Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/scipy/sparse/csgraph/tests/test_matching.py

@@ -0,0 +1,145 @@
+import numpy as np
+from numpy.testing import assert_array_equal, assert_equal
+import pytest
+
+from scipy.sparse import csr_matrix, coo_matrix, diags
+from scipy.sparse.csgraph import maximum_bipartite_matching
+
+
+def test_raises_on_dense_input():
+    with pytest.raises(TypeError):
+        graph = np.array([[0, 1], [0, 0]])
+        maximum_bipartite_matching(graph)
+
+
+def test_empty_graph():
+    graph = csr_matrix((0, 0))
+    x = maximum_bipartite_matching(graph, perm_type='row')
+    y = maximum_bipartite_matching(graph, perm_type='column')
+    expected_matching = np.array([])
+    assert_array_equal(expected_matching, x)
+    assert_array_equal(expected_matching, y)
+
+
+def test_empty_left_partition():
+    graph = csr_matrix((2, 0))
+    x = maximum_bipartite_matching(graph, perm_type='row')
+    y = maximum_bipartite_matching(graph, perm_type='column')
+    assert_array_equal(np.array([]), x)
+    assert_array_equal(np.array([-1, -1]), y)
+
+
+def test_empty_right_partition():
+    graph = csr_matrix((0, 3))
+    x = maximum_bipartite_matching(graph, perm_type='row')
+    y = maximum_bipartite_matching(graph, perm_type='column')
+    assert_array_equal(np.array([-1, -1, -1]), x)
+    assert_array_equal(np.array([]), y)
+
+
+def test_graph_with_no_edges():
+    graph = csr_matrix((2, 2))
+    x = maximum_bipartite_matching(graph, perm_type='row')
+    y = maximum_bipartite_matching(graph, perm_type='column')
+    assert_array_equal(np.array([-1, -1]), x)
+    assert_array_equal(np.array([-1, -1]), y)
+
+
+def test_graph_that_causes_augmentation():
+    # In this graph, column 1 is initially assigned to row 1, but it should be
+    # reassigned to make room for row 2.
+    graph = csr_matrix([[1, 1], [1, 0]])
+    x = maximum_bipartite_matching(graph, perm_type='column')
+    y = maximum_bipartite_matching(graph, perm_type='row')
+    expected_matching = np.array([1, 0])
+    assert_array_equal(expected_matching, x)
+    assert_array_equal(expected_matching, y)
+
+
+def test_graph_with_more_rows_than_columns():
+    graph = csr_matrix([[1, 1], [1, 0], [0, 1]])
+    x = maximum_bipartite_matching(graph, perm_type='column')
+    y = maximum_bipartite_matching(graph, perm_type='row')
+    assert_array_equal(np.array([0, -1, 1]), x)
+    assert_array_equal(np.array([0, 2]), y)
+
+
+def test_graph_with_more_columns_than_rows():
+    graph = csr_matrix([[1, 1, 0], [0, 0, 1]])
+    x = maximum_bipartite_matching(graph, perm_type='column')
+    y = maximum_bipartite_matching(graph, perm_type='row')
+    assert_array_equal(np.array([0, 2]), x)
+    assert_array_equal(np.array([0, -1, 1]), y)
+
+
+def test_explicit_zeros_count_as_edges():
+    data = [0, 0]
+    indices = [1, 0]
+    indptr = [0, 1, 2]
+    graph = csr_matrix((data, indices, indptr), shape=(2, 2))
+    x = maximum_bipartite_matching(graph, perm_type='row')
+    y = maximum_bipartite_matching(graph, perm_type='column')
+    expected_matching = np.array([1, 0])
+    assert_array_equal(expected_matching, x)
+    assert_array_equal(expected_matching, y)
+
+
+def test_feasibility_of_result():
+    # This is a regression test for GitHub issue #11458
+    data = np.ones(50, dtype=int)
+    indices = [11, 12, 19, 22, 23, 5, 22, 3, 8, 10, 5, 6, 11, 12, 13, 5, 13,
+               14, 20, 22, 3, 15, 3, 13, 14, 11, 12, 19, 22, 23, 5, 22, 3, 8,
+               10, 5, 6, 11, 12, 13, 5, 13, 14, 20, 22, 3, 15, 3, 13, 14]
+    indptr = [0, 5, 7, 10, 10, 15, 20, 22, 22, 23, 25, 30, 32, 35, 35, 40, 45,
+              47, 47, 48, 50]
+    graph = csr_matrix((data, indices, indptr), shape=(20, 25))
+    x = maximum_bipartite_matching(graph, perm_type='row')
+    y = maximum_bipartite_matching(graph, perm_type='column')
+    assert (x != -1).sum() == 13
+    assert (y != -1).sum() == 13
+    # Ensure that each element of the matching is in fact an edge in the graph.
+    for u, v in zip(range(graph.shape[0]), y):
+        if v != -1:
+            assert graph[u, v]
+    for u, v in zip(x, range(graph.shape[1])):
+        if u != -1:
+            assert graph[u, v]
+
+
+def test_large_random_graph_with_one_edge_incident_to_each_vertex():
+    np.random.seed(42)
+    A = diags(np.ones(25), offsets=0, format='csr')
+    rand_perm = np.random.permutation(25)
+    rand_perm2 = np.random.permutation(25)
+
+    Rrow = np.arange(25)
+    Rcol = rand_perm
+    Rdata = np.ones(25, dtype=int)
+    Rmat = coo_matrix((Rdata, (Rrow, Rcol))).tocsr()
+
+    Crow = rand_perm2
+    Ccol = np.arange(25)
+    Cdata = np.ones(25, dtype=int)
+    Cmat = coo_matrix((Cdata, (Crow, Ccol))).tocsr()
+    # Randomly permute identity matrix
+    B = Rmat * A * Cmat
+
+    # Row permute
+    perm = maximum_bipartite_matching(B, perm_type='row')
+    Rrow = np.arange(25)
+    Rcol = perm
+    Rdata = np.ones(25, dtype=int)
+    Rmat = coo_matrix((Rdata, (Rrow, Rcol))).tocsr()
+    C1 = Rmat * B
+
+    # Column permute
+    perm2 = maximum_bipartite_matching(B, perm_type='column')
+    Crow = perm2
+    Ccol = np.arange(25)
+    Cdata = np.ones(25, dtype=int)
+    Cmat = coo_matrix((Cdata, (Crow, Ccol))).tocsr()
+    C2 = B * Cmat
+
+    # Should get identity matrix back
+    assert_equal(any(C1.diagonal() == 0), False)
+    assert_equal(any(C2.diagonal() == 0), False)