Mercurial > repos > shellac > sam_consensus_v3
diff env/lib/python3.9/site-packages/networkx/algorithms/tests/test_cycles.py @ 0:4f3585e2f14b draft default tip
"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"
author | shellac |
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date | Mon, 22 Mar 2021 18:12:50 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/env/lib/python3.9/site-packages/networkx/algorithms/tests/test_cycles.py Mon Mar 22 18:12:50 2021 +0000 @@ -0,0 +1,350 @@ +import pytest +import networkx +import networkx as nx + +from networkx.algorithms import find_cycle +from networkx.algorithms import minimum_cycle_basis + +FORWARD = nx.algorithms.edgedfs.FORWARD +REVERSE = nx.algorithms.edgedfs.REVERSE + + +class TestCycles: + @classmethod + def setup_class(cls): + G = networkx.Graph() + nx.add_cycle(G, [0, 1, 2, 3]) + nx.add_cycle(G, [0, 3, 4, 5]) + nx.add_cycle(G, [0, 1, 6, 7, 8]) + G.add_edge(8, 9) + cls.G = G + + def is_cyclic_permutation(self, a, b): + n = len(a) + if len(b) != n: + return False + l = a + a + return any(l[i : i + n] == b for i in range(n)) + + def test_cycle_basis(self): + G = self.G + cy = networkx.cycle_basis(G, 0) + sort_cy = sorted(sorted(c) for c in cy) + assert sort_cy == [[0, 1, 2, 3], [0, 1, 6, 7, 8], [0, 3, 4, 5]] + cy = networkx.cycle_basis(G, 1) + sort_cy = sorted(sorted(c) for c in cy) + assert sort_cy == [[0, 1, 2, 3], [0, 1, 6, 7, 8], [0, 3, 4, 5]] + cy = networkx.cycle_basis(G, 9) + sort_cy = sorted(sorted(c) for c in cy) + assert sort_cy == [[0, 1, 2, 3], [0, 1, 6, 7, 8], [0, 3, 4, 5]] + # test disconnected graphs + nx.add_cycle(G, "ABC") + cy = networkx.cycle_basis(G, 9) + sort_cy = sorted(sorted(c) for c in cy[:-1]) + [sorted(cy[-1])] + assert sort_cy == [[0, 1, 2, 3], [0, 1, 6, 7, 8], [0, 3, 4, 5], ["A", "B", "C"]] + + def test_cycle_basis2(self): + with pytest.raises(nx.NetworkXNotImplemented): + G = nx.DiGraph() + cy = networkx.cycle_basis(G, 0) + + def test_cycle_basis3(self): + with pytest.raises(nx.NetworkXNotImplemented): + G = nx.MultiGraph() + cy = networkx.cycle_basis(G, 0) + + def test_simple_cycles(self): + edges = [(0, 0), (0, 1), (0, 2), (1, 2), (2, 0), (2, 1), (2, 2)] + G = nx.DiGraph(edges) + cc = sorted(nx.simple_cycles(G)) + ca = [[0], [0, 1, 2], [0, 2], [1, 2], [2]] + assert len(cc) == len(ca) + for c in cc: + assert any(self.is_cyclic_permutation(c, rc) for rc in ca) + + def test_simple_cycles_graph(self): + with pytest.raises(nx.NetworkXNotImplemented): + G = nx.Graph() + c = sorted(nx.simple_cycles(G)) + + def test_unsortable(self): + # TODO What does this test do? das 6/2013 + G = nx.DiGraph() + nx.add_cycle(G, ["a", 1]) + c = list(nx.simple_cycles(G)) + + def test_simple_cycles_small(self): + G = nx.DiGraph() + nx.add_cycle(G, [1, 2, 3]) + c = sorted(nx.simple_cycles(G)) + assert len(c) == 1 + assert self.is_cyclic_permutation(c[0], [1, 2, 3]) + nx.add_cycle(G, [10, 20, 30]) + cc = sorted(nx.simple_cycles(G)) + assert len(cc) == 2 + ca = [[1, 2, 3], [10, 20, 30]] + for c in cc: + assert any(self.is_cyclic_permutation(c, rc) for rc in ca) + + def test_simple_cycles_empty(self): + G = nx.DiGraph() + assert list(nx.simple_cycles(G)) == [] + + def test_complete_directed_graph(self): + # see table 2 in Johnson's paper + ncircuits = [1, 5, 20, 84, 409, 2365, 16064] + for n, c in zip(range(2, 9), ncircuits): + G = nx.DiGraph(nx.complete_graph(n)) + assert len(list(nx.simple_cycles(G))) == c + + def worst_case_graph(self, k): + # see figure 1 in Johnson's paper + # this graph has exactly 3k simple cycles + G = nx.DiGraph() + for n in range(2, k + 2): + G.add_edge(1, n) + G.add_edge(n, k + 2) + G.add_edge(2 * k + 1, 1) + for n in range(k + 2, 2 * k + 2): + G.add_edge(n, 2 * k + 2) + G.add_edge(n, n + 1) + G.add_edge(2 * k + 3, k + 2) + for n in range(2 * k + 3, 3 * k + 3): + G.add_edge(2 * k + 2, n) + G.add_edge(n, 3 * k + 3) + G.add_edge(3 * k + 3, 2 * k + 2) + return G + + def test_worst_case_graph(self): + # see figure 1 in Johnson's paper + for k in range(3, 10): + G = self.worst_case_graph(k) + l = len(list(nx.simple_cycles(G))) + assert l == 3 * k + + def test_recursive_simple_and_not(self): + for k in range(2, 10): + G = self.worst_case_graph(k) + cc = sorted(nx.simple_cycles(G)) + rcc = sorted(nx.recursive_simple_cycles(G)) + assert len(cc) == len(rcc) + for c in cc: + assert any(self.is_cyclic_permutation(c, r) for r in rcc) + for rc in rcc: + assert any(self.is_cyclic_permutation(rc, c) for c in cc) + + def test_simple_graph_with_reported_bug(self): + G = nx.DiGraph() + edges = [ + (0, 2), + (0, 3), + (1, 0), + (1, 3), + (2, 1), + (2, 4), + (3, 2), + (3, 4), + (4, 0), + (4, 1), + (4, 5), + (5, 0), + (5, 1), + (5, 2), + (5, 3), + ] + G.add_edges_from(edges) + cc = sorted(nx.simple_cycles(G)) + assert len(cc) == 26 + rcc = sorted(nx.recursive_simple_cycles(G)) + assert len(cc) == len(rcc) + for c in cc: + assert any(self.is_cyclic_permutation(c, rc) for rc in rcc) + for rc in rcc: + assert any(self.is_cyclic_permutation(rc, c) for c in cc) + + +# These tests might fail with hash randomization since they depend on +# edge_dfs. For more information, see the comments in: +# networkx/algorithms/traversal/tests/test_edgedfs.py + + +class TestFindCycle: + @classmethod + def setup_class(cls): + cls.nodes = [0, 1, 2, 3] + cls.edges = [(-1, 0), (0, 1), (1, 0), (1, 0), (2, 1), (3, 1)] + + def test_graph_nocycle(self): + G = nx.Graph(self.edges) + pytest.raises(nx.exception.NetworkXNoCycle, find_cycle, G, self.nodes) + + def test_graph_cycle(self): + G = nx.Graph(self.edges) + G.add_edge(2, 0) + x = list(find_cycle(G, self.nodes)) + x_ = [(0, 1), (1, 2), (2, 0)] + assert x == x_ + + def test_graph_orientation_none(self): + G = nx.Graph(self.edges) + G.add_edge(2, 0) + x = list(find_cycle(G, self.nodes, orientation=None)) + x_ = [(0, 1), (1, 2), (2, 0)] + assert x == x_ + + def test_graph_orientation_original(self): + G = nx.Graph(self.edges) + G.add_edge(2, 0) + x = list(find_cycle(G, self.nodes, orientation="original")) + x_ = [(0, 1, FORWARD), (1, 2, FORWARD), (2, 0, FORWARD)] + assert x == x_ + + def test_digraph(self): + G = nx.DiGraph(self.edges) + x = list(find_cycle(G, self.nodes)) + x_ = [(0, 1), (1, 0)] + assert x == x_ + + def test_digraph_orientation_none(self): + G = nx.DiGraph(self.edges) + x = list(find_cycle(G, self.nodes, orientation=None)) + x_ = [(0, 1), (1, 0)] + assert x == x_ + + def test_digraph_orientation_original(self): + G = nx.DiGraph(self.edges) + x = list(find_cycle(G, self.nodes, orientation="original")) + x_ = [(0, 1, FORWARD), (1, 0, FORWARD)] + assert x == x_ + + def test_multigraph(self): + G = nx.MultiGraph(self.edges) + x = list(find_cycle(G, self.nodes)) + x_ = [(0, 1, 0), (1, 0, 1)] # or (1, 0, 2) + # Hash randomization...could be any edge. + assert x[0] == x_[0] + assert x[1][:2] == x_[1][:2] + + def test_multidigraph(self): + G = nx.MultiDiGraph(self.edges) + x = list(find_cycle(G, self.nodes)) + x_ = [(0, 1, 0), (1, 0, 0)] # (1, 0, 1) + assert x[0] == x_[0] + assert x[1][:2] == x_[1][:2] + + def test_digraph_ignore(self): + G = nx.DiGraph(self.edges) + x = list(find_cycle(G, self.nodes, orientation="ignore")) + x_ = [(0, 1, FORWARD), (1, 0, FORWARD)] + assert x == x_ + + def test_digraph_reverse(self): + G = nx.DiGraph(self.edges) + x = list(find_cycle(G, self.nodes, orientation="reverse")) + x_ = [(1, 0, REVERSE), (0, 1, REVERSE)] + assert x == x_ + + def test_multidigraph_ignore(self): + G = nx.MultiDiGraph(self.edges) + x = list(find_cycle(G, self.nodes, orientation="ignore")) + x_ = [(0, 1, 0, FORWARD), (1, 0, 0, FORWARD)] # or (1, 0, 1, 1) + assert x[0] == x_[0] + assert x[1][:2] == x_[1][:2] + assert x[1][3] == x_[1][3] + + def test_multidigraph_ignore2(self): + # Loop traversed an edge while ignoring its orientation. + G = nx.MultiDiGraph([(0, 1), (1, 2), (1, 2)]) + x = list(find_cycle(G, [0, 1, 2], orientation="ignore")) + x_ = [(1, 2, 0, FORWARD), (1, 2, 1, REVERSE)] + assert x == x_ + + def test_multidigraph_original(self): + # Node 2 doesn't need to be searched again from visited from 4. + # The goal here is to cover the case when 2 to be researched from 4, + # when 4 is visited from the first time (so we must make sure that 4 + # is not visited from 2, and hence, we respect the edge orientation). + G = nx.MultiDiGraph([(0, 1), (1, 2), (2, 3), (4, 2)]) + pytest.raises( + nx.exception.NetworkXNoCycle, + find_cycle, + G, + [0, 1, 2, 3, 4], + orientation="original", + ) + + def test_dag(self): + G = nx.DiGraph([(0, 1), (0, 2), (1, 2)]) + pytest.raises( + nx.exception.NetworkXNoCycle, find_cycle, G, orientation="original" + ) + x = list(find_cycle(G, orientation="ignore")) + assert x == [(0, 1, FORWARD), (1, 2, FORWARD), (0, 2, REVERSE)] + + def test_prev_explored(self): + # https://github.com/networkx/networkx/issues/2323 + + G = nx.DiGraph() + G.add_edges_from([(1, 0), (2, 0), (1, 2), (2, 1)]) + pytest.raises(nx.NetworkXNoCycle, find_cycle, G, source=0) + x = list(nx.find_cycle(G, 1)) + x_ = [(1, 2), (2, 1)] + assert x == x_ + + x = list(nx.find_cycle(G, 2)) + x_ = [(2, 1), (1, 2)] + assert x == x_ + + x = list(nx.find_cycle(G)) + x_ = [(1, 2), (2, 1)] + assert x == x_ + + def test_no_cycle(self): + # https://github.com/networkx/networkx/issues/2439 + + G = nx.DiGraph() + G.add_edges_from([(1, 2), (2, 0), (3, 1), (3, 2)]) + pytest.raises(nx.NetworkXNoCycle, find_cycle, G, source=0) + pytest.raises(nx.NetworkXNoCycle, find_cycle, G) + + +def assert_basis_equal(a, b): + assert sorted(a) == sorted(b) + + +class TestMinimumCycles: + @classmethod + def setup_class(cls): + T = nx.Graph() + nx.add_cycle(T, [1, 2, 3, 4], weight=1) + T.add_edge(2, 4, weight=5) + cls.diamond_graph = T + + def test_unweighted_diamond(self): + mcb = minimum_cycle_basis(self.diamond_graph) + assert_basis_equal([sorted(c) for c in mcb], [[1, 2, 4], [2, 3, 4]]) + + def test_weighted_diamond(self): + mcb = minimum_cycle_basis(self.diamond_graph, weight="weight") + assert_basis_equal([sorted(c) for c in mcb], [[1, 2, 4], [1, 2, 3, 4]]) + + def test_dimensionality(self): + # checks |MCB|=|E|-|V|+|NC| + ntrial = 10 + for _ in range(ntrial): + rg = nx.erdos_renyi_graph(10, 0.3) + nnodes = rg.number_of_nodes() + nedges = rg.number_of_edges() + ncomp = nx.number_connected_components(rg) + + dim_mcb = len(minimum_cycle_basis(rg)) + assert dim_mcb == nedges - nnodes + ncomp + + def test_complete_graph(self): + cg = nx.complete_graph(5) + mcb = minimum_cycle_basis(cg) + assert all([len(cycle) == 3 for cycle in mcb]) + + def test_tree_graph(self): + tg = nx.balanced_tree(3, 3) + assert not minimum_cycle_basis(tg)