_cut_size(G, S, T)
+        # The cut looks like this: o-{-o--o-}-o
+        expected = 2 * ((1 / 4) + (1 / 2))
+        assert expected == size
+
+    def test_directed(self):
+        G = nx.DiGraph([(0, 1), (1, 2), (2, 3)])
+        S = {1, 2}
+        T = set(G) - S
+        size = nx.normalized_cut_size(G, S, T)
+        # The cut looks like this: o-{->o-->o-}->o
+        expected = 2 * ((1 / 2) + (1 / 1))
+        assert expected == size
+
+
+class TestConductance:
+    """Unit tests for the :func:`~networkx.conductance` function."""
+
+    def test_graph(self):
+        G = nx.barbell_graph(5, 0)
+        # Consider the singleton sets containing the "bridge" nodes.
+        # There is only one cut edge, and each set has volume five.
+        S = {4}
+        T = {5}
+        conductance = nx.conductance(G, S, T)
+        expected = 1 / 5
+        assert expected == conductance
+
+
+class TestEdgeExpansion:
+    """Unit tests for the :func:`~networkx.edge_expansion` function."""
+
+    def test_graph(self):
+        G = nx.barbell_graph(5, 0)
+        S = set(range(5))
+        T = set(G) - S
+        expansion = nx.edge_expansion(G, S, T)
+        expected = 1 / 5
+        assert expected == expansion
+
+
+class TestNodeExpansion:
+    """Unit tests for the :func:`~networkx.node_expansion` function.
+
+    """
+
+    def test_graph(self):
+        G = nx.path_graph(8)
+        S = {3, 4, 5}
+        expansion = nx.node_expansion(G, S)
+        # The neighborhood of S has cardinality five, and S has
+        # cardinality three.
+        expected = 5 / 3
+        assert expected == expansion
+
+
+class TestBoundaryExpansion:
+    """Unit tests for the :func:`~networkx.boundary_expansion` function.
+
+    """
+
+    def test_graph(self):
+        G = nx.complete_graph(10)
+        S = set(range(4))
+        expansion = nx.boundary_expansion(G, S)
+        # The node boundary of S has cardinality six, and S has
+        # cardinality three.
+        expected = 6 / 4
+        assert expected == expansion
+
+
+class TestMixingExpansion:
+    """Unit tests for the :func:`~networkx.mixing_expansion` function.
+
+    """
+
+    def test_graph(self):
+        G = nx.barbell_graph(5, 0)
+        S = set(range(5))
+        T = set(G) - S
+        expansion = nx.mixing_expansion(G, S, T)
+        # There is one cut edge, and the total number of edges in the
+        # graph is twice the total number of edges in a clique of size
+        # five, plus one more for the bridge.
+        expected = 1 / (2 * (5 * 4 + 1))
+        assert expected == expansion