ai-content-maker/.venv/Lib/site-packages/networkx/tests/test_convert_numpy.py

675 lines
25 KiB
Python

import pytest
np = pytest.importorskip("numpy")
npt = pytest.importorskip("numpy.testing")
import networkx as nx
from networkx.generators.classic import barbell_graph, cycle_graph, path_graph
from networkx.utils import graphs_equal
def test_to_numpy_matrix_deprecation():
pytest.deprecated_call(nx.to_numpy_matrix, nx.Graph())
def test_from_numpy_matrix_deprecation():
pytest.deprecated_call(nx.from_numpy_matrix, np.eye(2))
def test_to_numpy_recarray_deprecation():
pytest.deprecated_call(nx.to_numpy_recarray, nx.Graph())
class TestConvertNumpyMatrix:
# TODO: This entire class can be removed when to/from_numpy_matrix
# deprecation expires
def setup_method(self):
self.G1 = barbell_graph(10, 3)
self.G2 = cycle_graph(10, create_using=nx.DiGraph)
self.G3 = self.create_weighted(nx.Graph())
self.G4 = self.create_weighted(nx.DiGraph())
def test_exceptions(self):
G = np.array("a")
pytest.raises(nx.NetworkXError, nx.to_networkx_graph, G)
def create_weighted(self, G):
g = cycle_graph(4)
G.add_nodes_from(g)
G.add_weighted_edges_from((u, v, 10 + u) for u, v in g.edges())
return G
def assert_equal(self, G1, G2):
assert sorted(G1.nodes()) == sorted(G2.nodes())
assert sorted(G1.edges()) == sorted(G2.edges())
def identity_conversion(self, G, A, create_using):
assert A.sum() > 0
GG = nx.from_numpy_matrix(A, create_using=create_using)
self.assert_equal(G, GG)
GW = nx.to_networkx_graph(A, create_using=create_using)
self.assert_equal(G, GW)
GI = nx.empty_graph(0, create_using).__class__(A)
self.assert_equal(G, GI)
def test_shape(self):
"Conversion from non-square array."
A = np.array([[1, 2, 3], [4, 5, 6]])
pytest.raises(nx.NetworkXError, nx.from_numpy_matrix, A)
def test_identity_graph_matrix(self):
"Conversion from graph to matrix to graph."
A = nx.to_numpy_matrix(self.G1)
self.identity_conversion(self.G1, A, nx.Graph())
def test_identity_graph_array(self):
"Conversion from graph to array to graph."
A = nx.to_numpy_matrix(self.G1)
A = np.asarray(A)
self.identity_conversion(self.G1, A, nx.Graph())
def test_identity_digraph_matrix(self):
"""Conversion from digraph to matrix to digraph."""
A = nx.to_numpy_matrix(self.G2)
self.identity_conversion(self.G2, A, nx.DiGraph())
def test_identity_digraph_array(self):
"""Conversion from digraph to array to digraph."""
A = nx.to_numpy_matrix(self.G2)
A = np.asarray(A)
self.identity_conversion(self.G2, A, nx.DiGraph())
def test_identity_weighted_graph_matrix(self):
"""Conversion from weighted graph to matrix to weighted graph."""
A = nx.to_numpy_matrix(self.G3)
self.identity_conversion(self.G3, A, nx.Graph())
def test_identity_weighted_graph_array(self):
"""Conversion from weighted graph to array to weighted graph."""
A = nx.to_numpy_matrix(self.G3)
A = np.asarray(A)
self.identity_conversion(self.G3, A, nx.Graph())
def test_identity_weighted_digraph_matrix(self):
"""Conversion from weighted digraph to matrix to weighted digraph."""
A = nx.to_numpy_matrix(self.G4)
self.identity_conversion(self.G4, A, nx.DiGraph())
def test_identity_weighted_digraph_array(self):
"""Conversion from weighted digraph to array to weighted digraph."""
A = nx.to_numpy_matrix(self.G4)
A = np.asarray(A)
self.identity_conversion(self.G4, A, nx.DiGraph())
def test_nodelist(self):
"""Conversion from graph to matrix to graph with nodelist."""
P4 = path_graph(4)
P3 = path_graph(3)
nodelist = list(P3)
A = nx.to_numpy_matrix(P4, nodelist=nodelist)
GA = nx.Graph(A)
self.assert_equal(GA, P3)
assert nx.to_numpy_matrix(P3, nodelist=[]).shape == (0, 0)
# Test nodelist duplicates.
long_nodelist = nodelist + [0]
pytest.raises(nx.NetworkXError, nx.to_numpy_matrix, P3, nodelist=long_nodelist)
# Test nodelist contains non-nodes
nonnodelist = [-1, 0, 1, 2]
pytest.raises(nx.NetworkXError, nx.to_numpy_matrix, P3, nodelist=nonnodelist)
def test_weight_keyword(self):
WP4 = nx.Graph()
WP4.add_edges_from((n, n + 1, dict(weight=0.5, other=0.3)) for n in range(3))
P4 = path_graph(4)
A = nx.to_numpy_matrix(P4)
np.testing.assert_equal(A, nx.to_numpy_matrix(WP4, weight=None))
np.testing.assert_equal(0.5 * A, nx.to_numpy_matrix(WP4))
np.testing.assert_equal(0.3 * A, nx.to_numpy_matrix(WP4, weight="other"))
def test_from_numpy_matrix_type(self):
pytest.importorskip("scipy")
A = np.matrix([[1]])
G = nx.from_numpy_matrix(A)
assert type(G[0][0]["weight"]) == int
A = np.matrix([[1]]).astype(float)
G = nx.from_numpy_matrix(A)
assert type(G[0][0]["weight"]) == float
A = np.matrix([[1]]).astype(str)
G = nx.from_numpy_matrix(A)
assert type(G[0][0]["weight"]) == str
A = np.matrix([[1]]).astype(bool)
G = nx.from_numpy_matrix(A)
assert type(G[0][0]["weight"]) == bool
A = np.matrix([[1]]).astype(complex)
G = nx.from_numpy_matrix(A)
assert type(G[0][0]["weight"]) == complex
A = np.matrix([[1]]).astype(object)
pytest.raises(TypeError, nx.from_numpy_matrix, A)
G = nx.cycle_graph(3)
A = nx.adjacency_matrix(G).todense()
H = nx.from_numpy_matrix(A)
assert all(type(m) == int and type(n) == int for m, n in H.edges())
H = nx.from_numpy_array(A)
assert all(type(m) == int and type(n) == int for m, n in H.edges())
def test_from_numpy_matrix_dtype(self):
dt = [("weight", float), ("cost", int)]
A = np.matrix([[(1.0, 2)]], dtype=dt)
G = nx.from_numpy_matrix(A)
assert type(G[0][0]["weight"]) == float
assert type(G[0][0]["cost"]) == int
assert G[0][0]["cost"] == 2
assert G[0][0]["weight"] == 1.0
def test_to_numpy_recarray(self):
G = nx.Graph()
G.add_edge(1, 2, weight=7.0, cost=5)
A = nx.to_numpy_recarray(G, dtype=[("weight", float), ("cost", int)])
assert sorted(A.dtype.names) == ["cost", "weight"]
assert A.weight[0, 1] == 7.0
assert A.weight[0, 0] == 0.0
assert A.cost[0, 1] == 5
assert A.cost[0, 0] == 0
def test_numpy_multigraph(self):
G = nx.MultiGraph()
G.add_edge(1, 2, weight=7)
G.add_edge(1, 2, weight=70)
A = nx.to_numpy_matrix(G)
assert A[1, 0] == 77
A = nx.to_numpy_matrix(G, multigraph_weight=min)
assert A[1, 0] == 7
A = nx.to_numpy_matrix(G, multigraph_weight=max)
assert A[1, 0] == 70
def test_from_numpy_matrix_parallel_edges(self):
"""Tests that the :func:`networkx.from_numpy_matrix` function
interprets integer weights as the number of parallel edges when
creating a multigraph.
"""
A = np.matrix([[1, 1], [1, 2]])
# First, with a simple graph, each integer entry in the adjacency
# matrix is interpreted as the weight of a single edge in the graph.
expected = nx.DiGraph()
edges = [(0, 0), (0, 1), (1, 0)]
expected.add_weighted_edges_from([(u, v, 1) for (u, v) in edges])
expected.add_edge(1, 1, weight=2)
actual = nx.from_numpy_matrix(A, parallel_edges=True, create_using=nx.DiGraph)
assert graphs_equal(actual, expected)
actual = nx.from_numpy_matrix(A, parallel_edges=False, create_using=nx.DiGraph)
assert graphs_equal(actual, expected)
# Now each integer entry in the adjacency matrix is interpreted as the
# number of parallel edges in the graph if the appropriate keyword
# argument is specified.
edges = [(0, 0), (0, 1), (1, 0), (1, 1), (1, 1)]
expected = nx.MultiDiGraph()
expected.add_weighted_edges_from([(u, v, 1) for (u, v) in edges])
actual = nx.from_numpy_matrix(
A, parallel_edges=True, create_using=nx.MultiDiGraph
)
assert graphs_equal(actual, expected)
expected = nx.MultiDiGraph()
expected.add_edges_from(set(edges), weight=1)
# The sole self-loop (edge 0) on vertex 1 should have weight 2.
expected[1][1][0]["weight"] = 2
actual = nx.from_numpy_matrix(
A, parallel_edges=False, create_using=nx.MultiDiGraph
)
assert graphs_equal(actual, expected)
def test_symmetric(self):
"""Tests that a symmetric matrix has edges added only once to an
undirected multigraph when using :func:`networkx.from_numpy_matrix`.
"""
A = np.matrix([[0, 1], [1, 0]])
G = nx.from_numpy_matrix(A, create_using=nx.MultiGraph)
expected = nx.MultiGraph()
expected.add_edge(0, 1, weight=1)
assert graphs_equal(G, expected)
def test_dtype_int_graph(self):
"""Test that setting dtype int actually gives an integer matrix.
For more information, see GitHub pull request #1363.
"""
G = nx.complete_graph(3)
A = nx.to_numpy_matrix(G, dtype=int)
assert A.dtype == int
def test_dtype_int_multigraph(self):
"""Test that setting dtype int actually gives an integer matrix.
For more information, see GitHub pull request #1363.
"""
G = nx.MultiGraph(nx.complete_graph(3))
A = nx.to_numpy_matrix(G, dtype=int)
assert A.dtype == int
class TestConvertNumpyArray:
def setup_method(self):
self.G1 = barbell_graph(10, 3)
self.G2 = cycle_graph(10, create_using=nx.DiGraph)
self.G3 = self.create_weighted(nx.Graph())
self.G4 = self.create_weighted(nx.DiGraph())
def create_weighted(self, G):
g = cycle_graph(4)
G.add_nodes_from(g)
G.add_weighted_edges_from((u, v, 10 + u) for u, v in g.edges())
return G
def assert_equal(self, G1, G2):
assert sorted(G1.nodes()) == sorted(G2.nodes())
assert sorted(G1.edges()) == sorted(G2.edges())
def identity_conversion(self, G, A, create_using):
assert A.sum() > 0
GG = nx.from_numpy_array(A, create_using=create_using)
self.assert_equal(G, GG)
GW = nx.to_networkx_graph(A, create_using=create_using)
self.assert_equal(G, GW)
GI = nx.empty_graph(0, create_using).__class__(A)
self.assert_equal(G, GI)
def test_shape(self):
"Conversion from non-square array."
A = np.array([[1, 2, 3], [4, 5, 6]])
pytest.raises(nx.NetworkXError, nx.from_numpy_array, A)
def test_identity_graph_array(self):
"Conversion from graph to array to graph."
A = nx.to_numpy_array(self.G1)
self.identity_conversion(self.G1, A, nx.Graph())
def test_identity_digraph_array(self):
"""Conversion from digraph to array to digraph."""
A = nx.to_numpy_array(self.G2)
self.identity_conversion(self.G2, A, nx.DiGraph())
def test_identity_weighted_graph_array(self):
"""Conversion from weighted graph to array to weighted graph."""
A = nx.to_numpy_array(self.G3)
self.identity_conversion(self.G3, A, nx.Graph())
def test_identity_weighted_digraph_array(self):
"""Conversion from weighted digraph to array to weighted digraph."""
A = nx.to_numpy_array(self.G4)
self.identity_conversion(self.G4, A, nx.DiGraph())
def test_nodelist(self):
"""Conversion from graph to array to graph with nodelist."""
P4 = path_graph(4)
P3 = path_graph(3)
nodelist = list(P3)
A = nx.to_numpy_array(P4, nodelist=nodelist)
GA = nx.Graph(A)
self.assert_equal(GA, P3)
# Make nodelist ambiguous by containing duplicates.
nodelist += [nodelist[0]]
pytest.raises(nx.NetworkXError, nx.to_numpy_array, P3, nodelist=nodelist)
def test_weight_keyword(self):
WP4 = nx.Graph()
WP4.add_edges_from((n, n + 1, dict(weight=0.5, other=0.3)) for n in range(3))
P4 = path_graph(4)
A = nx.to_numpy_array(P4)
np.testing.assert_equal(A, nx.to_numpy_array(WP4, weight=None))
np.testing.assert_equal(0.5 * A, nx.to_numpy_array(WP4))
np.testing.assert_equal(0.3 * A, nx.to_numpy_array(WP4, weight="other"))
def test_from_numpy_array_type(self):
A = np.array([[1]])
G = nx.from_numpy_array(A)
assert type(G[0][0]["weight"]) == int
A = np.array([[1]]).astype(float)
G = nx.from_numpy_array(A)
assert type(G[0][0]["weight"]) == float
A = np.array([[1]]).astype(str)
G = nx.from_numpy_array(A)
assert type(G[0][0]["weight"]) == str
A = np.array([[1]]).astype(bool)
G = nx.from_numpy_array(A)
assert type(G[0][0]["weight"]) == bool
A = np.array([[1]]).astype(complex)
G = nx.from_numpy_array(A)
assert type(G[0][0]["weight"]) == complex
A = np.array([[1]]).astype(object)
pytest.raises(TypeError, nx.from_numpy_array, A)
def test_from_numpy_array_dtype(self):
dt = [("weight", float), ("cost", int)]
A = np.array([[(1.0, 2)]], dtype=dt)
G = nx.from_numpy_array(A)
assert type(G[0][0]["weight"]) == float
assert type(G[0][0]["cost"]) == int
assert G[0][0]["cost"] == 2
assert G[0][0]["weight"] == 1.0
def test_from_numpy_array_parallel_edges(self):
"""Tests that the :func:`networkx.from_numpy_array` function
interprets integer weights as the number of parallel edges when
creating a multigraph.
"""
A = np.array([[1, 1], [1, 2]])
# First, with a simple graph, each integer entry in the adjacency
# matrix is interpreted as the weight of a single edge in the graph.
expected = nx.DiGraph()
edges = [(0, 0), (0, 1), (1, 0)]
expected.add_weighted_edges_from([(u, v, 1) for (u, v) in edges])
expected.add_edge(1, 1, weight=2)
actual = nx.from_numpy_array(A, parallel_edges=True, create_using=nx.DiGraph)
assert graphs_equal(actual, expected)
actual = nx.from_numpy_array(A, parallel_edges=False, create_using=nx.DiGraph)
assert graphs_equal(actual, expected)
# Now each integer entry in the adjacency matrix is interpreted as the
# number of parallel edges in the graph if the appropriate keyword
# argument is specified.
edges = [(0, 0), (0, 1), (1, 0), (1, 1), (1, 1)]
expected = nx.MultiDiGraph()
expected.add_weighted_edges_from([(u, v, 1) for (u, v) in edges])
actual = nx.from_numpy_array(
A, parallel_edges=True, create_using=nx.MultiDiGraph
)
assert graphs_equal(actual, expected)
expected = nx.MultiDiGraph()
expected.add_edges_from(set(edges), weight=1)
# The sole self-loop (edge 0) on vertex 1 should have weight 2.
expected[1][1][0]["weight"] = 2
actual = nx.from_numpy_array(
A, parallel_edges=False, create_using=nx.MultiDiGraph
)
assert graphs_equal(actual, expected)
def test_symmetric(self):
"""Tests that a symmetric array has edges added only once to an
undirected multigraph when using :func:`networkx.from_numpy_array`.
"""
A = np.array([[0, 1], [1, 0]])
G = nx.from_numpy_array(A, create_using=nx.MultiGraph)
expected = nx.MultiGraph()
expected.add_edge(0, 1, weight=1)
assert graphs_equal(G, expected)
def test_dtype_int_graph(self):
"""Test that setting dtype int actually gives an integer array.
For more information, see GitHub pull request #1363.
"""
G = nx.complete_graph(3)
A = nx.to_numpy_array(G, dtype=int)
assert A.dtype == int
def test_dtype_int_multigraph(self):
"""Test that setting dtype int actually gives an integer array.
For more information, see GitHub pull request #1363.
"""
G = nx.MultiGraph(nx.complete_graph(3))
A = nx.to_numpy_array(G, dtype=int)
assert A.dtype == int
@pytest.fixture
def recarray_test_graph():
G = nx.Graph()
G.add_edge(1, 2, weight=7.0, cost=5)
return G
def test_to_numpy_recarray(recarray_test_graph):
A = nx.to_numpy_recarray(
recarray_test_graph, dtype=[("weight", float), ("cost", int)]
)
assert sorted(A.dtype.names) == ["cost", "weight"]
assert A.weight[0, 1] == 7.0
assert A.weight[0, 0] == 0.0
assert A.cost[0, 1] == 5
assert A.cost[0, 0] == 0
with pytest.raises(AttributeError, match="has no attribute"):
A.color[0, 1]
def test_to_numpy_recarray_default_dtype(recarray_test_graph):
A = nx.to_numpy_recarray(recarray_test_graph)
assert A.dtype.names == ("weight",)
assert A.weight[0, 0] == 0
assert A.weight[0, 1] == 7
with pytest.raises(AttributeError, match="has no attribute"):
A.cost[0, 1]
def test_to_numpy_recarray_directed(recarray_test_graph):
G = recarray_test_graph.to_directed()
G.remove_edge(2, 1)
A = nx.to_numpy_recarray(G, dtype=[("weight", float), ("cost", int)])
np.testing.assert_array_equal(A.weight, np.array([[0, 7.0], [0, 0]]))
np.testing.assert_array_equal(A.cost, np.array([[0, 5], [0, 0]]))
def test_to_numpy_recarray_default_dtype_no_weight():
G = nx.Graph()
G.add_edge(0, 1, color="red")
with pytest.raises(KeyError):
A = nx.to_numpy_recarray(G)
A = nx.to_numpy_recarray(G, dtype=[("color", "U8")])
assert A.color[0, 1] == "red"
@pytest.fixture
def recarray_nodelist_test_graph():
G = nx.Graph()
G.add_edges_from(
[(0, 1, {"weight": 1.0}), (0, 2, {"weight": 2.0}), (1, 2, {"weight": 0.5})]
)
return G
def test_to_numpy_recarray_nodelist(recarray_nodelist_test_graph):
A = nx.to_numpy_recarray(recarray_nodelist_test_graph, nodelist=[0, 1])
np.testing.assert_array_equal(A.weight, np.array([[0, 1], [1, 0]]))
@pytest.mark.parametrize(
("nodelist", "errmsg"),
(([2, 3], "in nodelist is not in G"), ([1, 1], "nodelist contains duplicates")),
)
def test_to_numpy_recarray_bad_nodelist(recarray_nodelist_test_graph, nodelist, errmsg):
with pytest.raises(nx.NetworkXError, match=errmsg):
A = nx.to_numpy_recarray(recarray_nodelist_test_graph, nodelist=nodelist)
@pytest.fixture
def multigraph_test_graph():
G = nx.MultiGraph()
G.add_edge(1, 2, weight=7)
G.add_edge(1, 2, weight=70)
return G
@pytest.mark.parametrize(("operator", "expected"), ((sum, 77), (min, 7), (max, 70)))
def test_numpy_multigraph(multigraph_test_graph, operator, expected):
A = nx.to_numpy_array(multigraph_test_graph, multigraph_weight=operator)
assert A[1, 0] == expected
def test_to_numpy_array_multigraph_nodelist(multigraph_test_graph):
G = multigraph_test_graph
G.add_edge(0, 1, weight=3)
A = nx.to_numpy_array(G, nodelist=[1, 2])
assert A.shape == (2, 2)
assert A[1, 0] == 77
@pytest.mark.parametrize(
"G, expected",
[
(nx.Graph(), np.array([[0, 1 + 2j], [1 + 2j, 0]], dtype=complex)),
(nx.DiGraph(), np.array([[0, 1 + 2j], [0, 0]], dtype=complex)),
],
)
def test_to_numpy_array_complex_weights(G, expected):
G.add_edge(0, 1, weight=1 + 2j)
A = nx.to_numpy_array(G, dtype=complex)
npt.assert_array_equal(A, expected)
def test_to_numpy_array_arbitrary_weights():
G = nx.DiGraph()
w = 922337203685477580102 # Out of range for int64
G.add_edge(0, 1, weight=922337203685477580102) # val not representable by int64
A = nx.to_numpy_array(G, dtype=object)
expected = np.array([[0, w], [0, 0]], dtype=object)
npt.assert_array_equal(A, expected)
# Undirected
A = nx.to_numpy_array(G.to_undirected(), dtype=object)
expected = np.array([[0, w], [w, 0]], dtype=object)
npt.assert_array_equal(A, expected)
@pytest.mark.parametrize(
"func, expected",
((min, -1), (max, 10), (sum, 11), (np.mean, 11 / 3), (np.median, 2)),
)
def test_to_numpy_array_multiweight_reduction(func, expected):
"""Test various functions for reducing multiedge weights."""
G = nx.MultiDiGraph()
weights = [-1, 2, 10.0]
for w in weights:
G.add_edge(0, 1, weight=w)
A = nx.to_numpy_array(G, multigraph_weight=func, dtype=float)
assert np.allclose(A, [[0, expected], [0, 0]])
# Undirected case
A = nx.to_numpy_array(G.to_undirected(), multigraph_weight=func, dtype=float)
assert np.allclose(A, [[0, expected], [expected, 0]])
@pytest.mark.parametrize(
("G, expected"),
[
(nx.Graph(), [[(0, 0), (10, 5)], [(10, 5), (0, 0)]]),
(nx.DiGraph(), [[(0, 0), (10, 5)], [(0, 0), (0, 0)]]),
],
)
def test_to_numpy_array_structured_dtype_attrs_from_fields(G, expected):
"""When `dtype` is structured (i.e. has names) and `weight` is None, use
the named fields of the dtype to look up edge attributes."""
G.add_edge(0, 1, weight=10, cost=5.0)
dtype = np.dtype([("weight", int), ("cost", int)])
A = nx.to_numpy_array(G, dtype=dtype, weight=None)
expected = np.asarray(expected, dtype=dtype)
npt.assert_array_equal(A, expected)
def test_to_numpy_array_structured_dtype_single_attr_default():
G = nx.path_graph(3)
dtype = np.dtype([("weight", float)]) # A single named field
A = nx.to_numpy_array(G, dtype=dtype, weight=None)
expected = np.array([[0, 1, 0], [1, 0, 1], [0, 1, 0]], dtype=float)
npt.assert_array_equal(A["weight"], expected)
@pytest.mark.parametrize(
("field_name", "expected_attr_val"),
[
("weight", 1),
("cost", 3),
],
)
def test_to_numpy_array_structured_dtype_single_attr(field_name, expected_attr_val):
G = nx.Graph()
G.add_edge(0, 1, cost=3)
dtype = np.dtype([(field_name, float)])
A = nx.to_numpy_array(G, dtype=dtype, weight=None)
expected = np.array([[0, expected_attr_val], [expected_attr_val, 0]], dtype=float)
npt.assert_array_equal(A[field_name], expected)
@pytest.mark.parametrize("graph_type", (nx.Graph, nx.DiGraph))
@pytest.mark.parametrize(
"edge",
[
(0, 1), # No edge attributes
(0, 1, {"weight": 10}), # One edge attr
(0, 1, {"weight": 5, "flow": -4}), # Multiple but not all edge attrs
(0, 1, {"weight": 2.0, "cost": 10, "flow": -45}), # All attrs
],
)
def test_to_numpy_array_structured_dtype_multiple_fields(graph_type, edge):
G = graph_type([edge])
dtype = np.dtype([("weight", float), ("cost", float), ("flow", float)])
A = nx.to_numpy_array(G, dtype=dtype, weight=None)
for attr in dtype.names:
expected = nx.to_numpy_array(G, dtype=float, weight=attr)
npt.assert_array_equal(A[attr], expected)
@pytest.mark.parametrize("G", (nx.Graph(), nx.DiGraph()))
def test_to_numpy_array_structured_dtype_scalar_nonedge(G):
G.add_edge(0, 1, weight=10)
dtype = np.dtype([("weight", float), ("cost", float)])
A = nx.to_numpy_array(G, dtype=dtype, weight=None, nonedge=np.nan)
for attr in dtype.names:
expected = nx.to_numpy_array(G, dtype=float, weight=attr, nonedge=np.nan)
npt.assert_array_equal(A[attr], expected)
@pytest.mark.parametrize("G", (nx.Graph(), nx.DiGraph()))
def test_to_numpy_array_structured_dtype_nonedge_ary(G):
"""Similar to the scalar case, except has a different non-edge value for
each named field."""
G.add_edge(0, 1, weight=10)
dtype = np.dtype([("weight", float), ("cost", float)])
nonedges = np.array([(0, np.inf)], dtype=dtype)
A = nx.to_numpy_array(G, dtype=dtype, weight=None, nonedge=nonedges)
for attr in dtype.names:
nonedge = nonedges[attr]
expected = nx.to_numpy_array(G, dtype=float, weight=attr, nonedge=nonedge)
npt.assert_array_equal(A[attr], expected)
def test_to_numpy_array_structured_dtype_with_weight_raises():
"""Using both a structured dtype (with named fields) and specifying a `weight`
parameter is ambiguous."""
G = nx.path_graph(3)
dtype = np.dtype([("weight", int), ("cost", int)])
exception_msg = "Specifying `weight` not supported for structured dtypes"
with pytest.raises(ValueError, match=exception_msg):
nx.to_numpy_array(G, dtype=dtype) # Default is weight="weight"
with pytest.raises(ValueError, match=exception_msg):
nx.to_numpy_array(G, dtype=dtype, weight="cost")
@pytest.mark.parametrize("graph_type", (nx.MultiGraph, nx.MultiDiGraph))
def test_to_numpy_array_structured_multigraph_raises(graph_type):
G = nx.path_graph(3, create_using=graph_type)
dtype = np.dtype([("weight", int), ("cost", int)])
with pytest.raises(nx.NetworkXError, match="Structured arrays are not supported"):
nx.to_numpy_array(G, dtype=dtype, weight=None)