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102 lines
3.2 KiB
Python
102 lines
3.2 KiB
Python
5 years ago
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from __future__ import division, print_function, absolute_import
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import numpy as np
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from numpy.testing import assert_equal, assert_array_almost_equal
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from scipy.sparse import csgraph
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def test_weak_connections():
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Xde = np.array([[0, 1, 0],
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[0, 0, 0],
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[0, 0, 0]])
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Xsp = csgraph.csgraph_from_dense(Xde, null_value=0)
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for X in Xsp, Xde:
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n_components, labels =\
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csgraph.connected_components(X, directed=True,
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connection='weak')
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assert_equal(n_components, 2)
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assert_array_almost_equal(labels, [0, 0, 1])
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def test_strong_connections():
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X1de = np.array([[0, 1, 0],
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[0, 0, 0],
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[0, 0, 0]])
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X2de = X1de + X1de.T
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X1sp = csgraph.csgraph_from_dense(X1de, null_value=0)
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X2sp = csgraph.csgraph_from_dense(X2de, null_value=0)
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for X in X1sp, X1de:
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n_components, labels =\
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csgraph.connected_components(X, directed=True,
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connection='strong')
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assert_equal(n_components, 3)
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labels.sort()
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assert_array_almost_equal(labels, [0, 1, 2])
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for X in X2sp, X2de:
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n_components, labels =\
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csgraph.connected_components(X, directed=True,
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connection='strong')
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assert_equal(n_components, 2)
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labels.sort()
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assert_array_almost_equal(labels, [0, 0, 1])
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def test_strong_connections2():
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X = np.array([[0, 0, 0, 0, 0, 0],
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[1, 0, 1, 0, 0, 0],
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[0, 0, 0, 1, 0, 0],
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[0, 0, 1, 0, 1, 0],
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[0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 1, 0]])
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n_components, labels =\
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csgraph.connected_components(X, directed=True,
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connection='strong')
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assert_equal(n_components, 5)
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labels.sort()
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assert_array_almost_equal(labels, [0, 1, 2, 2, 3, 4])
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def test_weak_connections2():
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X = np.array([[0, 0, 0, 0, 0, 0],
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[1, 0, 0, 0, 0, 0],
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[0, 0, 0, 1, 0, 0],
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[0, 0, 1, 0, 1, 0],
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[0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 1, 0]])
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n_components, labels =\
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csgraph.connected_components(X, directed=True,
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connection='weak')
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assert_equal(n_components, 2)
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labels.sort()
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assert_array_almost_equal(labels, [0, 0, 1, 1, 1, 1])
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def test_ticket1876():
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# Regression test: this failed in the original implementation
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# There should be two strongly-connected components; previously gave one
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g = np.array([[0, 1, 1, 0],
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[1, 0, 0, 1],
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[0, 0, 0, 1],
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[0, 0, 1, 0]])
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n_components, labels = csgraph.connected_components(g, connection='strong')
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assert_equal(n_components, 2)
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assert_equal(labels[0], labels[1])
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assert_equal(labels[2], labels[3])
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def test_fully_connected_graph():
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# Fully connected dense matrices raised an exception.
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# https://github.com/scipy/scipy/issues/3818
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g = np.ones((4, 4))
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n_components, labels = csgraph.connected_components(g)
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assert_equal(n_components, 1)
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