def test_invalid_max_size(self):
"""Test if function raises a ``ValueError`` when an invalid max_size is requested"""
dim = 5
with pytest.raises(
ValueError,
match="max_size must be less than number of nodes in graph"):
subgraph.resize([0, 1], nx.complete_graph(dim), 2, dim)
def test_target_big(self, graph):
"""Test if function raises a ``ValueError`` when a too large number is given for
``target`` """
with pytest.raises(
ValueError,
match="target must be greater than two and less than"):
subgraph.resize(subgraphs=[[0, 1]], graph=graph, target=5)
def test_tie(self, monkeypatch):
"""Test if function correctly settles ties with random selection. This test starts with
the problem of a 6-dimensional complete graph and a 4-node subgraph, with the objective
of shrinking down to 3 nodes. In this case, any of the 4 nodes in the subgraph is an
equally good candidate for removal since all nodes have the same degree. The test
monkeypatches the ``np.random.shuffle`` function to simply permute the list according to
an offset, e.g. for an offset of 2 the list [0, 1, 2, 3] gets permuted to [2, 3, 0,
1]. Using this we expect the node to be removed by ``resize`` in this case to have label
equal to the offset."""
dim = 6
g = nx.complete_graph(dim)
s = [0, 1, 2, 3]
def permute(l, offset):
d = len(l)
ll = l.copy()
for _i in range(d):
l[_i] = ll[(_i + offset) % d]
for i in range(4):
permute_i = functools.partial(permute, offset=i)
with monkeypatch.context() as m:
m.setattr(np.random, "shuffle", permute_i)
resized = subgraph.resize(s, g, min_size=3, max_size=3)
resized_subgraph = resized[3]
removed_node = list(set(s) - set(resized_subgraph))[0]
assert removed_node == i
def test_full_range(self, dim, min_size, max_size):
"""Test if function correctly resizes to full range of requested sizes"""
g = nx.complete_graph(dim)
resized = subgraph.resize([0, 1, 2], g, min_size, max_size)
r = range(min_size, max_size + 1)
assert set(resized.keys()) == set(r)
subgraph_sizes = [len(resized[i]) for i in r]
assert subgraph_sizes == list(r)
def test_callable_input(self, graph):
"""Tests if function returns the correct output given a custom method set by the user"""
objective_return = (0, [0])
def custom_method(*args, **kwargs):
"""Mockup of custom-method function fed to ``search``"""
return objective_return
result = subgraph.resize(subgraphs=[[0, 1]],
graph=graph,
target=4,
resize_options={"method": custom_method})
assert result == objective_return
def test_valid_input(self, graph, monkeypatch, methods):
"""Tests if function returns the correct output under normal conditions. The resizing
method is here monkey patched to return a known result."""
objective_return = (0, [0])
def custom_method(*args, **kwargs):
"""Mockup of custom-method function fed to ``resize``"""
return objective_return
with monkeypatch.context() as m:
m.setattr(subgraph, "RESIZE_DICT", {methods: custom_method})
result = subgraph.resize(subgraphs=[[0, 1]],
graph=graph,
target=4,
resize_options={"method": methods})
assert result == objective_return
def test_resize_integration(graph, target, methods):
"""Test if function returns resized subgraphs of the correct form given an input list of
variable sized subgraphs specified by ``subgraphs``. The output should be a list of ``len(
10)``, each element containing itself a list corresponding to a subgraph that should be of
``len(target)``. Each element in the subraph list should correspond to a node of the input
graph. Note that graph nodes are numbered in this test as [0, 1, 4, 9, ...] (i.e., squares of
the usual list) as a simple mapping to explore that the resized subgraph returned is still a
valid subgraph."""
graph = nx.relabel_nodes(graph, lambda x: x**2)
graph_nodes = set(graph.nodes)
s_relabeled = [(np.array(s)**2).tolist() for s in subgraphs]
resized = subgraph.resize(subgraphs=s_relabeled,
graph=graph,
target=target,
resize_options={"method": methods})
resized = np.array(resized)
dims = resized.shape
assert len(dims) == 2
assert dims[0] == len(s_relabeled)
assert dims[1] == target
assert all(set(sample).issubset(graph_nodes) for sample in resized)
def test_correct_resize(self):
"""Test if function correctly resizes on a fixed example where the ideal resizing is
known. The example is a lollipop graph of 6 fully connected nodes and 2 nodes on the
lollipop stick. An edge between node zero and node ``dim - 1`` (the lollipop node
connecting to the stick) is removed and a starting subgraph of nodes ``[2, 3, 4, 5,
6]`` is selected. The objective is to add-on 1 and 2 nodes and remove 1 node."""
dim = 6
g = nx.lollipop_graph(dim, 2)
g.remove_edge(0, dim - 1)
s = [2, 3, 4, 5, 6]
min_size = 4
max_size = 7
ideal = {
4: [2, 3, 4, 5],
5: [2, 3, 4, 5, 6],
6: [1, 2, 3, 4, 5, 6],
7: [0, 1, 2, 3, 4, 5, 6],
}
resized = subgraph.resize(s, g, min_size, max_size)
assert ideal == resized
def test_target_wrong_type(self, graph):
"""Test if function raises a ``TypeError`` when incorrect type given for ``target`` """
with pytest.raises(TypeError, match="target must be an integer"):
subgraph.resize(subgraphs=[[0, 1]], graph=graph, target=[])
def test_invalid_max_vs_min(self):
"""Test if function raises a ``ValueError`` when max_size is less than min_size"""
dim = 5
with pytest.raises(ValueError,
match="max_size must not be less than min_size"):
subgraph.resize([0, 1], nx.complete_graph(dim), 4, 3)
def test_invalid_min_size(self):
"""Test if function raises a ``ValueError`` when an invalid min_size is requested"""
dim = 5
with pytest.raises(ValueError, match="min_size must be at least 1"):
subgraph.resize([0, 1], nx.complete_graph(dim), 0, 3)
def test_input_not_subgraph(self):
"""Test if function raises a ``ValueError`` when input is not a subgraph"""
dim = 5
with pytest.raises(ValueError, match="Input is not a valid subgraph"):
subgraph.resize([dim + 1], nx.complete_graph(dim), 2, 3)
