38 lines
1.1 KiB
Python
38 lines
1.1 KiB
Python
# test_beamsearch.py - unit tests for the beamsearch module
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#
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# Copyright 2016-2019 NetworkX developers.
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#
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# This file is part of NetworkX.
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#
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# NetworkX is distributed under a BSD license; see LICENSE.txt for more
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# information.
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"""Unit tests for the beam search functions."""
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from unittest import TestCase
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import networkx as nx
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def identity(x):
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return x
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class TestBeamSearch(TestCase):
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"""Unit tests for the beam search function."""
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def test_narrow(self):
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"""Tests that a narrow beam width may cause an incomplete search."""
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# In this search, we enqueue only the neighbor 3 at the first
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# step, then only the neighbor 2 at the second step. Once at
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# node 2, the search chooses node 3, since it has a higher value
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# that node 1, but node 3 has already been visited, so the
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# search terminates.
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G = nx.cycle_graph(4)
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edges = nx.bfs_beam_edges(G, 0, identity, width=1)
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assert list(edges) == [(0, 3), (3, 2)]
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def test_wide(self):
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G = nx.cycle_graph(4)
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edges = nx.bfs_beam_edges(G, 0, identity, width=2)
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assert list(edges) == [(0, 3), (0, 1), (3, 2)]
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