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author | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
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committer | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
commit | 4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch) | |
tree | ee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/networkx/linalg/tests/test_laplacian.py | |
parent | cc961e04ba734dd72309fb548a2f97d67d578813 (diff) | |
download | gn-ai-master.tar.gz |
Diffstat (limited to '.venv/lib/python3.12/site-packages/networkx/linalg/tests/test_laplacian.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/networkx/linalg/tests/test_laplacian.py | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/networkx/linalg/tests/test_laplacian.py b/.venv/lib/python3.12/site-packages/networkx/linalg/tests/test_laplacian.py new file mode 100644 index 00000000..23f1b28e --- /dev/null +++ b/.venv/lib/python3.12/site-packages/networkx/linalg/tests/test_laplacian.py @@ -0,0 +1,336 @@ +import pytest + +np = pytest.importorskip("numpy") +pytest.importorskip("scipy") + +import networkx as nx +from networkx.generators.degree_seq import havel_hakimi_graph +from networkx.generators.expanders import margulis_gabber_galil_graph + + +class TestLaplacian: + @classmethod + def setup_class(cls): + deg = [3, 2, 2, 1, 0] + cls.G = havel_hakimi_graph(deg) + cls.WG = nx.Graph( + (u, v, {"weight": 0.5, "other": 0.3}) for (u, v) in cls.G.edges() + ) + cls.WG.add_node(4) + cls.MG = nx.MultiGraph(cls.G) + + # Graph with clsloops + cls.Gsl = cls.G.copy() + for node in cls.Gsl.nodes(): + cls.Gsl.add_edge(node, node) + + # Graph used as an example in Sec. 4.1 of Langville and Meyer, + # "Google's PageRank and Beyond". + cls.DiG = nx.DiGraph() + cls.DiG.add_edges_from( + ( + (1, 2), + (1, 3), + (3, 1), + (3, 2), + (3, 5), + (4, 5), + (4, 6), + (5, 4), + (5, 6), + (6, 4), + ) + ) + cls.DiMG = nx.MultiDiGraph(cls.DiG) + cls.DiWG = nx.DiGraph( + (u, v, {"weight": 0.5, "other": 0.3}) for (u, v) in cls.DiG.edges() + ) + cls.DiGsl = cls.DiG.copy() + for node in cls.DiGsl.nodes(): + cls.DiGsl.add_edge(node, node) + + def test_laplacian(self): + "Graph Laplacian" + # fmt: off + NL = np.array([[ 3, -1, -1, -1, 0], + [-1, 2, -1, 0, 0], + [-1, -1, 2, 0, 0], + [-1, 0, 0, 1, 0], + [ 0, 0, 0, 0, 0]]) + # fmt: on + WL = 0.5 * NL + OL = 0.3 * NL + # fmt: off + DiNL = np.array([[ 2, -1, -1, 0, 0, 0], + [ 0, 0, 0, 0, 0, 0], + [-1, -1, 3, -1, 0, 0], + [ 0, 0, 0, 2, -1, -1], + [ 0, 0, 0, -1, 2, -1], + [ 0, 0, 0, 0, -1, 1]]) + # fmt: on + DiWL = 0.5 * DiNL + DiOL = 0.3 * DiNL + np.testing.assert_equal(nx.laplacian_matrix(self.G).todense(), NL) + np.testing.assert_equal(nx.laplacian_matrix(self.MG).todense(), NL) + np.testing.assert_equal( + nx.laplacian_matrix(self.G, nodelist=[0, 1]).todense(), + np.array([[1, -1], [-1, 1]]), + ) + np.testing.assert_equal(nx.laplacian_matrix(self.WG).todense(), WL) + np.testing.assert_equal(nx.laplacian_matrix(self.WG, weight=None).todense(), NL) + np.testing.assert_equal( + nx.laplacian_matrix(self.WG, weight="other").todense(), OL + ) + + np.testing.assert_equal(nx.laplacian_matrix(self.DiG).todense(), DiNL) + np.testing.assert_equal(nx.laplacian_matrix(self.DiMG).todense(), DiNL) + np.testing.assert_equal( + nx.laplacian_matrix(self.DiG, nodelist=[1, 2]).todense(), + np.array([[1, -1], [0, 0]]), + ) + np.testing.assert_equal(nx.laplacian_matrix(self.DiWG).todense(), DiWL) + np.testing.assert_equal( + nx.laplacian_matrix(self.DiWG, weight=None).todense(), DiNL + ) + np.testing.assert_equal( + nx.laplacian_matrix(self.DiWG, weight="other").todense(), DiOL + ) + + def test_normalized_laplacian(self): + "Generalized Graph Laplacian" + # fmt: off + G = np.array([[ 1. , -0.408, -0.408, -0.577, 0.], + [-0.408, 1. , -0.5 , 0. , 0.], + [-0.408, -0.5 , 1. , 0. , 0.], + [-0.577, 0. , 0. , 1. , 0.], + [ 0. , 0. , 0. , 0. , 0.]]) + GL = np.array([[ 1. , -0.408, -0.408, -0.577, 0. ], + [-0.408, 1. , -0.5 , 0. , 0. ], + [-0.408, -0.5 , 1. , 0. , 0. ], + [-0.577, 0. , 0. , 1. , 0. ], + [ 0. , 0. , 0. , 0. , 0. ]]) + Lsl = np.array([[ 0.75 , -0.2887, -0.2887, -0.3536, 0. ], + [-0.2887, 0.6667, -0.3333, 0. , 0. ], + [-0.2887, -0.3333, 0.6667, 0. , 0. ], + [-0.3536, 0. , 0. , 0.5 , 0. ], + [ 0. , 0. , 0. , 0. , 0. ]]) + + DiG = np.array([[ 1. , 0. , -0.4082, 0. , 0. , 0. ], + [ 0. , 0. , 0. , 0. , 0. , 0. ], + [-0.4082, 0. , 1. , 0. , -0.4082, 0. ], + [ 0. , 0. , 0. , 1. , -0.5 , -0.7071], + [ 0. , 0. , 0. , -0.5 , 1. , -0.7071], + [ 0. , 0. , 0. , -0.7071, 0. , 1. ]]) + DiGL = np.array([[ 1. , 0. , -0.4082, 0. , 0. , 0. ], + [ 0. , 0. , 0. , 0. , 0. , 0. ], + [-0.4082, 0. , 1. , -0.4082, 0. , 0. ], + [ 0. , 0. , 0. , 1. , -0.5 , -0.7071], + [ 0. , 0. , 0. , -0.5 , 1. , -0.7071], + [ 0. , 0. , 0. , 0. , -0.7071, 1. ]]) + DiLsl = np.array([[ 0.6667, -0.5774, -0.2887, 0. , 0. , 0. ], + [ 0. , 0. , 0. , 0. , 0. , 0. ], + [-0.2887, -0.5 , 0.75 , -0.2887, 0. , 0. ], + [ 0. , 0. , 0. , 0.6667, -0.3333, -0.4082], + [ 0. , 0. , 0. , -0.3333, 0.6667, -0.4082], + [ 0. , 0. , 0. , 0. , -0.4082, 0.5 ]]) + # fmt: on + + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.G, nodelist=range(5)).todense(), + G, + decimal=3, + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.G).todense(), GL, decimal=3 + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.MG).todense(), GL, decimal=3 + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.WG).todense(), GL, decimal=3 + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.WG, weight="other").todense(), + GL, + decimal=3, + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.Gsl).todense(), Lsl, decimal=3 + ) + + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix( + self.DiG, + nodelist=range(1, 1 + 6), + ).todense(), + DiG, + decimal=3, + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.DiG).todense(), DiGL, decimal=3 + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.DiMG).todense(), DiGL, decimal=3 + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.DiWG).todense(), DiGL, decimal=3 + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.DiWG, weight="other").todense(), + DiGL, + decimal=3, + ) + np.testing.assert_almost_equal( + nx.normalized_laplacian_matrix(self.DiGsl).todense(), DiLsl, decimal=3 + ) + + +def test_directed_laplacian(): + "Directed Laplacian" + # Graph used as an example in Sec. 4.1 of Langville and Meyer, + # "Google's PageRank and Beyond". The graph contains dangling nodes, so + # the pagerank random walk is selected by directed_laplacian + G = nx.DiGraph() + G.add_edges_from( + ( + (1, 2), + (1, 3), + (3, 1), + (3, 2), + (3, 5), + (4, 5), + (4, 6), + (5, 4), + (5, 6), + (6, 4), + ) + ) + # fmt: off + GL = np.array([[ 0.9833, -0.2941, -0.3882, -0.0291, -0.0231, -0.0261], + [-0.2941, 0.8333, -0.2339, -0.0536, -0.0589, -0.0554], + [-0.3882, -0.2339, 0.9833, -0.0278, -0.0896, -0.0251], + [-0.0291, -0.0536, -0.0278, 0.9833, -0.4878, -0.6675], + [-0.0231, -0.0589, -0.0896, -0.4878, 0.9833, -0.2078], + [-0.0261, -0.0554, -0.0251, -0.6675, -0.2078, 0.9833]]) + # fmt: on + L = nx.directed_laplacian_matrix(G, alpha=0.9, nodelist=sorted(G)) + np.testing.assert_almost_equal(L, GL, decimal=3) + + # Make the graph strongly connected, so we can use a random and lazy walk + G.add_edges_from(((2, 5), (6, 1))) + # fmt: off + GL = np.array([[ 1. , -0.3062, -0.4714, 0. , 0. , -0.3227], + [-0.3062, 1. , -0.1443, 0. , -0.3162, 0. ], + [-0.4714, -0.1443, 1. , 0. , -0.0913, 0. ], + [ 0. , 0. , 0. , 1. , -0.5 , -0.5 ], + [ 0. , -0.3162, -0.0913, -0.5 , 1. , -0.25 ], + [-0.3227, 0. , 0. , -0.5 , -0.25 , 1. ]]) + # fmt: on + L = nx.directed_laplacian_matrix( + G, alpha=0.9, nodelist=sorted(G), walk_type="random" + ) + np.testing.assert_almost_equal(L, GL, decimal=3) + + # fmt: off + GL = np.array([[ 0.5 , -0.1531, -0.2357, 0. , 0. , -0.1614], + [-0.1531, 0.5 , -0.0722, 0. , -0.1581, 0. ], + [-0.2357, -0.0722, 0.5 , 0. , -0.0456, 0. ], + [ 0. , 0. , 0. , 0.5 , -0.25 , -0.25 ], + [ 0. , -0.1581, -0.0456, -0.25 , 0.5 , -0.125 ], + [-0.1614, 0. , 0. , -0.25 , -0.125 , 0.5 ]]) + # fmt: on + L = nx.directed_laplacian_matrix(G, alpha=0.9, nodelist=sorted(G), walk_type="lazy") + np.testing.assert_almost_equal(L, GL, decimal=3) + + # Make a strongly connected periodic graph + G = nx.DiGraph() + G.add_edges_from(((1, 2), (2, 4), (4, 1), (1, 3), (3, 4))) + # fmt: off + GL = np.array([[ 0.5 , -0.176, -0.176, -0.25 ], + [-0.176, 0.5 , 0. , -0.176], + [-0.176, 0. , 0.5 , -0.176], + [-0.25 , -0.176, -0.176, 0.5 ]]) + # fmt: on + L = nx.directed_laplacian_matrix(G, alpha=0.9, nodelist=sorted(G)) + np.testing.assert_almost_equal(L, GL, decimal=3) + + +def test_directed_combinatorial_laplacian(): + "Directed combinatorial Laplacian" + # Graph used as an example in Sec. 4.1 of Langville and Meyer, + # "Google's PageRank and Beyond". The graph contains dangling nodes, so + # the pagerank random walk is selected by directed_laplacian + G = nx.DiGraph() + G.add_edges_from( + ( + (1, 2), + (1, 3), + (3, 1), + (3, 2), + (3, 5), + (4, 5), + (4, 6), + (5, 4), + (5, 6), + (6, 4), + ) + ) + # fmt: off + GL = np.array([[ 0.0366, -0.0132, -0.0153, -0.0034, -0.0020, -0.0027], + [-0.0132, 0.0450, -0.0111, -0.0076, -0.0062, -0.0069], + [-0.0153, -0.0111, 0.0408, -0.0035, -0.0083, -0.0027], + [-0.0034, -0.0076, -0.0035, 0.3688, -0.1356, -0.2187], + [-0.0020, -0.0062, -0.0083, -0.1356, 0.2026, -0.0505], + [-0.0027, -0.0069, -0.0027, -0.2187, -0.0505, 0.2815]]) + # fmt: on + + L = nx.directed_combinatorial_laplacian_matrix(G, alpha=0.9, nodelist=sorted(G)) + np.testing.assert_almost_equal(L, GL, decimal=3) + + # Make the graph strongly connected, so we can use a random and lazy walk + G.add_edges_from(((2, 5), (6, 1))) + + # fmt: off + GL = np.array([[ 0.1395, -0.0349, -0.0465, 0. , 0. , -0.0581], + [-0.0349, 0.093 , -0.0116, 0. , -0.0465, 0. ], + [-0.0465, -0.0116, 0.0698, 0. , -0.0116, 0. ], + [ 0. , 0. , 0. , 0.2326, -0.1163, -0.1163], + [ 0. , -0.0465, -0.0116, -0.1163, 0.2326, -0.0581], + [-0.0581, 0. , 0. , -0.1163, -0.0581, 0.2326]]) + # fmt: on + + L = nx.directed_combinatorial_laplacian_matrix( + G, alpha=0.9, nodelist=sorted(G), walk_type="random" + ) + np.testing.assert_almost_equal(L, GL, decimal=3) + + # fmt: off + GL = np.array([[ 0.0698, -0.0174, -0.0233, 0. , 0. , -0.0291], + [-0.0174, 0.0465, -0.0058, 0. , -0.0233, 0. ], + [-0.0233, -0.0058, 0.0349, 0. , -0.0058, 0. ], + [ 0. , 0. , 0. , 0.1163, -0.0581, -0.0581], + [ 0. , -0.0233, -0.0058, -0.0581, 0.1163, -0.0291], + [-0.0291, 0. , 0. , -0.0581, -0.0291, 0.1163]]) + # fmt: on + + L = nx.directed_combinatorial_laplacian_matrix( + G, alpha=0.9, nodelist=sorted(G), walk_type="lazy" + ) + np.testing.assert_almost_equal(L, GL, decimal=3) + + E = nx.DiGraph(margulis_gabber_galil_graph(2)) + L = nx.directed_combinatorial_laplacian_matrix(E) + # fmt: off + expected = np.array( + [[ 0.16666667, -0.08333333, -0.08333333, 0. ], + [-0.08333333, 0.16666667, 0. , -0.08333333], + [-0.08333333, 0. , 0.16666667, -0.08333333], + [ 0. , -0.08333333, -0.08333333, 0.16666667]] + ) + # fmt: on + np.testing.assert_almost_equal(L, expected, decimal=6) + + with pytest.raises(nx.NetworkXError): + nx.directed_combinatorial_laplacian_matrix(G, walk_type="pagerank", alpha=100) + with pytest.raises(nx.NetworkXError): + nx.directed_combinatorial_laplacian_matrix(G, walk_type="silly") |