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import pytest
import networkx as nx
class TestImmediateDominators:
def test_exceptions(self):
G = nx.Graph()
G.add_node(0)
pytest.raises(nx.NetworkXNotImplemented, nx.immediate_dominators, G, 0)
G = nx.MultiGraph(G)
pytest.raises(nx.NetworkXNotImplemented, nx.immediate_dominators, G, 0)
G = nx.DiGraph([[0, 0]])
pytest.raises(nx.NetworkXError, nx.immediate_dominators, G, 1)
def test_singleton(self):
G = nx.DiGraph()
G.add_node(0)
assert nx.immediate_dominators(G, 0) == {0: 0}
G.add_edge(0, 0)
assert nx.immediate_dominators(G, 0) == {0: 0}
def test_path(self):
n = 5
G = nx.path_graph(n, create_using=nx.DiGraph())
assert nx.immediate_dominators(G, 0) == {i: max(i - 1, 0) for i in range(n)}
def test_cycle(self):
n = 5
G = nx.cycle_graph(n, create_using=nx.DiGraph())
assert nx.immediate_dominators(G, 0) == {i: max(i - 1, 0) for i in range(n)}
def test_unreachable(self):
n = 5
assert n > 1
G = nx.path_graph(n, create_using=nx.DiGraph())
assert nx.immediate_dominators(G, n // 2) == {
i: max(i - 1, n // 2) for i in range(n // 2, n)
}
def test_irreducible1(self):
"""
Graph taken from figure 2 of "A simple, fast dominance algorithm." (2006).
https://hdl.handle.net/1911/96345
"""
edges = [(1, 2), (2, 1), (3, 2), (4, 1), (5, 3), (5, 4)]
G = nx.DiGraph(edges)
assert nx.immediate_dominators(G, 5) == {i: 5 for i in range(1, 6)}
def test_irreducible2(self):
"""
Graph taken from figure 4 of "A simple, fast dominance algorithm." (2006).
https://hdl.handle.net/1911/96345
"""
edges = [(1, 2), (2, 1), (2, 3), (3, 2), (4, 2), (4, 3), (5, 1), (6, 4), (6, 5)]
G = nx.DiGraph(edges)
result = nx.immediate_dominators(G, 6)
assert result == {i: 6 for i in range(1, 7)}
def test_domrel_png(self):
# Graph taken from https://commons.wikipedia.org/wiki/File:Domrel.png
edges = [(1, 2), (2, 3), (2, 4), (2, 6), (3, 5), (4, 5), (5, 2)]
G = nx.DiGraph(edges)
result = nx.immediate_dominators(G, 1)
assert result == {1: 1, 2: 1, 3: 2, 4: 2, 5: 2, 6: 2}
# Test postdominance.
result = nx.immediate_dominators(G.reverse(copy=False), 6)
assert result == {1: 2, 2: 6, 3: 5, 4: 5, 5: 2, 6: 6}
def test_boost_example(self):
# Graph taken from Figure 1 of
# http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/lengauer_tarjan_dominator.htm
edges = [(0, 1), (1, 2), (1, 3), (2, 7), (3, 4), (4, 5), (4, 6), (5, 7), (6, 4)]
G = nx.DiGraph(edges)
result = nx.immediate_dominators(G, 0)
assert result == {0: 0, 1: 0, 2: 1, 3: 1, 4: 3, 5: 4, 6: 4, 7: 1}
# Test postdominance.
result = nx.immediate_dominators(G.reverse(copy=False), 7)
assert result == {0: 1, 1: 7, 2: 7, 3: 4, 4: 5, 5: 7, 6: 4, 7: 7}
class TestDominanceFrontiers:
def test_exceptions(self):
G = nx.Graph()
G.add_node(0)
pytest.raises(nx.NetworkXNotImplemented, nx.dominance_frontiers, G, 0)
G = nx.MultiGraph(G)
pytest.raises(nx.NetworkXNotImplemented, nx.dominance_frontiers, G, 0)
G = nx.DiGraph([[0, 0]])
pytest.raises(nx.NetworkXError, nx.dominance_frontiers, G, 1)
def test_singleton(self):
G = nx.DiGraph()
G.add_node(0)
assert nx.dominance_frontiers(G, 0) == {0: set()}
G.add_edge(0, 0)
assert nx.dominance_frontiers(G, 0) == {0: set()}
def test_path(self):
n = 5
G = nx.path_graph(n, create_using=nx.DiGraph())
assert nx.dominance_frontiers(G, 0) == {i: set() for i in range(n)}
def test_cycle(self):
n = 5
G = nx.cycle_graph(n, create_using=nx.DiGraph())
assert nx.dominance_frontiers(G, 0) == {i: set() for i in range(n)}
def test_unreachable(self):
n = 5
assert n > 1
G = nx.path_graph(n, create_using=nx.DiGraph())
assert nx.dominance_frontiers(G, n // 2) == {i: set() for i in range(n // 2, n)}
def test_irreducible1(self):
"""
Graph taken from figure 2 of "A simple, fast dominance algorithm." (2006).
https://hdl.handle.net/1911/96345
"""
edges = [(1, 2), (2, 1), (3, 2), (4, 1), (5, 3), (5, 4)]
G = nx.DiGraph(edges)
assert dict(nx.dominance_frontiers(G, 5).items()) == {
1: {2},
2: {1},
3: {2},
4: {1},
5: set(),
}
def test_irreducible2(self):
"""
Graph taken from figure 4 of "A simple, fast dominance algorithm." (2006).
https://hdl.handle.net/1911/96345
"""
edges = [(1, 2), (2, 1), (2, 3), (3, 2), (4, 2), (4, 3), (5, 1), (6, 4), (6, 5)]
G = nx.DiGraph(edges)
assert nx.dominance_frontiers(G, 6) == {
1: {2},
2: {1, 3},
3: {2},
4: {2, 3},
5: {1},
6: set(),
}
def test_domrel_png(self):
# Graph taken from https://commons.wikipedia.org/wiki/File:Domrel.png
edges = [(1, 2), (2, 3), (2, 4), (2, 6), (3, 5), (4, 5), (5, 2)]
G = nx.DiGraph(edges)
assert nx.dominance_frontiers(G, 1) == {
1: set(),
2: {2},
3: {5},
4: {5},
5: {2},
6: set(),
}
# Test postdominance.
result = nx.dominance_frontiers(G.reverse(copy=False), 6)
assert result == {1: set(), 2: {2}, 3: {2}, 4: {2}, 5: {2}, 6: set()}
def test_boost_example(self):
# Graph taken from Figure 1 of
# http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/lengauer_tarjan_dominator.htm
edges = [(0, 1), (1, 2), (1, 3), (2, 7), (3, 4), (4, 5), (4, 6), (5, 7), (6, 4)]
G = nx.DiGraph(edges)
assert nx.dominance_frontiers(G, 0) == {
0: set(),
1: set(),
2: {7},
3: {7},
4: {4, 7},
5: {7},
6: {4},
7: set(),
}
# Test postdominance.
result = nx.dominance_frontiers(G.reverse(copy=False), 7)
expected = {
0: set(),
1: set(),
2: {1},
3: {1},
4: {1, 4},
5: {1},
6: {4},
7: set(),
}
assert result == expected
def test_discard_issue(self):
# https://github.com/networkx/networkx/issues/2071
g = nx.DiGraph()
g.add_edges_from(
[
("b0", "b1"),
("b1", "b2"),
("b2", "b3"),
("b3", "b1"),
("b1", "b5"),
("b5", "b6"),
("b5", "b8"),
("b6", "b7"),
("b8", "b7"),
("b7", "b3"),
("b3", "b4"),
]
)
df = nx.dominance_frontiers(g, "b0")
assert df == {
"b4": set(),
"b5": {"b3"},
"b6": {"b7"},
"b7": {"b3"},
"b0": set(),
"b1": {"b1"},
"b2": {"b3"},
"b3": {"b1"},
"b8": {"b7"},
}
def test_loop(self):
g = nx.DiGraph()
g.add_edges_from([("a", "b"), ("b", "c"), ("b", "a")])
df = nx.dominance_frontiers(g, "a")
assert df == {"a": set(), "b": set(), "c": set()}
def test_missing_immediate_doms(self):
# see https://github.com/networkx/networkx/issues/2070
g = nx.DiGraph()
edges = [
("entry_1", "b1"),
("b1", "b2"),
("b2", "b3"),
("b3", "exit"),
("entry_2", "b3"),
]
# entry_1
# |
# b1
# |
# b2 entry_2
# | /
# b3
# |
# exit
g.add_edges_from(edges)
# formerly raised KeyError on entry_2 when parsing b3
# because entry_2 does not have immediate doms (no path)
nx.dominance_frontiers(g, "entry_1")
def test_loops_larger(self):
# from
# http://ecee.colorado.edu/~waite/Darmstadt/motion.html
g = nx.DiGraph()
edges = [
("entry", "exit"),
("entry", "1"),
("1", "2"),
("2", "3"),
("3", "4"),
("4", "5"),
("5", "6"),
("6", "exit"),
("6", "2"),
("5", "3"),
("4", "4"),
]
g.add_edges_from(edges)
df = nx.dominance_frontiers(g, "entry")
answer = {
"entry": set(),
"1": {"exit"},
"2": {"exit", "2"},
"3": {"exit", "3", "2"},
"4": {"exit", "4", "3", "2"},
"5": {"exit", "3", "2"},
"6": {"exit", "2"},
"exit": set(),
}
for n in df:
assert set(df[n]) == set(answer[n])
|
