reconnect moved files to git repo

venv/lib/python3.11/site-packages/sklearn/utils/tests/test_graph.py

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+import numpy as np
+import pytest
+from scipy.sparse.csgraph import connected_components
+
+from sklearn.metrics.pairwise import pairwise_distances
+from sklearn.neighbors import kneighbors_graph
+from sklearn.utils.graph import _fix_connected_components
+
+
+def test_fix_connected_components():
+    # Test that _fix_connected_components reduces the number of component to 1.
+    X = np.array([0, 1, 2, 5, 6, 7])[:, None]
+    graph = kneighbors_graph(X, n_neighbors=2, mode="distance")
+
+    n_connected_components, labels = connected_components(graph)
+    assert n_connected_components > 1
+
+    graph = _fix_connected_components(X, graph, n_connected_components, labels)
+
+    n_connected_components, labels = connected_components(graph)
+    assert n_connected_components == 1
+
+
+def test_fix_connected_components_precomputed():
+    # Test that _fix_connected_components accepts precomputed distance matrix.
+    X = np.array([0, 1, 2, 5, 6, 7])[:, None]
+    graph = kneighbors_graph(X, n_neighbors=2, mode="distance")
+
+    n_connected_components, labels = connected_components(graph)
+    assert n_connected_components > 1
+
+    distances = pairwise_distances(X)
+    graph = _fix_connected_components(
+        distances, graph, n_connected_components, labels, metric="precomputed"
+    )
+
+    n_connected_components, labels = connected_components(graph)
+    assert n_connected_components == 1
+
+    # but it does not work with precomputed neighbors graph
+    with pytest.raises(RuntimeError, match="does not work with a sparse"):
+        _fix_connected_components(
+            graph, graph, n_connected_components, labels, metric="precomputed"
+        )
+
+
+def test_fix_connected_components_wrong_mode():
+    # Test that the an error is raised if the mode string is incorrect.
+    X = np.array([0, 1, 2, 5, 6, 7])[:, None]
+    graph = kneighbors_graph(X, n_neighbors=2, mode="distance")
+    n_connected_components, labels = connected_components(graph)
+
+    with pytest.raises(ValueError, match="Unknown mode"):
+        graph = _fix_connected_components(
+            X, graph, n_connected_components, labels, mode="foo"
+        )
+
+
+def test_fix_connected_components_connectivity_mode():
+    # Test that the connectivity mode fill new connections with ones.
+    X = np.array([0, 1, 6, 7])[:, None]
+    graph = kneighbors_graph(X, n_neighbors=1, mode="connectivity")
+    n_connected_components, labels = connected_components(graph)
+    graph = _fix_connected_components(
+        X, graph, n_connected_components, labels, mode="connectivity"
+    )
+    assert np.all(graph.data == 1)
+
+
+def test_fix_connected_components_distance_mode():
+    # Test that the distance mode does not fill new connections with ones.
+    X = np.array([0, 1, 6, 7])[:, None]
+    graph = kneighbors_graph(X, n_neighbors=1, mode="distance")
+    assert np.all(graph.data == 1)
+
+    n_connected_components, labels = connected_components(graph)
+    graph = _fix_connected_components(
+        X, graph, n_connected_components, labels, mode="distance"
+    )
+    assert not np.all(graph.data == 1)