diff env/lib/python3.9/site-packages/networkx/algorithms/bipartite/tests/test_spectral_bipartivity.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/bipartite/tests/test_spectral_bipartivity.py	Mon Mar 22 18:12:50 2021 +0000
@@ -0,0 +1,85 @@
+import pytest
+
+import networkx as nx
+from networkx.algorithms.bipartite import spectral_bipartivity as sb
+from networkx.testing import almost_equal
+
+# Examples from Figure 1
+# E. Estrada and J. A. Rodríguez-Velázquez, "Spectral measures of
+# bipartivity in complex networks", PhysRev E 72, 046105 (2005)
+
+
+class TestSpectralBipartivity:
+    @classmethod
+    def setup_class(cls):
+        global scipy
+        scipy = pytest.importorskip("scipy")
+
+    def test_star_like(self):
+        # star-like
+
+        G = nx.star_graph(2)
+        G.add_edge(1, 2)
+        assert almost_equal(sb(G), 0.843, places=3)
+
+        G = nx.star_graph(3)
+        G.add_edge(1, 2)
+        assert almost_equal(sb(G), 0.871, places=3)
+
+        G = nx.star_graph(4)
+        G.add_edge(1, 2)
+        assert almost_equal(sb(G), 0.890, places=3)
+
+    def test_k23_like(self):
+        # K2,3-like
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(0, 1)
+        assert almost_equal(sb(G), 0.769, places=3)
+
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(2, 4)
+        assert almost_equal(sb(G), 0.829, places=3)
+
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(2, 4)
+        G.add_edge(3, 4)
+        assert almost_equal(sb(G), 0.731, places=3)
+
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(0, 1)
+        G.add_edge(2, 4)
+        assert almost_equal(sb(G), 0.692, places=3)
+
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(2, 4)
+        G.add_edge(3, 4)
+        G.add_edge(0, 1)
+        assert almost_equal(sb(G), 0.645, places=3)
+
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(2, 4)
+        G.add_edge(3, 4)
+        G.add_edge(2, 3)
+        assert almost_equal(sb(G), 0.645, places=3)
+
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(2, 4)
+        G.add_edge(3, 4)
+        G.add_edge(2, 3)
+        G.add_edge(0, 1)
+        assert almost_equal(sb(G), 0.597, places=3)
+
+    def test_single_nodes(self):
+
+        # single nodes
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(2, 4)
+        sbn = sb(G, nodes=[1, 2])
+        assert almost_equal(sbn[1], 0.85, places=2)
+        assert almost_equal(sbn[2], 0.77, places=2)
+
+        G = nx.complete_bipartite_graph(2, 3)
+        G.add_edge(0, 1)
+        sbn = sb(G, nodes=[1, 2])
+        assert almost_equal(sbn[1], 0.73, places=2)
+        assert almost_equal(sbn[2], 0.82, places=2)