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- evalkit_tf446/lib/python3.10/site-packages/networkx/algorithms/flow/tests/gl1.gpickle.bz2 +3 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/__init__.py +34 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/atlas.py +180 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/cographs.py +68 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/community.py +1070 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/degree_seq.py +867 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/ego.py +66 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/expanders.py +474 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/geometric.py +1048 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/internet_as_graphs.py +441 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/intersection.py +125 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/joint_degree_seq.py +664 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/lattice.py +367 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/line.py +500 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/mycielski.py +110 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/random_graphs.py +1400 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/stochastic.py +54 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/__init__.py +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_atlas.py +75 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_cographs.py +18 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_community.py +362 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_degree_seq.py +230 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_intersection.py +28 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_mycielski.py +30 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_small.py +208 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_spectral_graph_forge.py +49 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_sudoku.py +92 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/time_series.py +74 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/trees.py +1071 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/generators/triads.py +94 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/__init__.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_all_random_functions.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_convert.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_convert_numpy.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_convert_pandas.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_convert_scipy.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_exceptions.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_import.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_lazy_imports.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_relabel.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/test_convert_numpy.py +532 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/test_convert_pandas.py +349 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/test_convert_scipy.py +282 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/tests/test_import.py +11 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/utils/__init__.py +8 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/utils/__pycache__/__init__.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/utils/__pycache__/backends.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/utils/__pycache__/configs.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/utils/__pycache__/decorators.cpython-310.pyc +0 -0
- evalkit_tf446/lib/python3.10/site-packages/networkx/utils/__pycache__/heaps.cpython-310.pyc +0 -0
evalkit_tf446/lib/python3.10/site-packages/networkx/algorithms/flow/tests/gl1.gpickle.bz2
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version https://git-lfs.github.com/spec/v1
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oid sha256:cf8f81ceb5eaaee1621aa60b892d83e596a6173f6f6517359b679ff3daa1b0f8
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size 44623
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evalkit_tf446/lib/python3.10/site-packages/networkx/generators/__init__.py
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"""
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A package for generating various graphs in networkx.
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"""
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from networkx.generators.atlas import *
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from networkx.generators.classic import *
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from networkx.generators.cographs import *
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from networkx.generators.community import *
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from networkx.generators.degree_seq import *
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from networkx.generators.directed import *
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from networkx.generators.duplication import *
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from networkx.generators.ego import *
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from networkx.generators.expanders import *
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from networkx.generators.geometric import *
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from networkx.generators.harary_graph import *
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from networkx.generators.internet_as_graphs import *
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from networkx.generators.intersection import *
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from networkx.generators.interval_graph import *
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from networkx.generators.joint_degree_seq import *
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from networkx.generators.lattice import *
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from networkx.generators.line import *
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from networkx.generators.mycielski import *
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from networkx.generators.nonisomorphic_trees import *
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from networkx.generators.random_clustered import *
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from networkx.generators.random_graphs import *
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from networkx.generators.small import *
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from networkx.generators.social import *
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from networkx.generators.spectral_graph_forge import *
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from networkx.generators.stochastic import *
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from networkx.generators.sudoku import *
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from networkx.generators.time_series import *
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from networkx.generators.trees import *
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from networkx.generators.triads import *
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evalkit_tf446/lib/python3.10/site-packages/networkx/generators/atlas.py
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"""
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Generators for the small graph atlas.
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"""
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import gzip
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import importlib.resources
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import os
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import os.path
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from itertools import islice
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import networkx as nx
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__all__ = ["graph_atlas", "graph_atlas_g"]
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#: The total number of graphs in the atlas.
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#:
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#: The graphs are labeled starting from 0 and extending to (but not
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#: including) this number.
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NUM_GRAPHS = 1253
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#: The path to the data file containing the graph edge lists.
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#:
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#: This is the absolute path of the gzipped text file containing the
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#: edge list for each graph in the atlas. The file contains one entry
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#: per graph in the atlas, in sequential order, starting from graph
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#: number 0 and extending through graph number 1252 (see
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#: :data:`NUM_GRAPHS`). Each entry looks like
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#:
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#: .. sourcecode:: text
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+
#:
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#: GRAPH 6
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#: NODES 3
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#: 0 1
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#: 0 2
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#:
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#: where the first two lines are the graph's index in the atlas and the
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#: number of nodes in the graph, and the remaining lines are the edge
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#: list.
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| 39 |
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#:
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| 40 |
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#: This file was generated from a Python list of graphs via code like
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#: the following::
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| 42 |
+
#:
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| 43 |
+
#: import gzip
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| 44 |
+
#: from networkx.generators.atlas import graph_atlas_g
|
| 45 |
+
#: from networkx.readwrite.edgelist import write_edgelist
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+
#:
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+
#: with gzip.open('atlas.dat.gz', 'wb') as f:
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#: for i, G in enumerate(graph_atlas_g()):
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#: f.write(bytes(f'GRAPH {i}\n', encoding='utf-8'))
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| 50 |
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#: f.write(bytes(f'NODES {len(G)}\n', encoding='utf-8'))
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#: write_edgelist(G, f, data=False)
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| 52 |
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#:
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| 53 |
+
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# Path to the atlas file
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| 55 |
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ATLAS_FILE = importlib.resources.files("networkx.generators") / "atlas.dat.gz"
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+
|
| 57 |
+
|
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def _generate_graphs():
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"""Sequentially read the file containing the edge list data for the
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graphs in the atlas and generate the graphs one at a time.
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| 61 |
+
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This function reads the file given in :data:`.ATLAS_FILE`.
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| 63 |
+
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| 64 |
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"""
|
| 65 |
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with gzip.open(ATLAS_FILE, "rb") as f:
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| 66 |
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line = f.readline()
|
| 67 |
+
while line and line.startswith(b"GRAPH"):
|
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# The first two lines of each entry tell us the index of the
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# graph in the list and the number of nodes in the graph.
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| 70 |
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# They look like this:
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+
#
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# GRAPH 3
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# NODES 2
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| 74 |
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#
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graph_index = int(line[6:].rstrip())
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line = f.readline()
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| 77 |
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num_nodes = int(line[6:].rstrip())
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# The remaining lines contain the edge list, until the next
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| 79 |
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# GRAPH line (or until the end of the file).
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edgelist = []
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line = f.readline()
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| 82 |
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while line and not line.startswith(b"GRAPH"):
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edgelist.append(line.rstrip())
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line = f.readline()
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G = nx.Graph()
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G.name = f"G{graph_index}"
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G.add_nodes_from(range(num_nodes))
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G.add_edges_from(tuple(map(int, e.split())) for e in edgelist)
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yield G
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| 91 |
+
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@nx._dispatchable(graphs=None, returns_graph=True)
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def graph_atlas(i):
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"""Returns graph number `i` from the Graph Atlas.
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| 95 |
+
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| 96 |
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For more information, see :func:`.graph_atlas_g`.
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| 97 |
+
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| 98 |
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Parameters
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| 99 |
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----------
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| 100 |
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i : int
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| 101 |
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The index of the graph from the atlas to get. The graph at index
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| 102 |
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0 is assumed to be the null graph.
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| 103 |
+
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| 104 |
+
Returns
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| 105 |
+
-------
|
| 106 |
+
list
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| 107 |
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A list of :class:`~networkx.Graph` objects, the one at index *i*
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| 108 |
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corresponding to the graph *i* in the Graph Atlas.
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| 109 |
+
|
| 110 |
+
See also
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| 111 |
+
--------
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| 112 |
+
graph_atlas_g
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| 113 |
+
|
| 114 |
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Notes
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| 115 |
+
-----
|
| 116 |
+
The time required by this function increases linearly with the
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| 117 |
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argument `i`, since it reads a large file sequentially in order to
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| 118 |
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generate the graph [1]_.
|
| 119 |
+
|
| 120 |
+
References
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| 121 |
+
----------
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| 122 |
+
.. [1] Ronald C. Read and Robin J. Wilson, *An Atlas of Graphs*.
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| 123 |
+
Oxford University Press, 1998.
|
| 124 |
+
|
| 125 |
+
"""
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| 126 |
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if not (0 <= i < NUM_GRAPHS):
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| 127 |
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raise ValueError(f"index must be between 0 and {NUM_GRAPHS}")
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| 128 |
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return next(islice(_generate_graphs(), i, None))
|
| 129 |
+
|
| 130 |
+
|
| 131 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 132 |
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def graph_atlas_g():
|
| 133 |
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"""Returns the list of all graphs with up to seven nodes named in the
|
| 134 |
+
Graph Atlas.
|
| 135 |
+
|
| 136 |
+
The graphs are listed in increasing order by
|
| 137 |
+
|
| 138 |
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1. number of nodes,
|
| 139 |
+
2. number of edges,
|
| 140 |
+
3. degree sequence (for example 111223 < 112222),
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| 141 |
+
4. number of automorphisms,
|
| 142 |
+
|
| 143 |
+
in that order, with three exceptions as described in the *Notes*
|
| 144 |
+
section below. This causes the list to correspond with the index of
|
| 145 |
+
the graphs in the Graph Atlas [atlas]_, with the first graph,
|
| 146 |
+
``G[0]``, being the null graph.
|
| 147 |
+
|
| 148 |
+
Returns
|
| 149 |
+
-------
|
| 150 |
+
list
|
| 151 |
+
A list of :class:`~networkx.Graph` objects, the one at index *i*
|
| 152 |
+
corresponding to the graph *i* in the Graph Atlas.
|
| 153 |
+
|
| 154 |
+
See also
|
| 155 |
+
--------
|
| 156 |
+
graph_atlas
|
| 157 |
+
|
| 158 |
+
Notes
|
| 159 |
+
-----
|
| 160 |
+
This function may be expensive in both time and space, since it
|
| 161 |
+
reads a large file sequentially in order to populate the list.
|
| 162 |
+
|
| 163 |
+
Although the NetworkX atlas functions match the order of graphs
|
| 164 |
+
given in the "Atlas of Graphs" book, there are (at least) three
|
| 165 |
+
errors in the ordering described in the book. The following three
|
| 166 |
+
pairs of nodes violate the lexicographically nondecreasing sorted
|
| 167 |
+
degree sequence rule:
|
| 168 |
+
|
| 169 |
+
- graphs 55 and 56 with degree sequences 001111 and 000112,
|
| 170 |
+
- graphs 1007 and 1008 with degree sequences 3333444 and 3333336,
|
| 171 |
+
- graphs 1012 and 1213 with degree sequences 1244555 and 1244456.
|
| 172 |
+
|
| 173 |
+
References
|
| 174 |
+
----------
|
| 175 |
+
.. [atlas] Ronald C. Read and Robin J. Wilson,
|
| 176 |
+
*An Atlas of Graphs*.
|
| 177 |
+
Oxford University Press, 1998.
|
| 178 |
+
|
| 179 |
+
"""
|
| 180 |
+
return list(_generate_graphs())
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/cographs.py
ADDED
|
@@ -0,0 +1,68 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
r"""Generators for cographs
|
| 2 |
+
|
| 3 |
+
A cograph is a graph containing no path on four vertices.
|
| 4 |
+
Cographs or $P_4$-free graphs can be obtained from a single vertex
|
| 5 |
+
by disjoint union and complementation operations.
|
| 6 |
+
|
| 7 |
+
References
|
| 8 |
+
----------
|
| 9 |
+
.. [0] D.G. Corneil, H. Lerchs, L.Stewart Burlingham,
|
| 10 |
+
"Complement reducible graphs",
|
| 11 |
+
Discrete Applied Mathematics, Volume 3, Issue 3, 1981, Pages 163-174,
|
| 12 |
+
ISSN 0166-218X.
|
| 13 |
+
"""
|
| 14 |
+
|
| 15 |
+
import networkx as nx
|
| 16 |
+
from networkx.utils import py_random_state
|
| 17 |
+
|
| 18 |
+
__all__ = ["random_cograph"]
|
| 19 |
+
|
| 20 |
+
|
| 21 |
+
@py_random_state(1)
|
| 22 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 23 |
+
def random_cograph(n, seed=None):
|
| 24 |
+
r"""Returns a random cograph with $2 ^ n$ nodes.
|
| 25 |
+
|
| 26 |
+
A cograph is a graph containing no path on four vertices.
|
| 27 |
+
Cographs or $P_4$-free graphs can be obtained from a single vertex
|
| 28 |
+
by disjoint union and complementation operations.
|
| 29 |
+
|
| 30 |
+
This generator starts off from a single vertex and performs disjoint
|
| 31 |
+
union and full join operations on itself.
|
| 32 |
+
The decision on which operation will take place is random.
|
| 33 |
+
|
| 34 |
+
Parameters
|
| 35 |
+
----------
|
| 36 |
+
n : int
|
| 37 |
+
The order of the cograph.
|
| 38 |
+
seed : integer, random_state, or None (default)
|
| 39 |
+
Indicator of random number generation state.
|
| 40 |
+
See :ref:`Randomness<randomness>`.
|
| 41 |
+
|
| 42 |
+
Returns
|
| 43 |
+
-------
|
| 44 |
+
G : A random graph containing no path on four vertices.
|
| 45 |
+
|
| 46 |
+
See Also
|
| 47 |
+
--------
|
| 48 |
+
full_join
|
| 49 |
+
union
|
| 50 |
+
|
| 51 |
+
References
|
| 52 |
+
----------
|
| 53 |
+
.. [1] D.G. Corneil, H. Lerchs, L.Stewart Burlingham,
|
| 54 |
+
"Complement reducible graphs",
|
| 55 |
+
Discrete Applied Mathematics, Volume 3, Issue 3, 1981, Pages 163-174,
|
| 56 |
+
ISSN 0166-218X.
|
| 57 |
+
"""
|
| 58 |
+
R = nx.empty_graph(1)
|
| 59 |
+
|
| 60 |
+
for i in range(n):
|
| 61 |
+
RR = nx.relabel_nodes(R.copy(), lambda x: x + len(R))
|
| 62 |
+
|
| 63 |
+
if seed.randint(0, 1) == 0:
|
| 64 |
+
R = nx.full_join(R, RR)
|
| 65 |
+
else:
|
| 66 |
+
R = nx.disjoint_union(R, RR)
|
| 67 |
+
|
| 68 |
+
return R
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/community.py
ADDED
|
@@ -0,0 +1,1070 @@
|
|
|
|
|
|
|
|
|
|
|
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|
|
| 1 |
+
"""Generators for classes of graphs used in studying social networks."""
|
| 2 |
+
|
| 3 |
+
import itertools
|
| 4 |
+
import math
|
| 5 |
+
|
| 6 |
+
import networkx as nx
|
| 7 |
+
from networkx.utils import py_random_state
|
| 8 |
+
|
| 9 |
+
__all__ = [
|
| 10 |
+
"caveman_graph",
|
| 11 |
+
"connected_caveman_graph",
|
| 12 |
+
"relaxed_caveman_graph",
|
| 13 |
+
"random_partition_graph",
|
| 14 |
+
"planted_partition_graph",
|
| 15 |
+
"gaussian_random_partition_graph",
|
| 16 |
+
"ring_of_cliques",
|
| 17 |
+
"windmill_graph",
|
| 18 |
+
"stochastic_block_model",
|
| 19 |
+
"LFR_benchmark_graph",
|
| 20 |
+
]
|
| 21 |
+
|
| 22 |
+
|
| 23 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 24 |
+
def caveman_graph(l, k):
|
| 25 |
+
"""Returns a caveman graph of `l` cliques of size `k`.
|
| 26 |
+
|
| 27 |
+
Parameters
|
| 28 |
+
----------
|
| 29 |
+
l : int
|
| 30 |
+
Number of cliques
|
| 31 |
+
k : int
|
| 32 |
+
Size of cliques
|
| 33 |
+
|
| 34 |
+
Returns
|
| 35 |
+
-------
|
| 36 |
+
G : NetworkX Graph
|
| 37 |
+
caveman graph
|
| 38 |
+
|
| 39 |
+
Notes
|
| 40 |
+
-----
|
| 41 |
+
This returns an undirected graph, it can be converted to a directed
|
| 42 |
+
graph using :func:`nx.to_directed`, or a multigraph using
|
| 43 |
+
``nx.MultiGraph(nx.caveman_graph(l, k))``. Only the undirected version is
|
| 44 |
+
described in [1]_ and it is unclear which of the directed
|
| 45 |
+
generalizations is most useful.
|
| 46 |
+
|
| 47 |
+
Examples
|
| 48 |
+
--------
|
| 49 |
+
>>> G = nx.caveman_graph(3, 3)
|
| 50 |
+
|
| 51 |
+
See also
|
| 52 |
+
--------
|
| 53 |
+
|
| 54 |
+
connected_caveman_graph
|
| 55 |
+
|
| 56 |
+
References
|
| 57 |
+
----------
|
| 58 |
+
.. [1] Watts, D. J. 'Networks, Dynamics, and the Small-World Phenomenon.'
|
| 59 |
+
Amer. J. Soc. 105, 493-527, 1999.
|
| 60 |
+
"""
|
| 61 |
+
# l disjoint cliques of size k
|
| 62 |
+
G = nx.empty_graph(l * k)
|
| 63 |
+
if k > 1:
|
| 64 |
+
for start in range(0, l * k, k):
|
| 65 |
+
edges = itertools.combinations(range(start, start + k), 2)
|
| 66 |
+
G.add_edges_from(edges)
|
| 67 |
+
return G
|
| 68 |
+
|
| 69 |
+
|
| 70 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 71 |
+
def connected_caveman_graph(l, k):
|
| 72 |
+
"""Returns a connected caveman graph of `l` cliques of size `k`.
|
| 73 |
+
|
| 74 |
+
The connected caveman graph is formed by creating `n` cliques of size
|
| 75 |
+
`k`, then a single edge in each clique is rewired to a node in an
|
| 76 |
+
adjacent clique.
|
| 77 |
+
|
| 78 |
+
Parameters
|
| 79 |
+
----------
|
| 80 |
+
l : int
|
| 81 |
+
number of cliques
|
| 82 |
+
k : int
|
| 83 |
+
size of cliques (k at least 2 or NetworkXError is raised)
|
| 84 |
+
|
| 85 |
+
Returns
|
| 86 |
+
-------
|
| 87 |
+
G : NetworkX Graph
|
| 88 |
+
connected caveman graph
|
| 89 |
+
|
| 90 |
+
Raises
|
| 91 |
+
------
|
| 92 |
+
NetworkXError
|
| 93 |
+
If the size of cliques `k` is smaller than 2.
|
| 94 |
+
|
| 95 |
+
Notes
|
| 96 |
+
-----
|
| 97 |
+
This returns an undirected graph, it can be converted to a directed
|
| 98 |
+
graph using :func:`nx.to_directed`, or a multigraph using
|
| 99 |
+
``nx.MultiGraph(nx.caveman_graph(l, k))``. Only the undirected version is
|
| 100 |
+
described in [1]_ and it is unclear which of the directed
|
| 101 |
+
generalizations is most useful.
|
| 102 |
+
|
| 103 |
+
Examples
|
| 104 |
+
--------
|
| 105 |
+
>>> G = nx.connected_caveman_graph(3, 3)
|
| 106 |
+
|
| 107 |
+
References
|
| 108 |
+
----------
|
| 109 |
+
.. [1] Watts, D. J. 'Networks, Dynamics, and the Small-World Phenomenon.'
|
| 110 |
+
Amer. J. Soc. 105, 493-527, 1999.
|
| 111 |
+
"""
|
| 112 |
+
if k < 2:
|
| 113 |
+
raise nx.NetworkXError(
|
| 114 |
+
"The size of cliques in a connected caveman graph must be at least 2."
|
| 115 |
+
)
|
| 116 |
+
|
| 117 |
+
G = nx.caveman_graph(l, k)
|
| 118 |
+
for start in range(0, l * k, k):
|
| 119 |
+
G.remove_edge(start, start + 1)
|
| 120 |
+
G.add_edge(start, (start - 1) % (l * k))
|
| 121 |
+
return G
|
| 122 |
+
|
| 123 |
+
|
| 124 |
+
@py_random_state(3)
|
| 125 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 126 |
+
def relaxed_caveman_graph(l, k, p, seed=None):
|
| 127 |
+
"""Returns a relaxed caveman graph.
|
| 128 |
+
|
| 129 |
+
A relaxed caveman graph starts with `l` cliques of size `k`. Edges are
|
| 130 |
+
then randomly rewired with probability `p` to link different cliques.
|
| 131 |
+
|
| 132 |
+
Parameters
|
| 133 |
+
----------
|
| 134 |
+
l : int
|
| 135 |
+
Number of groups
|
| 136 |
+
k : int
|
| 137 |
+
Size of cliques
|
| 138 |
+
p : float
|
| 139 |
+
Probability of rewiring each edge.
|
| 140 |
+
seed : integer, random_state, or None (default)
|
| 141 |
+
Indicator of random number generation state.
|
| 142 |
+
See :ref:`Randomness<randomness>`.
|
| 143 |
+
|
| 144 |
+
Returns
|
| 145 |
+
-------
|
| 146 |
+
G : NetworkX Graph
|
| 147 |
+
Relaxed Caveman Graph
|
| 148 |
+
|
| 149 |
+
Raises
|
| 150 |
+
------
|
| 151 |
+
NetworkXError
|
| 152 |
+
If p is not in [0,1]
|
| 153 |
+
|
| 154 |
+
Examples
|
| 155 |
+
--------
|
| 156 |
+
>>> G = nx.relaxed_caveman_graph(2, 3, 0.1, seed=42)
|
| 157 |
+
|
| 158 |
+
References
|
| 159 |
+
----------
|
| 160 |
+
.. [1] Santo Fortunato, Community Detection in Graphs,
|
| 161 |
+
Physics Reports Volume 486, Issues 3-5, February 2010, Pages 75-174.
|
| 162 |
+
https://arxiv.org/abs/0906.0612
|
| 163 |
+
"""
|
| 164 |
+
G = nx.caveman_graph(l, k)
|
| 165 |
+
nodes = list(G)
|
| 166 |
+
for u, v in G.edges():
|
| 167 |
+
if seed.random() < p: # rewire the edge
|
| 168 |
+
x = seed.choice(nodes)
|
| 169 |
+
if G.has_edge(u, x):
|
| 170 |
+
continue
|
| 171 |
+
G.remove_edge(u, v)
|
| 172 |
+
G.add_edge(u, x)
|
| 173 |
+
return G
|
| 174 |
+
|
| 175 |
+
|
| 176 |
+
@py_random_state(3)
|
| 177 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 178 |
+
def random_partition_graph(sizes, p_in, p_out, seed=None, directed=False):
|
| 179 |
+
"""Returns the random partition graph with a partition of sizes.
|
| 180 |
+
|
| 181 |
+
A partition graph is a graph of communities with sizes defined by
|
| 182 |
+
s in sizes. Nodes in the same group are connected with probability
|
| 183 |
+
p_in and nodes of different groups are connected with probability
|
| 184 |
+
p_out.
|
| 185 |
+
|
| 186 |
+
Parameters
|
| 187 |
+
----------
|
| 188 |
+
sizes : list of ints
|
| 189 |
+
Sizes of groups
|
| 190 |
+
p_in : float
|
| 191 |
+
probability of edges with in groups
|
| 192 |
+
p_out : float
|
| 193 |
+
probability of edges between groups
|
| 194 |
+
directed : boolean optional, default=False
|
| 195 |
+
Whether to create a directed graph
|
| 196 |
+
seed : integer, random_state, or None (default)
|
| 197 |
+
Indicator of random number generation state.
|
| 198 |
+
See :ref:`Randomness<randomness>`.
|
| 199 |
+
|
| 200 |
+
Returns
|
| 201 |
+
-------
|
| 202 |
+
G : NetworkX Graph or DiGraph
|
| 203 |
+
random partition graph of size sum(gs)
|
| 204 |
+
|
| 205 |
+
Raises
|
| 206 |
+
------
|
| 207 |
+
NetworkXError
|
| 208 |
+
If p_in or p_out is not in [0,1]
|
| 209 |
+
|
| 210 |
+
Examples
|
| 211 |
+
--------
|
| 212 |
+
>>> G = nx.random_partition_graph([10, 10, 10], 0.25, 0.01)
|
| 213 |
+
>>> len(G)
|
| 214 |
+
30
|
| 215 |
+
>>> partition = G.graph["partition"]
|
| 216 |
+
>>> len(partition)
|
| 217 |
+
3
|
| 218 |
+
|
| 219 |
+
Notes
|
| 220 |
+
-----
|
| 221 |
+
This is a generalization of the planted-l-partition described in
|
| 222 |
+
[1]_. It allows for the creation of groups of any size.
|
| 223 |
+
|
| 224 |
+
The partition is store as a graph attribute 'partition'.
|
| 225 |
+
|
| 226 |
+
References
|
| 227 |
+
----------
|
| 228 |
+
.. [1] Santo Fortunato 'Community Detection in Graphs' Physical Reports
|
| 229 |
+
Volume 486, Issue 3-5 p. 75-174. https://arxiv.org/abs/0906.0612
|
| 230 |
+
"""
|
| 231 |
+
# Use geometric method for O(n+m) complexity algorithm
|
| 232 |
+
# partition = nx.community_sets(nx.get_node_attributes(G, 'affiliation'))
|
| 233 |
+
if not 0.0 <= p_in <= 1.0:
|
| 234 |
+
raise nx.NetworkXError("p_in must be in [0,1]")
|
| 235 |
+
if not 0.0 <= p_out <= 1.0:
|
| 236 |
+
raise nx.NetworkXError("p_out must be in [0,1]")
|
| 237 |
+
|
| 238 |
+
# create connection matrix
|
| 239 |
+
num_blocks = len(sizes)
|
| 240 |
+
p = [[p_out for s in range(num_blocks)] for r in range(num_blocks)]
|
| 241 |
+
for r in range(num_blocks):
|
| 242 |
+
p[r][r] = p_in
|
| 243 |
+
|
| 244 |
+
return stochastic_block_model(
|
| 245 |
+
sizes,
|
| 246 |
+
p,
|
| 247 |
+
nodelist=None,
|
| 248 |
+
seed=seed,
|
| 249 |
+
directed=directed,
|
| 250 |
+
selfloops=False,
|
| 251 |
+
sparse=True,
|
| 252 |
+
)
|
| 253 |
+
|
| 254 |
+
|
| 255 |
+
@py_random_state(4)
|
| 256 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 257 |
+
def planted_partition_graph(l, k, p_in, p_out, seed=None, directed=False):
|
| 258 |
+
"""Returns the planted l-partition graph.
|
| 259 |
+
|
| 260 |
+
This model partitions a graph with n=l*k vertices in
|
| 261 |
+
l groups with k vertices each. Vertices of the same
|
| 262 |
+
group are linked with a probability p_in, and vertices
|
| 263 |
+
of different groups are linked with probability p_out.
|
| 264 |
+
|
| 265 |
+
Parameters
|
| 266 |
+
----------
|
| 267 |
+
l : int
|
| 268 |
+
Number of groups
|
| 269 |
+
k : int
|
| 270 |
+
Number of vertices in each group
|
| 271 |
+
p_in : float
|
| 272 |
+
probability of connecting vertices within a group
|
| 273 |
+
p_out : float
|
| 274 |
+
probability of connected vertices between groups
|
| 275 |
+
seed : integer, random_state, or None (default)
|
| 276 |
+
Indicator of random number generation state.
|
| 277 |
+
See :ref:`Randomness<randomness>`.
|
| 278 |
+
directed : bool,optional (default=False)
|
| 279 |
+
If True return a directed graph
|
| 280 |
+
|
| 281 |
+
Returns
|
| 282 |
+
-------
|
| 283 |
+
G : NetworkX Graph or DiGraph
|
| 284 |
+
planted l-partition graph
|
| 285 |
+
|
| 286 |
+
Raises
|
| 287 |
+
------
|
| 288 |
+
NetworkXError
|
| 289 |
+
If `p_in`, `p_out` are not in `[0, 1]`
|
| 290 |
+
|
| 291 |
+
Examples
|
| 292 |
+
--------
|
| 293 |
+
>>> G = nx.planted_partition_graph(4, 3, 0.5, 0.1, seed=42)
|
| 294 |
+
|
| 295 |
+
See Also
|
| 296 |
+
--------
|
| 297 |
+
random_partition_model
|
| 298 |
+
|
| 299 |
+
References
|
| 300 |
+
----------
|
| 301 |
+
.. [1] A. Condon, R.M. Karp, Algorithms for graph partitioning
|
| 302 |
+
on the planted partition model,
|
| 303 |
+
Random Struct. Algor. 18 (2001) 116-140.
|
| 304 |
+
|
| 305 |
+
.. [2] Santo Fortunato 'Community Detection in Graphs' Physical Reports
|
| 306 |
+
Volume 486, Issue 3-5 p. 75-174. https://arxiv.org/abs/0906.0612
|
| 307 |
+
"""
|
| 308 |
+
return random_partition_graph([k] * l, p_in, p_out, seed=seed, directed=directed)
|
| 309 |
+
|
| 310 |
+
|
| 311 |
+
@py_random_state(6)
|
| 312 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 313 |
+
def gaussian_random_partition_graph(n, s, v, p_in, p_out, directed=False, seed=None):
|
| 314 |
+
"""Generate a Gaussian random partition graph.
|
| 315 |
+
|
| 316 |
+
A Gaussian random partition graph is created by creating k partitions
|
| 317 |
+
each with a size drawn from a normal distribution with mean s and variance
|
| 318 |
+
s/v. Nodes are connected within clusters with probability p_in and
|
| 319 |
+
between clusters with probability p_out[1]
|
| 320 |
+
|
| 321 |
+
Parameters
|
| 322 |
+
----------
|
| 323 |
+
n : int
|
| 324 |
+
Number of nodes in the graph
|
| 325 |
+
s : float
|
| 326 |
+
Mean cluster size
|
| 327 |
+
v : float
|
| 328 |
+
Shape parameter. The variance of cluster size distribution is s/v.
|
| 329 |
+
p_in : float
|
| 330 |
+
Probability of intra cluster connection.
|
| 331 |
+
p_out : float
|
| 332 |
+
Probability of inter cluster connection.
|
| 333 |
+
directed : boolean, optional default=False
|
| 334 |
+
Whether to create a directed graph or not
|
| 335 |
+
seed : integer, random_state, or None (default)
|
| 336 |
+
Indicator of random number generation state.
|
| 337 |
+
See :ref:`Randomness<randomness>`.
|
| 338 |
+
|
| 339 |
+
Returns
|
| 340 |
+
-------
|
| 341 |
+
G : NetworkX Graph or DiGraph
|
| 342 |
+
gaussian random partition graph
|
| 343 |
+
|
| 344 |
+
Raises
|
| 345 |
+
------
|
| 346 |
+
NetworkXError
|
| 347 |
+
If s is > n
|
| 348 |
+
If p_in or p_out is not in [0,1]
|
| 349 |
+
|
| 350 |
+
Notes
|
| 351 |
+
-----
|
| 352 |
+
Note the number of partitions is dependent on s,v and n, and that the
|
| 353 |
+
last partition may be considerably smaller, as it is sized to simply
|
| 354 |
+
fill out the nodes [1]
|
| 355 |
+
|
| 356 |
+
See Also
|
| 357 |
+
--------
|
| 358 |
+
random_partition_graph
|
| 359 |
+
|
| 360 |
+
Examples
|
| 361 |
+
--------
|
| 362 |
+
>>> G = nx.gaussian_random_partition_graph(100, 10, 10, 0.25, 0.1)
|
| 363 |
+
>>> len(G)
|
| 364 |
+
100
|
| 365 |
+
|
| 366 |
+
References
|
| 367 |
+
----------
|
| 368 |
+
.. [1] Ulrik Brandes, Marco Gaertler, Dorothea Wagner,
|
| 369 |
+
Experiments on Graph Clustering Algorithms,
|
| 370 |
+
In the proceedings of the 11th Europ. Symp. Algorithms, 2003.
|
| 371 |
+
"""
|
| 372 |
+
if s > n:
|
| 373 |
+
raise nx.NetworkXError("s must be <= n")
|
| 374 |
+
assigned = 0
|
| 375 |
+
sizes = []
|
| 376 |
+
while True:
|
| 377 |
+
size = int(seed.gauss(s, s / v + 0.5))
|
| 378 |
+
if size < 1: # how to handle 0 or negative sizes?
|
| 379 |
+
continue
|
| 380 |
+
if assigned + size >= n:
|
| 381 |
+
sizes.append(n - assigned)
|
| 382 |
+
break
|
| 383 |
+
assigned += size
|
| 384 |
+
sizes.append(size)
|
| 385 |
+
return random_partition_graph(sizes, p_in, p_out, seed=seed, directed=directed)
|
| 386 |
+
|
| 387 |
+
|
| 388 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 389 |
+
def ring_of_cliques(num_cliques, clique_size):
|
| 390 |
+
"""Defines a "ring of cliques" graph.
|
| 391 |
+
|
| 392 |
+
A ring of cliques graph is consisting of cliques, connected through single
|
| 393 |
+
links. Each clique is a complete graph.
|
| 394 |
+
|
| 395 |
+
Parameters
|
| 396 |
+
----------
|
| 397 |
+
num_cliques : int
|
| 398 |
+
Number of cliques
|
| 399 |
+
clique_size : int
|
| 400 |
+
Size of cliques
|
| 401 |
+
|
| 402 |
+
Returns
|
| 403 |
+
-------
|
| 404 |
+
G : NetworkX Graph
|
| 405 |
+
ring of cliques graph
|
| 406 |
+
|
| 407 |
+
Raises
|
| 408 |
+
------
|
| 409 |
+
NetworkXError
|
| 410 |
+
If the number of cliques is lower than 2 or
|
| 411 |
+
if the size of cliques is smaller than 2.
|
| 412 |
+
|
| 413 |
+
Examples
|
| 414 |
+
--------
|
| 415 |
+
>>> G = nx.ring_of_cliques(8, 4)
|
| 416 |
+
|
| 417 |
+
See Also
|
| 418 |
+
--------
|
| 419 |
+
connected_caveman_graph
|
| 420 |
+
|
| 421 |
+
Notes
|
| 422 |
+
-----
|
| 423 |
+
The `connected_caveman_graph` graph removes a link from each clique to
|
| 424 |
+
connect it with the next clique. Instead, the `ring_of_cliques` graph
|
| 425 |
+
simply adds the link without removing any link from the cliques.
|
| 426 |
+
"""
|
| 427 |
+
if num_cliques < 2:
|
| 428 |
+
raise nx.NetworkXError("A ring of cliques must have at least two cliques")
|
| 429 |
+
if clique_size < 2:
|
| 430 |
+
raise nx.NetworkXError("The cliques must have at least two nodes")
|
| 431 |
+
|
| 432 |
+
G = nx.Graph()
|
| 433 |
+
for i in range(num_cliques):
|
| 434 |
+
edges = itertools.combinations(
|
| 435 |
+
range(i * clique_size, i * clique_size + clique_size), 2
|
| 436 |
+
)
|
| 437 |
+
G.add_edges_from(edges)
|
| 438 |
+
G.add_edge(
|
| 439 |
+
i * clique_size + 1, (i + 1) * clique_size % (num_cliques * clique_size)
|
| 440 |
+
)
|
| 441 |
+
return G
|
| 442 |
+
|
| 443 |
+
|
| 444 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 445 |
+
def windmill_graph(n, k):
|
| 446 |
+
"""Generate a windmill graph.
|
| 447 |
+
A windmill graph is a graph of `n` cliques each of size `k` that are all
|
| 448 |
+
joined at one node.
|
| 449 |
+
It can be thought of as taking a disjoint union of `n` cliques of size `k`,
|
| 450 |
+
selecting one point from each, and contracting all of the selected points.
|
| 451 |
+
Alternatively, one could generate `n` cliques of size `k-1` and one node
|
| 452 |
+
that is connected to all other nodes in the graph.
|
| 453 |
+
|
| 454 |
+
Parameters
|
| 455 |
+
----------
|
| 456 |
+
n : int
|
| 457 |
+
Number of cliques
|
| 458 |
+
k : int
|
| 459 |
+
Size of cliques
|
| 460 |
+
|
| 461 |
+
Returns
|
| 462 |
+
-------
|
| 463 |
+
G : NetworkX Graph
|
| 464 |
+
windmill graph with n cliques of size k
|
| 465 |
+
|
| 466 |
+
Raises
|
| 467 |
+
------
|
| 468 |
+
NetworkXError
|
| 469 |
+
If the number of cliques is less than two
|
| 470 |
+
If the size of the cliques are less than two
|
| 471 |
+
|
| 472 |
+
Examples
|
| 473 |
+
--------
|
| 474 |
+
>>> G = nx.windmill_graph(4, 5)
|
| 475 |
+
|
| 476 |
+
Notes
|
| 477 |
+
-----
|
| 478 |
+
The node labeled `0` will be the node connected to all other nodes.
|
| 479 |
+
Note that windmill graphs are usually denoted `Wd(k,n)`, so the parameters
|
| 480 |
+
are in the opposite order as the parameters of this method.
|
| 481 |
+
"""
|
| 482 |
+
if n < 2:
|
| 483 |
+
msg = "A windmill graph must have at least two cliques"
|
| 484 |
+
raise nx.NetworkXError(msg)
|
| 485 |
+
if k < 2:
|
| 486 |
+
raise nx.NetworkXError("The cliques must have at least two nodes")
|
| 487 |
+
|
| 488 |
+
G = nx.disjoint_union_all(
|
| 489 |
+
itertools.chain(
|
| 490 |
+
[nx.complete_graph(k)], (nx.complete_graph(k - 1) for _ in range(n - 1))
|
| 491 |
+
)
|
| 492 |
+
)
|
| 493 |
+
G.add_edges_from((0, i) for i in range(k, G.number_of_nodes()))
|
| 494 |
+
return G
|
| 495 |
+
|
| 496 |
+
|
| 497 |
+
@py_random_state(3)
|
| 498 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 499 |
+
def stochastic_block_model(
|
| 500 |
+
sizes, p, nodelist=None, seed=None, directed=False, selfloops=False, sparse=True
|
| 501 |
+
):
|
| 502 |
+
"""Returns a stochastic block model graph.
|
| 503 |
+
|
| 504 |
+
This model partitions the nodes in blocks of arbitrary sizes, and places
|
| 505 |
+
edges between pairs of nodes independently, with a probability that depends
|
| 506 |
+
on the blocks.
|
| 507 |
+
|
| 508 |
+
Parameters
|
| 509 |
+
----------
|
| 510 |
+
sizes : list of ints
|
| 511 |
+
Sizes of blocks
|
| 512 |
+
p : list of list of floats
|
| 513 |
+
Element (r,s) gives the density of edges going from the nodes
|
| 514 |
+
of group r to nodes of group s.
|
| 515 |
+
p must match the number of groups (len(sizes) == len(p)),
|
| 516 |
+
and it must be symmetric if the graph is undirected.
|
| 517 |
+
nodelist : list, optional
|
| 518 |
+
The block tags are assigned according to the node identifiers
|
| 519 |
+
in nodelist. If nodelist is None, then the ordering is the
|
| 520 |
+
range [0,sum(sizes)-1].
|
| 521 |
+
seed : integer, random_state, or None (default)
|
| 522 |
+
Indicator of random number generation state.
|
| 523 |
+
See :ref:`Randomness<randomness>`.
|
| 524 |
+
directed : boolean optional, default=False
|
| 525 |
+
Whether to create a directed graph or not.
|
| 526 |
+
selfloops : boolean optional, default=False
|
| 527 |
+
Whether to include self-loops or not.
|
| 528 |
+
sparse: boolean optional, default=True
|
| 529 |
+
Use the sparse heuristic to speed up the generator.
|
| 530 |
+
|
| 531 |
+
Returns
|
| 532 |
+
-------
|
| 533 |
+
g : NetworkX Graph or DiGraph
|
| 534 |
+
Stochastic block model graph of size sum(sizes)
|
| 535 |
+
|
| 536 |
+
Raises
|
| 537 |
+
------
|
| 538 |
+
NetworkXError
|
| 539 |
+
If probabilities are not in [0,1].
|
| 540 |
+
If the probability matrix is not square (directed case).
|
| 541 |
+
If the probability matrix is not symmetric (undirected case).
|
| 542 |
+
If the sizes list does not match nodelist or the probability matrix.
|
| 543 |
+
If nodelist contains duplicate.
|
| 544 |
+
|
| 545 |
+
Examples
|
| 546 |
+
--------
|
| 547 |
+
>>> sizes = [75, 75, 300]
|
| 548 |
+
>>> probs = [[0.25, 0.05, 0.02], [0.05, 0.35, 0.07], [0.02, 0.07, 0.40]]
|
| 549 |
+
>>> g = nx.stochastic_block_model(sizes, probs, seed=0)
|
| 550 |
+
>>> len(g)
|
| 551 |
+
450
|
| 552 |
+
>>> H = nx.quotient_graph(g, g.graph["partition"], relabel=True)
|
| 553 |
+
>>> for v in H.nodes(data=True):
|
| 554 |
+
... print(round(v[1]["density"], 3))
|
| 555 |
+
0.245
|
| 556 |
+
0.348
|
| 557 |
+
0.405
|
| 558 |
+
>>> for v in H.edges(data=True):
|
| 559 |
+
... print(round(1.0 * v[2]["weight"] / (sizes[v[0]] * sizes[v[1]]), 3))
|
| 560 |
+
0.051
|
| 561 |
+
0.022
|
| 562 |
+
0.07
|
| 563 |
+
|
| 564 |
+
See Also
|
| 565 |
+
--------
|
| 566 |
+
random_partition_graph
|
| 567 |
+
planted_partition_graph
|
| 568 |
+
gaussian_random_partition_graph
|
| 569 |
+
gnp_random_graph
|
| 570 |
+
|
| 571 |
+
References
|
| 572 |
+
----------
|
| 573 |
+
.. [1] Holland, P. W., Laskey, K. B., & Leinhardt, S.,
|
| 574 |
+
"Stochastic blockmodels: First steps",
|
| 575 |
+
Social networks, 5(2), 109-137, 1983.
|
| 576 |
+
"""
|
| 577 |
+
# Check if dimensions match
|
| 578 |
+
if len(sizes) != len(p):
|
| 579 |
+
raise nx.NetworkXException("'sizes' and 'p' do not match.")
|
| 580 |
+
# Check for probability symmetry (undirected) and shape (directed)
|
| 581 |
+
for row in p:
|
| 582 |
+
if len(p) != len(row):
|
| 583 |
+
raise nx.NetworkXException("'p' must be a square matrix.")
|
| 584 |
+
if not directed:
|
| 585 |
+
p_transpose = [list(i) for i in zip(*p)]
|
| 586 |
+
for i in zip(p, p_transpose):
|
| 587 |
+
for j in zip(i[0], i[1]):
|
| 588 |
+
if abs(j[0] - j[1]) > 1e-08:
|
| 589 |
+
raise nx.NetworkXException("'p' must be symmetric.")
|
| 590 |
+
# Check for probability range
|
| 591 |
+
for row in p:
|
| 592 |
+
for prob in row:
|
| 593 |
+
if prob < 0 or prob > 1:
|
| 594 |
+
raise nx.NetworkXException("Entries of 'p' not in [0,1].")
|
| 595 |
+
# Check for nodelist consistency
|
| 596 |
+
if nodelist is not None:
|
| 597 |
+
if len(nodelist) != sum(sizes):
|
| 598 |
+
raise nx.NetworkXException("'nodelist' and 'sizes' do not match.")
|
| 599 |
+
if len(nodelist) != len(set(nodelist)):
|
| 600 |
+
raise nx.NetworkXException("nodelist contains duplicate.")
|
| 601 |
+
else:
|
| 602 |
+
nodelist = range(sum(sizes))
|
| 603 |
+
|
| 604 |
+
# Setup the graph conditionally to the directed switch.
|
| 605 |
+
block_range = range(len(sizes))
|
| 606 |
+
if directed:
|
| 607 |
+
g = nx.DiGraph()
|
| 608 |
+
block_iter = itertools.product(block_range, block_range)
|
| 609 |
+
else:
|
| 610 |
+
g = nx.Graph()
|
| 611 |
+
block_iter = itertools.combinations_with_replacement(block_range, 2)
|
| 612 |
+
# Split nodelist in a partition (list of sets).
|
| 613 |
+
size_cumsum = [sum(sizes[0:x]) for x in range(len(sizes) + 1)]
|
| 614 |
+
g.graph["partition"] = [
|
| 615 |
+
set(nodelist[size_cumsum[x] : size_cumsum[x + 1]])
|
| 616 |
+
for x in range(len(size_cumsum) - 1)
|
| 617 |
+
]
|
| 618 |
+
# Setup nodes and graph name
|
| 619 |
+
for block_id, nodes in enumerate(g.graph["partition"]):
|
| 620 |
+
for node in nodes:
|
| 621 |
+
g.add_node(node, block=block_id)
|
| 622 |
+
|
| 623 |
+
g.name = "stochastic_block_model"
|
| 624 |
+
|
| 625 |
+
# Test for edge existence
|
| 626 |
+
parts = g.graph["partition"]
|
| 627 |
+
for i, j in block_iter:
|
| 628 |
+
if i == j:
|
| 629 |
+
if directed:
|
| 630 |
+
if selfloops:
|
| 631 |
+
edges = itertools.product(parts[i], parts[i])
|
| 632 |
+
else:
|
| 633 |
+
edges = itertools.permutations(parts[i], 2)
|
| 634 |
+
else:
|
| 635 |
+
edges = itertools.combinations(parts[i], 2)
|
| 636 |
+
if selfloops:
|
| 637 |
+
edges = itertools.chain(edges, zip(parts[i], parts[i]))
|
| 638 |
+
for e in edges:
|
| 639 |
+
if seed.random() < p[i][j]:
|
| 640 |
+
g.add_edge(*e)
|
| 641 |
+
else:
|
| 642 |
+
edges = itertools.product(parts[i], parts[j])
|
| 643 |
+
if sparse:
|
| 644 |
+
if p[i][j] == 1: # Test edges cases p_ij = 0 or 1
|
| 645 |
+
for e in edges:
|
| 646 |
+
g.add_edge(*e)
|
| 647 |
+
elif p[i][j] > 0:
|
| 648 |
+
while True:
|
| 649 |
+
try:
|
| 650 |
+
logrand = math.log(seed.random())
|
| 651 |
+
skip = math.floor(logrand / math.log(1 - p[i][j]))
|
| 652 |
+
# consume "skip" edges
|
| 653 |
+
next(itertools.islice(edges, skip, skip), None)
|
| 654 |
+
e = next(edges)
|
| 655 |
+
g.add_edge(*e) # __safe
|
| 656 |
+
except StopIteration:
|
| 657 |
+
break
|
| 658 |
+
else:
|
| 659 |
+
for e in edges:
|
| 660 |
+
if seed.random() < p[i][j]:
|
| 661 |
+
g.add_edge(*e) # __safe
|
| 662 |
+
return g
|
| 663 |
+
|
| 664 |
+
|
| 665 |
+
def _zipf_rv_below(gamma, xmin, threshold, seed):
|
| 666 |
+
"""Returns a random value chosen from the bounded Zipf distribution.
|
| 667 |
+
|
| 668 |
+
Repeatedly draws values from the Zipf distribution until the
|
| 669 |
+
threshold is met, then returns that value.
|
| 670 |
+
"""
|
| 671 |
+
result = nx.utils.zipf_rv(gamma, xmin, seed)
|
| 672 |
+
while result > threshold:
|
| 673 |
+
result = nx.utils.zipf_rv(gamma, xmin, seed)
|
| 674 |
+
return result
|
| 675 |
+
|
| 676 |
+
|
| 677 |
+
def _powerlaw_sequence(gamma, low, high, condition, length, max_iters, seed):
|
| 678 |
+
"""Returns a list of numbers obeying a constrained power law distribution.
|
| 679 |
+
|
| 680 |
+
``gamma`` and ``low`` are the parameters for the Zipf distribution.
|
| 681 |
+
|
| 682 |
+
``high`` is the maximum allowed value for values draw from the Zipf
|
| 683 |
+
distribution. For more information, see :func:`_zipf_rv_below`.
|
| 684 |
+
|
| 685 |
+
``condition`` and ``length`` are Boolean-valued functions on
|
| 686 |
+
lists. While generating the list, random values are drawn and
|
| 687 |
+
appended to the list until ``length`` is satisfied by the created
|
| 688 |
+
list. Once ``condition`` is satisfied, the sequence generated in
|
| 689 |
+
this way is returned.
|
| 690 |
+
|
| 691 |
+
``max_iters`` indicates the number of times to generate a list
|
| 692 |
+
satisfying ``length``. If the number of iterations exceeds this
|
| 693 |
+
value, :exc:`~networkx.exception.ExceededMaxIterations` is raised.
|
| 694 |
+
|
| 695 |
+
seed : integer, random_state, or None (default)
|
| 696 |
+
Indicator of random number generation state.
|
| 697 |
+
See :ref:`Randomness<randomness>`.
|
| 698 |
+
"""
|
| 699 |
+
for i in range(max_iters):
|
| 700 |
+
seq = []
|
| 701 |
+
while not length(seq):
|
| 702 |
+
seq.append(_zipf_rv_below(gamma, low, high, seed))
|
| 703 |
+
if condition(seq):
|
| 704 |
+
return seq
|
| 705 |
+
raise nx.ExceededMaxIterations("Could not create power law sequence")
|
| 706 |
+
|
| 707 |
+
|
| 708 |
+
def _hurwitz_zeta(x, q, tolerance):
|
| 709 |
+
"""The Hurwitz zeta function, or the Riemann zeta function of two arguments.
|
| 710 |
+
|
| 711 |
+
``x`` must be greater than one and ``q`` must be positive.
|
| 712 |
+
|
| 713 |
+
This function repeatedly computes subsequent partial sums until
|
| 714 |
+
convergence, as decided by ``tolerance``.
|
| 715 |
+
"""
|
| 716 |
+
z = 0
|
| 717 |
+
z_prev = -float("inf")
|
| 718 |
+
k = 0
|
| 719 |
+
while abs(z - z_prev) > tolerance:
|
| 720 |
+
z_prev = z
|
| 721 |
+
z += 1 / ((k + q) ** x)
|
| 722 |
+
k += 1
|
| 723 |
+
return z
|
| 724 |
+
|
| 725 |
+
|
| 726 |
+
def _generate_min_degree(gamma, average_degree, max_degree, tolerance, max_iters):
|
| 727 |
+
"""Returns a minimum degree from the given average degree."""
|
| 728 |
+
# Defines zeta function whether or not Scipy is available
|
| 729 |
+
try:
|
| 730 |
+
from scipy.special import zeta
|
| 731 |
+
except ImportError:
|
| 732 |
+
|
| 733 |
+
def zeta(x, q):
|
| 734 |
+
return _hurwitz_zeta(x, q, tolerance)
|
| 735 |
+
|
| 736 |
+
min_deg_top = max_degree
|
| 737 |
+
min_deg_bot = 1
|
| 738 |
+
min_deg_mid = (min_deg_top - min_deg_bot) / 2 + min_deg_bot
|
| 739 |
+
itrs = 0
|
| 740 |
+
mid_avg_deg = 0
|
| 741 |
+
while abs(mid_avg_deg - average_degree) > tolerance:
|
| 742 |
+
if itrs > max_iters:
|
| 743 |
+
raise nx.ExceededMaxIterations("Could not match average_degree")
|
| 744 |
+
mid_avg_deg = 0
|
| 745 |
+
for x in range(int(min_deg_mid), max_degree + 1):
|
| 746 |
+
mid_avg_deg += (x ** (-gamma + 1)) / zeta(gamma, min_deg_mid)
|
| 747 |
+
if mid_avg_deg > average_degree:
|
| 748 |
+
min_deg_top = min_deg_mid
|
| 749 |
+
min_deg_mid = (min_deg_top - min_deg_bot) / 2 + min_deg_bot
|
| 750 |
+
else:
|
| 751 |
+
min_deg_bot = min_deg_mid
|
| 752 |
+
min_deg_mid = (min_deg_top - min_deg_bot) / 2 + min_deg_bot
|
| 753 |
+
itrs += 1
|
| 754 |
+
# return int(min_deg_mid + 0.5)
|
| 755 |
+
return round(min_deg_mid)
|
| 756 |
+
|
| 757 |
+
|
| 758 |
+
def _generate_communities(degree_seq, community_sizes, mu, max_iters, seed):
|
| 759 |
+
"""Returns a list of sets, each of which represents a community.
|
| 760 |
+
|
| 761 |
+
``degree_seq`` is the degree sequence that must be met by the
|
| 762 |
+
graph.
|
| 763 |
+
|
| 764 |
+
``community_sizes`` is the community size distribution that must be
|
| 765 |
+
met by the generated list of sets.
|
| 766 |
+
|
| 767 |
+
``mu`` is a float in the interval [0, 1] indicating the fraction of
|
| 768 |
+
intra-community edges incident to each node.
|
| 769 |
+
|
| 770 |
+
``max_iters`` is the number of times to try to add a node to a
|
| 771 |
+
community. This must be greater than the length of
|
| 772 |
+
``degree_seq``, otherwise this function will always fail. If
|
| 773 |
+
the number of iterations exceeds this value,
|
| 774 |
+
:exc:`~networkx.exception.ExceededMaxIterations` is raised.
|
| 775 |
+
|
| 776 |
+
seed : integer, random_state, or None (default)
|
| 777 |
+
Indicator of random number generation state.
|
| 778 |
+
See :ref:`Randomness<randomness>`.
|
| 779 |
+
|
| 780 |
+
The communities returned by this are sets of integers in the set {0,
|
| 781 |
+
..., *n* - 1}, where *n* is the length of ``degree_seq``.
|
| 782 |
+
|
| 783 |
+
"""
|
| 784 |
+
# This assumes the nodes in the graph will be natural numbers.
|
| 785 |
+
result = [set() for _ in community_sizes]
|
| 786 |
+
n = len(degree_seq)
|
| 787 |
+
free = list(range(n))
|
| 788 |
+
for i in range(max_iters):
|
| 789 |
+
v = free.pop()
|
| 790 |
+
c = seed.choice(range(len(community_sizes)))
|
| 791 |
+
# s = int(degree_seq[v] * (1 - mu) + 0.5)
|
| 792 |
+
s = round(degree_seq[v] * (1 - mu))
|
| 793 |
+
# If the community is large enough, add the node to the chosen
|
| 794 |
+
# community. Otherwise, return it to the list of unaffiliated
|
| 795 |
+
# nodes.
|
| 796 |
+
if s < community_sizes[c]:
|
| 797 |
+
result[c].add(v)
|
| 798 |
+
else:
|
| 799 |
+
free.append(v)
|
| 800 |
+
# If the community is too big, remove a node from it.
|
| 801 |
+
if len(result[c]) > community_sizes[c]:
|
| 802 |
+
free.append(result[c].pop())
|
| 803 |
+
if not free:
|
| 804 |
+
return result
|
| 805 |
+
msg = "Could not assign communities; try increasing min_community"
|
| 806 |
+
raise nx.ExceededMaxIterations(msg)
|
| 807 |
+
|
| 808 |
+
|
| 809 |
+
@py_random_state(11)
|
| 810 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 811 |
+
def LFR_benchmark_graph(
|
| 812 |
+
n,
|
| 813 |
+
tau1,
|
| 814 |
+
tau2,
|
| 815 |
+
mu,
|
| 816 |
+
average_degree=None,
|
| 817 |
+
min_degree=None,
|
| 818 |
+
max_degree=None,
|
| 819 |
+
min_community=None,
|
| 820 |
+
max_community=None,
|
| 821 |
+
tol=1.0e-7,
|
| 822 |
+
max_iters=500,
|
| 823 |
+
seed=None,
|
| 824 |
+
):
|
| 825 |
+
r"""Returns the LFR benchmark graph.
|
| 826 |
+
|
| 827 |
+
This algorithm proceeds as follows:
|
| 828 |
+
|
| 829 |
+
1) Find a degree sequence with a power law distribution, and minimum
|
| 830 |
+
value ``min_degree``, which has approximate average degree
|
| 831 |
+
``average_degree``. This is accomplished by either
|
| 832 |
+
|
| 833 |
+
a) specifying ``min_degree`` and not ``average_degree``,
|
| 834 |
+
b) specifying ``average_degree`` and not ``min_degree``, in which
|
| 835 |
+
case a suitable minimum degree will be found.
|
| 836 |
+
|
| 837 |
+
``max_degree`` can also be specified, otherwise it will be set to
|
| 838 |
+
``n``. Each node *u* will have $\mu \mathrm{deg}(u)$ edges
|
| 839 |
+
joining it to nodes in communities other than its own and $(1 -
|
| 840 |
+
\mu) \mathrm{deg}(u)$ edges joining it to nodes in its own
|
| 841 |
+
community.
|
| 842 |
+
2) Generate community sizes according to a power law distribution
|
| 843 |
+
with exponent ``tau2``. If ``min_community`` and
|
| 844 |
+
``max_community`` are not specified they will be selected to be
|
| 845 |
+
``min_degree`` and ``max_degree``, respectively. Community sizes
|
| 846 |
+
are generated until the sum of their sizes equals ``n``.
|
| 847 |
+
3) Each node will be randomly assigned a community with the
|
| 848 |
+
condition that the community is large enough for the node's
|
| 849 |
+
intra-community degree, $(1 - \mu) \mathrm{deg}(u)$ as
|
| 850 |
+
described in step 2. If a community grows too large, a random node
|
| 851 |
+
will be selected for reassignment to a new community, until all
|
| 852 |
+
nodes have been assigned a community.
|
| 853 |
+
4) Each node *u* then adds $(1 - \mu) \mathrm{deg}(u)$
|
| 854 |
+
intra-community edges and $\mu \mathrm{deg}(u)$ inter-community
|
| 855 |
+
edges.
|
| 856 |
+
|
| 857 |
+
Parameters
|
| 858 |
+
----------
|
| 859 |
+
n : int
|
| 860 |
+
Number of nodes in the created graph.
|
| 861 |
+
|
| 862 |
+
tau1 : float
|
| 863 |
+
Power law exponent for the degree distribution of the created
|
| 864 |
+
graph. This value must be strictly greater than one.
|
| 865 |
+
|
| 866 |
+
tau2 : float
|
| 867 |
+
Power law exponent for the community size distribution in the
|
| 868 |
+
created graph. This value must be strictly greater than one.
|
| 869 |
+
|
| 870 |
+
mu : float
|
| 871 |
+
Fraction of inter-community edges incident to each node. This
|
| 872 |
+
value must be in the interval [0, 1].
|
| 873 |
+
|
| 874 |
+
average_degree : float
|
| 875 |
+
Desired average degree of nodes in the created graph. This value
|
| 876 |
+
must be in the interval [0, *n*]. Exactly one of this and
|
| 877 |
+
``min_degree`` must be specified, otherwise a
|
| 878 |
+
:exc:`NetworkXError` is raised.
|
| 879 |
+
|
| 880 |
+
min_degree : int
|
| 881 |
+
Minimum degree of nodes in the created graph. This value must be
|
| 882 |
+
in the interval [0, *n*]. Exactly one of this and
|
| 883 |
+
``average_degree`` must be specified, otherwise a
|
| 884 |
+
:exc:`NetworkXError` is raised.
|
| 885 |
+
|
| 886 |
+
max_degree : int
|
| 887 |
+
Maximum degree of nodes in the created graph. If not specified,
|
| 888 |
+
this is set to ``n``, the total number of nodes in the graph.
|
| 889 |
+
|
| 890 |
+
min_community : int
|
| 891 |
+
Minimum size of communities in the graph. If not specified, this
|
| 892 |
+
is set to ``min_degree``.
|
| 893 |
+
|
| 894 |
+
max_community : int
|
| 895 |
+
Maximum size of communities in the graph. If not specified, this
|
| 896 |
+
is set to ``n``, the total number of nodes in the graph.
|
| 897 |
+
|
| 898 |
+
tol : float
|
| 899 |
+
Tolerance when comparing floats, specifically when comparing
|
| 900 |
+
average degree values.
|
| 901 |
+
|
| 902 |
+
max_iters : int
|
| 903 |
+
Maximum number of iterations to try to create the community sizes,
|
| 904 |
+
degree distribution, and community affiliations.
|
| 905 |
+
|
| 906 |
+
seed : integer, random_state, or None (default)
|
| 907 |
+
Indicator of random number generation state.
|
| 908 |
+
See :ref:`Randomness<randomness>`.
|
| 909 |
+
|
| 910 |
+
Returns
|
| 911 |
+
-------
|
| 912 |
+
G : NetworkX graph
|
| 913 |
+
The LFR benchmark graph generated according to the specified
|
| 914 |
+
parameters.
|
| 915 |
+
|
| 916 |
+
Each node in the graph has a node attribute ``'community'`` that
|
| 917 |
+
stores the community (that is, the set of nodes) that includes
|
| 918 |
+
it.
|
| 919 |
+
|
| 920 |
+
Raises
|
| 921 |
+
------
|
| 922 |
+
NetworkXError
|
| 923 |
+
If any of the parameters do not meet their upper and lower bounds:
|
| 924 |
+
|
| 925 |
+
- ``tau1`` and ``tau2`` must be strictly greater than 1.
|
| 926 |
+
- ``mu`` must be in [0, 1].
|
| 927 |
+
- ``max_degree`` must be in {1, ..., *n*}.
|
| 928 |
+
- ``min_community`` and ``max_community`` must be in {0, ...,
|
| 929 |
+
*n*}.
|
| 930 |
+
|
| 931 |
+
If not exactly one of ``average_degree`` and ``min_degree`` is
|
| 932 |
+
specified.
|
| 933 |
+
|
| 934 |
+
If ``min_degree`` is not specified and a suitable ``min_degree``
|
| 935 |
+
cannot be found.
|
| 936 |
+
|
| 937 |
+
ExceededMaxIterations
|
| 938 |
+
If a valid degree sequence cannot be created within
|
| 939 |
+
``max_iters`` number of iterations.
|
| 940 |
+
|
| 941 |
+
If a valid set of community sizes cannot be created within
|
| 942 |
+
``max_iters`` number of iterations.
|
| 943 |
+
|
| 944 |
+
If a valid community assignment cannot be created within ``10 *
|
| 945 |
+
n * max_iters`` number of iterations.
|
| 946 |
+
|
| 947 |
+
Examples
|
| 948 |
+
--------
|
| 949 |
+
Basic usage::
|
| 950 |
+
|
| 951 |
+
>>> from networkx.generators.community import LFR_benchmark_graph
|
| 952 |
+
>>> n = 250
|
| 953 |
+
>>> tau1 = 3
|
| 954 |
+
>>> tau2 = 1.5
|
| 955 |
+
>>> mu = 0.1
|
| 956 |
+
>>> G = LFR_benchmark_graph(
|
| 957 |
+
... n, tau1, tau2, mu, average_degree=5, min_community=20, seed=10
|
| 958 |
+
... )
|
| 959 |
+
|
| 960 |
+
Continuing the example above, you can get the communities from the
|
| 961 |
+
node attributes of the graph::
|
| 962 |
+
|
| 963 |
+
>>> communities = {frozenset(G.nodes[v]["community"]) for v in G}
|
| 964 |
+
|
| 965 |
+
Notes
|
| 966 |
+
-----
|
| 967 |
+
This algorithm differs slightly from the original way it was
|
| 968 |
+
presented in [1].
|
| 969 |
+
|
| 970 |
+
1) Rather than connecting the graph via a configuration model then
|
| 971 |
+
rewiring to match the intra-community and inter-community
|
| 972 |
+
degrees, we do this wiring explicitly at the end, which should be
|
| 973 |
+
equivalent.
|
| 974 |
+
2) The code posted on the author's website [2] calculates the random
|
| 975 |
+
power law distributed variables and their average using
|
| 976 |
+
continuous approximations, whereas we use the discrete
|
| 977 |
+
distributions here as both degree and community size are
|
| 978 |
+
discrete.
|
| 979 |
+
|
| 980 |
+
Though the authors describe the algorithm as quite robust, testing
|
| 981 |
+
during development indicates that a somewhat narrower parameter set
|
| 982 |
+
is likely to successfully produce a graph. Some suggestions have
|
| 983 |
+
been provided in the event of exceptions.
|
| 984 |
+
|
| 985 |
+
References
|
| 986 |
+
----------
|
| 987 |
+
.. [1] "Benchmark graphs for testing community detection algorithms",
|
| 988 |
+
Andrea Lancichinetti, Santo Fortunato, and Filippo Radicchi,
|
| 989 |
+
Phys. Rev. E 78, 046110 2008
|
| 990 |
+
.. [2] https://www.santofortunato.net/resources
|
| 991 |
+
|
| 992 |
+
"""
|
| 993 |
+
# Perform some basic parameter validation.
|
| 994 |
+
if not tau1 > 1:
|
| 995 |
+
raise nx.NetworkXError("tau1 must be greater than one")
|
| 996 |
+
if not tau2 > 1:
|
| 997 |
+
raise nx.NetworkXError("tau2 must be greater than one")
|
| 998 |
+
if not 0 <= mu <= 1:
|
| 999 |
+
raise nx.NetworkXError("mu must be in the interval [0, 1]")
|
| 1000 |
+
|
| 1001 |
+
# Validate parameters for generating the degree sequence.
|
| 1002 |
+
if max_degree is None:
|
| 1003 |
+
max_degree = n
|
| 1004 |
+
elif not 0 < max_degree <= n:
|
| 1005 |
+
raise nx.NetworkXError("max_degree must be in the interval (0, n]")
|
| 1006 |
+
if not ((min_degree is None) ^ (average_degree is None)):
|
| 1007 |
+
raise nx.NetworkXError(
|
| 1008 |
+
"Must assign exactly one of min_degree and average_degree"
|
| 1009 |
+
)
|
| 1010 |
+
if min_degree is None:
|
| 1011 |
+
min_degree = _generate_min_degree(
|
| 1012 |
+
tau1, average_degree, max_degree, tol, max_iters
|
| 1013 |
+
)
|
| 1014 |
+
|
| 1015 |
+
# Generate a degree sequence with a power law distribution.
|
| 1016 |
+
low, high = min_degree, max_degree
|
| 1017 |
+
|
| 1018 |
+
def condition(seq):
|
| 1019 |
+
return sum(seq) % 2 == 0
|
| 1020 |
+
|
| 1021 |
+
def length(seq):
|
| 1022 |
+
return len(seq) >= n
|
| 1023 |
+
|
| 1024 |
+
deg_seq = _powerlaw_sequence(tau1, low, high, condition, length, max_iters, seed)
|
| 1025 |
+
|
| 1026 |
+
# Validate parameters for generating the community size sequence.
|
| 1027 |
+
if min_community is None:
|
| 1028 |
+
min_community = min(deg_seq)
|
| 1029 |
+
if max_community is None:
|
| 1030 |
+
max_community = max(deg_seq)
|
| 1031 |
+
|
| 1032 |
+
# Generate a community size sequence with a power law distribution.
|
| 1033 |
+
#
|
| 1034 |
+
# TODO The original code incremented the number of iterations each
|
| 1035 |
+
# time a new Zipf random value was drawn from the distribution. This
|
| 1036 |
+
# differed from the way the number of iterations was incremented in
|
| 1037 |
+
# `_powerlaw_degree_sequence`, so this code was changed to match
|
| 1038 |
+
# that one. As a result, this code is allowed many more chances to
|
| 1039 |
+
# generate a valid community size sequence.
|
| 1040 |
+
low, high = min_community, max_community
|
| 1041 |
+
|
| 1042 |
+
def condition(seq):
|
| 1043 |
+
return sum(seq) == n
|
| 1044 |
+
|
| 1045 |
+
def length(seq):
|
| 1046 |
+
return sum(seq) >= n
|
| 1047 |
+
|
| 1048 |
+
comms = _powerlaw_sequence(tau2, low, high, condition, length, max_iters, seed)
|
| 1049 |
+
|
| 1050 |
+
# Generate the communities based on the given degree sequence and
|
| 1051 |
+
# community sizes.
|
| 1052 |
+
max_iters *= 10 * n
|
| 1053 |
+
communities = _generate_communities(deg_seq, comms, mu, max_iters, seed)
|
| 1054 |
+
|
| 1055 |
+
# Finally, generate the benchmark graph based on the given
|
| 1056 |
+
# communities, joining nodes according to the intra- and
|
| 1057 |
+
# inter-community degrees.
|
| 1058 |
+
G = nx.Graph()
|
| 1059 |
+
G.add_nodes_from(range(n))
|
| 1060 |
+
for c in communities:
|
| 1061 |
+
for u in c:
|
| 1062 |
+
while G.degree(u) < round(deg_seq[u] * (1 - mu)):
|
| 1063 |
+
v = seed.choice(list(c))
|
| 1064 |
+
G.add_edge(u, v)
|
| 1065 |
+
while G.degree(u) < deg_seq[u]:
|
| 1066 |
+
v = seed.choice(range(n))
|
| 1067 |
+
if v not in c:
|
| 1068 |
+
G.add_edge(u, v)
|
| 1069 |
+
G.nodes[u]["community"] = c
|
| 1070 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/degree_seq.py
ADDED
|
@@ -0,0 +1,867 @@
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|
| 1 |
+
"""Generate graphs with a given degree sequence or expected degree sequence."""
|
| 2 |
+
|
| 3 |
+
import heapq
|
| 4 |
+
import math
|
| 5 |
+
from itertools import chain, combinations, zip_longest
|
| 6 |
+
from operator import itemgetter
|
| 7 |
+
|
| 8 |
+
import networkx as nx
|
| 9 |
+
from networkx.utils import py_random_state, random_weighted_sample
|
| 10 |
+
|
| 11 |
+
__all__ = [
|
| 12 |
+
"configuration_model",
|
| 13 |
+
"directed_configuration_model",
|
| 14 |
+
"expected_degree_graph",
|
| 15 |
+
"havel_hakimi_graph",
|
| 16 |
+
"directed_havel_hakimi_graph",
|
| 17 |
+
"degree_sequence_tree",
|
| 18 |
+
"random_degree_sequence_graph",
|
| 19 |
+
]
|
| 20 |
+
|
| 21 |
+
chaini = chain.from_iterable
|
| 22 |
+
|
| 23 |
+
|
| 24 |
+
def _to_stublist(degree_sequence):
|
| 25 |
+
"""Returns a list of degree-repeated node numbers.
|
| 26 |
+
|
| 27 |
+
``degree_sequence`` is a list of nonnegative integers representing
|
| 28 |
+
the degrees of nodes in a graph.
|
| 29 |
+
|
| 30 |
+
This function returns a list of node numbers with multiplicities
|
| 31 |
+
according to the given degree sequence. For example, if the first
|
| 32 |
+
element of ``degree_sequence`` is ``3``, then the first node number,
|
| 33 |
+
``0``, will appear at the head of the returned list three times. The
|
| 34 |
+
node numbers are assumed to be the numbers zero through
|
| 35 |
+
``len(degree_sequence) - 1``.
|
| 36 |
+
|
| 37 |
+
Examples
|
| 38 |
+
--------
|
| 39 |
+
|
| 40 |
+
>>> degree_sequence = [1, 2, 3]
|
| 41 |
+
>>> _to_stublist(degree_sequence)
|
| 42 |
+
[0, 1, 1, 2, 2, 2]
|
| 43 |
+
|
| 44 |
+
If a zero appears in the sequence, that means the node exists but
|
| 45 |
+
has degree zero, so that number will be skipped in the returned
|
| 46 |
+
list::
|
| 47 |
+
|
| 48 |
+
>>> degree_sequence = [2, 0, 1]
|
| 49 |
+
>>> _to_stublist(degree_sequence)
|
| 50 |
+
[0, 0, 2]
|
| 51 |
+
|
| 52 |
+
"""
|
| 53 |
+
return list(chaini([n] * d for n, d in enumerate(degree_sequence)))
|
| 54 |
+
|
| 55 |
+
|
| 56 |
+
def _configuration_model(
|
| 57 |
+
deg_sequence, create_using, directed=False, in_deg_sequence=None, seed=None
|
| 58 |
+
):
|
| 59 |
+
"""Helper function for generating either undirected or directed
|
| 60 |
+
configuration model graphs.
|
| 61 |
+
|
| 62 |
+
``deg_sequence`` is a list of nonnegative integers representing the
|
| 63 |
+
degree of the node whose label is the index of the list element.
|
| 64 |
+
|
| 65 |
+
``create_using`` see :func:`~networkx.empty_graph`.
|
| 66 |
+
|
| 67 |
+
``directed`` and ``in_deg_sequence`` are required if you want the
|
| 68 |
+
returned graph to be generated using the directed configuration
|
| 69 |
+
model algorithm. If ``directed`` is ``False``, then ``deg_sequence``
|
| 70 |
+
is interpreted as the degree sequence of an undirected graph and
|
| 71 |
+
``in_deg_sequence`` is ignored. Otherwise, if ``directed`` is
|
| 72 |
+
``True``, then ``deg_sequence`` is interpreted as the out-degree
|
| 73 |
+
sequence and ``in_deg_sequence`` as the in-degree sequence of a
|
| 74 |
+
directed graph.
|
| 75 |
+
|
| 76 |
+
.. note::
|
| 77 |
+
|
| 78 |
+
``deg_sequence`` and ``in_deg_sequence`` need not be the same
|
| 79 |
+
length.
|
| 80 |
+
|
| 81 |
+
``seed`` is a random.Random or numpy.random.RandomState instance
|
| 82 |
+
|
| 83 |
+
This function returns a graph, directed if and only if ``directed``
|
| 84 |
+
is ``True``, generated according to the configuration model
|
| 85 |
+
algorithm. For more information on the algorithm, see the
|
| 86 |
+
:func:`configuration_model` or :func:`directed_configuration_model`
|
| 87 |
+
functions.
|
| 88 |
+
|
| 89 |
+
"""
|
| 90 |
+
n = len(deg_sequence)
|
| 91 |
+
G = nx.empty_graph(n, create_using)
|
| 92 |
+
# If empty, return the null graph immediately.
|
| 93 |
+
if n == 0:
|
| 94 |
+
return G
|
| 95 |
+
# Build a list of available degree-repeated nodes. For example,
|
| 96 |
+
# for degree sequence [3, 2, 1, 1, 1], the "stub list" is
|
| 97 |
+
# initially [0, 0, 0, 1, 1, 2, 3, 4], that is, node 0 has degree
|
| 98 |
+
# 3 and thus is repeated 3 times, etc.
|
| 99 |
+
#
|
| 100 |
+
# Also, shuffle the stub list in order to get a random sequence of
|
| 101 |
+
# node pairs.
|
| 102 |
+
if directed:
|
| 103 |
+
pairs = zip_longest(deg_sequence, in_deg_sequence, fillvalue=0)
|
| 104 |
+
# Unzip the list of pairs into a pair of lists.
|
| 105 |
+
out_deg, in_deg = zip(*pairs)
|
| 106 |
+
|
| 107 |
+
out_stublist = _to_stublist(out_deg)
|
| 108 |
+
in_stublist = _to_stublist(in_deg)
|
| 109 |
+
|
| 110 |
+
seed.shuffle(out_stublist)
|
| 111 |
+
seed.shuffle(in_stublist)
|
| 112 |
+
else:
|
| 113 |
+
stublist = _to_stublist(deg_sequence)
|
| 114 |
+
# Choose a random balanced bipartition of the stublist, which
|
| 115 |
+
# gives a random pairing of nodes. In this implementation, we
|
| 116 |
+
# shuffle the list and then split it in half.
|
| 117 |
+
n = len(stublist)
|
| 118 |
+
half = n // 2
|
| 119 |
+
seed.shuffle(stublist)
|
| 120 |
+
out_stublist, in_stublist = stublist[:half], stublist[half:]
|
| 121 |
+
G.add_edges_from(zip(out_stublist, in_stublist))
|
| 122 |
+
return G
|
| 123 |
+
|
| 124 |
+
|
| 125 |
+
@py_random_state(2)
|
| 126 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 127 |
+
def configuration_model(deg_sequence, create_using=None, seed=None):
|
| 128 |
+
"""Returns a random graph with the given degree sequence.
|
| 129 |
+
|
| 130 |
+
The configuration model generates a random pseudograph (graph with
|
| 131 |
+
parallel edges and self loops) by randomly assigning edges to
|
| 132 |
+
match the given degree sequence.
|
| 133 |
+
|
| 134 |
+
Parameters
|
| 135 |
+
----------
|
| 136 |
+
deg_sequence : list of nonnegative integers
|
| 137 |
+
Each list entry corresponds to the degree of a node.
|
| 138 |
+
create_using : NetworkX graph constructor, optional (default MultiGraph)
|
| 139 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 140 |
+
seed : integer, random_state, or None (default)
|
| 141 |
+
Indicator of random number generation state.
|
| 142 |
+
See :ref:`Randomness<randomness>`.
|
| 143 |
+
|
| 144 |
+
Returns
|
| 145 |
+
-------
|
| 146 |
+
G : MultiGraph
|
| 147 |
+
A graph with the specified degree sequence.
|
| 148 |
+
Nodes are labeled starting at 0 with an index
|
| 149 |
+
corresponding to the position in deg_sequence.
|
| 150 |
+
|
| 151 |
+
Raises
|
| 152 |
+
------
|
| 153 |
+
NetworkXError
|
| 154 |
+
If the degree sequence does not have an even sum.
|
| 155 |
+
|
| 156 |
+
See Also
|
| 157 |
+
--------
|
| 158 |
+
is_graphical
|
| 159 |
+
|
| 160 |
+
Notes
|
| 161 |
+
-----
|
| 162 |
+
As described by Newman [1]_.
|
| 163 |
+
|
| 164 |
+
A non-graphical degree sequence (not realizable by some simple
|
| 165 |
+
graph) is allowed since this function returns graphs with self
|
| 166 |
+
loops and parallel edges. An exception is raised if the degree
|
| 167 |
+
sequence does not have an even sum.
|
| 168 |
+
|
| 169 |
+
This configuration model construction process can lead to
|
| 170 |
+
duplicate edges and loops. You can remove the self-loops and
|
| 171 |
+
parallel edges (see below) which will likely result in a graph
|
| 172 |
+
that doesn't have the exact degree sequence specified.
|
| 173 |
+
|
| 174 |
+
The density of self-loops and parallel edges tends to decrease as
|
| 175 |
+
the number of nodes increases. However, typically the number of
|
| 176 |
+
self-loops will approach a Poisson distribution with a nonzero mean,
|
| 177 |
+
and similarly for the number of parallel edges. Consider a node
|
| 178 |
+
with *k* stubs. The probability of being joined to another stub of
|
| 179 |
+
the same node is basically (*k* - *1*) / *N*, where *k* is the
|
| 180 |
+
degree and *N* is the number of nodes. So the probability of a
|
| 181 |
+
self-loop scales like *c* / *N* for some constant *c*. As *N* grows,
|
| 182 |
+
this means we expect *c* self-loops. Similarly for parallel edges.
|
| 183 |
+
|
| 184 |
+
References
|
| 185 |
+
----------
|
| 186 |
+
.. [1] M.E.J. Newman, "The structure and function of complex networks",
|
| 187 |
+
SIAM REVIEW 45-2, pp 167-256, 2003.
|
| 188 |
+
|
| 189 |
+
Examples
|
| 190 |
+
--------
|
| 191 |
+
You can create a degree sequence following a particular distribution
|
| 192 |
+
by using the one of the distribution functions in
|
| 193 |
+
:mod:`~networkx.utils.random_sequence` (or one of your own). For
|
| 194 |
+
example, to create an undirected multigraph on one hundred nodes
|
| 195 |
+
with degree sequence chosen from the power law distribution:
|
| 196 |
+
|
| 197 |
+
>>> sequence = nx.random_powerlaw_tree_sequence(100, tries=5000)
|
| 198 |
+
>>> G = nx.configuration_model(sequence)
|
| 199 |
+
>>> len(G)
|
| 200 |
+
100
|
| 201 |
+
>>> actual_degrees = [d for v, d in G.degree()]
|
| 202 |
+
>>> actual_degrees == sequence
|
| 203 |
+
True
|
| 204 |
+
|
| 205 |
+
The returned graph is a multigraph, which may have parallel
|
| 206 |
+
edges. To remove any parallel edges from the returned graph:
|
| 207 |
+
|
| 208 |
+
>>> G = nx.Graph(G)
|
| 209 |
+
|
| 210 |
+
Similarly, to remove self-loops:
|
| 211 |
+
|
| 212 |
+
>>> G.remove_edges_from(nx.selfloop_edges(G))
|
| 213 |
+
|
| 214 |
+
"""
|
| 215 |
+
if sum(deg_sequence) % 2 != 0:
|
| 216 |
+
msg = "Invalid degree sequence: sum of degrees must be even, not odd"
|
| 217 |
+
raise nx.NetworkXError(msg)
|
| 218 |
+
|
| 219 |
+
G = nx.empty_graph(0, create_using, default=nx.MultiGraph)
|
| 220 |
+
if G.is_directed():
|
| 221 |
+
raise nx.NetworkXNotImplemented("not implemented for directed graphs")
|
| 222 |
+
|
| 223 |
+
G = _configuration_model(deg_sequence, G, seed=seed)
|
| 224 |
+
|
| 225 |
+
return G
|
| 226 |
+
|
| 227 |
+
|
| 228 |
+
@py_random_state(3)
|
| 229 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 230 |
+
def directed_configuration_model(
|
| 231 |
+
in_degree_sequence, out_degree_sequence, create_using=None, seed=None
|
| 232 |
+
):
|
| 233 |
+
"""Returns a directed_random graph with the given degree sequences.
|
| 234 |
+
|
| 235 |
+
The configuration model generates a random directed pseudograph
|
| 236 |
+
(graph with parallel edges and self loops) by randomly assigning
|
| 237 |
+
edges to match the given degree sequences.
|
| 238 |
+
|
| 239 |
+
Parameters
|
| 240 |
+
----------
|
| 241 |
+
in_degree_sequence : list of nonnegative integers
|
| 242 |
+
Each list entry corresponds to the in-degree of a node.
|
| 243 |
+
out_degree_sequence : list of nonnegative integers
|
| 244 |
+
Each list entry corresponds to the out-degree of a node.
|
| 245 |
+
create_using : NetworkX graph constructor, optional (default MultiDiGraph)
|
| 246 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 247 |
+
seed : integer, random_state, or None (default)
|
| 248 |
+
Indicator of random number generation state.
|
| 249 |
+
See :ref:`Randomness<randomness>`.
|
| 250 |
+
|
| 251 |
+
Returns
|
| 252 |
+
-------
|
| 253 |
+
G : MultiDiGraph
|
| 254 |
+
A graph with the specified degree sequences.
|
| 255 |
+
Nodes are labeled starting at 0 with an index
|
| 256 |
+
corresponding to the position in deg_sequence.
|
| 257 |
+
|
| 258 |
+
Raises
|
| 259 |
+
------
|
| 260 |
+
NetworkXError
|
| 261 |
+
If the degree sequences do not have the same sum.
|
| 262 |
+
|
| 263 |
+
See Also
|
| 264 |
+
--------
|
| 265 |
+
configuration_model
|
| 266 |
+
|
| 267 |
+
Notes
|
| 268 |
+
-----
|
| 269 |
+
Algorithm as described by Newman [1]_.
|
| 270 |
+
|
| 271 |
+
A non-graphical degree sequence (not realizable by some simple
|
| 272 |
+
graph) is allowed since this function returns graphs with self
|
| 273 |
+
loops and parallel edges. An exception is raised if the degree
|
| 274 |
+
sequences does not have the same sum.
|
| 275 |
+
|
| 276 |
+
This configuration model construction process can lead to
|
| 277 |
+
duplicate edges and loops. You can remove the self-loops and
|
| 278 |
+
parallel edges (see below) which will likely result in a graph
|
| 279 |
+
that doesn't have the exact degree sequence specified. This
|
| 280 |
+
"finite-size effect" decreases as the size of the graph increases.
|
| 281 |
+
|
| 282 |
+
References
|
| 283 |
+
----------
|
| 284 |
+
.. [1] Newman, M. E. J. and Strogatz, S. H. and Watts, D. J.
|
| 285 |
+
Random graphs with arbitrary degree distributions and their applications
|
| 286 |
+
Phys. Rev. E, 64, 026118 (2001)
|
| 287 |
+
|
| 288 |
+
Examples
|
| 289 |
+
--------
|
| 290 |
+
One can modify the in- and out-degree sequences from an existing
|
| 291 |
+
directed graph in order to create a new directed graph. For example,
|
| 292 |
+
here we modify the directed path graph:
|
| 293 |
+
|
| 294 |
+
>>> D = nx.DiGraph([(0, 1), (1, 2), (2, 3)])
|
| 295 |
+
>>> din = list(d for n, d in D.in_degree())
|
| 296 |
+
>>> dout = list(d for n, d in D.out_degree())
|
| 297 |
+
>>> din.append(1)
|
| 298 |
+
>>> dout[0] = 2
|
| 299 |
+
>>> # We now expect an edge from node 0 to a new node, node 3.
|
| 300 |
+
... D = nx.directed_configuration_model(din, dout)
|
| 301 |
+
|
| 302 |
+
The returned graph is a directed multigraph, which may have parallel
|
| 303 |
+
edges. To remove any parallel edges from the returned graph:
|
| 304 |
+
|
| 305 |
+
>>> D = nx.DiGraph(D)
|
| 306 |
+
|
| 307 |
+
Similarly, to remove self-loops:
|
| 308 |
+
|
| 309 |
+
>>> D.remove_edges_from(nx.selfloop_edges(D))
|
| 310 |
+
|
| 311 |
+
"""
|
| 312 |
+
if sum(in_degree_sequence) != sum(out_degree_sequence):
|
| 313 |
+
msg = "Invalid degree sequences: sequences must have equal sums"
|
| 314 |
+
raise nx.NetworkXError(msg)
|
| 315 |
+
|
| 316 |
+
if create_using is None:
|
| 317 |
+
create_using = nx.MultiDiGraph
|
| 318 |
+
|
| 319 |
+
G = _configuration_model(
|
| 320 |
+
out_degree_sequence,
|
| 321 |
+
create_using,
|
| 322 |
+
directed=True,
|
| 323 |
+
in_deg_sequence=in_degree_sequence,
|
| 324 |
+
seed=seed,
|
| 325 |
+
)
|
| 326 |
+
|
| 327 |
+
name = "directed configuration_model {} nodes {} edges"
|
| 328 |
+
return G
|
| 329 |
+
|
| 330 |
+
|
| 331 |
+
@py_random_state(1)
|
| 332 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 333 |
+
def expected_degree_graph(w, seed=None, selfloops=True):
|
| 334 |
+
r"""Returns a random graph with given expected degrees.
|
| 335 |
+
|
| 336 |
+
Given a sequence of expected degrees $W=(w_0,w_1,\ldots,w_{n-1})$
|
| 337 |
+
of length $n$ this algorithm assigns an edge between node $u$ and
|
| 338 |
+
node $v$ with probability
|
| 339 |
+
|
| 340 |
+
.. math::
|
| 341 |
+
|
| 342 |
+
p_{uv} = \frac{w_u w_v}{\sum_k w_k} .
|
| 343 |
+
|
| 344 |
+
Parameters
|
| 345 |
+
----------
|
| 346 |
+
w : list
|
| 347 |
+
The list of expected degrees.
|
| 348 |
+
selfloops: bool (default=True)
|
| 349 |
+
Set to False to remove the possibility of self-loop edges.
|
| 350 |
+
seed : integer, random_state, or None (default)
|
| 351 |
+
Indicator of random number generation state.
|
| 352 |
+
See :ref:`Randomness<randomness>`.
|
| 353 |
+
|
| 354 |
+
Returns
|
| 355 |
+
-------
|
| 356 |
+
Graph
|
| 357 |
+
|
| 358 |
+
Examples
|
| 359 |
+
--------
|
| 360 |
+
>>> z = [10 for i in range(100)]
|
| 361 |
+
>>> G = nx.expected_degree_graph(z)
|
| 362 |
+
|
| 363 |
+
Notes
|
| 364 |
+
-----
|
| 365 |
+
The nodes have integer labels corresponding to index of expected degrees
|
| 366 |
+
input sequence.
|
| 367 |
+
|
| 368 |
+
The complexity of this algorithm is $\mathcal{O}(n+m)$ where $n$ is the
|
| 369 |
+
number of nodes and $m$ is the expected number of edges.
|
| 370 |
+
|
| 371 |
+
The model in [1]_ includes the possibility of self-loop edges.
|
| 372 |
+
Set selfloops=False to produce a graph without self loops.
|
| 373 |
+
|
| 374 |
+
For finite graphs this model doesn't produce exactly the given
|
| 375 |
+
expected degree sequence. Instead the expected degrees are as
|
| 376 |
+
follows.
|
| 377 |
+
|
| 378 |
+
For the case without self loops (selfloops=False),
|
| 379 |
+
|
| 380 |
+
.. math::
|
| 381 |
+
|
| 382 |
+
E[deg(u)] = \sum_{v \ne u} p_{uv}
|
| 383 |
+
= w_u \left( 1 - \frac{w_u}{\sum_k w_k} \right) .
|
| 384 |
+
|
| 385 |
+
|
| 386 |
+
NetworkX uses the standard convention that a self-loop edge counts 2
|
| 387 |
+
in the degree of a node, so with self loops (selfloops=True),
|
| 388 |
+
|
| 389 |
+
.. math::
|
| 390 |
+
|
| 391 |
+
E[deg(u)] = \sum_{v \ne u} p_{uv} + 2 p_{uu}
|
| 392 |
+
= w_u \left( 1 + \frac{w_u}{\sum_k w_k} \right) .
|
| 393 |
+
|
| 394 |
+
References
|
| 395 |
+
----------
|
| 396 |
+
.. [1] Fan Chung and L. Lu, Connected components in random graphs with
|
| 397 |
+
given expected degree sequences, Ann. Combinatorics, 6,
|
| 398 |
+
pp. 125-145, 2002.
|
| 399 |
+
.. [2] Joel Miller and Aric Hagberg,
|
| 400 |
+
Efficient generation of networks with given expected degrees,
|
| 401 |
+
in Algorithms and Models for the Web-Graph (WAW 2011),
|
| 402 |
+
Alan Frieze, Paul Horn, and Paweł Prałat (Eds), LNCS 6732,
|
| 403 |
+
pp. 115-126, 2011.
|
| 404 |
+
"""
|
| 405 |
+
n = len(w)
|
| 406 |
+
G = nx.empty_graph(n)
|
| 407 |
+
|
| 408 |
+
# If there are no nodes are no edges in the graph, return the empty graph.
|
| 409 |
+
if n == 0 or max(w) == 0:
|
| 410 |
+
return G
|
| 411 |
+
|
| 412 |
+
rho = 1 / sum(w)
|
| 413 |
+
# Sort the weights in decreasing order. The original order of the
|
| 414 |
+
# weights dictates the order of the (integer) node labels, so we
|
| 415 |
+
# need to remember the permutation applied in the sorting.
|
| 416 |
+
order = sorted(enumerate(w), key=itemgetter(1), reverse=True)
|
| 417 |
+
mapping = {c: u for c, (u, v) in enumerate(order)}
|
| 418 |
+
seq = [v for u, v in order]
|
| 419 |
+
last = n
|
| 420 |
+
if not selfloops:
|
| 421 |
+
last -= 1
|
| 422 |
+
for u in range(last):
|
| 423 |
+
v = u
|
| 424 |
+
if not selfloops:
|
| 425 |
+
v += 1
|
| 426 |
+
factor = seq[u] * rho
|
| 427 |
+
p = min(seq[v] * factor, 1)
|
| 428 |
+
while v < n and p > 0:
|
| 429 |
+
if p != 1:
|
| 430 |
+
r = seed.random()
|
| 431 |
+
v += math.floor(math.log(r, 1 - p))
|
| 432 |
+
if v < n:
|
| 433 |
+
q = min(seq[v] * factor, 1)
|
| 434 |
+
if seed.random() < q / p:
|
| 435 |
+
G.add_edge(mapping[u], mapping[v])
|
| 436 |
+
v += 1
|
| 437 |
+
p = q
|
| 438 |
+
return G
|
| 439 |
+
|
| 440 |
+
|
| 441 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 442 |
+
def havel_hakimi_graph(deg_sequence, create_using=None):
|
| 443 |
+
"""Returns a simple graph with given degree sequence constructed
|
| 444 |
+
using the Havel-Hakimi algorithm.
|
| 445 |
+
|
| 446 |
+
Parameters
|
| 447 |
+
----------
|
| 448 |
+
deg_sequence: list of integers
|
| 449 |
+
Each integer corresponds to the degree of a node (need not be sorted).
|
| 450 |
+
create_using : NetworkX graph constructor, optional (default=nx.Graph)
|
| 451 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 452 |
+
Directed graphs are not allowed.
|
| 453 |
+
|
| 454 |
+
Raises
|
| 455 |
+
------
|
| 456 |
+
NetworkXException
|
| 457 |
+
For a non-graphical degree sequence (i.e. one
|
| 458 |
+
not realizable by some simple graph).
|
| 459 |
+
|
| 460 |
+
Notes
|
| 461 |
+
-----
|
| 462 |
+
The Havel-Hakimi algorithm constructs a simple graph by
|
| 463 |
+
successively connecting the node of highest degree to other nodes
|
| 464 |
+
of highest degree, resorting remaining nodes by degree, and
|
| 465 |
+
repeating the process. The resulting graph has a high
|
| 466 |
+
degree-associativity. Nodes are labeled 1,.., len(deg_sequence),
|
| 467 |
+
corresponding to their position in deg_sequence.
|
| 468 |
+
|
| 469 |
+
The basic algorithm is from Hakimi [1]_ and was generalized by
|
| 470 |
+
Kleitman and Wang [2]_.
|
| 471 |
+
|
| 472 |
+
References
|
| 473 |
+
----------
|
| 474 |
+
.. [1] Hakimi S., On Realizability of a Set of Integers as
|
| 475 |
+
Degrees of the Vertices of a Linear Graph. I,
|
| 476 |
+
Journal of SIAM, 10(3), pp. 496-506 (1962)
|
| 477 |
+
.. [2] Kleitman D.J. and Wang D.L.
|
| 478 |
+
Algorithms for Constructing Graphs and Digraphs with Given Valences
|
| 479 |
+
and Factors Discrete Mathematics, 6(1), pp. 79-88 (1973)
|
| 480 |
+
"""
|
| 481 |
+
if not nx.is_graphical(deg_sequence):
|
| 482 |
+
raise nx.NetworkXError("Invalid degree sequence")
|
| 483 |
+
|
| 484 |
+
p = len(deg_sequence)
|
| 485 |
+
G = nx.empty_graph(p, create_using)
|
| 486 |
+
if G.is_directed():
|
| 487 |
+
raise nx.NetworkXError("Directed graphs are not supported")
|
| 488 |
+
num_degs = [[] for i in range(p)]
|
| 489 |
+
dmax, dsum, n = 0, 0, 0
|
| 490 |
+
for d in deg_sequence:
|
| 491 |
+
# Process only the non-zero integers
|
| 492 |
+
if d > 0:
|
| 493 |
+
num_degs[d].append(n)
|
| 494 |
+
dmax, dsum, n = max(dmax, d), dsum + d, n + 1
|
| 495 |
+
# Return graph if no edges
|
| 496 |
+
if n == 0:
|
| 497 |
+
return G
|
| 498 |
+
|
| 499 |
+
modstubs = [(0, 0)] * (dmax + 1)
|
| 500 |
+
# Successively reduce degree sequence by removing the maximum degree
|
| 501 |
+
while n > 0:
|
| 502 |
+
# Retrieve the maximum degree in the sequence
|
| 503 |
+
while len(num_degs[dmax]) == 0:
|
| 504 |
+
dmax -= 1
|
| 505 |
+
# If there are not enough stubs to connect to, then the sequence is
|
| 506 |
+
# not graphical
|
| 507 |
+
if dmax > n - 1:
|
| 508 |
+
raise nx.NetworkXError("Non-graphical integer sequence")
|
| 509 |
+
|
| 510 |
+
# Remove largest stub in list
|
| 511 |
+
source = num_degs[dmax].pop()
|
| 512 |
+
n -= 1
|
| 513 |
+
# Reduce the next dmax largest stubs
|
| 514 |
+
mslen = 0
|
| 515 |
+
k = dmax
|
| 516 |
+
for i in range(dmax):
|
| 517 |
+
while len(num_degs[k]) == 0:
|
| 518 |
+
k -= 1
|
| 519 |
+
target = num_degs[k].pop()
|
| 520 |
+
G.add_edge(source, target)
|
| 521 |
+
n -= 1
|
| 522 |
+
if k > 1:
|
| 523 |
+
modstubs[mslen] = (k - 1, target)
|
| 524 |
+
mslen += 1
|
| 525 |
+
# Add back to the list any nonzero stubs that were removed
|
| 526 |
+
for i in range(mslen):
|
| 527 |
+
(stubval, stubtarget) = modstubs[i]
|
| 528 |
+
num_degs[stubval].append(stubtarget)
|
| 529 |
+
n += 1
|
| 530 |
+
|
| 531 |
+
return G
|
| 532 |
+
|
| 533 |
+
|
| 534 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 535 |
+
def directed_havel_hakimi_graph(in_deg_sequence, out_deg_sequence, create_using=None):
|
| 536 |
+
"""Returns a directed graph with the given degree sequences.
|
| 537 |
+
|
| 538 |
+
Parameters
|
| 539 |
+
----------
|
| 540 |
+
in_deg_sequence : list of integers
|
| 541 |
+
Each list entry corresponds to the in-degree of a node.
|
| 542 |
+
out_deg_sequence : list of integers
|
| 543 |
+
Each list entry corresponds to the out-degree of a node.
|
| 544 |
+
create_using : NetworkX graph constructor, optional (default DiGraph)
|
| 545 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 546 |
+
|
| 547 |
+
Returns
|
| 548 |
+
-------
|
| 549 |
+
G : DiGraph
|
| 550 |
+
A graph with the specified degree sequences.
|
| 551 |
+
Nodes are labeled starting at 0 with an index
|
| 552 |
+
corresponding to the position in deg_sequence
|
| 553 |
+
|
| 554 |
+
Raises
|
| 555 |
+
------
|
| 556 |
+
NetworkXError
|
| 557 |
+
If the degree sequences are not digraphical.
|
| 558 |
+
|
| 559 |
+
See Also
|
| 560 |
+
--------
|
| 561 |
+
configuration_model
|
| 562 |
+
|
| 563 |
+
Notes
|
| 564 |
+
-----
|
| 565 |
+
Algorithm as described by Kleitman and Wang [1]_.
|
| 566 |
+
|
| 567 |
+
References
|
| 568 |
+
----------
|
| 569 |
+
.. [1] D.J. Kleitman and D.L. Wang
|
| 570 |
+
Algorithms for Constructing Graphs and Digraphs with Given Valences
|
| 571 |
+
and Factors Discrete Mathematics, 6(1), pp. 79-88 (1973)
|
| 572 |
+
"""
|
| 573 |
+
in_deg_sequence = nx.utils.make_list_of_ints(in_deg_sequence)
|
| 574 |
+
out_deg_sequence = nx.utils.make_list_of_ints(out_deg_sequence)
|
| 575 |
+
|
| 576 |
+
# Process the sequences and form two heaps to store degree pairs with
|
| 577 |
+
# either zero or nonzero out degrees
|
| 578 |
+
sumin, sumout = 0, 0
|
| 579 |
+
nin, nout = len(in_deg_sequence), len(out_deg_sequence)
|
| 580 |
+
maxn = max(nin, nout)
|
| 581 |
+
G = nx.empty_graph(maxn, create_using, default=nx.DiGraph)
|
| 582 |
+
if maxn == 0:
|
| 583 |
+
return G
|
| 584 |
+
maxin = 0
|
| 585 |
+
stubheap, zeroheap = [], []
|
| 586 |
+
for n in range(maxn):
|
| 587 |
+
in_deg, out_deg = 0, 0
|
| 588 |
+
if n < nout:
|
| 589 |
+
out_deg = out_deg_sequence[n]
|
| 590 |
+
if n < nin:
|
| 591 |
+
in_deg = in_deg_sequence[n]
|
| 592 |
+
if in_deg < 0 or out_deg < 0:
|
| 593 |
+
raise nx.NetworkXError(
|
| 594 |
+
"Invalid degree sequences. Sequence values must be positive."
|
| 595 |
+
)
|
| 596 |
+
sumin, sumout, maxin = sumin + in_deg, sumout + out_deg, max(maxin, in_deg)
|
| 597 |
+
if in_deg > 0:
|
| 598 |
+
stubheap.append((-1 * out_deg, -1 * in_deg, n))
|
| 599 |
+
elif out_deg > 0:
|
| 600 |
+
zeroheap.append((-1 * out_deg, n))
|
| 601 |
+
if sumin != sumout:
|
| 602 |
+
raise nx.NetworkXError(
|
| 603 |
+
"Invalid degree sequences. Sequences must have equal sums."
|
| 604 |
+
)
|
| 605 |
+
heapq.heapify(stubheap)
|
| 606 |
+
heapq.heapify(zeroheap)
|
| 607 |
+
|
| 608 |
+
modstubs = [(0, 0, 0)] * (maxin + 1)
|
| 609 |
+
# Successively reduce degree sequence by removing the maximum
|
| 610 |
+
while stubheap:
|
| 611 |
+
# Remove first value in the sequence with a non-zero in degree
|
| 612 |
+
(freeout, freein, target) = heapq.heappop(stubheap)
|
| 613 |
+
freein *= -1
|
| 614 |
+
if freein > len(stubheap) + len(zeroheap):
|
| 615 |
+
raise nx.NetworkXError("Non-digraphical integer sequence")
|
| 616 |
+
|
| 617 |
+
# Attach arcs from the nodes with the most stubs
|
| 618 |
+
mslen = 0
|
| 619 |
+
for i in range(freein):
|
| 620 |
+
if zeroheap and (not stubheap or stubheap[0][0] > zeroheap[0][0]):
|
| 621 |
+
(stubout, stubsource) = heapq.heappop(zeroheap)
|
| 622 |
+
stubin = 0
|
| 623 |
+
else:
|
| 624 |
+
(stubout, stubin, stubsource) = heapq.heappop(stubheap)
|
| 625 |
+
if stubout == 0:
|
| 626 |
+
raise nx.NetworkXError("Non-digraphical integer sequence")
|
| 627 |
+
G.add_edge(stubsource, target)
|
| 628 |
+
# Check if source is now totally connected
|
| 629 |
+
if stubout + 1 < 0 or stubin < 0:
|
| 630 |
+
modstubs[mslen] = (stubout + 1, stubin, stubsource)
|
| 631 |
+
mslen += 1
|
| 632 |
+
|
| 633 |
+
# Add the nodes back to the heaps that still have available stubs
|
| 634 |
+
for i in range(mslen):
|
| 635 |
+
stub = modstubs[i]
|
| 636 |
+
if stub[1] < 0:
|
| 637 |
+
heapq.heappush(stubheap, stub)
|
| 638 |
+
else:
|
| 639 |
+
heapq.heappush(zeroheap, (stub[0], stub[2]))
|
| 640 |
+
if freeout < 0:
|
| 641 |
+
heapq.heappush(zeroheap, (freeout, target))
|
| 642 |
+
|
| 643 |
+
return G
|
| 644 |
+
|
| 645 |
+
|
| 646 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 647 |
+
def degree_sequence_tree(deg_sequence, create_using=None):
|
| 648 |
+
"""Make a tree for the given degree sequence.
|
| 649 |
+
|
| 650 |
+
A tree has #nodes-#edges=1 so
|
| 651 |
+
the degree sequence must have
|
| 652 |
+
len(deg_sequence)-sum(deg_sequence)/2=1
|
| 653 |
+
"""
|
| 654 |
+
# The sum of the degree sequence must be even (for any undirected graph).
|
| 655 |
+
degree_sum = sum(deg_sequence)
|
| 656 |
+
if degree_sum % 2 != 0:
|
| 657 |
+
msg = "Invalid degree sequence: sum of degrees must be even, not odd"
|
| 658 |
+
raise nx.NetworkXError(msg)
|
| 659 |
+
if len(deg_sequence) - degree_sum // 2 != 1:
|
| 660 |
+
msg = (
|
| 661 |
+
"Invalid degree sequence: tree must have number of nodes equal"
|
| 662 |
+
" to one less than the number of edges"
|
| 663 |
+
)
|
| 664 |
+
raise nx.NetworkXError(msg)
|
| 665 |
+
G = nx.empty_graph(0, create_using)
|
| 666 |
+
if G.is_directed():
|
| 667 |
+
raise nx.NetworkXError("Directed Graph not supported")
|
| 668 |
+
|
| 669 |
+
# Sort all degrees greater than 1 in decreasing order.
|
| 670 |
+
#
|
| 671 |
+
# TODO Does this need to be sorted in reverse order?
|
| 672 |
+
deg = sorted((s for s in deg_sequence if s > 1), reverse=True)
|
| 673 |
+
|
| 674 |
+
# make path graph as backbone
|
| 675 |
+
n = len(deg) + 2
|
| 676 |
+
nx.add_path(G, range(n))
|
| 677 |
+
last = n
|
| 678 |
+
|
| 679 |
+
# add the leaves
|
| 680 |
+
for source in range(1, n - 1):
|
| 681 |
+
nedges = deg.pop() - 2
|
| 682 |
+
for target in range(last, last + nedges):
|
| 683 |
+
G.add_edge(source, target)
|
| 684 |
+
last += nedges
|
| 685 |
+
|
| 686 |
+
# in case we added one too many
|
| 687 |
+
if len(G) > len(deg_sequence):
|
| 688 |
+
G.remove_node(0)
|
| 689 |
+
return G
|
| 690 |
+
|
| 691 |
+
|
| 692 |
+
@py_random_state(1)
|
| 693 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 694 |
+
def random_degree_sequence_graph(sequence, seed=None, tries=10):
|
| 695 |
+
r"""Returns a simple random graph with the given degree sequence.
|
| 696 |
+
|
| 697 |
+
If the maximum degree $d_m$ in the sequence is $O(m^{1/4})$ then the
|
| 698 |
+
algorithm produces almost uniform random graphs in $O(m d_m)$ time
|
| 699 |
+
where $m$ is the number of edges.
|
| 700 |
+
|
| 701 |
+
Parameters
|
| 702 |
+
----------
|
| 703 |
+
sequence : list of integers
|
| 704 |
+
Sequence of degrees
|
| 705 |
+
seed : integer, random_state, or None (default)
|
| 706 |
+
Indicator of random number generation state.
|
| 707 |
+
See :ref:`Randomness<randomness>`.
|
| 708 |
+
tries : int, optional
|
| 709 |
+
Maximum number of tries to create a graph
|
| 710 |
+
|
| 711 |
+
Returns
|
| 712 |
+
-------
|
| 713 |
+
G : Graph
|
| 714 |
+
A graph with the specified degree sequence.
|
| 715 |
+
Nodes are labeled starting at 0 with an index
|
| 716 |
+
corresponding to the position in the sequence.
|
| 717 |
+
|
| 718 |
+
Raises
|
| 719 |
+
------
|
| 720 |
+
NetworkXUnfeasible
|
| 721 |
+
If the degree sequence is not graphical.
|
| 722 |
+
NetworkXError
|
| 723 |
+
If a graph is not produced in specified number of tries
|
| 724 |
+
|
| 725 |
+
See Also
|
| 726 |
+
--------
|
| 727 |
+
is_graphical, configuration_model
|
| 728 |
+
|
| 729 |
+
Notes
|
| 730 |
+
-----
|
| 731 |
+
The generator algorithm [1]_ is not guaranteed to produce a graph.
|
| 732 |
+
|
| 733 |
+
References
|
| 734 |
+
----------
|
| 735 |
+
.. [1] Moshen Bayati, Jeong Han Kim, and Amin Saberi,
|
| 736 |
+
A sequential algorithm for generating random graphs.
|
| 737 |
+
Algorithmica, Volume 58, Number 4, 860-910,
|
| 738 |
+
DOI: 10.1007/s00453-009-9340-1
|
| 739 |
+
|
| 740 |
+
Examples
|
| 741 |
+
--------
|
| 742 |
+
>>> sequence = [1, 2, 2, 3]
|
| 743 |
+
>>> G = nx.random_degree_sequence_graph(sequence, seed=42)
|
| 744 |
+
>>> sorted(d for n, d in G.degree())
|
| 745 |
+
[1, 2, 2, 3]
|
| 746 |
+
"""
|
| 747 |
+
DSRG = DegreeSequenceRandomGraph(sequence, seed)
|
| 748 |
+
for try_n in range(tries):
|
| 749 |
+
try:
|
| 750 |
+
return DSRG.generate()
|
| 751 |
+
except nx.NetworkXUnfeasible:
|
| 752 |
+
pass
|
| 753 |
+
raise nx.NetworkXError(f"failed to generate graph in {tries} tries")
|
| 754 |
+
|
| 755 |
+
|
| 756 |
+
class DegreeSequenceRandomGraph:
|
| 757 |
+
# class to generate random graphs with a given degree sequence
|
| 758 |
+
# use random_degree_sequence_graph()
|
| 759 |
+
def __init__(self, degree, rng):
|
| 760 |
+
if not nx.is_graphical(degree):
|
| 761 |
+
raise nx.NetworkXUnfeasible("degree sequence is not graphical")
|
| 762 |
+
self.rng = rng
|
| 763 |
+
self.degree = list(degree)
|
| 764 |
+
# node labels are integers 0,...,n-1
|
| 765 |
+
self.m = sum(self.degree) / 2.0 # number of edges
|
| 766 |
+
try:
|
| 767 |
+
self.dmax = max(self.degree) # maximum degree
|
| 768 |
+
except ValueError:
|
| 769 |
+
self.dmax = 0
|
| 770 |
+
|
| 771 |
+
def generate(self):
|
| 772 |
+
# remaining_degree is mapping from int->remaining degree
|
| 773 |
+
self.remaining_degree = dict(enumerate(self.degree))
|
| 774 |
+
# add all nodes to make sure we get isolated nodes
|
| 775 |
+
self.graph = nx.Graph()
|
| 776 |
+
self.graph.add_nodes_from(self.remaining_degree)
|
| 777 |
+
# remove zero degree nodes
|
| 778 |
+
for n, d in list(self.remaining_degree.items()):
|
| 779 |
+
if d == 0:
|
| 780 |
+
del self.remaining_degree[n]
|
| 781 |
+
if len(self.remaining_degree) > 0:
|
| 782 |
+
# build graph in three phases according to how many unmatched edges
|
| 783 |
+
self.phase1()
|
| 784 |
+
self.phase2()
|
| 785 |
+
self.phase3()
|
| 786 |
+
return self.graph
|
| 787 |
+
|
| 788 |
+
def update_remaining(self, u, v, aux_graph=None):
|
| 789 |
+
# decrement remaining nodes, modify auxiliary graph if in phase3
|
| 790 |
+
if aux_graph is not None:
|
| 791 |
+
# remove edges from auxiliary graph
|
| 792 |
+
aux_graph.remove_edge(u, v)
|
| 793 |
+
if self.remaining_degree[u] == 1:
|
| 794 |
+
del self.remaining_degree[u]
|
| 795 |
+
if aux_graph is not None:
|
| 796 |
+
aux_graph.remove_node(u)
|
| 797 |
+
else:
|
| 798 |
+
self.remaining_degree[u] -= 1
|
| 799 |
+
if self.remaining_degree[v] == 1:
|
| 800 |
+
del self.remaining_degree[v]
|
| 801 |
+
if aux_graph is not None:
|
| 802 |
+
aux_graph.remove_node(v)
|
| 803 |
+
else:
|
| 804 |
+
self.remaining_degree[v] -= 1
|
| 805 |
+
|
| 806 |
+
def p(self, u, v):
|
| 807 |
+
# degree probability
|
| 808 |
+
return 1 - self.degree[u] * self.degree[v] / (4.0 * self.m)
|
| 809 |
+
|
| 810 |
+
def q(self, u, v):
|
| 811 |
+
# remaining degree probability
|
| 812 |
+
norm = max(self.remaining_degree.values()) ** 2
|
| 813 |
+
return self.remaining_degree[u] * self.remaining_degree[v] / norm
|
| 814 |
+
|
| 815 |
+
def suitable_edge(self):
|
| 816 |
+
"""Returns True if and only if an arbitrary remaining node can
|
| 817 |
+
potentially be joined with some other remaining node.
|
| 818 |
+
|
| 819 |
+
"""
|
| 820 |
+
nodes = iter(self.remaining_degree)
|
| 821 |
+
u = next(nodes)
|
| 822 |
+
return any(v not in self.graph[u] for v in nodes)
|
| 823 |
+
|
| 824 |
+
def phase1(self):
|
| 825 |
+
# choose node pairs from (degree) weighted distribution
|
| 826 |
+
rem_deg = self.remaining_degree
|
| 827 |
+
while sum(rem_deg.values()) >= 2 * self.dmax**2:
|
| 828 |
+
u, v = sorted(random_weighted_sample(rem_deg, 2, self.rng))
|
| 829 |
+
if self.graph.has_edge(u, v):
|
| 830 |
+
continue
|
| 831 |
+
if self.rng.random() < self.p(u, v): # accept edge
|
| 832 |
+
self.graph.add_edge(u, v)
|
| 833 |
+
self.update_remaining(u, v)
|
| 834 |
+
|
| 835 |
+
def phase2(self):
|
| 836 |
+
# choose remaining nodes uniformly at random and use rejection sampling
|
| 837 |
+
remaining_deg = self.remaining_degree
|
| 838 |
+
rng = self.rng
|
| 839 |
+
while len(remaining_deg) >= 2 * self.dmax:
|
| 840 |
+
while True:
|
| 841 |
+
u, v = sorted(rng.sample(list(remaining_deg.keys()), 2))
|
| 842 |
+
if self.graph.has_edge(u, v):
|
| 843 |
+
continue
|
| 844 |
+
if rng.random() < self.q(u, v):
|
| 845 |
+
break
|
| 846 |
+
if rng.random() < self.p(u, v): # accept edge
|
| 847 |
+
self.graph.add_edge(u, v)
|
| 848 |
+
self.update_remaining(u, v)
|
| 849 |
+
|
| 850 |
+
def phase3(self):
|
| 851 |
+
# build potential remaining edges and choose with rejection sampling
|
| 852 |
+
potential_edges = combinations(self.remaining_degree, 2)
|
| 853 |
+
# build auxiliary graph of potential edges not already in graph
|
| 854 |
+
H = nx.Graph(
|
| 855 |
+
[(u, v) for (u, v) in potential_edges if not self.graph.has_edge(u, v)]
|
| 856 |
+
)
|
| 857 |
+
rng = self.rng
|
| 858 |
+
while self.remaining_degree:
|
| 859 |
+
if not self.suitable_edge():
|
| 860 |
+
raise nx.NetworkXUnfeasible("no suitable edges left")
|
| 861 |
+
while True:
|
| 862 |
+
u, v = sorted(rng.choice(list(H.edges())))
|
| 863 |
+
if rng.random() < self.q(u, v):
|
| 864 |
+
break
|
| 865 |
+
if rng.random() < self.p(u, v): # accept edge
|
| 866 |
+
self.graph.add_edge(u, v)
|
| 867 |
+
self.update_remaining(u, v, aux_graph=H)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/ego.py
ADDED
|
@@ -0,0 +1,66 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
"""
|
| 2 |
+
Ego graph.
|
| 3 |
+
"""
|
| 4 |
+
|
| 5 |
+
__all__ = ["ego_graph"]
|
| 6 |
+
|
| 7 |
+
import networkx as nx
|
| 8 |
+
|
| 9 |
+
|
| 10 |
+
@nx._dispatchable(preserve_all_attrs=True, returns_graph=True)
|
| 11 |
+
def ego_graph(G, n, radius=1, center=True, undirected=False, distance=None):
|
| 12 |
+
"""Returns induced subgraph of neighbors centered at node n within
|
| 13 |
+
a given radius.
|
| 14 |
+
|
| 15 |
+
Parameters
|
| 16 |
+
----------
|
| 17 |
+
G : graph
|
| 18 |
+
A NetworkX Graph or DiGraph
|
| 19 |
+
|
| 20 |
+
n : node
|
| 21 |
+
A single node
|
| 22 |
+
|
| 23 |
+
radius : number, optional
|
| 24 |
+
Include all neighbors of distance<=radius from n.
|
| 25 |
+
|
| 26 |
+
center : bool, optional
|
| 27 |
+
If False, do not include center node in graph
|
| 28 |
+
|
| 29 |
+
undirected : bool, optional
|
| 30 |
+
If True use both in- and out-neighbors of directed graphs.
|
| 31 |
+
|
| 32 |
+
distance : key, optional
|
| 33 |
+
Use specified edge data key as distance. For example, setting
|
| 34 |
+
distance='weight' will use the edge weight to measure the
|
| 35 |
+
distance from the node n.
|
| 36 |
+
|
| 37 |
+
Notes
|
| 38 |
+
-----
|
| 39 |
+
For directed graphs D this produces the "out" neighborhood
|
| 40 |
+
or successors. If you want the neighborhood of predecessors
|
| 41 |
+
first reverse the graph with D.reverse(). If you want both
|
| 42 |
+
directions use the keyword argument undirected=True.
|
| 43 |
+
|
| 44 |
+
Node, edge, and graph attributes are copied to the returned subgraph.
|
| 45 |
+
"""
|
| 46 |
+
if undirected:
|
| 47 |
+
if distance is not None:
|
| 48 |
+
sp, _ = nx.single_source_dijkstra(
|
| 49 |
+
G.to_undirected(), n, cutoff=radius, weight=distance
|
| 50 |
+
)
|
| 51 |
+
else:
|
| 52 |
+
sp = dict(
|
| 53 |
+
nx.single_source_shortest_path_length(
|
| 54 |
+
G.to_undirected(), n, cutoff=radius
|
| 55 |
+
)
|
| 56 |
+
)
|
| 57 |
+
else:
|
| 58 |
+
if distance is not None:
|
| 59 |
+
sp, _ = nx.single_source_dijkstra(G, n, cutoff=radius, weight=distance)
|
| 60 |
+
else:
|
| 61 |
+
sp = dict(nx.single_source_shortest_path_length(G, n, cutoff=radius))
|
| 62 |
+
|
| 63 |
+
H = G.subgraph(sp).copy()
|
| 64 |
+
if not center:
|
| 65 |
+
H.remove_node(n)
|
| 66 |
+
return H
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/expanders.py
ADDED
|
@@ -0,0 +1,474 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
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|
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|
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|
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|
|
|
|
|
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|
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|
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|
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|
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|
|
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|
| 1 |
+
"""Provides explicit constructions of expander graphs."""
|
| 2 |
+
|
| 3 |
+
import itertools
|
| 4 |
+
|
| 5 |
+
import networkx as nx
|
| 6 |
+
|
| 7 |
+
__all__ = [
|
| 8 |
+
"margulis_gabber_galil_graph",
|
| 9 |
+
"chordal_cycle_graph",
|
| 10 |
+
"paley_graph",
|
| 11 |
+
"maybe_regular_expander",
|
| 12 |
+
"is_regular_expander",
|
| 13 |
+
"random_regular_expander_graph",
|
| 14 |
+
]
|
| 15 |
+
|
| 16 |
+
|
| 17 |
+
# Other discrete torus expanders can be constructed by using the following edge
|
| 18 |
+
# sets. For more information, see Chapter 4, "Expander Graphs", in
|
| 19 |
+
# "Pseudorandomness", by Salil Vadhan.
|
| 20 |
+
#
|
| 21 |
+
# For a directed expander, add edges from (x, y) to:
|
| 22 |
+
#
|
| 23 |
+
# (x, y),
|
| 24 |
+
# ((x + 1) % n, y),
|
| 25 |
+
# (x, (y + 1) % n),
|
| 26 |
+
# (x, (x + y) % n),
|
| 27 |
+
# (-y % n, x)
|
| 28 |
+
#
|
| 29 |
+
# For an undirected expander, add the reverse edges.
|
| 30 |
+
#
|
| 31 |
+
# Also appearing in the paper of Gabber and Galil:
|
| 32 |
+
#
|
| 33 |
+
# (x, y),
|
| 34 |
+
# (x, (x + y) % n),
|
| 35 |
+
# (x, (x + y + 1) % n),
|
| 36 |
+
# ((x + y) % n, y),
|
| 37 |
+
# ((x + y + 1) % n, y)
|
| 38 |
+
#
|
| 39 |
+
# and:
|
| 40 |
+
#
|
| 41 |
+
# (x, y),
|
| 42 |
+
# ((x + 2*y) % n, y),
|
| 43 |
+
# ((x + (2*y + 1)) % n, y),
|
| 44 |
+
# ((x + (2*y + 2)) % n, y),
|
| 45 |
+
# (x, (y + 2*x) % n),
|
| 46 |
+
# (x, (y + (2*x + 1)) % n),
|
| 47 |
+
# (x, (y + (2*x + 2)) % n),
|
| 48 |
+
#
|
| 49 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 50 |
+
def margulis_gabber_galil_graph(n, create_using=None):
|
| 51 |
+
r"""Returns the Margulis-Gabber-Galil undirected MultiGraph on `n^2` nodes.
|
| 52 |
+
|
| 53 |
+
The undirected MultiGraph is regular with degree `8`. Nodes are integer
|
| 54 |
+
pairs. The second-largest eigenvalue of the adjacency matrix of the graph
|
| 55 |
+
is at most `5 \sqrt{2}`, regardless of `n`.
|
| 56 |
+
|
| 57 |
+
Parameters
|
| 58 |
+
----------
|
| 59 |
+
n : int
|
| 60 |
+
Determines the number of nodes in the graph: `n^2`.
|
| 61 |
+
create_using : NetworkX graph constructor, optional (default MultiGraph)
|
| 62 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 63 |
+
|
| 64 |
+
Returns
|
| 65 |
+
-------
|
| 66 |
+
G : graph
|
| 67 |
+
The constructed undirected multigraph.
|
| 68 |
+
|
| 69 |
+
Raises
|
| 70 |
+
------
|
| 71 |
+
NetworkXError
|
| 72 |
+
If the graph is directed or not a multigraph.
|
| 73 |
+
|
| 74 |
+
"""
|
| 75 |
+
G = nx.empty_graph(0, create_using, default=nx.MultiGraph)
|
| 76 |
+
if G.is_directed() or not G.is_multigraph():
|
| 77 |
+
msg = "`create_using` must be an undirected multigraph."
|
| 78 |
+
raise nx.NetworkXError(msg)
|
| 79 |
+
|
| 80 |
+
for x, y in itertools.product(range(n), repeat=2):
|
| 81 |
+
for u, v in (
|
| 82 |
+
((x + 2 * y) % n, y),
|
| 83 |
+
((x + (2 * y + 1)) % n, y),
|
| 84 |
+
(x, (y + 2 * x) % n),
|
| 85 |
+
(x, (y + (2 * x + 1)) % n),
|
| 86 |
+
):
|
| 87 |
+
G.add_edge((x, y), (u, v))
|
| 88 |
+
G.graph["name"] = f"margulis_gabber_galil_graph({n})"
|
| 89 |
+
return G
|
| 90 |
+
|
| 91 |
+
|
| 92 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 93 |
+
def chordal_cycle_graph(p, create_using=None):
|
| 94 |
+
"""Returns the chordal cycle graph on `p` nodes.
|
| 95 |
+
|
| 96 |
+
The returned graph is a cycle graph on `p` nodes with chords joining each
|
| 97 |
+
vertex `x` to its inverse modulo `p`. This graph is a (mildly explicit)
|
| 98 |
+
3-regular expander [1]_.
|
| 99 |
+
|
| 100 |
+
`p` *must* be a prime number.
|
| 101 |
+
|
| 102 |
+
Parameters
|
| 103 |
+
----------
|
| 104 |
+
p : a prime number
|
| 105 |
+
|
| 106 |
+
The number of vertices in the graph. This also indicates where the
|
| 107 |
+
chordal edges in the cycle will be created.
|
| 108 |
+
|
| 109 |
+
create_using : NetworkX graph constructor, optional (default=nx.Graph)
|
| 110 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 111 |
+
|
| 112 |
+
Returns
|
| 113 |
+
-------
|
| 114 |
+
G : graph
|
| 115 |
+
The constructed undirected multigraph.
|
| 116 |
+
|
| 117 |
+
Raises
|
| 118 |
+
------
|
| 119 |
+
NetworkXError
|
| 120 |
+
|
| 121 |
+
If `create_using` indicates directed or not a multigraph.
|
| 122 |
+
|
| 123 |
+
References
|
| 124 |
+
----------
|
| 125 |
+
|
| 126 |
+
.. [1] Theorem 4.4.2 in A. Lubotzky. "Discrete groups, expanding graphs and
|
| 127 |
+
invariant measures", volume 125 of Progress in Mathematics.
|
| 128 |
+
Birkhäuser Verlag, Basel, 1994.
|
| 129 |
+
|
| 130 |
+
"""
|
| 131 |
+
G = nx.empty_graph(0, create_using, default=nx.MultiGraph)
|
| 132 |
+
if G.is_directed() or not G.is_multigraph():
|
| 133 |
+
msg = "`create_using` must be an undirected multigraph."
|
| 134 |
+
raise nx.NetworkXError(msg)
|
| 135 |
+
|
| 136 |
+
for x in range(p):
|
| 137 |
+
left = (x - 1) % p
|
| 138 |
+
right = (x + 1) % p
|
| 139 |
+
# Here we apply Fermat's Little Theorem to compute the multiplicative
|
| 140 |
+
# inverse of x in Z/pZ. By Fermat's Little Theorem,
|
| 141 |
+
#
|
| 142 |
+
# x^p = x (mod p)
|
| 143 |
+
#
|
| 144 |
+
# Therefore,
|
| 145 |
+
#
|
| 146 |
+
# x * x^(p - 2) = 1 (mod p)
|
| 147 |
+
#
|
| 148 |
+
# The number 0 is a special case: we just let its inverse be itself.
|
| 149 |
+
chord = pow(x, p - 2, p) if x > 0 else 0
|
| 150 |
+
for y in (left, right, chord):
|
| 151 |
+
G.add_edge(x, y)
|
| 152 |
+
G.graph["name"] = f"chordal_cycle_graph({p})"
|
| 153 |
+
return G
|
| 154 |
+
|
| 155 |
+
|
| 156 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 157 |
+
def paley_graph(p, create_using=None):
|
| 158 |
+
r"""Returns the Paley $\frac{(p-1)}{2}$ -regular graph on $p$ nodes.
|
| 159 |
+
|
| 160 |
+
The returned graph is a graph on $\mathbb{Z}/p\mathbb{Z}$ with edges between $x$ and $y$
|
| 161 |
+
if and only if $x-y$ is a nonzero square in $\mathbb{Z}/p\mathbb{Z}$.
|
| 162 |
+
|
| 163 |
+
If $p \equiv 1 \pmod 4$, $-1$ is a square in $\mathbb{Z}/p\mathbb{Z}$ and therefore $x-y$ is a square if and
|
| 164 |
+
only if $y-x$ is also a square, i.e the edges in the Paley graph are symmetric.
|
| 165 |
+
|
| 166 |
+
If $p \equiv 3 \pmod 4$, $-1$ is not a square in $\mathbb{Z}/p\mathbb{Z}$ and therefore either $x-y$ or $y-x$
|
| 167 |
+
is a square in $\mathbb{Z}/p\mathbb{Z}$ but not both.
|
| 168 |
+
|
| 169 |
+
Note that a more general definition of Paley graphs extends this construction
|
| 170 |
+
to graphs over $q=p^n$ vertices, by using the finite field $F_q$ instead of $\mathbb{Z}/p\mathbb{Z}$.
|
| 171 |
+
This construction requires to compute squares in general finite fields and is
|
| 172 |
+
not what is implemented here (i.e `paley_graph(25)` does not return the true
|
| 173 |
+
Paley graph associated with $5^2$).
|
| 174 |
+
|
| 175 |
+
Parameters
|
| 176 |
+
----------
|
| 177 |
+
p : int, an odd prime number.
|
| 178 |
+
|
| 179 |
+
create_using : NetworkX graph constructor, optional (default=nx.Graph)
|
| 180 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 181 |
+
|
| 182 |
+
Returns
|
| 183 |
+
-------
|
| 184 |
+
G : graph
|
| 185 |
+
The constructed directed graph.
|
| 186 |
+
|
| 187 |
+
Raises
|
| 188 |
+
------
|
| 189 |
+
NetworkXError
|
| 190 |
+
If the graph is a multigraph.
|
| 191 |
+
|
| 192 |
+
References
|
| 193 |
+
----------
|
| 194 |
+
Chapter 13 in B. Bollobas, Random Graphs. Second edition.
|
| 195 |
+
Cambridge Studies in Advanced Mathematics, 73.
|
| 196 |
+
Cambridge University Press, Cambridge (2001).
|
| 197 |
+
"""
|
| 198 |
+
G = nx.empty_graph(0, create_using, default=nx.DiGraph)
|
| 199 |
+
if G.is_multigraph():
|
| 200 |
+
msg = "`create_using` cannot be a multigraph."
|
| 201 |
+
raise nx.NetworkXError(msg)
|
| 202 |
+
|
| 203 |
+
# Compute the squares in Z/pZ.
|
| 204 |
+
# Make it a set to uniquify (there are exactly (p-1)/2 squares in Z/pZ
|
| 205 |
+
# when is prime).
|
| 206 |
+
square_set = {(x**2) % p for x in range(1, p) if (x**2) % p != 0}
|
| 207 |
+
|
| 208 |
+
for x in range(p):
|
| 209 |
+
for x2 in square_set:
|
| 210 |
+
G.add_edge(x, (x + x2) % p)
|
| 211 |
+
G.graph["name"] = f"paley({p})"
|
| 212 |
+
return G
|
| 213 |
+
|
| 214 |
+
|
| 215 |
+
@nx.utils.decorators.np_random_state("seed")
|
| 216 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 217 |
+
def maybe_regular_expander(n, d, *, create_using=None, max_tries=100, seed=None):
|
| 218 |
+
r"""Utility for creating a random regular expander.
|
| 219 |
+
|
| 220 |
+
Returns a random $d$-regular graph on $n$ nodes which is an expander
|
| 221 |
+
graph with very good probability.
|
| 222 |
+
|
| 223 |
+
Parameters
|
| 224 |
+
----------
|
| 225 |
+
n : int
|
| 226 |
+
The number of nodes.
|
| 227 |
+
d : int
|
| 228 |
+
The degree of each node.
|
| 229 |
+
create_using : Graph Instance or Constructor
|
| 230 |
+
Indicator of type of graph to return.
|
| 231 |
+
If a Graph-type instance, then clear and use it.
|
| 232 |
+
If a constructor, call it to create an empty graph.
|
| 233 |
+
Use the Graph constructor by default.
|
| 234 |
+
max_tries : int. (default: 100)
|
| 235 |
+
The number of allowed loops when generating each independent cycle
|
| 236 |
+
seed : (default: None)
|
| 237 |
+
Seed used to set random number generation state. See :ref`Randomness<randomness>`.
|
| 238 |
+
|
| 239 |
+
Notes
|
| 240 |
+
-----
|
| 241 |
+
The nodes are numbered from $0$ to $n - 1$.
|
| 242 |
+
|
| 243 |
+
The graph is generated by taking $d / 2$ random independent cycles.
|
| 244 |
+
|
| 245 |
+
Joel Friedman proved that in this model the resulting
|
| 246 |
+
graph is an expander with probability
|
| 247 |
+
$1 - O(n^{-\tau})$ where $\tau = \lceil (\sqrt{d - 1}) / 2 \rceil - 1$. [1]_
|
| 248 |
+
|
| 249 |
+
Examples
|
| 250 |
+
--------
|
| 251 |
+
>>> G = nx.maybe_regular_expander(n=200, d=6, seed=8020)
|
| 252 |
+
|
| 253 |
+
Returns
|
| 254 |
+
-------
|
| 255 |
+
G : graph
|
| 256 |
+
The constructed undirected graph.
|
| 257 |
+
|
| 258 |
+
Raises
|
| 259 |
+
------
|
| 260 |
+
NetworkXError
|
| 261 |
+
If $d % 2 != 0$ as the degree must be even.
|
| 262 |
+
If $n - 1$ is less than $ 2d $ as the graph is complete at most.
|
| 263 |
+
If max_tries is reached
|
| 264 |
+
|
| 265 |
+
See Also
|
| 266 |
+
--------
|
| 267 |
+
is_regular_expander
|
| 268 |
+
random_regular_expander_graph
|
| 269 |
+
|
| 270 |
+
References
|
| 271 |
+
----------
|
| 272 |
+
.. [1] Joel Friedman,
|
| 273 |
+
A Proof of Alon’s Second Eigenvalue Conjecture and Related Problems, 2004
|
| 274 |
+
https://arxiv.org/abs/cs/0405020
|
| 275 |
+
|
| 276 |
+
"""
|
| 277 |
+
|
| 278 |
+
import numpy as np
|
| 279 |
+
|
| 280 |
+
if n < 1:
|
| 281 |
+
raise nx.NetworkXError("n must be a positive integer")
|
| 282 |
+
|
| 283 |
+
if not (d >= 2):
|
| 284 |
+
raise nx.NetworkXError("d must be greater than or equal to 2")
|
| 285 |
+
|
| 286 |
+
if not (d % 2 == 0):
|
| 287 |
+
raise nx.NetworkXError("d must be even")
|
| 288 |
+
|
| 289 |
+
if not (n - 1 >= d):
|
| 290 |
+
raise nx.NetworkXError(
|
| 291 |
+
f"Need n-1>= d to have room for {d//2} independent cycles with {n} nodes"
|
| 292 |
+
)
|
| 293 |
+
|
| 294 |
+
G = nx.empty_graph(n, create_using)
|
| 295 |
+
|
| 296 |
+
if n < 2:
|
| 297 |
+
return G
|
| 298 |
+
|
| 299 |
+
cycles = []
|
| 300 |
+
edges = set()
|
| 301 |
+
|
| 302 |
+
# Create d / 2 cycles
|
| 303 |
+
for i in range(d // 2):
|
| 304 |
+
iterations = max_tries
|
| 305 |
+
# Make sure the cycles are independent to have a regular graph
|
| 306 |
+
while len(edges) != (i + 1) * n:
|
| 307 |
+
iterations -= 1
|
| 308 |
+
# Faster than random.permutation(n) since there are only
|
| 309 |
+
# (n-1)! distinct cycles against n! permutations of size n
|
| 310 |
+
cycle = seed.permutation(n - 1).tolist()
|
| 311 |
+
cycle.append(n - 1)
|
| 312 |
+
|
| 313 |
+
new_edges = {
|
| 314 |
+
(u, v)
|
| 315 |
+
for u, v in nx.utils.pairwise(cycle, cyclic=True)
|
| 316 |
+
if (u, v) not in edges and (v, u) not in edges
|
| 317 |
+
}
|
| 318 |
+
# If the new cycle has no edges in common with previous cycles
|
| 319 |
+
# then add it to the list otherwise try again
|
| 320 |
+
if len(new_edges) == n:
|
| 321 |
+
cycles.append(cycle)
|
| 322 |
+
edges.update(new_edges)
|
| 323 |
+
|
| 324 |
+
if iterations == 0:
|
| 325 |
+
raise nx.NetworkXError("Too many iterations in maybe_regular_expander")
|
| 326 |
+
|
| 327 |
+
G.add_edges_from(edges)
|
| 328 |
+
|
| 329 |
+
return G
|
| 330 |
+
|
| 331 |
+
|
| 332 |
+
@nx.utils.not_implemented_for("directed")
|
| 333 |
+
@nx.utils.not_implemented_for("multigraph")
|
| 334 |
+
@nx._dispatchable(preserve_edge_attrs={"G": {"weight": 1}})
|
| 335 |
+
def is_regular_expander(G, *, epsilon=0):
|
| 336 |
+
r"""Determines whether the graph G is a regular expander. [1]_
|
| 337 |
+
|
| 338 |
+
An expander graph is a sparse graph with strong connectivity properties.
|
| 339 |
+
|
| 340 |
+
More precisely, this helper checks whether the graph is a
|
| 341 |
+
regular $(n, d, \lambda)$-expander with $\lambda$ close to
|
| 342 |
+
the Alon-Boppana bound and given by
|
| 343 |
+
$\lambda = 2 \sqrt{d - 1} + \epsilon$. [2]_
|
| 344 |
+
|
| 345 |
+
In the case where $\epsilon = 0$ then if the graph successfully passes the test
|
| 346 |
+
it is a Ramanujan graph. [3]_
|
| 347 |
+
|
| 348 |
+
A Ramanujan graph has spectral gap almost as large as possible, which makes them
|
| 349 |
+
excellent expanders.
|
| 350 |
+
|
| 351 |
+
Parameters
|
| 352 |
+
----------
|
| 353 |
+
G : NetworkX graph
|
| 354 |
+
epsilon : int, float, default=0
|
| 355 |
+
|
| 356 |
+
Returns
|
| 357 |
+
-------
|
| 358 |
+
bool
|
| 359 |
+
Whether the given graph is a regular $(n, d, \lambda)$-expander
|
| 360 |
+
where $\lambda = 2 \sqrt{d - 1} + \epsilon$.
|
| 361 |
+
|
| 362 |
+
Examples
|
| 363 |
+
--------
|
| 364 |
+
>>> G = nx.random_regular_expander_graph(20, 4)
|
| 365 |
+
>>> nx.is_regular_expander(G)
|
| 366 |
+
True
|
| 367 |
+
|
| 368 |
+
See Also
|
| 369 |
+
--------
|
| 370 |
+
maybe_regular_expander
|
| 371 |
+
random_regular_expander_graph
|
| 372 |
+
|
| 373 |
+
References
|
| 374 |
+
----------
|
| 375 |
+
.. [1] Expander graph, https://en.wikipedia.org/wiki/Expander_graph
|
| 376 |
+
.. [2] Alon-Boppana bound, https://en.wikipedia.org/wiki/Alon%E2%80%93Boppana_bound
|
| 377 |
+
.. [3] Ramanujan graphs, https://en.wikipedia.org/wiki/Ramanujan_graph
|
| 378 |
+
|
| 379 |
+
"""
|
| 380 |
+
|
| 381 |
+
import numpy as np
|
| 382 |
+
from scipy.sparse.linalg import eigsh
|
| 383 |
+
|
| 384 |
+
if epsilon < 0:
|
| 385 |
+
raise nx.NetworkXError("epsilon must be non negative")
|
| 386 |
+
|
| 387 |
+
if not nx.is_regular(G):
|
| 388 |
+
return False
|
| 389 |
+
|
| 390 |
+
_, d = nx.utils.arbitrary_element(G.degree)
|
| 391 |
+
|
| 392 |
+
A = nx.adjacency_matrix(G, dtype=float)
|
| 393 |
+
lams = eigsh(A, which="LM", k=2, return_eigenvectors=False)
|
| 394 |
+
|
| 395 |
+
# lambda2 is the second biggest eigenvalue
|
| 396 |
+
lambda2 = min(lams)
|
| 397 |
+
|
| 398 |
+
# Use bool() to convert numpy scalar to Python Boolean
|
| 399 |
+
return bool(abs(lambda2) < 2 ** np.sqrt(d - 1) + epsilon)
|
| 400 |
+
|
| 401 |
+
|
| 402 |
+
@nx.utils.decorators.np_random_state("seed")
|
| 403 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 404 |
+
def random_regular_expander_graph(
|
| 405 |
+
n, d, *, epsilon=0, create_using=None, max_tries=100, seed=None
|
| 406 |
+
):
|
| 407 |
+
r"""Returns a random regular expander graph on $n$ nodes with degree $d$.
|
| 408 |
+
|
| 409 |
+
An expander graph is a sparse graph with strong connectivity properties. [1]_
|
| 410 |
+
|
| 411 |
+
More precisely the returned graph is a $(n, d, \lambda)$-expander with
|
| 412 |
+
$\lambda = 2 \sqrt{d - 1} + \epsilon$, close to the Alon-Boppana bound. [2]_
|
| 413 |
+
|
| 414 |
+
In the case where $\epsilon = 0$ it returns a Ramanujan graph.
|
| 415 |
+
A Ramanujan graph has spectral gap almost as large as possible,
|
| 416 |
+
which makes them excellent expanders. [3]_
|
| 417 |
+
|
| 418 |
+
Parameters
|
| 419 |
+
----------
|
| 420 |
+
n : int
|
| 421 |
+
The number of nodes.
|
| 422 |
+
d : int
|
| 423 |
+
The degree of each node.
|
| 424 |
+
epsilon : int, float, default=0
|
| 425 |
+
max_tries : int, (default: 100)
|
| 426 |
+
The number of allowed loops, also used in the maybe_regular_expander utility
|
| 427 |
+
seed : (default: None)
|
| 428 |
+
Seed used to set random number generation state. See :ref`Randomness<randomness>`.
|
| 429 |
+
|
| 430 |
+
Raises
|
| 431 |
+
------
|
| 432 |
+
NetworkXError
|
| 433 |
+
If max_tries is reached
|
| 434 |
+
|
| 435 |
+
Examples
|
| 436 |
+
--------
|
| 437 |
+
>>> G = nx.random_regular_expander_graph(20, 4)
|
| 438 |
+
>>> nx.is_regular_expander(G)
|
| 439 |
+
True
|
| 440 |
+
|
| 441 |
+
Notes
|
| 442 |
+
-----
|
| 443 |
+
This loops over `maybe_regular_expander` and can be slow when
|
| 444 |
+
$n$ is too big or $\epsilon$ too small.
|
| 445 |
+
|
| 446 |
+
See Also
|
| 447 |
+
--------
|
| 448 |
+
maybe_regular_expander
|
| 449 |
+
is_regular_expander
|
| 450 |
+
|
| 451 |
+
References
|
| 452 |
+
----------
|
| 453 |
+
.. [1] Expander graph, https://en.wikipedia.org/wiki/Expander_graph
|
| 454 |
+
.. [2] Alon-Boppana bound, https://en.wikipedia.org/wiki/Alon%E2%80%93Boppana_bound
|
| 455 |
+
.. [3] Ramanujan graphs, https://en.wikipedia.org/wiki/Ramanujan_graph
|
| 456 |
+
|
| 457 |
+
"""
|
| 458 |
+
G = maybe_regular_expander(
|
| 459 |
+
n, d, create_using=create_using, max_tries=max_tries, seed=seed
|
| 460 |
+
)
|
| 461 |
+
iterations = max_tries
|
| 462 |
+
|
| 463 |
+
while not is_regular_expander(G, epsilon=epsilon):
|
| 464 |
+
iterations -= 1
|
| 465 |
+
G = maybe_regular_expander(
|
| 466 |
+
n=n, d=d, create_using=create_using, max_tries=max_tries, seed=seed
|
| 467 |
+
)
|
| 468 |
+
|
| 469 |
+
if iterations == 0:
|
| 470 |
+
raise nx.NetworkXError(
|
| 471 |
+
"Too many iterations in random_regular_expander_graph"
|
| 472 |
+
)
|
| 473 |
+
|
| 474 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/geometric.py
ADDED
|
@@ -0,0 +1,1048 @@
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|
|
| 1 |
+
"""Generators for geometric graphs."""
|
| 2 |
+
|
| 3 |
+
import math
|
| 4 |
+
from bisect import bisect_left
|
| 5 |
+
from itertools import accumulate, combinations, product
|
| 6 |
+
|
| 7 |
+
import networkx as nx
|
| 8 |
+
from networkx.utils import py_random_state
|
| 9 |
+
|
| 10 |
+
__all__ = [
|
| 11 |
+
"geometric_edges",
|
| 12 |
+
"geographical_threshold_graph",
|
| 13 |
+
"navigable_small_world_graph",
|
| 14 |
+
"random_geometric_graph",
|
| 15 |
+
"soft_random_geometric_graph",
|
| 16 |
+
"thresholded_random_geometric_graph",
|
| 17 |
+
"waxman_graph",
|
| 18 |
+
"geometric_soft_configuration_graph",
|
| 19 |
+
]
|
| 20 |
+
|
| 21 |
+
|
| 22 |
+
@nx._dispatchable(node_attrs="pos_name")
|
| 23 |
+
def geometric_edges(G, radius, p=2, *, pos_name="pos"):
|
| 24 |
+
"""Returns edge list of node pairs within `radius` of each other.
|
| 25 |
+
|
| 26 |
+
Parameters
|
| 27 |
+
----------
|
| 28 |
+
G : networkx graph
|
| 29 |
+
The graph from which to generate the edge list. The nodes in `G` should
|
| 30 |
+
have an attribute ``pos`` corresponding to the node position, which is
|
| 31 |
+
used to compute the distance to other nodes.
|
| 32 |
+
radius : scalar
|
| 33 |
+
The distance threshold. Edges are included in the edge list if the
|
| 34 |
+
distance between the two nodes is less than `radius`.
|
| 35 |
+
pos_name : string, default="pos"
|
| 36 |
+
The name of the node attribute which represents the position of each
|
| 37 |
+
node in 2D coordinates. Every node in the Graph must have this attribute.
|
| 38 |
+
p : scalar, default=2
|
| 39 |
+
The `Minkowski distance metric
|
| 40 |
+
<https://en.wikipedia.org/wiki/Minkowski_distance>`_ used to compute
|
| 41 |
+
distances. The default value is 2, i.e. Euclidean distance.
|
| 42 |
+
|
| 43 |
+
Returns
|
| 44 |
+
-------
|
| 45 |
+
edges : list
|
| 46 |
+
List of edges whose distances are less than `radius`
|
| 47 |
+
|
| 48 |
+
Notes
|
| 49 |
+
-----
|
| 50 |
+
Radius uses Minkowski distance metric `p`.
|
| 51 |
+
If scipy is available, `scipy.spatial.cKDTree` is used to speed computation.
|
| 52 |
+
|
| 53 |
+
Examples
|
| 54 |
+
--------
|
| 55 |
+
Create a graph with nodes that have a "pos" attribute representing 2D
|
| 56 |
+
coordinates.
|
| 57 |
+
|
| 58 |
+
>>> G = nx.Graph()
|
| 59 |
+
>>> G.add_nodes_from(
|
| 60 |
+
... [
|
| 61 |
+
... (0, {"pos": (0, 0)}),
|
| 62 |
+
... (1, {"pos": (3, 0)}),
|
| 63 |
+
... (2, {"pos": (8, 0)}),
|
| 64 |
+
... ]
|
| 65 |
+
... )
|
| 66 |
+
>>> nx.geometric_edges(G, radius=1)
|
| 67 |
+
[]
|
| 68 |
+
>>> nx.geometric_edges(G, radius=4)
|
| 69 |
+
[(0, 1)]
|
| 70 |
+
>>> nx.geometric_edges(G, radius=6)
|
| 71 |
+
[(0, 1), (1, 2)]
|
| 72 |
+
>>> nx.geometric_edges(G, radius=9)
|
| 73 |
+
[(0, 1), (0, 2), (1, 2)]
|
| 74 |
+
"""
|
| 75 |
+
# Input validation - every node must have a "pos" attribute
|
| 76 |
+
for n, pos in G.nodes(data=pos_name):
|
| 77 |
+
if pos is None:
|
| 78 |
+
raise nx.NetworkXError(
|
| 79 |
+
f"Node {n} (and all nodes) must have a '{pos_name}' attribute."
|
| 80 |
+
)
|
| 81 |
+
|
| 82 |
+
# NOTE: See _geometric_edges for the actual implementation. The reason this
|
| 83 |
+
# is split into two functions is to avoid the overhead of input validation
|
| 84 |
+
# every time the function is called internally in one of the other
|
| 85 |
+
# geometric generators
|
| 86 |
+
return _geometric_edges(G, radius, p, pos_name)
|
| 87 |
+
|
| 88 |
+
|
| 89 |
+
def _geometric_edges(G, radius, p, pos_name):
|
| 90 |
+
"""
|
| 91 |
+
Implements `geometric_edges` without input validation. See `geometric_edges`
|
| 92 |
+
for complete docstring.
|
| 93 |
+
"""
|
| 94 |
+
nodes_pos = G.nodes(data=pos_name)
|
| 95 |
+
try:
|
| 96 |
+
import scipy as sp
|
| 97 |
+
except ImportError:
|
| 98 |
+
# no scipy KDTree so compute by for-loop
|
| 99 |
+
radius_p = radius**p
|
| 100 |
+
edges = [
|
| 101 |
+
(u, v)
|
| 102 |
+
for (u, pu), (v, pv) in combinations(nodes_pos, 2)
|
| 103 |
+
if sum(abs(a - b) ** p for a, b in zip(pu, pv)) <= radius_p
|
| 104 |
+
]
|
| 105 |
+
return edges
|
| 106 |
+
# scipy KDTree is available
|
| 107 |
+
nodes, coords = list(zip(*nodes_pos))
|
| 108 |
+
kdtree = sp.spatial.cKDTree(coords) # Cannot provide generator.
|
| 109 |
+
edge_indexes = kdtree.query_pairs(radius, p)
|
| 110 |
+
edges = [(nodes[u], nodes[v]) for u, v in sorted(edge_indexes)]
|
| 111 |
+
return edges
|
| 112 |
+
|
| 113 |
+
|
| 114 |
+
@py_random_state(5)
|
| 115 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 116 |
+
def random_geometric_graph(
|
| 117 |
+
n, radius, dim=2, pos=None, p=2, seed=None, *, pos_name="pos"
|
| 118 |
+
):
|
| 119 |
+
"""Returns a random geometric graph in the unit cube of dimensions `dim`.
|
| 120 |
+
|
| 121 |
+
The random geometric graph model places `n` nodes uniformly at
|
| 122 |
+
random in the unit cube. Two nodes are joined by an edge if the
|
| 123 |
+
distance between the nodes is at most `radius`.
|
| 124 |
+
|
| 125 |
+
Edges are determined using a KDTree when SciPy is available.
|
| 126 |
+
This reduces the time complexity from $O(n^2)$ to $O(n)$.
|
| 127 |
+
|
| 128 |
+
Parameters
|
| 129 |
+
----------
|
| 130 |
+
n : int or iterable
|
| 131 |
+
Number of nodes or iterable of nodes
|
| 132 |
+
radius: float
|
| 133 |
+
Distance threshold value
|
| 134 |
+
dim : int, optional
|
| 135 |
+
Dimension of graph
|
| 136 |
+
pos : dict, optional
|
| 137 |
+
A dictionary keyed by node with node positions as values.
|
| 138 |
+
p : float, optional
|
| 139 |
+
Which Minkowski distance metric to use. `p` has to meet the condition
|
| 140 |
+
``1 <= p <= infinity``.
|
| 141 |
+
|
| 142 |
+
If this argument is not specified, the :math:`L^2` metric
|
| 143 |
+
(the Euclidean distance metric), p = 2 is used.
|
| 144 |
+
This should not be confused with the `p` of an Erdős-Rényi random
|
| 145 |
+
graph, which represents probability.
|
| 146 |
+
seed : integer, random_state, or None (default)
|
| 147 |
+
Indicator of random number generation state.
|
| 148 |
+
See :ref:`Randomness<randomness>`.
|
| 149 |
+
pos_name : string, default="pos"
|
| 150 |
+
The name of the node attribute which represents the position
|
| 151 |
+
in 2D coordinates of the node in the returned graph.
|
| 152 |
+
|
| 153 |
+
Returns
|
| 154 |
+
-------
|
| 155 |
+
Graph
|
| 156 |
+
A random geometric graph, undirected and without self-loops.
|
| 157 |
+
Each node has a node attribute ``'pos'`` that stores the
|
| 158 |
+
position of that node in Euclidean space as provided by the
|
| 159 |
+
``pos`` keyword argument or, if ``pos`` was not provided, as
|
| 160 |
+
generated by this function.
|
| 161 |
+
|
| 162 |
+
Examples
|
| 163 |
+
--------
|
| 164 |
+
Create a random geometric graph on twenty nodes where nodes are joined by
|
| 165 |
+
an edge if their distance is at most 0.1::
|
| 166 |
+
|
| 167 |
+
>>> G = nx.random_geometric_graph(20, 0.1)
|
| 168 |
+
|
| 169 |
+
Notes
|
| 170 |
+
-----
|
| 171 |
+
This uses a *k*-d tree to build the graph.
|
| 172 |
+
|
| 173 |
+
The `pos` keyword argument can be used to specify node positions so you
|
| 174 |
+
can create an arbitrary distribution and domain for positions.
|
| 175 |
+
|
| 176 |
+
For example, to use a 2D Gaussian distribution of node positions with mean
|
| 177 |
+
(0, 0) and standard deviation 2::
|
| 178 |
+
|
| 179 |
+
>>> import random
|
| 180 |
+
>>> n = 20
|
| 181 |
+
>>> pos = {i: (random.gauss(0, 2), random.gauss(0, 2)) for i in range(n)}
|
| 182 |
+
>>> G = nx.random_geometric_graph(n, 0.2, pos=pos)
|
| 183 |
+
|
| 184 |
+
References
|
| 185 |
+
----------
|
| 186 |
+
.. [1] Penrose, Mathew, *Random Geometric Graphs*,
|
| 187 |
+
Oxford Studies in Probability, 5, 2003.
|
| 188 |
+
|
| 189 |
+
"""
|
| 190 |
+
# TODO Is this function just a special case of the geographical
|
| 191 |
+
# threshold graph?
|
| 192 |
+
#
|
| 193 |
+
# half_radius = {v: radius / 2 for v in n}
|
| 194 |
+
# return geographical_threshold_graph(nodes, theta=1, alpha=1,
|
| 195 |
+
# weight=half_radius)
|
| 196 |
+
#
|
| 197 |
+
G = nx.empty_graph(n)
|
| 198 |
+
# If no positions are provided, choose uniformly random vectors in
|
| 199 |
+
# Euclidean space of the specified dimension.
|
| 200 |
+
if pos is None:
|
| 201 |
+
pos = {v: [seed.random() for i in range(dim)] for v in G}
|
| 202 |
+
nx.set_node_attributes(G, pos, pos_name)
|
| 203 |
+
|
| 204 |
+
G.add_edges_from(_geometric_edges(G, radius, p, pos_name))
|
| 205 |
+
return G
|
| 206 |
+
|
| 207 |
+
|
| 208 |
+
@py_random_state(6)
|
| 209 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 210 |
+
def soft_random_geometric_graph(
|
| 211 |
+
n, radius, dim=2, pos=None, p=2, p_dist=None, seed=None, *, pos_name="pos"
|
| 212 |
+
):
|
| 213 |
+
r"""Returns a soft random geometric graph in the unit cube.
|
| 214 |
+
|
| 215 |
+
The soft random geometric graph [1] model places `n` nodes uniformly at
|
| 216 |
+
random in the unit cube in dimension `dim`. Two nodes of distance, `dist`,
|
| 217 |
+
computed by the `p`-Minkowski distance metric are joined by an edge with
|
| 218 |
+
probability `p_dist` if the computed distance metric value of the nodes
|
| 219 |
+
is at most `radius`, otherwise they are not joined.
|
| 220 |
+
|
| 221 |
+
Edges within `radius` of each other are determined using a KDTree when
|
| 222 |
+
SciPy is available. This reduces the time complexity from :math:`O(n^2)`
|
| 223 |
+
to :math:`O(n)`.
|
| 224 |
+
|
| 225 |
+
Parameters
|
| 226 |
+
----------
|
| 227 |
+
n : int or iterable
|
| 228 |
+
Number of nodes or iterable of nodes
|
| 229 |
+
radius: float
|
| 230 |
+
Distance threshold value
|
| 231 |
+
dim : int, optional
|
| 232 |
+
Dimension of graph
|
| 233 |
+
pos : dict, optional
|
| 234 |
+
A dictionary keyed by node with node positions as values.
|
| 235 |
+
p : float, optional
|
| 236 |
+
Which Minkowski distance metric to use.
|
| 237 |
+
`p` has to meet the condition ``1 <= p <= infinity``.
|
| 238 |
+
|
| 239 |
+
If this argument is not specified, the :math:`L^2` metric
|
| 240 |
+
(the Euclidean distance metric), p = 2 is used.
|
| 241 |
+
|
| 242 |
+
This should not be confused with the `p` of an Erdős-Rényi random
|
| 243 |
+
graph, which represents probability.
|
| 244 |
+
p_dist : function, optional
|
| 245 |
+
A probability density function computing the probability of
|
| 246 |
+
connecting two nodes that are of distance, dist, computed by the
|
| 247 |
+
Minkowski distance metric. The probability density function, `p_dist`,
|
| 248 |
+
must be any function that takes the metric value as input
|
| 249 |
+
and outputs a single probability value between 0-1. The scipy.stats
|
| 250 |
+
package has many probability distribution functions implemented and
|
| 251 |
+
tools for custom probability distribution definitions [2], and passing
|
| 252 |
+
the .pdf method of scipy.stats distributions can be used here. If the
|
| 253 |
+
probability function, `p_dist`, is not supplied, the default function
|
| 254 |
+
is an exponential distribution with rate parameter :math:`\lambda=1`.
|
| 255 |
+
seed : integer, random_state, or None (default)
|
| 256 |
+
Indicator of random number generation state.
|
| 257 |
+
See :ref:`Randomness<randomness>`.
|
| 258 |
+
pos_name : string, default="pos"
|
| 259 |
+
The name of the node attribute which represents the position
|
| 260 |
+
in 2D coordinates of the node in the returned graph.
|
| 261 |
+
|
| 262 |
+
Returns
|
| 263 |
+
-------
|
| 264 |
+
Graph
|
| 265 |
+
A soft random geometric graph, undirected and without self-loops.
|
| 266 |
+
Each node has a node attribute ``'pos'`` that stores the
|
| 267 |
+
position of that node in Euclidean space as provided by the
|
| 268 |
+
``pos`` keyword argument or, if ``pos`` was not provided, as
|
| 269 |
+
generated by this function.
|
| 270 |
+
|
| 271 |
+
Examples
|
| 272 |
+
--------
|
| 273 |
+
Default Graph:
|
| 274 |
+
|
| 275 |
+
G = nx.soft_random_geometric_graph(50, 0.2)
|
| 276 |
+
|
| 277 |
+
Custom Graph:
|
| 278 |
+
|
| 279 |
+
Create a soft random geometric graph on 100 uniformly distributed nodes
|
| 280 |
+
where nodes are joined by an edge with probability computed from an
|
| 281 |
+
exponential distribution with rate parameter :math:`\lambda=1` if their
|
| 282 |
+
Euclidean distance is at most 0.2.
|
| 283 |
+
|
| 284 |
+
Notes
|
| 285 |
+
-----
|
| 286 |
+
This uses a *k*-d tree to build the graph.
|
| 287 |
+
|
| 288 |
+
The `pos` keyword argument can be used to specify node positions so you
|
| 289 |
+
can create an arbitrary distribution and domain for positions.
|
| 290 |
+
|
| 291 |
+
For example, to use a 2D Gaussian distribution of node positions with mean
|
| 292 |
+
(0, 0) and standard deviation 2
|
| 293 |
+
|
| 294 |
+
The scipy.stats package can be used to define the probability distribution
|
| 295 |
+
with the .pdf method used as `p_dist`.
|
| 296 |
+
|
| 297 |
+
::
|
| 298 |
+
|
| 299 |
+
>>> import random
|
| 300 |
+
>>> import math
|
| 301 |
+
>>> n = 100
|
| 302 |
+
>>> pos = {i: (random.gauss(0, 2), random.gauss(0, 2)) for i in range(n)}
|
| 303 |
+
>>> p_dist = lambda dist: math.exp(-dist)
|
| 304 |
+
>>> G = nx.soft_random_geometric_graph(n, 0.2, pos=pos, p_dist=p_dist)
|
| 305 |
+
|
| 306 |
+
References
|
| 307 |
+
----------
|
| 308 |
+
.. [1] Penrose, Mathew D. "Connectivity of soft random geometric graphs."
|
| 309 |
+
The Annals of Applied Probability 26.2 (2016): 986-1028.
|
| 310 |
+
.. [2] scipy.stats -
|
| 311 |
+
https://docs.scipy.org/doc/scipy/reference/tutorial/stats.html
|
| 312 |
+
|
| 313 |
+
"""
|
| 314 |
+
G = nx.empty_graph(n)
|
| 315 |
+
G.name = f"soft_random_geometric_graph({n}, {radius}, {dim})"
|
| 316 |
+
# If no positions are provided, choose uniformly random vectors in
|
| 317 |
+
# Euclidean space of the specified dimension.
|
| 318 |
+
if pos is None:
|
| 319 |
+
pos = {v: [seed.random() for i in range(dim)] for v in G}
|
| 320 |
+
nx.set_node_attributes(G, pos, pos_name)
|
| 321 |
+
|
| 322 |
+
# if p_dist function not supplied the default function is an exponential
|
| 323 |
+
# distribution with rate parameter :math:`\lambda=1`.
|
| 324 |
+
if p_dist is None:
|
| 325 |
+
|
| 326 |
+
def p_dist(dist):
|
| 327 |
+
return math.exp(-dist)
|
| 328 |
+
|
| 329 |
+
def should_join(edge):
|
| 330 |
+
u, v = edge
|
| 331 |
+
dist = (sum(abs(a - b) ** p for a, b in zip(pos[u], pos[v]))) ** (1 / p)
|
| 332 |
+
return seed.random() < p_dist(dist)
|
| 333 |
+
|
| 334 |
+
G.add_edges_from(filter(should_join, _geometric_edges(G, radius, p, pos_name)))
|
| 335 |
+
return G
|
| 336 |
+
|
| 337 |
+
|
| 338 |
+
@py_random_state(7)
|
| 339 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 340 |
+
def geographical_threshold_graph(
|
| 341 |
+
n,
|
| 342 |
+
theta,
|
| 343 |
+
dim=2,
|
| 344 |
+
pos=None,
|
| 345 |
+
weight=None,
|
| 346 |
+
metric=None,
|
| 347 |
+
p_dist=None,
|
| 348 |
+
seed=None,
|
| 349 |
+
*,
|
| 350 |
+
pos_name="pos",
|
| 351 |
+
weight_name="weight",
|
| 352 |
+
):
|
| 353 |
+
r"""Returns a geographical threshold graph.
|
| 354 |
+
|
| 355 |
+
The geographical threshold graph model places $n$ nodes uniformly at
|
| 356 |
+
random in a rectangular domain. Each node $u$ is assigned a weight
|
| 357 |
+
$w_u$. Two nodes $u$ and $v$ are joined by an edge if
|
| 358 |
+
|
| 359 |
+
.. math::
|
| 360 |
+
|
| 361 |
+
(w_u + w_v)p_{dist}(r) \ge \theta
|
| 362 |
+
|
| 363 |
+
where `r` is the distance between `u` and `v`, `p_dist` is any function of
|
| 364 |
+
`r`, and :math:`\theta` as the threshold parameter. `p_dist` is used to
|
| 365 |
+
give weight to the distance between nodes when deciding whether or not
|
| 366 |
+
they should be connected. The larger `p_dist` is, the more prone nodes
|
| 367 |
+
separated by `r` are to be connected, and vice versa.
|
| 368 |
+
|
| 369 |
+
Parameters
|
| 370 |
+
----------
|
| 371 |
+
n : int or iterable
|
| 372 |
+
Number of nodes or iterable of nodes
|
| 373 |
+
theta: float
|
| 374 |
+
Threshold value
|
| 375 |
+
dim : int, optional
|
| 376 |
+
Dimension of graph
|
| 377 |
+
pos : dict
|
| 378 |
+
Node positions as a dictionary of tuples keyed by node.
|
| 379 |
+
weight : dict
|
| 380 |
+
Node weights as a dictionary of numbers keyed by node.
|
| 381 |
+
metric : function
|
| 382 |
+
A metric on vectors of numbers (represented as lists or
|
| 383 |
+
tuples). This must be a function that accepts two lists (or
|
| 384 |
+
tuples) as input and yields a number as output. The function
|
| 385 |
+
must also satisfy the four requirements of a `metric`_.
|
| 386 |
+
Specifically, if $d$ is the function and $x$, $y$,
|
| 387 |
+
and $z$ are vectors in the graph, then $d$ must satisfy
|
| 388 |
+
|
| 389 |
+
1. $d(x, y) \ge 0$,
|
| 390 |
+
2. $d(x, y) = 0$ if and only if $x = y$,
|
| 391 |
+
3. $d(x, y) = d(y, x)$,
|
| 392 |
+
4. $d(x, z) \le d(x, y) + d(y, z)$.
|
| 393 |
+
|
| 394 |
+
If this argument is not specified, the Euclidean distance metric is
|
| 395 |
+
used.
|
| 396 |
+
|
| 397 |
+
.. _metric: https://en.wikipedia.org/wiki/Metric_%28mathematics%29
|
| 398 |
+
p_dist : function, optional
|
| 399 |
+
Any function used to give weight to the distance between nodes when
|
| 400 |
+
deciding whether or not they should be connected. `p_dist` was
|
| 401 |
+
originally conceived as a probability density function giving the
|
| 402 |
+
probability of connecting two nodes that are of metric distance `r`
|
| 403 |
+
apart. The implementation here allows for more arbitrary definitions
|
| 404 |
+
of `p_dist` that do not need to correspond to valid probability
|
| 405 |
+
density functions. The :mod:`scipy.stats` package has many
|
| 406 |
+
probability density functions implemented and tools for custom
|
| 407 |
+
probability density definitions, and passing the ``.pdf`` method of
|
| 408 |
+
scipy.stats distributions can be used here. If ``p_dist=None``
|
| 409 |
+
(the default), the exponential function :math:`r^{-2}` is used.
|
| 410 |
+
seed : integer, random_state, or None (default)
|
| 411 |
+
Indicator of random number generation state.
|
| 412 |
+
See :ref:`Randomness<randomness>`.
|
| 413 |
+
pos_name : string, default="pos"
|
| 414 |
+
The name of the node attribute which represents the position
|
| 415 |
+
in 2D coordinates of the node in the returned graph.
|
| 416 |
+
weight_name : string, default="weight"
|
| 417 |
+
The name of the node attribute which represents the weight
|
| 418 |
+
of the node in the returned graph.
|
| 419 |
+
|
| 420 |
+
Returns
|
| 421 |
+
-------
|
| 422 |
+
Graph
|
| 423 |
+
A random geographic threshold graph, undirected and without
|
| 424 |
+
self-loops.
|
| 425 |
+
|
| 426 |
+
Each node has a node attribute ``pos`` that stores the
|
| 427 |
+
position of that node in Euclidean space as provided by the
|
| 428 |
+
``pos`` keyword argument or, if ``pos`` was not provided, as
|
| 429 |
+
generated by this function. Similarly, each node has a node
|
| 430 |
+
attribute ``weight`` that stores the weight of that node as
|
| 431 |
+
provided or as generated.
|
| 432 |
+
|
| 433 |
+
Examples
|
| 434 |
+
--------
|
| 435 |
+
Specify an alternate distance metric using the ``metric`` keyword
|
| 436 |
+
argument. For example, to use the `taxicab metric`_ instead of the
|
| 437 |
+
default `Euclidean metric`_::
|
| 438 |
+
|
| 439 |
+
>>> dist = lambda x, y: sum(abs(a - b) for a, b in zip(x, y))
|
| 440 |
+
>>> G = nx.geographical_threshold_graph(10, 0.1, metric=dist)
|
| 441 |
+
|
| 442 |
+
.. _taxicab metric: https://en.wikipedia.org/wiki/Taxicab_geometry
|
| 443 |
+
.. _Euclidean metric: https://en.wikipedia.org/wiki/Euclidean_distance
|
| 444 |
+
|
| 445 |
+
Notes
|
| 446 |
+
-----
|
| 447 |
+
If weights are not specified they are assigned to nodes by drawing randomly
|
| 448 |
+
from the exponential distribution with rate parameter $\lambda=1$.
|
| 449 |
+
To specify weights from a different distribution, use the `weight` keyword
|
| 450 |
+
argument::
|
| 451 |
+
|
| 452 |
+
>>> import random
|
| 453 |
+
>>> n = 20
|
| 454 |
+
>>> w = {i: random.expovariate(5.0) for i in range(n)}
|
| 455 |
+
>>> G = nx.geographical_threshold_graph(20, 50, weight=w)
|
| 456 |
+
|
| 457 |
+
If node positions are not specified they are randomly assigned from the
|
| 458 |
+
uniform distribution.
|
| 459 |
+
|
| 460 |
+
References
|
| 461 |
+
----------
|
| 462 |
+
.. [1] Masuda, N., Miwa, H., Konno, N.:
|
| 463 |
+
Geographical threshold graphs with small-world and scale-free
|
| 464 |
+
properties.
|
| 465 |
+
Physical Review E 71, 036108 (2005)
|
| 466 |
+
.. [2] Milan Bradonjić, Aric Hagberg and Allon G. Percus,
|
| 467 |
+
Giant component and connectivity in geographical threshold graphs,
|
| 468 |
+
in Algorithms and Models for the Web-Graph (WAW 2007),
|
| 469 |
+
Antony Bonato and Fan Chung (Eds), pp. 209--216, 2007
|
| 470 |
+
"""
|
| 471 |
+
G = nx.empty_graph(n)
|
| 472 |
+
# If no weights are provided, choose them from an exponential
|
| 473 |
+
# distribution.
|
| 474 |
+
if weight is None:
|
| 475 |
+
weight = {v: seed.expovariate(1) for v in G}
|
| 476 |
+
# If no positions are provided, choose uniformly random vectors in
|
| 477 |
+
# Euclidean space of the specified dimension.
|
| 478 |
+
if pos is None:
|
| 479 |
+
pos = {v: [seed.random() for i in range(dim)] for v in G}
|
| 480 |
+
# If no distance metric is provided, use Euclidean distance.
|
| 481 |
+
if metric is None:
|
| 482 |
+
metric = math.dist
|
| 483 |
+
nx.set_node_attributes(G, weight, weight_name)
|
| 484 |
+
nx.set_node_attributes(G, pos, pos_name)
|
| 485 |
+
|
| 486 |
+
# if p_dist is not supplied, use default r^-2
|
| 487 |
+
if p_dist is None:
|
| 488 |
+
|
| 489 |
+
def p_dist(r):
|
| 490 |
+
return r**-2
|
| 491 |
+
|
| 492 |
+
# Returns ``True`` if and only if the nodes whose attributes are
|
| 493 |
+
# ``du`` and ``dv`` should be joined, according to the threshold
|
| 494 |
+
# condition.
|
| 495 |
+
def should_join(pair):
|
| 496 |
+
u, v = pair
|
| 497 |
+
u_pos, v_pos = pos[u], pos[v]
|
| 498 |
+
u_weight, v_weight = weight[u], weight[v]
|
| 499 |
+
return (u_weight + v_weight) * p_dist(metric(u_pos, v_pos)) >= theta
|
| 500 |
+
|
| 501 |
+
G.add_edges_from(filter(should_join, combinations(G, 2)))
|
| 502 |
+
return G
|
| 503 |
+
|
| 504 |
+
|
| 505 |
+
@py_random_state(6)
|
| 506 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 507 |
+
def waxman_graph(
|
| 508 |
+
n,
|
| 509 |
+
beta=0.4,
|
| 510 |
+
alpha=0.1,
|
| 511 |
+
L=None,
|
| 512 |
+
domain=(0, 0, 1, 1),
|
| 513 |
+
metric=None,
|
| 514 |
+
seed=None,
|
| 515 |
+
*,
|
| 516 |
+
pos_name="pos",
|
| 517 |
+
):
|
| 518 |
+
r"""Returns a Waxman random graph.
|
| 519 |
+
|
| 520 |
+
The Waxman random graph model places `n` nodes uniformly at random
|
| 521 |
+
in a rectangular domain. Each pair of nodes at distance `d` is
|
| 522 |
+
joined by an edge with probability
|
| 523 |
+
|
| 524 |
+
.. math::
|
| 525 |
+
p = \beta \exp(-d / \alpha L).
|
| 526 |
+
|
| 527 |
+
This function implements both Waxman models, using the `L` keyword
|
| 528 |
+
argument.
|
| 529 |
+
|
| 530 |
+
* Waxman-1: if `L` is not specified, it is set to be the maximum distance
|
| 531 |
+
between any pair of nodes.
|
| 532 |
+
* Waxman-2: if `L` is specified, the distance between a pair of nodes is
|
| 533 |
+
chosen uniformly at random from the interval `[0, L]`.
|
| 534 |
+
|
| 535 |
+
Parameters
|
| 536 |
+
----------
|
| 537 |
+
n : int or iterable
|
| 538 |
+
Number of nodes or iterable of nodes
|
| 539 |
+
beta: float
|
| 540 |
+
Model parameter
|
| 541 |
+
alpha: float
|
| 542 |
+
Model parameter
|
| 543 |
+
L : float, optional
|
| 544 |
+
Maximum distance between nodes. If not specified, the actual distance
|
| 545 |
+
is calculated.
|
| 546 |
+
domain : four-tuple of numbers, optional
|
| 547 |
+
Domain size, given as a tuple of the form `(x_min, y_min, x_max,
|
| 548 |
+
y_max)`.
|
| 549 |
+
metric : function
|
| 550 |
+
A metric on vectors of numbers (represented as lists or
|
| 551 |
+
tuples). This must be a function that accepts two lists (or
|
| 552 |
+
tuples) as input and yields a number as output. The function
|
| 553 |
+
must also satisfy the four requirements of a `metric`_.
|
| 554 |
+
Specifically, if $d$ is the function and $x$, $y$,
|
| 555 |
+
and $z$ are vectors in the graph, then $d$ must satisfy
|
| 556 |
+
|
| 557 |
+
1. $d(x, y) \ge 0$,
|
| 558 |
+
2. $d(x, y) = 0$ if and only if $x = y$,
|
| 559 |
+
3. $d(x, y) = d(y, x)$,
|
| 560 |
+
4. $d(x, z) \le d(x, y) + d(y, z)$.
|
| 561 |
+
|
| 562 |
+
If this argument is not specified, the Euclidean distance metric is
|
| 563 |
+
used.
|
| 564 |
+
|
| 565 |
+
.. _metric: https://en.wikipedia.org/wiki/Metric_%28mathematics%29
|
| 566 |
+
|
| 567 |
+
seed : integer, random_state, or None (default)
|
| 568 |
+
Indicator of random number generation state.
|
| 569 |
+
See :ref:`Randomness<randomness>`.
|
| 570 |
+
pos_name : string, default="pos"
|
| 571 |
+
The name of the node attribute which represents the position
|
| 572 |
+
in 2D coordinates of the node in the returned graph.
|
| 573 |
+
|
| 574 |
+
Returns
|
| 575 |
+
-------
|
| 576 |
+
Graph
|
| 577 |
+
A random Waxman graph, undirected and without self-loops. Each
|
| 578 |
+
node has a node attribute ``'pos'`` that stores the position of
|
| 579 |
+
that node in Euclidean space as generated by this function.
|
| 580 |
+
|
| 581 |
+
Examples
|
| 582 |
+
--------
|
| 583 |
+
Specify an alternate distance metric using the ``metric`` keyword
|
| 584 |
+
argument. For example, to use the "`taxicab metric`_" instead of the
|
| 585 |
+
default `Euclidean metric`_::
|
| 586 |
+
|
| 587 |
+
>>> dist = lambda x, y: sum(abs(a - b) for a, b in zip(x, y))
|
| 588 |
+
>>> G = nx.waxman_graph(10, 0.5, 0.1, metric=dist)
|
| 589 |
+
|
| 590 |
+
.. _taxicab metric: https://en.wikipedia.org/wiki/Taxicab_geometry
|
| 591 |
+
.. _Euclidean metric: https://en.wikipedia.org/wiki/Euclidean_distance
|
| 592 |
+
|
| 593 |
+
Notes
|
| 594 |
+
-----
|
| 595 |
+
Starting in NetworkX 2.0 the parameters alpha and beta align with their
|
| 596 |
+
usual roles in the probability distribution. In earlier versions their
|
| 597 |
+
positions in the expression were reversed. Their position in the calling
|
| 598 |
+
sequence reversed as well to minimize backward incompatibility.
|
| 599 |
+
|
| 600 |
+
References
|
| 601 |
+
----------
|
| 602 |
+
.. [1] B. M. Waxman, *Routing of multipoint connections*.
|
| 603 |
+
IEEE J. Select. Areas Commun. 6(9),(1988) 1617--1622.
|
| 604 |
+
"""
|
| 605 |
+
G = nx.empty_graph(n)
|
| 606 |
+
(xmin, ymin, xmax, ymax) = domain
|
| 607 |
+
# Each node gets a uniformly random position in the given rectangle.
|
| 608 |
+
pos = {v: (seed.uniform(xmin, xmax), seed.uniform(ymin, ymax)) for v in G}
|
| 609 |
+
nx.set_node_attributes(G, pos, pos_name)
|
| 610 |
+
# If no distance metric is provided, use Euclidean distance.
|
| 611 |
+
if metric is None:
|
| 612 |
+
metric = math.dist
|
| 613 |
+
# If the maximum distance L is not specified (that is, we are in the
|
| 614 |
+
# Waxman-1 model), then find the maximum distance between any pair
|
| 615 |
+
# of nodes.
|
| 616 |
+
#
|
| 617 |
+
# In the Waxman-1 model, join nodes randomly based on distance. In
|
| 618 |
+
# the Waxman-2 model, join randomly based on random l.
|
| 619 |
+
if L is None:
|
| 620 |
+
L = max(metric(x, y) for x, y in combinations(pos.values(), 2))
|
| 621 |
+
|
| 622 |
+
def dist(u, v):
|
| 623 |
+
return metric(pos[u], pos[v])
|
| 624 |
+
|
| 625 |
+
else:
|
| 626 |
+
|
| 627 |
+
def dist(u, v):
|
| 628 |
+
return seed.random() * L
|
| 629 |
+
|
| 630 |
+
# `pair` is the pair of nodes to decide whether to join.
|
| 631 |
+
def should_join(pair):
|
| 632 |
+
return seed.random() < beta * math.exp(-dist(*pair) / (alpha * L))
|
| 633 |
+
|
| 634 |
+
G.add_edges_from(filter(should_join, combinations(G, 2)))
|
| 635 |
+
return G
|
| 636 |
+
|
| 637 |
+
|
| 638 |
+
@py_random_state(5)
|
| 639 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 640 |
+
def navigable_small_world_graph(n, p=1, q=1, r=2, dim=2, seed=None):
|
| 641 |
+
r"""Returns a navigable small-world graph.
|
| 642 |
+
|
| 643 |
+
A navigable small-world graph is a directed grid with additional long-range
|
| 644 |
+
connections that are chosen randomly.
|
| 645 |
+
|
| 646 |
+
[...] we begin with a set of nodes [...] that are identified with the set
|
| 647 |
+
of lattice points in an $n \times n$ square,
|
| 648 |
+
$\{(i, j): i \in \{1, 2, \ldots, n\}, j \in \{1, 2, \ldots, n\}\}$,
|
| 649 |
+
and we define the *lattice distance* between two nodes $(i, j)$ and
|
| 650 |
+
$(k, l)$ to be the number of "lattice steps" separating them:
|
| 651 |
+
$d((i, j), (k, l)) = |k - i| + |l - j|$.
|
| 652 |
+
|
| 653 |
+
For a universal constant $p >= 1$, the node $u$ has a directed edge to
|
| 654 |
+
every other node within lattice distance $p$---these are its *local
|
| 655 |
+
contacts*. For universal constants $q >= 0$ and $r >= 0$ we also
|
| 656 |
+
construct directed edges from $u$ to $q$ other nodes (the *long-range
|
| 657 |
+
contacts*) using independent random trials; the $i$th directed edge from
|
| 658 |
+
$u$ has endpoint $v$ with probability proportional to $[d(u,v)]^{-r}$.
|
| 659 |
+
|
| 660 |
+
-- [1]_
|
| 661 |
+
|
| 662 |
+
Parameters
|
| 663 |
+
----------
|
| 664 |
+
n : int
|
| 665 |
+
The length of one side of the lattice; the number of nodes in
|
| 666 |
+
the graph is therefore $n^2$.
|
| 667 |
+
p : int
|
| 668 |
+
The diameter of short range connections. Each node is joined with every
|
| 669 |
+
other node within this lattice distance.
|
| 670 |
+
q : int
|
| 671 |
+
The number of long-range connections for each node.
|
| 672 |
+
r : float
|
| 673 |
+
Exponent for decaying probability of connections. The probability of
|
| 674 |
+
connecting to a node at lattice distance $d$ is $1/d^r$.
|
| 675 |
+
dim : int
|
| 676 |
+
Dimension of grid
|
| 677 |
+
seed : integer, random_state, or None (default)
|
| 678 |
+
Indicator of random number generation state.
|
| 679 |
+
See :ref:`Randomness<randomness>`.
|
| 680 |
+
|
| 681 |
+
References
|
| 682 |
+
----------
|
| 683 |
+
.. [1] J. Kleinberg. The small-world phenomenon: An algorithmic
|
| 684 |
+
perspective. Proc. 32nd ACM Symposium on Theory of Computing, 2000.
|
| 685 |
+
"""
|
| 686 |
+
if p < 1:
|
| 687 |
+
raise nx.NetworkXException("p must be >= 1")
|
| 688 |
+
if q < 0:
|
| 689 |
+
raise nx.NetworkXException("q must be >= 0")
|
| 690 |
+
if r < 0:
|
| 691 |
+
raise nx.NetworkXException("r must be >= 0")
|
| 692 |
+
|
| 693 |
+
G = nx.DiGraph()
|
| 694 |
+
nodes = list(product(range(n), repeat=dim))
|
| 695 |
+
for p1 in nodes:
|
| 696 |
+
probs = [0]
|
| 697 |
+
for p2 in nodes:
|
| 698 |
+
if p1 == p2:
|
| 699 |
+
continue
|
| 700 |
+
d = sum((abs(b - a) for a, b in zip(p1, p2)))
|
| 701 |
+
if d <= p:
|
| 702 |
+
G.add_edge(p1, p2)
|
| 703 |
+
probs.append(d**-r)
|
| 704 |
+
cdf = list(accumulate(probs))
|
| 705 |
+
for _ in range(q):
|
| 706 |
+
target = nodes[bisect_left(cdf, seed.uniform(0, cdf[-1]))]
|
| 707 |
+
G.add_edge(p1, target)
|
| 708 |
+
return G
|
| 709 |
+
|
| 710 |
+
|
| 711 |
+
@py_random_state(7)
|
| 712 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 713 |
+
def thresholded_random_geometric_graph(
|
| 714 |
+
n,
|
| 715 |
+
radius,
|
| 716 |
+
theta,
|
| 717 |
+
dim=2,
|
| 718 |
+
pos=None,
|
| 719 |
+
weight=None,
|
| 720 |
+
p=2,
|
| 721 |
+
seed=None,
|
| 722 |
+
*,
|
| 723 |
+
pos_name="pos",
|
| 724 |
+
weight_name="weight",
|
| 725 |
+
):
|
| 726 |
+
r"""Returns a thresholded random geometric graph in the unit cube.
|
| 727 |
+
|
| 728 |
+
The thresholded random geometric graph [1] model places `n` nodes
|
| 729 |
+
uniformly at random in the unit cube of dimensions `dim`. Each node
|
| 730 |
+
`u` is assigned a weight :math:`w_u`. Two nodes `u` and `v` are
|
| 731 |
+
joined by an edge if they are within the maximum connection distance,
|
| 732 |
+
`radius` computed by the `p`-Minkowski distance and the summation of
|
| 733 |
+
weights :math:`w_u` + :math:`w_v` is greater than or equal
|
| 734 |
+
to the threshold parameter `theta`.
|
| 735 |
+
|
| 736 |
+
Edges within `radius` of each other are determined using a KDTree when
|
| 737 |
+
SciPy is available. This reduces the time complexity from :math:`O(n^2)`
|
| 738 |
+
to :math:`O(n)`.
|
| 739 |
+
|
| 740 |
+
Parameters
|
| 741 |
+
----------
|
| 742 |
+
n : int or iterable
|
| 743 |
+
Number of nodes or iterable of nodes
|
| 744 |
+
radius: float
|
| 745 |
+
Distance threshold value
|
| 746 |
+
theta: float
|
| 747 |
+
Threshold value
|
| 748 |
+
dim : int, optional
|
| 749 |
+
Dimension of graph
|
| 750 |
+
pos : dict, optional
|
| 751 |
+
A dictionary keyed by node with node positions as values.
|
| 752 |
+
weight : dict, optional
|
| 753 |
+
Node weights as a dictionary of numbers keyed by node.
|
| 754 |
+
p : float, optional (default 2)
|
| 755 |
+
Which Minkowski distance metric to use. `p` has to meet the condition
|
| 756 |
+
``1 <= p <= infinity``.
|
| 757 |
+
|
| 758 |
+
If this argument is not specified, the :math:`L^2` metric
|
| 759 |
+
(the Euclidean distance metric), p = 2 is used.
|
| 760 |
+
|
| 761 |
+
This should not be confused with the `p` of an Erdős-Rényi random
|
| 762 |
+
graph, which represents probability.
|
| 763 |
+
seed : integer, random_state, or None (default)
|
| 764 |
+
Indicator of random number generation state.
|
| 765 |
+
See :ref:`Randomness<randomness>`.
|
| 766 |
+
pos_name : string, default="pos"
|
| 767 |
+
The name of the node attribute which represents the position
|
| 768 |
+
in 2D coordinates of the node in the returned graph.
|
| 769 |
+
weight_name : string, default="weight"
|
| 770 |
+
The name of the node attribute which represents the weight
|
| 771 |
+
of the node in the returned graph.
|
| 772 |
+
|
| 773 |
+
Returns
|
| 774 |
+
-------
|
| 775 |
+
Graph
|
| 776 |
+
A thresholded random geographic graph, undirected and without
|
| 777 |
+
self-loops.
|
| 778 |
+
|
| 779 |
+
Each node has a node attribute ``'pos'`` that stores the
|
| 780 |
+
position of that node in Euclidean space as provided by the
|
| 781 |
+
``pos`` keyword argument or, if ``pos`` was not provided, as
|
| 782 |
+
generated by this function. Similarly, each node has a nodethre
|
| 783 |
+
attribute ``'weight'`` that stores the weight of that node as
|
| 784 |
+
provided or as generated.
|
| 785 |
+
|
| 786 |
+
Examples
|
| 787 |
+
--------
|
| 788 |
+
Default Graph:
|
| 789 |
+
|
| 790 |
+
G = nx.thresholded_random_geometric_graph(50, 0.2, 0.1)
|
| 791 |
+
|
| 792 |
+
Custom Graph:
|
| 793 |
+
|
| 794 |
+
Create a thresholded random geometric graph on 50 uniformly distributed
|
| 795 |
+
nodes where nodes are joined by an edge if their sum weights drawn from
|
| 796 |
+
a exponential distribution with rate = 5 are >= theta = 0.1 and their
|
| 797 |
+
Euclidean distance is at most 0.2.
|
| 798 |
+
|
| 799 |
+
Notes
|
| 800 |
+
-----
|
| 801 |
+
This uses a *k*-d tree to build the graph.
|
| 802 |
+
|
| 803 |
+
The `pos` keyword argument can be used to specify node positions so you
|
| 804 |
+
can create an arbitrary distribution and domain for positions.
|
| 805 |
+
|
| 806 |
+
For example, to use a 2D Gaussian distribution of node positions with mean
|
| 807 |
+
(0, 0) and standard deviation 2
|
| 808 |
+
|
| 809 |
+
If weights are not specified they are assigned to nodes by drawing randomly
|
| 810 |
+
from the exponential distribution with rate parameter :math:`\lambda=1`.
|
| 811 |
+
To specify weights from a different distribution, use the `weight` keyword
|
| 812 |
+
argument::
|
| 813 |
+
|
| 814 |
+
::
|
| 815 |
+
|
| 816 |
+
>>> import random
|
| 817 |
+
>>> import math
|
| 818 |
+
>>> n = 50
|
| 819 |
+
>>> pos = {i: (random.gauss(0, 2), random.gauss(0, 2)) for i in range(n)}
|
| 820 |
+
>>> w = {i: random.expovariate(5.0) for i in range(n)}
|
| 821 |
+
>>> G = nx.thresholded_random_geometric_graph(n, 0.2, 0.1, 2, pos, w)
|
| 822 |
+
|
| 823 |
+
References
|
| 824 |
+
----------
|
| 825 |
+
.. [1] http://cole-maclean.github.io/blog/files/thesis.pdf
|
| 826 |
+
|
| 827 |
+
"""
|
| 828 |
+
G = nx.empty_graph(n)
|
| 829 |
+
G.name = f"thresholded_random_geometric_graph({n}, {radius}, {theta}, {dim})"
|
| 830 |
+
# If no weights are provided, choose them from an exponential
|
| 831 |
+
# distribution.
|
| 832 |
+
if weight is None:
|
| 833 |
+
weight = {v: seed.expovariate(1) for v in G}
|
| 834 |
+
# If no positions are provided, choose uniformly random vectors in
|
| 835 |
+
# Euclidean space of the specified dimension.
|
| 836 |
+
if pos is None:
|
| 837 |
+
pos = {v: [seed.random() for i in range(dim)] for v in G}
|
| 838 |
+
# If no distance metric is provided, use Euclidean distance.
|
| 839 |
+
nx.set_node_attributes(G, weight, weight_name)
|
| 840 |
+
nx.set_node_attributes(G, pos, pos_name)
|
| 841 |
+
|
| 842 |
+
edges = (
|
| 843 |
+
(u, v)
|
| 844 |
+
for u, v in _geometric_edges(G, radius, p, pos_name)
|
| 845 |
+
if weight[u] + weight[v] >= theta
|
| 846 |
+
)
|
| 847 |
+
G.add_edges_from(edges)
|
| 848 |
+
return G
|
| 849 |
+
|
| 850 |
+
|
| 851 |
+
@py_random_state(5)
|
| 852 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 853 |
+
def geometric_soft_configuration_graph(
|
| 854 |
+
*, beta, n=None, gamma=None, mean_degree=None, kappas=None, seed=None
|
| 855 |
+
):
|
| 856 |
+
r"""Returns a random graph from the geometric soft configuration model.
|
| 857 |
+
|
| 858 |
+
The $\mathbb{S}^1$ model [1]_ is the geometric soft configuration model
|
| 859 |
+
which is able to explain many fundamental features of real networks such as
|
| 860 |
+
small-world property, heteregenous degree distributions, high level of
|
| 861 |
+
clustering, and self-similarity.
|
| 862 |
+
|
| 863 |
+
In the geometric soft configuration model, a node $i$ is assigned two hidden
|
| 864 |
+
variables: a hidden degree $\kappa_i$, quantifying its popularity, influence,
|
| 865 |
+
or importance, and an angular position $\theta_i$ in a circle abstracting the
|
| 866 |
+
similarity space, where angular distances between nodes are a proxy for their
|
| 867 |
+
similarity. Focusing on the angular position, this model is often called
|
| 868 |
+
the $\mathbb{S}^1$ model (a one-dimensional sphere). The circle's radius is
|
| 869 |
+
adjusted to $R = N/2\pi$, where $N$ is the number of nodes, so that the density
|
| 870 |
+
is set to 1 without loss of generality.
|
| 871 |
+
|
| 872 |
+
The connection probability between any pair of nodes increases with
|
| 873 |
+
the product of their hidden degrees (i.e., their combined popularities),
|
| 874 |
+
and decreases with the angular distance between the two nodes.
|
| 875 |
+
Specifically, nodes $i$ and $j$ are connected with the probability
|
| 876 |
+
|
| 877 |
+
$p_{ij} = \frac{1}{1 + \frac{d_{ij}^\beta}{\left(\mu \kappa_i \kappa_j\right)^{\max(1, \beta)}}}$
|
| 878 |
+
|
| 879 |
+
where $d_{ij} = R\Delta\theta_{ij}$ is the arc length of the circle between
|
| 880 |
+
nodes $i$ and $j$ separated by an angular distance $\Delta\theta_{ij}$.
|
| 881 |
+
Parameters $\mu$ and $\beta$ (also called inverse temperature) control the
|
| 882 |
+
average degree and the clustering coefficient, respectively.
|
| 883 |
+
|
| 884 |
+
It can be shown [2]_ that the model undergoes a structural phase transition
|
| 885 |
+
at $\beta=1$ so that for $\beta<1$ networks are unclustered in the thermodynamic
|
| 886 |
+
limit (when $N\to \infty$) whereas for $\beta>1$ the ensemble generates
|
| 887 |
+
networks with finite clustering coefficient.
|
| 888 |
+
|
| 889 |
+
The $\mathbb{S}^1$ model can be expressed as a purely geometric model
|
| 890 |
+
$\mathbb{H}^2$ in the hyperbolic plane [3]_ by mapping the hidden degree of
|
| 891 |
+
each node into a radial coordinate as
|
| 892 |
+
|
| 893 |
+
$r_i = \hat{R} - \frac{2 \max(1, \beta)}{\beta \zeta} \ln \left(\frac{\kappa_i}{\kappa_0}\right)$
|
| 894 |
+
|
| 895 |
+
where $\hat{R}$ is the radius of the hyperbolic disk and $\zeta$ is the curvature,
|
| 896 |
+
|
| 897 |
+
$\hat{R} = \frac{2}{\zeta} \ln \left(\frac{N}{\pi}\right)
|
| 898 |
+
- \frac{2\max(1, \beta)}{\beta \zeta} \ln (\mu \kappa_0^2)$
|
| 899 |
+
|
| 900 |
+
The connection probability then reads
|
| 901 |
+
|
| 902 |
+
$p_{ij} = \frac{1}{1 + \exp\left({\frac{\beta\zeta}{2} (x_{ij} - \hat{R})}\right)}$
|
| 903 |
+
|
| 904 |
+
where
|
| 905 |
+
|
| 906 |
+
$x_{ij} = r_i + r_j + \frac{2}{\zeta} \ln \frac{\Delta\theta_{ij}}{2}$
|
| 907 |
+
|
| 908 |
+
is a good approximation of the hyperbolic distance between two nodes separated
|
| 909 |
+
by an angular distance $\Delta\theta_{ij}$ with radial coordinates $r_i$ and $r_j$.
|
| 910 |
+
For $\beta > 1$, the curvature $\zeta = 1$, for $\beta < 1$, $\zeta = \beta^{-1}$.
|
| 911 |
+
|
| 912 |
+
|
| 913 |
+
Parameters
|
| 914 |
+
----------
|
| 915 |
+
Either `n`, `gamma`, `mean_degree` are provided or `kappas`. The values of
|
| 916 |
+
`n`, `gamma`, `mean_degree` (if provided) are used to construct a random
|
| 917 |
+
kappa-dict keyed by node with values sampled from a power-law distribution.
|
| 918 |
+
|
| 919 |
+
beta : positive number
|
| 920 |
+
Inverse temperature, controlling the clustering coefficient.
|
| 921 |
+
n : int (default: None)
|
| 922 |
+
Size of the network (number of nodes).
|
| 923 |
+
If not provided, `kappas` must be provided and holds the nodes.
|
| 924 |
+
gamma : float (default: None)
|
| 925 |
+
Exponent of the power-law distribution for hidden degrees `kappas`.
|
| 926 |
+
If not provided, `kappas` must be provided directly.
|
| 927 |
+
mean_degree : float (default: None)
|
| 928 |
+
The mean degree in the network.
|
| 929 |
+
If not provided, `kappas` must be provided directly.
|
| 930 |
+
kappas : dict (default: None)
|
| 931 |
+
A dict keyed by node to its hidden degree value.
|
| 932 |
+
If not provided, random values are computed based on a power-law
|
| 933 |
+
distribution using `n`, `gamma` and `mean_degree`.
|
| 934 |
+
seed : int, random_state, or None (default)
|
| 935 |
+
Indicator of random number generation state.
|
| 936 |
+
See :ref:`Randomness<randomness>`.
|
| 937 |
+
|
| 938 |
+
Returns
|
| 939 |
+
-------
|
| 940 |
+
Graph
|
| 941 |
+
A random geometric soft configuration graph (undirected with no self-loops).
|
| 942 |
+
Each node has three node-attributes:
|
| 943 |
+
|
| 944 |
+
- ``kappa`` that represents the hidden degree.
|
| 945 |
+
|
| 946 |
+
- ``theta`` the position in the similarity space ($\mathbb{S}^1$) which is
|
| 947 |
+
also the angular position in the hyperbolic plane.
|
| 948 |
+
|
| 949 |
+
- ``radius`` the radial position in the hyperbolic plane
|
| 950 |
+
(based on the hidden degree).
|
| 951 |
+
|
| 952 |
+
|
| 953 |
+
Examples
|
| 954 |
+
--------
|
| 955 |
+
Generate a network with specified parameters:
|
| 956 |
+
|
| 957 |
+
>>> G = nx.geometric_soft_configuration_graph(
|
| 958 |
+
... beta=1.5, n=100, gamma=2.7, mean_degree=5
|
| 959 |
+
... )
|
| 960 |
+
|
| 961 |
+
Create a geometric soft configuration graph with 100 nodes. The $\beta$ parameter
|
| 962 |
+
is set to 1.5 and the exponent of the powerlaw distribution of the hidden
|
| 963 |
+
degrees is 2.7 with mean value of 5.
|
| 964 |
+
|
| 965 |
+
Generate a network with predefined hidden degrees:
|
| 966 |
+
|
| 967 |
+
>>> kappas = {i: 10 for i in range(100)}
|
| 968 |
+
>>> G = nx.geometric_soft_configuration_graph(beta=2.5, kappas=kappas)
|
| 969 |
+
|
| 970 |
+
Create a geometric soft configuration graph with 100 nodes. The $\beta$ parameter
|
| 971 |
+
is set to 2.5 and all nodes with hidden degree $\kappa=10$.
|
| 972 |
+
|
| 973 |
+
|
| 974 |
+
References
|
| 975 |
+
----------
|
| 976 |
+
.. [1] Serrano, M. Á., Krioukov, D., & Boguñá, M. (2008). Self-similarity
|
| 977 |
+
of complex networks and hidden metric spaces. Physical review letters, 100(7), 078701.
|
| 978 |
+
|
| 979 |
+
.. [2] van der Kolk, J., Serrano, M. Á., & Boguñá, M. (2022). An anomalous
|
| 980 |
+
topological phase transition in spatial random graphs. Communications Physics, 5(1), 245.
|
| 981 |
+
|
| 982 |
+
.. [3] Krioukov, D., Papadopoulos, F., Kitsak, M., Vahdat, A., & Boguná, M. (2010).
|
| 983 |
+
Hyperbolic geometry of complex networks. Physical Review E, 82(3), 036106.
|
| 984 |
+
|
| 985 |
+
"""
|
| 986 |
+
if beta <= 0:
|
| 987 |
+
raise nx.NetworkXError("The parameter beta cannot be smaller or equal to 0.")
|
| 988 |
+
|
| 989 |
+
if kappas is not None:
|
| 990 |
+
if not all((n is None, gamma is None, mean_degree is None)):
|
| 991 |
+
raise nx.NetworkXError(
|
| 992 |
+
"When kappas is input, n, gamma and mean_degree must not be."
|
| 993 |
+
)
|
| 994 |
+
|
| 995 |
+
n = len(kappas)
|
| 996 |
+
mean_degree = sum(kappas) / len(kappas)
|
| 997 |
+
else:
|
| 998 |
+
if any((n is None, gamma is None, mean_degree is None)):
|
| 999 |
+
raise nx.NetworkXError(
|
| 1000 |
+
"Please provide either kappas, or all 3 of: n, gamma and mean_degree."
|
| 1001 |
+
)
|
| 1002 |
+
|
| 1003 |
+
# Generate `n` hidden degrees from a powerlaw distribution
|
| 1004 |
+
# with given exponent `gamma` and mean value `mean_degree`
|
| 1005 |
+
gam_ratio = (gamma - 2) / (gamma - 1)
|
| 1006 |
+
kappa_0 = mean_degree * gam_ratio * (1 - 1 / n) / (1 - 1 / n**gam_ratio)
|
| 1007 |
+
base = 1 - 1 / n
|
| 1008 |
+
power = 1 / (1 - gamma)
|
| 1009 |
+
kappas = {i: kappa_0 * (1 - seed.random() * base) ** power for i in range(n)}
|
| 1010 |
+
|
| 1011 |
+
G = nx.Graph()
|
| 1012 |
+
R = n / (2 * math.pi)
|
| 1013 |
+
|
| 1014 |
+
# Approximate values for mu in the thermodynamic limit (when n -> infinity)
|
| 1015 |
+
if beta > 1:
|
| 1016 |
+
mu = beta * math.sin(math.pi / beta) / (2 * math.pi * mean_degree)
|
| 1017 |
+
elif beta == 1:
|
| 1018 |
+
mu = 1 / (2 * mean_degree * math.log(n))
|
| 1019 |
+
else:
|
| 1020 |
+
mu = (1 - beta) / (2**beta * mean_degree * n ** (1 - beta))
|
| 1021 |
+
|
| 1022 |
+
# Generate random positions on a circle
|
| 1023 |
+
thetas = {k: seed.uniform(0, 2 * math.pi) for k in kappas}
|
| 1024 |
+
|
| 1025 |
+
for u in kappas:
|
| 1026 |
+
for v in list(G):
|
| 1027 |
+
angle = math.pi - math.fabs(math.pi - math.fabs(thetas[u] - thetas[v]))
|
| 1028 |
+
dij = math.pow(R * angle, beta)
|
| 1029 |
+
mu_kappas = math.pow(mu * kappas[u] * kappas[v], max(1, beta))
|
| 1030 |
+
p_ij = 1 / (1 + dij / mu_kappas)
|
| 1031 |
+
|
| 1032 |
+
# Create an edge with a certain connection probability
|
| 1033 |
+
if seed.random() < p_ij:
|
| 1034 |
+
G.add_edge(u, v)
|
| 1035 |
+
G.add_node(u)
|
| 1036 |
+
|
| 1037 |
+
nx.set_node_attributes(G, thetas, "theta")
|
| 1038 |
+
nx.set_node_attributes(G, kappas, "kappa")
|
| 1039 |
+
|
| 1040 |
+
# Map hidden degrees into the radial coordinates
|
| 1041 |
+
zeta = 1 if beta > 1 else 1 / beta
|
| 1042 |
+
kappa_min = min(kappas.values())
|
| 1043 |
+
R_c = 2 * max(1, beta) / (beta * zeta)
|
| 1044 |
+
R_hat = (2 / zeta) * math.log(n / math.pi) - R_c * math.log(mu * kappa_min)
|
| 1045 |
+
radii = {node: R_hat - R_c * math.log(kappa) for node, kappa in kappas.items()}
|
| 1046 |
+
nx.set_node_attributes(G, radii, "radius")
|
| 1047 |
+
|
| 1048 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/internet_as_graphs.py
ADDED
|
@@ -0,0 +1,441 @@
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
|
|
|
|
|
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|
|
|
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|
|
|
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|
|
|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
"""Generates graphs resembling the Internet Autonomous System network"""
|
| 2 |
+
|
| 3 |
+
import networkx as nx
|
| 4 |
+
from networkx.utils import py_random_state
|
| 5 |
+
|
| 6 |
+
__all__ = ["random_internet_as_graph"]
|
| 7 |
+
|
| 8 |
+
|
| 9 |
+
def uniform_int_from_avg(a, m, seed):
|
| 10 |
+
"""Pick a random integer with uniform probability.
|
| 11 |
+
|
| 12 |
+
Returns a random integer uniformly taken from a distribution with
|
| 13 |
+
minimum value 'a' and average value 'm', X~U(a,b), E[X]=m, X in N where
|
| 14 |
+
b = 2*m - a.
|
| 15 |
+
|
| 16 |
+
Notes
|
| 17 |
+
-----
|
| 18 |
+
p = (b-floor(b))/2
|
| 19 |
+
X = X1 + X2; X1~U(a,floor(b)), X2~B(p)
|
| 20 |
+
E[X] = E[X1] + E[X2] = (floor(b)+a)/2 + (b-floor(b))/2 = (b+a)/2 = m
|
| 21 |
+
"""
|
| 22 |
+
|
| 23 |
+
from math import floor
|
| 24 |
+
|
| 25 |
+
assert m >= a
|
| 26 |
+
b = 2 * m - a
|
| 27 |
+
p = (b - floor(b)) / 2
|
| 28 |
+
X1 = round(seed.random() * (floor(b) - a) + a)
|
| 29 |
+
if seed.random() < p:
|
| 30 |
+
X2 = 1
|
| 31 |
+
else:
|
| 32 |
+
X2 = 0
|
| 33 |
+
return X1 + X2
|
| 34 |
+
|
| 35 |
+
|
| 36 |
+
def choose_pref_attach(degs, seed):
|
| 37 |
+
"""Pick a random value, with a probability given by its weight.
|
| 38 |
+
|
| 39 |
+
Returns a random choice among degs keys, each of which has a
|
| 40 |
+
probability proportional to the corresponding dictionary value.
|
| 41 |
+
|
| 42 |
+
Parameters
|
| 43 |
+
----------
|
| 44 |
+
degs: dictionary
|
| 45 |
+
It contains the possible values (keys) and the corresponding
|
| 46 |
+
probabilities (values)
|
| 47 |
+
seed: random state
|
| 48 |
+
|
| 49 |
+
Returns
|
| 50 |
+
-------
|
| 51 |
+
v: object
|
| 52 |
+
A key of degs or None if degs is empty
|
| 53 |
+
"""
|
| 54 |
+
|
| 55 |
+
if len(degs) == 0:
|
| 56 |
+
return None
|
| 57 |
+
s = sum(degs.values())
|
| 58 |
+
if s == 0:
|
| 59 |
+
return seed.choice(list(degs.keys()))
|
| 60 |
+
v = seed.random() * s
|
| 61 |
+
|
| 62 |
+
nodes = list(degs.keys())
|
| 63 |
+
i = 0
|
| 64 |
+
acc = degs[nodes[i]]
|
| 65 |
+
while v > acc:
|
| 66 |
+
i += 1
|
| 67 |
+
acc += degs[nodes[i]]
|
| 68 |
+
return nodes[i]
|
| 69 |
+
|
| 70 |
+
|
| 71 |
+
class AS_graph_generator:
|
| 72 |
+
"""Generates random internet AS graphs."""
|
| 73 |
+
|
| 74 |
+
def __init__(self, n, seed):
|
| 75 |
+
"""Initializes variables. Immediate numbers are taken from [1].
|
| 76 |
+
|
| 77 |
+
Parameters
|
| 78 |
+
----------
|
| 79 |
+
n: integer
|
| 80 |
+
Number of graph nodes
|
| 81 |
+
seed: random state
|
| 82 |
+
Indicator of random number generation state.
|
| 83 |
+
See :ref:`Randomness<randomness>`.
|
| 84 |
+
|
| 85 |
+
Returns
|
| 86 |
+
-------
|
| 87 |
+
GG: AS_graph_generator object
|
| 88 |
+
|
| 89 |
+
References
|
| 90 |
+
----------
|
| 91 |
+
[1] A. Elmokashfi, A. Kvalbein and C. Dovrolis, "On the Scalability of
|
| 92 |
+
BGP: The Role of Topology Growth," in IEEE Journal on Selected Areas
|
| 93 |
+
in Communications, vol. 28, no. 8, pp. 1250-1261, October 2010.
|
| 94 |
+
"""
|
| 95 |
+
|
| 96 |
+
self.seed = seed
|
| 97 |
+
self.n_t = min(n, round(self.seed.random() * 2 + 4)) # num of T nodes
|
| 98 |
+
self.n_m = round(0.15 * n) # number of M nodes
|
| 99 |
+
self.n_cp = round(0.05 * n) # number of CP nodes
|
| 100 |
+
self.n_c = max(0, n - self.n_t - self.n_m - self.n_cp) # number of C nodes
|
| 101 |
+
|
| 102 |
+
self.d_m = 2 + (2.5 * n) / 10000 # average multihoming degree for M nodes
|
| 103 |
+
self.d_cp = 2 + (1.5 * n) / 10000 # avg multihoming degree for CP nodes
|
| 104 |
+
self.d_c = 1 + (5 * n) / 100000 # average multihoming degree for C nodes
|
| 105 |
+
|
| 106 |
+
self.p_m_m = 1 + (2 * n) / 10000 # avg num of peer edges between M and M
|
| 107 |
+
self.p_cp_m = 0.2 + (2 * n) / 10000 # avg num of peer edges between CP, M
|
| 108 |
+
self.p_cp_cp = 0.05 + (2 * n) / 100000 # avg num of peer edges btwn CP, CP
|
| 109 |
+
|
| 110 |
+
self.t_m = 0.375 # probability M's provider is T
|
| 111 |
+
self.t_cp = 0.375 # probability CP's provider is T
|
| 112 |
+
self.t_c = 0.125 # probability C's provider is T
|
| 113 |
+
|
| 114 |
+
def t_graph(self):
|
| 115 |
+
"""Generates the core mesh network of tier one nodes of a AS graph.
|
| 116 |
+
|
| 117 |
+
Returns
|
| 118 |
+
-------
|
| 119 |
+
G: Networkx Graph
|
| 120 |
+
Core network
|
| 121 |
+
"""
|
| 122 |
+
|
| 123 |
+
self.G = nx.Graph()
|
| 124 |
+
for i in range(self.n_t):
|
| 125 |
+
self.G.add_node(i, type="T")
|
| 126 |
+
for r in self.regions:
|
| 127 |
+
self.regions[r].add(i)
|
| 128 |
+
for j in self.G.nodes():
|
| 129 |
+
if i != j:
|
| 130 |
+
self.add_edge(i, j, "peer")
|
| 131 |
+
self.customers[i] = set()
|
| 132 |
+
self.providers[i] = set()
|
| 133 |
+
return self.G
|
| 134 |
+
|
| 135 |
+
def add_edge(self, i, j, kind):
|
| 136 |
+
if kind == "transit":
|
| 137 |
+
customer = str(i)
|
| 138 |
+
else:
|
| 139 |
+
customer = "none"
|
| 140 |
+
self.G.add_edge(i, j, type=kind, customer=customer)
|
| 141 |
+
|
| 142 |
+
def choose_peer_pref_attach(self, node_list):
|
| 143 |
+
"""Pick a node with a probability weighted by its peer degree.
|
| 144 |
+
|
| 145 |
+
Pick a node from node_list with preferential attachment
|
| 146 |
+
computed only on their peer degree
|
| 147 |
+
"""
|
| 148 |
+
|
| 149 |
+
d = {}
|
| 150 |
+
for n in node_list:
|
| 151 |
+
d[n] = self.G.nodes[n]["peers"]
|
| 152 |
+
return choose_pref_attach(d, self.seed)
|
| 153 |
+
|
| 154 |
+
def choose_node_pref_attach(self, node_list):
|
| 155 |
+
"""Pick a node with a probability weighted by its degree.
|
| 156 |
+
|
| 157 |
+
Pick a node from node_list with preferential attachment
|
| 158 |
+
computed on their degree
|
| 159 |
+
"""
|
| 160 |
+
|
| 161 |
+
degs = dict(self.G.degree(node_list))
|
| 162 |
+
return choose_pref_attach(degs, self.seed)
|
| 163 |
+
|
| 164 |
+
def add_customer(self, i, j):
|
| 165 |
+
"""Keep the dictionaries 'customers' and 'providers' consistent."""
|
| 166 |
+
|
| 167 |
+
self.customers[j].add(i)
|
| 168 |
+
self.providers[i].add(j)
|
| 169 |
+
for z in self.providers[j]:
|
| 170 |
+
self.customers[z].add(i)
|
| 171 |
+
self.providers[i].add(z)
|
| 172 |
+
|
| 173 |
+
def add_node(self, i, kind, reg2prob, avg_deg, t_edge_prob):
|
| 174 |
+
"""Add a node and its customer transit edges to the graph.
|
| 175 |
+
|
| 176 |
+
Parameters
|
| 177 |
+
----------
|
| 178 |
+
i: object
|
| 179 |
+
Identifier of the new node
|
| 180 |
+
kind: string
|
| 181 |
+
Type of the new node. Options are: 'M' for middle node, 'CP' for
|
| 182 |
+
content provider and 'C' for customer.
|
| 183 |
+
reg2prob: float
|
| 184 |
+
Probability the new node can be in two different regions.
|
| 185 |
+
avg_deg: float
|
| 186 |
+
Average number of transit nodes of which node i is customer.
|
| 187 |
+
t_edge_prob: float
|
| 188 |
+
Probability node i establish a customer transit edge with a tier
|
| 189 |
+
one (T) node
|
| 190 |
+
|
| 191 |
+
Returns
|
| 192 |
+
-------
|
| 193 |
+
i: object
|
| 194 |
+
Identifier of the new node
|
| 195 |
+
"""
|
| 196 |
+
|
| 197 |
+
regs = 1 # regions in which node resides
|
| 198 |
+
if self.seed.random() < reg2prob: # node is in two regions
|
| 199 |
+
regs = 2
|
| 200 |
+
node_options = set()
|
| 201 |
+
|
| 202 |
+
self.G.add_node(i, type=kind, peers=0)
|
| 203 |
+
self.customers[i] = set()
|
| 204 |
+
self.providers[i] = set()
|
| 205 |
+
self.nodes[kind].add(i)
|
| 206 |
+
for r in self.seed.sample(list(self.regions), regs):
|
| 207 |
+
node_options = node_options.union(self.regions[r])
|
| 208 |
+
self.regions[r].add(i)
|
| 209 |
+
|
| 210 |
+
edge_num = uniform_int_from_avg(1, avg_deg, self.seed)
|
| 211 |
+
|
| 212 |
+
t_options = node_options.intersection(self.nodes["T"])
|
| 213 |
+
m_options = node_options.intersection(self.nodes["M"])
|
| 214 |
+
if i in m_options:
|
| 215 |
+
m_options.remove(i)
|
| 216 |
+
d = 0
|
| 217 |
+
while d < edge_num and (len(t_options) > 0 or len(m_options) > 0):
|
| 218 |
+
if len(m_options) == 0 or (
|
| 219 |
+
len(t_options) > 0 and self.seed.random() < t_edge_prob
|
| 220 |
+
): # add edge to a T node
|
| 221 |
+
j = self.choose_node_pref_attach(t_options)
|
| 222 |
+
t_options.remove(j)
|
| 223 |
+
else:
|
| 224 |
+
j = self.choose_node_pref_attach(m_options)
|
| 225 |
+
m_options.remove(j)
|
| 226 |
+
self.add_edge(i, j, "transit")
|
| 227 |
+
self.add_customer(i, j)
|
| 228 |
+
d += 1
|
| 229 |
+
|
| 230 |
+
return i
|
| 231 |
+
|
| 232 |
+
def add_m_peering_link(self, m, to_kind):
|
| 233 |
+
"""Add a peering link between two middle tier (M) nodes.
|
| 234 |
+
|
| 235 |
+
Target node j is drawn considering a preferential attachment based on
|
| 236 |
+
other M node peering degree.
|
| 237 |
+
|
| 238 |
+
Parameters
|
| 239 |
+
----------
|
| 240 |
+
m: object
|
| 241 |
+
Node identifier
|
| 242 |
+
to_kind: string
|
| 243 |
+
type for target node j (must be always M)
|
| 244 |
+
|
| 245 |
+
Returns
|
| 246 |
+
-------
|
| 247 |
+
success: boolean
|
| 248 |
+
"""
|
| 249 |
+
|
| 250 |
+
# candidates are of type 'M' and are not customers of m
|
| 251 |
+
node_options = self.nodes["M"].difference(self.customers[m])
|
| 252 |
+
# candidates are not providers of m
|
| 253 |
+
node_options = node_options.difference(self.providers[m])
|
| 254 |
+
# remove self
|
| 255 |
+
if m in node_options:
|
| 256 |
+
node_options.remove(m)
|
| 257 |
+
|
| 258 |
+
# remove candidates we are already connected to
|
| 259 |
+
for j in self.G.neighbors(m):
|
| 260 |
+
if j in node_options:
|
| 261 |
+
node_options.remove(j)
|
| 262 |
+
|
| 263 |
+
if len(node_options) > 0:
|
| 264 |
+
j = self.choose_peer_pref_attach(node_options)
|
| 265 |
+
self.add_edge(m, j, "peer")
|
| 266 |
+
self.G.nodes[m]["peers"] += 1
|
| 267 |
+
self.G.nodes[j]["peers"] += 1
|
| 268 |
+
return True
|
| 269 |
+
else:
|
| 270 |
+
return False
|
| 271 |
+
|
| 272 |
+
def add_cp_peering_link(self, cp, to_kind):
|
| 273 |
+
"""Add a peering link to a content provider (CP) node.
|
| 274 |
+
|
| 275 |
+
Target node j can be CP or M and it is drawn uniformly among the nodes
|
| 276 |
+
belonging to the same region as cp.
|
| 277 |
+
|
| 278 |
+
Parameters
|
| 279 |
+
----------
|
| 280 |
+
cp: object
|
| 281 |
+
Node identifier
|
| 282 |
+
to_kind: string
|
| 283 |
+
type for target node j (must be M or CP)
|
| 284 |
+
|
| 285 |
+
Returns
|
| 286 |
+
-------
|
| 287 |
+
success: boolean
|
| 288 |
+
"""
|
| 289 |
+
|
| 290 |
+
node_options = set()
|
| 291 |
+
for r in self.regions: # options include nodes in the same region(s)
|
| 292 |
+
if cp in self.regions[r]:
|
| 293 |
+
node_options = node_options.union(self.regions[r])
|
| 294 |
+
|
| 295 |
+
# options are restricted to the indicated kind ('M' or 'CP')
|
| 296 |
+
node_options = self.nodes[to_kind].intersection(node_options)
|
| 297 |
+
|
| 298 |
+
# remove self
|
| 299 |
+
if cp in node_options:
|
| 300 |
+
node_options.remove(cp)
|
| 301 |
+
|
| 302 |
+
# remove nodes that are cp's providers
|
| 303 |
+
node_options = node_options.difference(self.providers[cp])
|
| 304 |
+
|
| 305 |
+
# remove nodes we are already connected to
|
| 306 |
+
for j in self.G.neighbors(cp):
|
| 307 |
+
if j in node_options:
|
| 308 |
+
node_options.remove(j)
|
| 309 |
+
|
| 310 |
+
if len(node_options) > 0:
|
| 311 |
+
j = self.seed.sample(list(node_options), 1)[0]
|
| 312 |
+
self.add_edge(cp, j, "peer")
|
| 313 |
+
self.G.nodes[cp]["peers"] += 1
|
| 314 |
+
self.G.nodes[j]["peers"] += 1
|
| 315 |
+
return True
|
| 316 |
+
else:
|
| 317 |
+
return False
|
| 318 |
+
|
| 319 |
+
def graph_regions(self, rn):
|
| 320 |
+
"""Initializes AS network regions.
|
| 321 |
+
|
| 322 |
+
Parameters
|
| 323 |
+
----------
|
| 324 |
+
rn: integer
|
| 325 |
+
Number of regions
|
| 326 |
+
"""
|
| 327 |
+
|
| 328 |
+
self.regions = {}
|
| 329 |
+
for i in range(rn):
|
| 330 |
+
self.regions["REG" + str(i)] = set()
|
| 331 |
+
|
| 332 |
+
def add_peering_links(self, from_kind, to_kind):
|
| 333 |
+
"""Utility function to add peering links among node groups."""
|
| 334 |
+
peer_link_method = None
|
| 335 |
+
if from_kind == "M":
|
| 336 |
+
peer_link_method = self.add_m_peering_link
|
| 337 |
+
m = self.p_m_m
|
| 338 |
+
if from_kind == "CP":
|
| 339 |
+
peer_link_method = self.add_cp_peering_link
|
| 340 |
+
if to_kind == "M":
|
| 341 |
+
m = self.p_cp_m
|
| 342 |
+
else:
|
| 343 |
+
m = self.p_cp_cp
|
| 344 |
+
|
| 345 |
+
for i in self.nodes[from_kind]:
|
| 346 |
+
num = uniform_int_from_avg(0, m, self.seed)
|
| 347 |
+
for _ in range(num):
|
| 348 |
+
peer_link_method(i, to_kind)
|
| 349 |
+
|
| 350 |
+
def generate(self):
|
| 351 |
+
"""Generates a random AS network graph as described in [1].
|
| 352 |
+
|
| 353 |
+
Returns
|
| 354 |
+
-------
|
| 355 |
+
G: Graph object
|
| 356 |
+
|
| 357 |
+
Notes
|
| 358 |
+
-----
|
| 359 |
+
The process steps are the following: first we create the core network
|
| 360 |
+
of tier one nodes, then we add the middle tier (M), the content
|
| 361 |
+
provider (CP) and the customer (C) nodes along with their transit edges
|
| 362 |
+
(link i,j means i is customer of j). Finally we add peering links
|
| 363 |
+
between M nodes, between M and CP nodes and between CP node couples.
|
| 364 |
+
For a detailed description of the algorithm, please refer to [1].
|
| 365 |
+
|
| 366 |
+
References
|
| 367 |
+
----------
|
| 368 |
+
[1] A. Elmokashfi, A. Kvalbein and C. Dovrolis, "On the Scalability of
|
| 369 |
+
BGP: The Role of Topology Growth," in IEEE Journal on Selected Areas
|
| 370 |
+
in Communications, vol. 28, no. 8, pp. 1250-1261, October 2010.
|
| 371 |
+
"""
|
| 372 |
+
|
| 373 |
+
self.graph_regions(5)
|
| 374 |
+
self.customers = {}
|
| 375 |
+
self.providers = {}
|
| 376 |
+
self.nodes = {"T": set(), "M": set(), "CP": set(), "C": set()}
|
| 377 |
+
|
| 378 |
+
self.t_graph()
|
| 379 |
+
self.nodes["T"] = set(self.G.nodes())
|
| 380 |
+
|
| 381 |
+
i = len(self.nodes["T"])
|
| 382 |
+
for _ in range(self.n_m):
|
| 383 |
+
self.nodes["M"].add(self.add_node(i, "M", 0.2, self.d_m, self.t_m))
|
| 384 |
+
i += 1
|
| 385 |
+
for _ in range(self.n_cp):
|
| 386 |
+
self.nodes["CP"].add(self.add_node(i, "CP", 0.05, self.d_cp, self.t_cp))
|
| 387 |
+
i += 1
|
| 388 |
+
for _ in range(self.n_c):
|
| 389 |
+
self.nodes["C"].add(self.add_node(i, "C", 0, self.d_c, self.t_c))
|
| 390 |
+
i += 1
|
| 391 |
+
|
| 392 |
+
self.add_peering_links("M", "M")
|
| 393 |
+
self.add_peering_links("CP", "M")
|
| 394 |
+
self.add_peering_links("CP", "CP")
|
| 395 |
+
|
| 396 |
+
return self.G
|
| 397 |
+
|
| 398 |
+
|
| 399 |
+
@py_random_state(1)
|
| 400 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 401 |
+
def random_internet_as_graph(n, seed=None):
|
| 402 |
+
"""Generates a random undirected graph resembling the Internet AS network
|
| 403 |
+
|
| 404 |
+
Parameters
|
| 405 |
+
----------
|
| 406 |
+
n: integer in [1000, 10000]
|
| 407 |
+
Number of graph nodes
|
| 408 |
+
seed : integer, random_state, or None (default)
|
| 409 |
+
Indicator of random number generation state.
|
| 410 |
+
See :ref:`Randomness<randomness>`.
|
| 411 |
+
|
| 412 |
+
Returns
|
| 413 |
+
-------
|
| 414 |
+
G: Networkx Graph object
|
| 415 |
+
A randomly generated undirected graph
|
| 416 |
+
|
| 417 |
+
Notes
|
| 418 |
+
-----
|
| 419 |
+
This algorithm returns an undirected graph resembling the Internet
|
| 420 |
+
Autonomous System (AS) network, it uses the approach by Elmokashfi et al.
|
| 421 |
+
[1]_ and it grants the properties described in the related paper [1]_.
|
| 422 |
+
|
| 423 |
+
Each node models an autonomous system, with an attribute 'type' specifying
|
| 424 |
+
its kind; tier-1 (T), mid-level (M), customer (C) or content-provider (CP).
|
| 425 |
+
Each edge models an ADV communication link (hence, bidirectional) with
|
| 426 |
+
attributes:
|
| 427 |
+
|
| 428 |
+
- type: transit|peer, the kind of commercial agreement between nodes;
|
| 429 |
+
- customer: <node id>, the identifier of the node acting as customer
|
| 430 |
+
('none' if type is peer).
|
| 431 |
+
|
| 432 |
+
References
|
| 433 |
+
----------
|
| 434 |
+
.. [1] A. Elmokashfi, A. Kvalbein and C. Dovrolis, "On the Scalability of
|
| 435 |
+
BGP: The Role of Topology Growth," in IEEE Journal on Selected Areas
|
| 436 |
+
in Communications, vol. 28, no. 8, pp. 1250-1261, October 2010.
|
| 437 |
+
"""
|
| 438 |
+
|
| 439 |
+
GG = AS_graph_generator(n, seed)
|
| 440 |
+
G = GG.generate()
|
| 441 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/intersection.py
ADDED
|
@@ -0,0 +1,125 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
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|
|
|
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|
|
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|
|
|
| 1 |
+
"""
|
| 2 |
+
Generators for random intersection graphs.
|
| 3 |
+
"""
|
| 4 |
+
|
| 5 |
+
import networkx as nx
|
| 6 |
+
from networkx.utils import py_random_state
|
| 7 |
+
|
| 8 |
+
__all__ = [
|
| 9 |
+
"uniform_random_intersection_graph",
|
| 10 |
+
"k_random_intersection_graph",
|
| 11 |
+
"general_random_intersection_graph",
|
| 12 |
+
]
|
| 13 |
+
|
| 14 |
+
|
| 15 |
+
@py_random_state(3)
|
| 16 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 17 |
+
def uniform_random_intersection_graph(n, m, p, seed=None):
|
| 18 |
+
"""Returns a uniform random intersection graph.
|
| 19 |
+
|
| 20 |
+
Parameters
|
| 21 |
+
----------
|
| 22 |
+
n : int
|
| 23 |
+
The number of nodes in the first bipartite set (nodes)
|
| 24 |
+
m : int
|
| 25 |
+
The number of nodes in the second bipartite set (attributes)
|
| 26 |
+
p : float
|
| 27 |
+
Probability of connecting nodes between bipartite sets
|
| 28 |
+
seed : integer, random_state, or None (default)
|
| 29 |
+
Indicator of random number generation state.
|
| 30 |
+
See :ref:`Randomness<randomness>`.
|
| 31 |
+
|
| 32 |
+
See Also
|
| 33 |
+
--------
|
| 34 |
+
gnp_random_graph
|
| 35 |
+
|
| 36 |
+
References
|
| 37 |
+
----------
|
| 38 |
+
.. [1] K.B. Singer-Cohen, Random Intersection Graphs, 1995,
|
| 39 |
+
PhD thesis, Johns Hopkins University
|
| 40 |
+
.. [2] Fill, J. A., Scheinerman, E. R., and Singer-Cohen, K. B.,
|
| 41 |
+
Random intersection graphs when m = !(n):
|
| 42 |
+
An equivalence theorem relating the evolution of the g(n, m, p)
|
| 43 |
+
and g(n, p) models. Random Struct. Algorithms 16, 2 (2000), 156–176.
|
| 44 |
+
"""
|
| 45 |
+
from networkx.algorithms import bipartite
|
| 46 |
+
|
| 47 |
+
G = bipartite.random_graph(n, m, p, seed)
|
| 48 |
+
return nx.projected_graph(G, range(n))
|
| 49 |
+
|
| 50 |
+
|
| 51 |
+
@py_random_state(3)
|
| 52 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 53 |
+
def k_random_intersection_graph(n, m, k, seed=None):
|
| 54 |
+
"""Returns a intersection graph with randomly chosen attribute sets for
|
| 55 |
+
each node that are of equal size (k).
|
| 56 |
+
|
| 57 |
+
Parameters
|
| 58 |
+
----------
|
| 59 |
+
n : int
|
| 60 |
+
The number of nodes in the first bipartite set (nodes)
|
| 61 |
+
m : int
|
| 62 |
+
The number of nodes in the second bipartite set (attributes)
|
| 63 |
+
k : float
|
| 64 |
+
Size of attribute set to assign to each node.
|
| 65 |
+
seed : integer, random_state, or None (default)
|
| 66 |
+
Indicator of random number generation state.
|
| 67 |
+
See :ref:`Randomness<randomness>`.
|
| 68 |
+
|
| 69 |
+
See Also
|
| 70 |
+
--------
|
| 71 |
+
gnp_random_graph, uniform_random_intersection_graph
|
| 72 |
+
|
| 73 |
+
References
|
| 74 |
+
----------
|
| 75 |
+
.. [1] Godehardt, E., and Jaworski, J.
|
| 76 |
+
Two models of random intersection graphs and their applications.
|
| 77 |
+
Electronic Notes in Discrete Mathematics 10 (2001), 129--132.
|
| 78 |
+
"""
|
| 79 |
+
G = nx.empty_graph(n + m)
|
| 80 |
+
mset = range(n, n + m)
|
| 81 |
+
for v in range(n):
|
| 82 |
+
targets = seed.sample(mset, k)
|
| 83 |
+
G.add_edges_from(zip([v] * len(targets), targets))
|
| 84 |
+
return nx.projected_graph(G, range(n))
|
| 85 |
+
|
| 86 |
+
|
| 87 |
+
@py_random_state(3)
|
| 88 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 89 |
+
def general_random_intersection_graph(n, m, p, seed=None):
|
| 90 |
+
"""Returns a random intersection graph with independent probabilities
|
| 91 |
+
for connections between node and attribute sets.
|
| 92 |
+
|
| 93 |
+
Parameters
|
| 94 |
+
----------
|
| 95 |
+
n : int
|
| 96 |
+
The number of nodes in the first bipartite set (nodes)
|
| 97 |
+
m : int
|
| 98 |
+
The number of nodes in the second bipartite set (attributes)
|
| 99 |
+
p : list of floats of length m
|
| 100 |
+
Probabilities for connecting nodes to each attribute
|
| 101 |
+
seed : integer, random_state, or None (default)
|
| 102 |
+
Indicator of random number generation state.
|
| 103 |
+
See :ref:`Randomness<randomness>`.
|
| 104 |
+
|
| 105 |
+
See Also
|
| 106 |
+
--------
|
| 107 |
+
gnp_random_graph, uniform_random_intersection_graph
|
| 108 |
+
|
| 109 |
+
References
|
| 110 |
+
----------
|
| 111 |
+
.. [1] Nikoletseas, S. E., Raptopoulos, C., and Spirakis, P. G.
|
| 112 |
+
The existence and efficient construction of large independent sets
|
| 113 |
+
in general random intersection graphs. In ICALP (2004), J. D´ıaz,
|
| 114 |
+
J. Karhum¨aki, A. Lepist¨o, and D. Sannella, Eds., vol. 3142
|
| 115 |
+
of Lecture Notes in Computer Science, Springer, pp. 1029–1040.
|
| 116 |
+
"""
|
| 117 |
+
if len(p) != m:
|
| 118 |
+
raise ValueError("Probability list p must have m elements.")
|
| 119 |
+
G = nx.empty_graph(n + m)
|
| 120 |
+
mset = range(n, n + m)
|
| 121 |
+
for u in range(n):
|
| 122 |
+
for v, q in zip(mset, p):
|
| 123 |
+
if seed.random() < q:
|
| 124 |
+
G.add_edge(u, v)
|
| 125 |
+
return nx.projected_graph(G, range(n))
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/joint_degree_seq.py
ADDED
|
@@ -0,0 +1,664 @@
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|
| 1 |
+
"""Generate graphs with a given joint degree and directed joint degree"""
|
| 2 |
+
|
| 3 |
+
import networkx as nx
|
| 4 |
+
from networkx.utils import py_random_state
|
| 5 |
+
|
| 6 |
+
__all__ = [
|
| 7 |
+
"is_valid_joint_degree",
|
| 8 |
+
"is_valid_directed_joint_degree",
|
| 9 |
+
"joint_degree_graph",
|
| 10 |
+
"directed_joint_degree_graph",
|
| 11 |
+
]
|
| 12 |
+
|
| 13 |
+
|
| 14 |
+
@nx._dispatchable(graphs=None)
|
| 15 |
+
def is_valid_joint_degree(joint_degrees):
|
| 16 |
+
"""Checks whether the given joint degree dictionary is realizable.
|
| 17 |
+
|
| 18 |
+
A *joint degree dictionary* is a dictionary of dictionaries, in
|
| 19 |
+
which entry ``joint_degrees[k][l]`` is an integer representing the
|
| 20 |
+
number of edges joining nodes of degree *k* with nodes of degree
|
| 21 |
+
*l*. Such a dictionary is realizable as a simple graph if and only
|
| 22 |
+
if the following conditions are satisfied.
|
| 23 |
+
|
| 24 |
+
- each entry must be an integer,
|
| 25 |
+
- the total number of nodes of degree *k*, computed by
|
| 26 |
+
``sum(joint_degrees[k].values()) / k``, must be an integer,
|
| 27 |
+
- the total number of edges joining nodes of degree *k* with
|
| 28 |
+
nodes of degree *l* cannot exceed the total number of possible edges,
|
| 29 |
+
- each diagonal entry ``joint_degrees[k][k]`` must be even (this is
|
| 30 |
+
a convention assumed by the :func:`joint_degree_graph` function).
|
| 31 |
+
|
| 32 |
+
|
| 33 |
+
Parameters
|
| 34 |
+
----------
|
| 35 |
+
joint_degrees : dictionary of dictionary of integers
|
| 36 |
+
A joint degree dictionary in which entry ``joint_degrees[k][l]``
|
| 37 |
+
is the number of edges joining nodes of degree *k* with nodes of
|
| 38 |
+
degree *l*.
|
| 39 |
+
|
| 40 |
+
Returns
|
| 41 |
+
-------
|
| 42 |
+
bool
|
| 43 |
+
Whether the given joint degree dictionary is realizable as a
|
| 44 |
+
simple graph.
|
| 45 |
+
|
| 46 |
+
References
|
| 47 |
+
----------
|
| 48 |
+
.. [1] M. Gjoka, M. Kurant, A. Markopoulou, "2.5K Graphs: from Sampling
|
| 49 |
+
to Generation", IEEE Infocom, 2013.
|
| 50 |
+
.. [2] I. Stanton, A. Pinar, "Constructing and sampling graphs with a
|
| 51 |
+
prescribed joint degree distribution", Journal of Experimental
|
| 52 |
+
Algorithmics, 2012.
|
| 53 |
+
"""
|
| 54 |
+
|
| 55 |
+
degree_count = {}
|
| 56 |
+
for k in joint_degrees:
|
| 57 |
+
if k > 0:
|
| 58 |
+
k_size = sum(joint_degrees[k].values()) / k
|
| 59 |
+
if not k_size.is_integer():
|
| 60 |
+
return False
|
| 61 |
+
degree_count[k] = k_size
|
| 62 |
+
|
| 63 |
+
for k in joint_degrees:
|
| 64 |
+
for l in joint_degrees[k]:
|
| 65 |
+
if not float(joint_degrees[k][l]).is_integer():
|
| 66 |
+
return False
|
| 67 |
+
|
| 68 |
+
if (k != l) and (joint_degrees[k][l] > degree_count[k] * degree_count[l]):
|
| 69 |
+
return False
|
| 70 |
+
elif k == l:
|
| 71 |
+
if joint_degrees[k][k] > degree_count[k] * (degree_count[k] - 1):
|
| 72 |
+
return False
|
| 73 |
+
if joint_degrees[k][k] % 2 != 0:
|
| 74 |
+
return False
|
| 75 |
+
|
| 76 |
+
# if all above conditions have been satisfied then the input
|
| 77 |
+
# joint degree is realizable as a simple graph.
|
| 78 |
+
return True
|
| 79 |
+
|
| 80 |
+
|
| 81 |
+
def _neighbor_switch(G, w, unsat, h_node_residual, avoid_node_id=None):
|
| 82 |
+
"""Releases one free stub for ``w``, while preserving joint degree in G.
|
| 83 |
+
|
| 84 |
+
Parameters
|
| 85 |
+
----------
|
| 86 |
+
G : NetworkX graph
|
| 87 |
+
Graph in which the neighbor switch will take place.
|
| 88 |
+
w : integer
|
| 89 |
+
Node id for which we will execute this neighbor switch.
|
| 90 |
+
unsat : set of integers
|
| 91 |
+
Set of unsaturated node ids that have the same degree as w.
|
| 92 |
+
h_node_residual: dictionary of integers
|
| 93 |
+
Keeps track of the remaining stubs for a given node.
|
| 94 |
+
avoid_node_id: integer
|
| 95 |
+
Node id to avoid when selecting w_prime.
|
| 96 |
+
|
| 97 |
+
Notes
|
| 98 |
+
-----
|
| 99 |
+
First, it selects *w_prime*, an unsaturated node that has the same degree
|
| 100 |
+
as ``w``. Second, it selects *switch_node*, a neighbor node of ``w`` that
|
| 101 |
+
is not connected to *w_prime*. Then it executes an edge swap i.e. removes
|
| 102 |
+
(``w``,*switch_node*) and adds (*w_prime*,*switch_node*). Gjoka et. al. [1]
|
| 103 |
+
prove that such an edge swap is always possible.
|
| 104 |
+
|
| 105 |
+
References
|
| 106 |
+
----------
|
| 107 |
+
.. [1] M. Gjoka, B. Tillman, A. Markopoulou, "Construction of Simple
|
| 108 |
+
Graphs with a Target Joint Degree Matrix and Beyond", IEEE Infocom, '15
|
| 109 |
+
"""
|
| 110 |
+
|
| 111 |
+
if (avoid_node_id is None) or (h_node_residual[avoid_node_id] > 1):
|
| 112 |
+
# select unsaturated node w_prime that has the same degree as w
|
| 113 |
+
w_prime = next(iter(unsat))
|
| 114 |
+
else:
|
| 115 |
+
# assume that the node pair (v,w) has been selected for connection. if
|
| 116 |
+
# - neighbor_switch is called for node w,
|
| 117 |
+
# - nodes v and w have the same degree,
|
| 118 |
+
# - node v=avoid_node_id has only one stub left,
|
| 119 |
+
# then prevent v=avoid_node_id from being selected as w_prime.
|
| 120 |
+
|
| 121 |
+
iter_var = iter(unsat)
|
| 122 |
+
while True:
|
| 123 |
+
w_prime = next(iter_var)
|
| 124 |
+
if w_prime != avoid_node_id:
|
| 125 |
+
break
|
| 126 |
+
|
| 127 |
+
# select switch_node, a neighbor of w, that is not connected to w_prime
|
| 128 |
+
w_prime_neighbs = G[w_prime] # slightly faster declaring this variable
|
| 129 |
+
for v in G[w]:
|
| 130 |
+
if (v not in w_prime_neighbs) and (v != w_prime):
|
| 131 |
+
switch_node = v
|
| 132 |
+
break
|
| 133 |
+
|
| 134 |
+
# remove edge (w,switch_node), add edge (w_prime,switch_node) and update
|
| 135 |
+
# data structures
|
| 136 |
+
G.remove_edge(w, switch_node)
|
| 137 |
+
G.add_edge(w_prime, switch_node)
|
| 138 |
+
h_node_residual[w] += 1
|
| 139 |
+
h_node_residual[w_prime] -= 1
|
| 140 |
+
if h_node_residual[w_prime] == 0:
|
| 141 |
+
unsat.remove(w_prime)
|
| 142 |
+
|
| 143 |
+
|
| 144 |
+
@py_random_state(1)
|
| 145 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 146 |
+
def joint_degree_graph(joint_degrees, seed=None):
|
| 147 |
+
"""Generates a random simple graph with the given joint degree dictionary.
|
| 148 |
+
|
| 149 |
+
Parameters
|
| 150 |
+
----------
|
| 151 |
+
joint_degrees : dictionary of dictionary of integers
|
| 152 |
+
A joint degree dictionary in which entry ``joint_degrees[k][l]`` is the
|
| 153 |
+
number of edges joining nodes of degree *k* with nodes of degree *l*.
|
| 154 |
+
seed : integer, random_state, or None (default)
|
| 155 |
+
Indicator of random number generation state.
|
| 156 |
+
See :ref:`Randomness<randomness>`.
|
| 157 |
+
|
| 158 |
+
Returns
|
| 159 |
+
-------
|
| 160 |
+
G : Graph
|
| 161 |
+
A graph with the specified joint degree dictionary.
|
| 162 |
+
|
| 163 |
+
Raises
|
| 164 |
+
------
|
| 165 |
+
NetworkXError
|
| 166 |
+
If *joint_degrees* dictionary is not realizable.
|
| 167 |
+
|
| 168 |
+
Notes
|
| 169 |
+
-----
|
| 170 |
+
In each iteration of the "while loop" the algorithm picks two disconnected
|
| 171 |
+
nodes *v* and *w*, of degree *k* and *l* correspondingly, for which
|
| 172 |
+
``joint_degrees[k][l]`` has not reached its target yet. It then adds
|
| 173 |
+
edge (*v*, *w*) and increases the number of edges in graph G by one.
|
| 174 |
+
|
| 175 |
+
The intelligence of the algorithm lies in the fact that it is always
|
| 176 |
+
possible to add an edge between such disconnected nodes *v* and *w*,
|
| 177 |
+
even if one or both nodes do not have free stubs. That is made possible by
|
| 178 |
+
executing a "neighbor switch", an edge rewiring move that releases
|
| 179 |
+
a free stub while keeping the joint degree of G the same.
|
| 180 |
+
|
| 181 |
+
The algorithm continues for E (number of edges) iterations of
|
| 182 |
+
the "while loop", at the which point all entries of the given
|
| 183 |
+
``joint_degrees[k][l]`` have reached their target values and the
|
| 184 |
+
construction is complete.
|
| 185 |
+
|
| 186 |
+
References
|
| 187 |
+
----------
|
| 188 |
+
.. [1] M. Gjoka, B. Tillman, A. Markopoulou, "Construction of Simple
|
| 189 |
+
Graphs with a Target Joint Degree Matrix and Beyond", IEEE Infocom, '15
|
| 190 |
+
|
| 191 |
+
Examples
|
| 192 |
+
--------
|
| 193 |
+
>>> joint_degrees = {
|
| 194 |
+
... 1: {4: 1},
|
| 195 |
+
... 2: {2: 2, 3: 2, 4: 2},
|
| 196 |
+
... 3: {2: 2, 4: 1},
|
| 197 |
+
... 4: {1: 1, 2: 2, 3: 1},
|
| 198 |
+
... }
|
| 199 |
+
>>> G = nx.joint_degree_graph(joint_degrees)
|
| 200 |
+
>>>
|
| 201 |
+
"""
|
| 202 |
+
|
| 203 |
+
if not is_valid_joint_degree(joint_degrees):
|
| 204 |
+
msg = "Input joint degree dict not realizable as a simple graph"
|
| 205 |
+
raise nx.NetworkXError(msg)
|
| 206 |
+
|
| 207 |
+
# compute degree count from joint_degrees
|
| 208 |
+
degree_count = {k: sum(l.values()) // k for k, l in joint_degrees.items() if k > 0}
|
| 209 |
+
|
| 210 |
+
# start with empty N-node graph
|
| 211 |
+
N = sum(degree_count.values())
|
| 212 |
+
G = nx.empty_graph(N)
|
| 213 |
+
|
| 214 |
+
# for a given degree group, keep the list of all node ids
|
| 215 |
+
h_degree_nodelist = {}
|
| 216 |
+
|
| 217 |
+
# for a given node, keep track of the remaining stubs
|
| 218 |
+
h_node_residual = {}
|
| 219 |
+
|
| 220 |
+
# populate h_degree_nodelist and h_node_residual
|
| 221 |
+
nodeid = 0
|
| 222 |
+
for degree, num_nodes in degree_count.items():
|
| 223 |
+
h_degree_nodelist[degree] = range(nodeid, nodeid + num_nodes)
|
| 224 |
+
for v in h_degree_nodelist[degree]:
|
| 225 |
+
h_node_residual[v] = degree
|
| 226 |
+
nodeid += int(num_nodes)
|
| 227 |
+
|
| 228 |
+
# iterate over every degree pair (k,l) and add the number of edges given
|
| 229 |
+
# for each pair
|
| 230 |
+
for k in joint_degrees:
|
| 231 |
+
for l in joint_degrees[k]:
|
| 232 |
+
# n_edges_add is the number of edges to add for the
|
| 233 |
+
# degree pair (k,l)
|
| 234 |
+
n_edges_add = joint_degrees[k][l]
|
| 235 |
+
|
| 236 |
+
if (n_edges_add > 0) and (k >= l):
|
| 237 |
+
# number of nodes with degree k and l
|
| 238 |
+
k_size = degree_count[k]
|
| 239 |
+
l_size = degree_count[l]
|
| 240 |
+
|
| 241 |
+
# k_nodes and l_nodes consist of all nodes of degree k and l
|
| 242 |
+
k_nodes = h_degree_nodelist[k]
|
| 243 |
+
l_nodes = h_degree_nodelist[l]
|
| 244 |
+
|
| 245 |
+
# k_unsat and l_unsat consist of nodes of degree k and l that
|
| 246 |
+
# are unsaturated (nodes that have at least 1 available stub)
|
| 247 |
+
k_unsat = {v for v in k_nodes if h_node_residual[v] > 0}
|
| 248 |
+
|
| 249 |
+
if k != l:
|
| 250 |
+
l_unsat = {w for w in l_nodes if h_node_residual[w] > 0}
|
| 251 |
+
else:
|
| 252 |
+
l_unsat = k_unsat
|
| 253 |
+
n_edges_add = joint_degrees[k][l] // 2
|
| 254 |
+
|
| 255 |
+
while n_edges_add > 0:
|
| 256 |
+
# randomly pick nodes v and w that have degrees k and l
|
| 257 |
+
v = k_nodes[seed.randrange(k_size)]
|
| 258 |
+
w = l_nodes[seed.randrange(l_size)]
|
| 259 |
+
|
| 260 |
+
# if nodes v and w are disconnected then attempt to connect
|
| 261 |
+
if not G.has_edge(v, w) and (v != w):
|
| 262 |
+
# if node v has no free stubs then do neighbor switch
|
| 263 |
+
if h_node_residual[v] == 0:
|
| 264 |
+
_neighbor_switch(G, v, k_unsat, h_node_residual)
|
| 265 |
+
|
| 266 |
+
# if node w has no free stubs then do neighbor switch
|
| 267 |
+
if h_node_residual[w] == 0:
|
| 268 |
+
if k != l:
|
| 269 |
+
_neighbor_switch(G, w, l_unsat, h_node_residual)
|
| 270 |
+
else:
|
| 271 |
+
_neighbor_switch(
|
| 272 |
+
G, w, l_unsat, h_node_residual, avoid_node_id=v
|
| 273 |
+
)
|
| 274 |
+
|
| 275 |
+
# add edge (v, w) and update data structures
|
| 276 |
+
G.add_edge(v, w)
|
| 277 |
+
h_node_residual[v] -= 1
|
| 278 |
+
h_node_residual[w] -= 1
|
| 279 |
+
n_edges_add -= 1
|
| 280 |
+
|
| 281 |
+
if h_node_residual[v] == 0:
|
| 282 |
+
k_unsat.discard(v)
|
| 283 |
+
if h_node_residual[w] == 0:
|
| 284 |
+
l_unsat.discard(w)
|
| 285 |
+
return G
|
| 286 |
+
|
| 287 |
+
|
| 288 |
+
@nx._dispatchable(graphs=None)
|
| 289 |
+
def is_valid_directed_joint_degree(in_degrees, out_degrees, nkk):
|
| 290 |
+
"""Checks whether the given directed joint degree input is realizable
|
| 291 |
+
|
| 292 |
+
Parameters
|
| 293 |
+
----------
|
| 294 |
+
in_degrees : list of integers
|
| 295 |
+
in degree sequence contains the in degrees of nodes.
|
| 296 |
+
out_degrees : list of integers
|
| 297 |
+
out degree sequence contains the out degrees of nodes.
|
| 298 |
+
nkk : dictionary of dictionary of integers
|
| 299 |
+
directed joint degree dictionary. for nodes of out degree k (first
|
| 300 |
+
level of dict) and nodes of in degree l (second level of dict)
|
| 301 |
+
describes the number of edges.
|
| 302 |
+
|
| 303 |
+
Returns
|
| 304 |
+
-------
|
| 305 |
+
boolean
|
| 306 |
+
returns true if given input is realizable, else returns false.
|
| 307 |
+
|
| 308 |
+
Notes
|
| 309 |
+
-----
|
| 310 |
+
Here is the list of conditions that the inputs (in/out degree sequences,
|
| 311 |
+
nkk) need to satisfy for simple directed graph realizability:
|
| 312 |
+
|
| 313 |
+
- Condition 0: in_degrees and out_degrees have the same length
|
| 314 |
+
- Condition 1: nkk[k][l] is integer for all k,l
|
| 315 |
+
- Condition 2: sum(nkk[k])/k = number of nodes with partition id k, is an
|
| 316 |
+
integer and matching degree sequence
|
| 317 |
+
- Condition 3: number of edges and non-chords between k and l cannot exceed
|
| 318 |
+
maximum possible number of edges
|
| 319 |
+
|
| 320 |
+
|
| 321 |
+
References
|
| 322 |
+
----------
|
| 323 |
+
[1] B. Tillman, A. Markopoulou, C. T. Butts & M. Gjoka,
|
| 324 |
+
"Construction of Directed 2K Graphs". In Proc. of KDD 2017.
|
| 325 |
+
"""
|
| 326 |
+
V = {} # number of nodes with in/out degree.
|
| 327 |
+
forbidden = {}
|
| 328 |
+
if len(in_degrees) != len(out_degrees):
|
| 329 |
+
return False
|
| 330 |
+
|
| 331 |
+
for idx in range(len(in_degrees)):
|
| 332 |
+
i = in_degrees[idx]
|
| 333 |
+
o = out_degrees[idx]
|
| 334 |
+
V[(i, 0)] = V.get((i, 0), 0) + 1
|
| 335 |
+
V[(o, 1)] = V.get((o, 1), 0) + 1
|
| 336 |
+
|
| 337 |
+
forbidden[(o, i)] = forbidden.get((o, i), 0) + 1
|
| 338 |
+
|
| 339 |
+
S = {} # number of edges going from in/out degree nodes.
|
| 340 |
+
for k in nkk:
|
| 341 |
+
for l in nkk[k]:
|
| 342 |
+
val = nkk[k][l]
|
| 343 |
+
if not float(val).is_integer(): # condition 1
|
| 344 |
+
return False
|
| 345 |
+
|
| 346 |
+
if val > 0:
|
| 347 |
+
S[(k, 1)] = S.get((k, 1), 0) + val
|
| 348 |
+
S[(l, 0)] = S.get((l, 0), 0) + val
|
| 349 |
+
# condition 3
|
| 350 |
+
if val + forbidden.get((k, l), 0) > V[(k, 1)] * V[(l, 0)]:
|
| 351 |
+
return False
|
| 352 |
+
|
| 353 |
+
return all(S[s] / s[0] == V[s] for s in S)
|
| 354 |
+
|
| 355 |
+
|
| 356 |
+
def _directed_neighbor_switch(
|
| 357 |
+
G, w, unsat, h_node_residual_out, chords, h_partition_in, partition
|
| 358 |
+
):
|
| 359 |
+
"""Releases one free stub for node w, while preserving joint degree in G.
|
| 360 |
+
|
| 361 |
+
Parameters
|
| 362 |
+
----------
|
| 363 |
+
G : networkx directed graph
|
| 364 |
+
graph within which the edge swap will take place.
|
| 365 |
+
w : integer
|
| 366 |
+
node id for which we need to perform a neighbor switch.
|
| 367 |
+
unsat: set of integers
|
| 368 |
+
set of node ids that have the same degree as w and are unsaturated.
|
| 369 |
+
h_node_residual_out: dict of integers
|
| 370 |
+
for a given node, keeps track of the remaining stubs to be added.
|
| 371 |
+
chords: set of tuples
|
| 372 |
+
keeps track of available positions to add edges.
|
| 373 |
+
h_partition_in: dict of integers
|
| 374 |
+
for a given node, keeps track of its partition id (in degree).
|
| 375 |
+
partition: integer
|
| 376 |
+
partition id to check if chords have to be updated.
|
| 377 |
+
|
| 378 |
+
Notes
|
| 379 |
+
-----
|
| 380 |
+
First, it selects node w_prime that (1) has the same degree as w and
|
| 381 |
+
(2) is unsaturated. Then, it selects node v, a neighbor of w, that is
|
| 382 |
+
not connected to w_prime and does an edge swap i.e. removes (w,v) and
|
| 383 |
+
adds (w_prime,v). If neighbor switch is not possible for w using
|
| 384 |
+
w_prime and v, then return w_prime; in [1] it's proven that
|
| 385 |
+
such unsaturated nodes can be used.
|
| 386 |
+
|
| 387 |
+
References
|
| 388 |
+
----------
|
| 389 |
+
[1] B. Tillman, A. Markopoulou, C. T. Butts & M. Gjoka,
|
| 390 |
+
"Construction of Directed 2K Graphs". In Proc. of KDD 2017.
|
| 391 |
+
"""
|
| 392 |
+
w_prime = unsat.pop()
|
| 393 |
+
unsat.add(w_prime)
|
| 394 |
+
# select node t, a neighbor of w, that is not connected to w_prime
|
| 395 |
+
w_neighbs = list(G.successors(w))
|
| 396 |
+
# slightly faster declaring this variable
|
| 397 |
+
w_prime_neighbs = list(G.successors(w_prime))
|
| 398 |
+
|
| 399 |
+
for v in w_neighbs:
|
| 400 |
+
if (v not in w_prime_neighbs) and w_prime != v:
|
| 401 |
+
# removes (w,v), add (w_prime,v) and update data structures
|
| 402 |
+
G.remove_edge(w, v)
|
| 403 |
+
G.add_edge(w_prime, v)
|
| 404 |
+
|
| 405 |
+
if h_partition_in[v] == partition:
|
| 406 |
+
chords.add((w, v))
|
| 407 |
+
chords.discard((w_prime, v))
|
| 408 |
+
|
| 409 |
+
h_node_residual_out[w] += 1
|
| 410 |
+
h_node_residual_out[w_prime] -= 1
|
| 411 |
+
if h_node_residual_out[w_prime] == 0:
|
| 412 |
+
unsat.remove(w_prime)
|
| 413 |
+
return None
|
| 414 |
+
|
| 415 |
+
# If neighbor switch didn't work, use unsaturated node
|
| 416 |
+
return w_prime
|
| 417 |
+
|
| 418 |
+
|
| 419 |
+
def _directed_neighbor_switch_rev(
|
| 420 |
+
G, w, unsat, h_node_residual_in, chords, h_partition_out, partition
|
| 421 |
+
):
|
| 422 |
+
"""The reverse of directed_neighbor_switch.
|
| 423 |
+
|
| 424 |
+
Parameters
|
| 425 |
+
----------
|
| 426 |
+
G : networkx directed graph
|
| 427 |
+
graph within which the edge swap will take place.
|
| 428 |
+
w : integer
|
| 429 |
+
node id for which we need to perform a neighbor switch.
|
| 430 |
+
unsat: set of integers
|
| 431 |
+
set of node ids that have the same degree as w and are unsaturated.
|
| 432 |
+
h_node_residual_in: dict of integers
|
| 433 |
+
for a given node, keeps track of the remaining stubs to be added.
|
| 434 |
+
chords: set of tuples
|
| 435 |
+
keeps track of available positions to add edges.
|
| 436 |
+
h_partition_out: dict of integers
|
| 437 |
+
for a given node, keeps track of its partition id (out degree).
|
| 438 |
+
partition: integer
|
| 439 |
+
partition id to check if chords have to be updated.
|
| 440 |
+
|
| 441 |
+
Notes
|
| 442 |
+
-----
|
| 443 |
+
Same operation as directed_neighbor_switch except it handles this operation
|
| 444 |
+
for incoming edges instead of outgoing.
|
| 445 |
+
"""
|
| 446 |
+
w_prime = unsat.pop()
|
| 447 |
+
unsat.add(w_prime)
|
| 448 |
+
# slightly faster declaring these as variables.
|
| 449 |
+
w_neighbs = list(G.predecessors(w))
|
| 450 |
+
w_prime_neighbs = list(G.predecessors(w_prime))
|
| 451 |
+
# select node v, a neighbor of w, that is not connected to w_prime.
|
| 452 |
+
for v in w_neighbs:
|
| 453 |
+
if (v not in w_prime_neighbs) and w_prime != v:
|
| 454 |
+
# removes (v,w), add (v,w_prime) and update data structures.
|
| 455 |
+
G.remove_edge(v, w)
|
| 456 |
+
G.add_edge(v, w_prime)
|
| 457 |
+
if h_partition_out[v] == partition:
|
| 458 |
+
chords.add((v, w))
|
| 459 |
+
chords.discard((v, w_prime))
|
| 460 |
+
|
| 461 |
+
h_node_residual_in[w] += 1
|
| 462 |
+
h_node_residual_in[w_prime] -= 1
|
| 463 |
+
if h_node_residual_in[w_prime] == 0:
|
| 464 |
+
unsat.remove(w_prime)
|
| 465 |
+
return None
|
| 466 |
+
|
| 467 |
+
# If neighbor switch didn't work, use the unsaturated node.
|
| 468 |
+
return w_prime
|
| 469 |
+
|
| 470 |
+
|
| 471 |
+
@py_random_state(3)
|
| 472 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 473 |
+
def directed_joint_degree_graph(in_degrees, out_degrees, nkk, seed=None):
|
| 474 |
+
"""Generates a random simple directed graph with the joint degree.
|
| 475 |
+
|
| 476 |
+
Parameters
|
| 477 |
+
----------
|
| 478 |
+
degree_seq : list of tuples (of size 3)
|
| 479 |
+
degree sequence contains tuples of nodes with node id, in degree and
|
| 480 |
+
out degree.
|
| 481 |
+
nkk : dictionary of dictionary of integers
|
| 482 |
+
directed joint degree dictionary, for nodes of out degree k (first
|
| 483 |
+
level of dict) and nodes of in degree l (second level of dict)
|
| 484 |
+
describes the number of edges.
|
| 485 |
+
seed : hashable object, optional
|
| 486 |
+
Seed for random number generator.
|
| 487 |
+
|
| 488 |
+
Returns
|
| 489 |
+
-------
|
| 490 |
+
G : Graph
|
| 491 |
+
A directed graph with the specified inputs.
|
| 492 |
+
|
| 493 |
+
Raises
|
| 494 |
+
------
|
| 495 |
+
NetworkXError
|
| 496 |
+
If degree_seq and nkk are not realizable as a simple directed graph.
|
| 497 |
+
|
| 498 |
+
|
| 499 |
+
Notes
|
| 500 |
+
-----
|
| 501 |
+
Similarly to the undirected version:
|
| 502 |
+
In each iteration of the "while loop" the algorithm picks two disconnected
|
| 503 |
+
nodes v and w, of degree k and l correspondingly, for which nkk[k][l] has
|
| 504 |
+
not reached its target yet i.e. (for given k,l): n_edges_add < nkk[k][l].
|
| 505 |
+
It then adds edge (v,w) and always increases the number of edges in graph G
|
| 506 |
+
by one.
|
| 507 |
+
|
| 508 |
+
The intelligence of the algorithm lies in the fact that it is always
|
| 509 |
+
possible to add an edge between disconnected nodes v and w, for which
|
| 510 |
+
nkk[degree(v)][degree(w)] has not reached its target, even if one or both
|
| 511 |
+
nodes do not have free stubs. If either node v or w does not have a free
|
| 512 |
+
stub, we perform a "neighbor switch", an edge rewiring move that releases a
|
| 513 |
+
free stub while keeping nkk the same.
|
| 514 |
+
|
| 515 |
+
The difference for the directed version lies in the fact that neighbor
|
| 516 |
+
switches might not be able to rewire, but in these cases unsaturated nodes
|
| 517 |
+
can be reassigned to use instead, see [1] for detailed description and
|
| 518 |
+
proofs.
|
| 519 |
+
|
| 520 |
+
The algorithm continues for E (number of edges in the graph) iterations of
|
| 521 |
+
the "while loop", at which point all entries of the given nkk[k][l] have
|
| 522 |
+
reached their target values and the construction is complete.
|
| 523 |
+
|
| 524 |
+
References
|
| 525 |
+
----------
|
| 526 |
+
[1] B. Tillman, A. Markopoulou, C. T. Butts & M. Gjoka,
|
| 527 |
+
"Construction of Directed 2K Graphs". In Proc. of KDD 2017.
|
| 528 |
+
|
| 529 |
+
Examples
|
| 530 |
+
--------
|
| 531 |
+
>>> in_degrees = [0, 1, 1, 2]
|
| 532 |
+
>>> out_degrees = [1, 1, 1, 1]
|
| 533 |
+
>>> nkk = {1: {1: 2, 2: 2}}
|
| 534 |
+
>>> G = nx.directed_joint_degree_graph(in_degrees, out_degrees, nkk)
|
| 535 |
+
>>>
|
| 536 |
+
"""
|
| 537 |
+
if not is_valid_directed_joint_degree(in_degrees, out_degrees, nkk):
|
| 538 |
+
msg = "Input is not realizable as a simple graph"
|
| 539 |
+
raise nx.NetworkXError(msg)
|
| 540 |
+
|
| 541 |
+
# start with an empty directed graph.
|
| 542 |
+
G = nx.DiGraph()
|
| 543 |
+
|
| 544 |
+
# for a given group, keep the list of all node ids.
|
| 545 |
+
h_degree_nodelist_in = {}
|
| 546 |
+
h_degree_nodelist_out = {}
|
| 547 |
+
# for a given group, keep the list of all unsaturated node ids.
|
| 548 |
+
h_degree_nodelist_in_unsat = {}
|
| 549 |
+
h_degree_nodelist_out_unsat = {}
|
| 550 |
+
# for a given node, keep track of the remaining stubs to be added.
|
| 551 |
+
h_node_residual_out = {}
|
| 552 |
+
h_node_residual_in = {}
|
| 553 |
+
# for a given node, keep track of the partition id.
|
| 554 |
+
h_partition_out = {}
|
| 555 |
+
h_partition_in = {}
|
| 556 |
+
# keep track of non-chords between pairs of partition ids.
|
| 557 |
+
non_chords = {}
|
| 558 |
+
|
| 559 |
+
# populate data structures
|
| 560 |
+
for idx, i in enumerate(in_degrees):
|
| 561 |
+
idx = int(idx)
|
| 562 |
+
if i > 0:
|
| 563 |
+
h_degree_nodelist_in.setdefault(i, [])
|
| 564 |
+
h_degree_nodelist_in_unsat.setdefault(i, set())
|
| 565 |
+
h_degree_nodelist_in[i].append(idx)
|
| 566 |
+
h_degree_nodelist_in_unsat[i].add(idx)
|
| 567 |
+
h_node_residual_in[idx] = i
|
| 568 |
+
h_partition_in[idx] = i
|
| 569 |
+
|
| 570 |
+
for idx, o in enumerate(out_degrees):
|
| 571 |
+
o = out_degrees[idx]
|
| 572 |
+
non_chords[(o, in_degrees[idx])] = non_chords.get((o, in_degrees[idx]), 0) + 1
|
| 573 |
+
idx = int(idx)
|
| 574 |
+
if o > 0:
|
| 575 |
+
h_degree_nodelist_out.setdefault(o, [])
|
| 576 |
+
h_degree_nodelist_out_unsat.setdefault(o, set())
|
| 577 |
+
h_degree_nodelist_out[o].append(idx)
|
| 578 |
+
h_degree_nodelist_out_unsat[o].add(idx)
|
| 579 |
+
h_node_residual_out[idx] = o
|
| 580 |
+
h_partition_out[idx] = o
|
| 581 |
+
|
| 582 |
+
G.add_node(idx)
|
| 583 |
+
|
| 584 |
+
nk_in = {}
|
| 585 |
+
nk_out = {}
|
| 586 |
+
for p in h_degree_nodelist_in:
|
| 587 |
+
nk_in[p] = len(h_degree_nodelist_in[p])
|
| 588 |
+
for p in h_degree_nodelist_out:
|
| 589 |
+
nk_out[p] = len(h_degree_nodelist_out[p])
|
| 590 |
+
|
| 591 |
+
# iterate over every degree pair (k,l) and add the number of edges given
|
| 592 |
+
# for each pair.
|
| 593 |
+
for k in nkk:
|
| 594 |
+
for l in nkk[k]:
|
| 595 |
+
n_edges_add = nkk[k][l]
|
| 596 |
+
|
| 597 |
+
if n_edges_add > 0:
|
| 598 |
+
# chords contains a random set of potential edges.
|
| 599 |
+
chords = set()
|
| 600 |
+
|
| 601 |
+
k_len = nk_out[k]
|
| 602 |
+
l_len = nk_in[l]
|
| 603 |
+
chords_sample = seed.sample(
|
| 604 |
+
range(k_len * l_len), n_edges_add + non_chords.get((k, l), 0)
|
| 605 |
+
)
|
| 606 |
+
|
| 607 |
+
num = 0
|
| 608 |
+
while len(chords) < n_edges_add:
|
| 609 |
+
i = h_degree_nodelist_out[k][chords_sample[num] % k_len]
|
| 610 |
+
j = h_degree_nodelist_in[l][chords_sample[num] // k_len]
|
| 611 |
+
num += 1
|
| 612 |
+
if i != j:
|
| 613 |
+
chords.add((i, j))
|
| 614 |
+
|
| 615 |
+
# k_unsat and l_unsat consist of nodes of in/out degree k and l
|
| 616 |
+
# that are unsaturated i.e. those nodes that have at least one
|
| 617 |
+
# available stub
|
| 618 |
+
k_unsat = h_degree_nodelist_out_unsat[k]
|
| 619 |
+
l_unsat = h_degree_nodelist_in_unsat[l]
|
| 620 |
+
|
| 621 |
+
while n_edges_add > 0:
|
| 622 |
+
v, w = chords.pop()
|
| 623 |
+
chords.add((v, w))
|
| 624 |
+
|
| 625 |
+
# if node v has no free stubs then do neighbor switch.
|
| 626 |
+
if h_node_residual_out[v] == 0:
|
| 627 |
+
_v = _directed_neighbor_switch(
|
| 628 |
+
G,
|
| 629 |
+
v,
|
| 630 |
+
k_unsat,
|
| 631 |
+
h_node_residual_out,
|
| 632 |
+
chords,
|
| 633 |
+
h_partition_in,
|
| 634 |
+
l,
|
| 635 |
+
)
|
| 636 |
+
if _v is not None:
|
| 637 |
+
v = _v
|
| 638 |
+
|
| 639 |
+
# if node w has no free stubs then do neighbor switch.
|
| 640 |
+
if h_node_residual_in[w] == 0:
|
| 641 |
+
_w = _directed_neighbor_switch_rev(
|
| 642 |
+
G,
|
| 643 |
+
w,
|
| 644 |
+
l_unsat,
|
| 645 |
+
h_node_residual_in,
|
| 646 |
+
chords,
|
| 647 |
+
h_partition_out,
|
| 648 |
+
k,
|
| 649 |
+
)
|
| 650 |
+
if _w is not None:
|
| 651 |
+
w = _w
|
| 652 |
+
|
| 653 |
+
# add edge (v,w) and update data structures.
|
| 654 |
+
G.add_edge(v, w)
|
| 655 |
+
h_node_residual_out[v] -= 1
|
| 656 |
+
h_node_residual_in[w] -= 1
|
| 657 |
+
n_edges_add -= 1
|
| 658 |
+
chords.discard((v, w))
|
| 659 |
+
|
| 660 |
+
if h_node_residual_out[v] == 0:
|
| 661 |
+
k_unsat.discard(v)
|
| 662 |
+
if h_node_residual_in[w] == 0:
|
| 663 |
+
l_unsat.discard(w)
|
| 664 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/lattice.py
ADDED
|
@@ -0,0 +1,367 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
| 1 |
+
"""Functions for generating grid graphs and lattices
|
| 2 |
+
|
| 3 |
+
The :func:`grid_2d_graph`, :func:`triangular_lattice_graph`, and
|
| 4 |
+
:func:`hexagonal_lattice_graph` functions correspond to the three
|
| 5 |
+
`regular tilings of the plane`_, the square, triangular, and hexagonal
|
| 6 |
+
tilings, respectively. :func:`grid_graph` and :func:`hypercube_graph`
|
| 7 |
+
are similar for arbitrary dimensions. Useful relevant discussion can
|
| 8 |
+
be found about `Triangular Tiling`_, and `Square, Hex and Triangle Grids`_
|
| 9 |
+
|
| 10 |
+
.. _regular tilings of the plane: https://en.wikipedia.org/wiki/List_of_regular_polytopes_and_compounds#Euclidean_tilings
|
| 11 |
+
.. _Square, Hex and Triangle Grids: http://www-cs-students.stanford.edu/~amitp/game-programming/grids/
|
| 12 |
+
.. _Triangular Tiling: https://en.wikipedia.org/wiki/Triangular_tiling
|
| 13 |
+
|
| 14 |
+
"""
|
| 15 |
+
|
| 16 |
+
from itertools import repeat
|
| 17 |
+
from math import sqrt
|
| 18 |
+
|
| 19 |
+
import networkx as nx
|
| 20 |
+
from networkx.classes import set_node_attributes
|
| 21 |
+
from networkx.exception import NetworkXError
|
| 22 |
+
from networkx.generators.classic import cycle_graph, empty_graph, path_graph
|
| 23 |
+
from networkx.relabel import relabel_nodes
|
| 24 |
+
from networkx.utils import flatten, nodes_or_number, pairwise
|
| 25 |
+
|
| 26 |
+
__all__ = [
|
| 27 |
+
"grid_2d_graph",
|
| 28 |
+
"grid_graph",
|
| 29 |
+
"hypercube_graph",
|
| 30 |
+
"triangular_lattice_graph",
|
| 31 |
+
"hexagonal_lattice_graph",
|
| 32 |
+
]
|
| 33 |
+
|
| 34 |
+
|
| 35 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 36 |
+
@nodes_or_number([0, 1])
|
| 37 |
+
def grid_2d_graph(m, n, periodic=False, create_using=None):
|
| 38 |
+
"""Returns the two-dimensional grid graph.
|
| 39 |
+
|
| 40 |
+
The grid graph has each node connected to its four nearest neighbors.
|
| 41 |
+
|
| 42 |
+
Parameters
|
| 43 |
+
----------
|
| 44 |
+
m, n : int or iterable container of nodes
|
| 45 |
+
If an integer, nodes are from `range(n)`.
|
| 46 |
+
If a container, elements become the coordinate of the nodes.
|
| 47 |
+
|
| 48 |
+
periodic : bool or iterable
|
| 49 |
+
If `periodic` is True, both dimensions are periodic. If False, none
|
| 50 |
+
are periodic. If `periodic` is iterable, it should yield 2 bool
|
| 51 |
+
values indicating whether the 1st and 2nd axes, respectively, are
|
| 52 |
+
periodic.
|
| 53 |
+
|
| 54 |
+
create_using : NetworkX graph constructor, optional (default=nx.Graph)
|
| 55 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 56 |
+
|
| 57 |
+
Returns
|
| 58 |
+
-------
|
| 59 |
+
NetworkX graph
|
| 60 |
+
The (possibly periodic) grid graph of the specified dimensions.
|
| 61 |
+
|
| 62 |
+
"""
|
| 63 |
+
G = empty_graph(0, create_using)
|
| 64 |
+
row_name, rows = m
|
| 65 |
+
col_name, cols = n
|
| 66 |
+
G.add_nodes_from((i, j) for i in rows for j in cols)
|
| 67 |
+
G.add_edges_from(((i, j), (pi, j)) for pi, i in pairwise(rows) for j in cols)
|
| 68 |
+
G.add_edges_from(((i, j), (i, pj)) for i in rows for pj, j in pairwise(cols))
|
| 69 |
+
|
| 70 |
+
try:
|
| 71 |
+
periodic_r, periodic_c = periodic
|
| 72 |
+
except TypeError:
|
| 73 |
+
periodic_r = periodic_c = periodic
|
| 74 |
+
|
| 75 |
+
if periodic_r and len(rows) > 2:
|
| 76 |
+
first = rows[0]
|
| 77 |
+
last = rows[-1]
|
| 78 |
+
G.add_edges_from(((first, j), (last, j)) for j in cols)
|
| 79 |
+
if periodic_c and len(cols) > 2:
|
| 80 |
+
first = cols[0]
|
| 81 |
+
last = cols[-1]
|
| 82 |
+
G.add_edges_from(((i, first), (i, last)) for i in rows)
|
| 83 |
+
# both directions for directed
|
| 84 |
+
if G.is_directed():
|
| 85 |
+
G.add_edges_from((v, u) for u, v in G.edges())
|
| 86 |
+
return G
|
| 87 |
+
|
| 88 |
+
|
| 89 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 90 |
+
def grid_graph(dim, periodic=False):
|
| 91 |
+
"""Returns the *n*-dimensional grid graph.
|
| 92 |
+
|
| 93 |
+
The dimension *n* is the length of the list `dim` and the size in
|
| 94 |
+
each dimension is the value of the corresponding list element.
|
| 95 |
+
|
| 96 |
+
Parameters
|
| 97 |
+
----------
|
| 98 |
+
dim : list or tuple of numbers or iterables of nodes
|
| 99 |
+
'dim' is a tuple or list with, for each dimension, either a number
|
| 100 |
+
that is the size of that dimension or an iterable of nodes for
|
| 101 |
+
that dimension. The dimension of the grid_graph is the length
|
| 102 |
+
of `dim`.
|
| 103 |
+
|
| 104 |
+
periodic : bool or iterable
|
| 105 |
+
If `periodic` is True, all dimensions are periodic. If False all
|
| 106 |
+
dimensions are not periodic. If `periodic` is iterable, it should
|
| 107 |
+
yield `dim` bool values each of which indicates whether the
|
| 108 |
+
corresponding axis is periodic.
|
| 109 |
+
|
| 110 |
+
Returns
|
| 111 |
+
-------
|
| 112 |
+
NetworkX graph
|
| 113 |
+
The (possibly periodic) grid graph of the specified dimensions.
|
| 114 |
+
|
| 115 |
+
Examples
|
| 116 |
+
--------
|
| 117 |
+
To produce a 2 by 3 by 4 grid graph, a graph on 24 nodes:
|
| 118 |
+
|
| 119 |
+
>>> from networkx import grid_graph
|
| 120 |
+
>>> G = grid_graph(dim=(2, 3, 4))
|
| 121 |
+
>>> len(G)
|
| 122 |
+
24
|
| 123 |
+
>>> G = grid_graph(dim=(range(7, 9), range(3, 6)))
|
| 124 |
+
>>> len(G)
|
| 125 |
+
6
|
| 126 |
+
"""
|
| 127 |
+
from networkx.algorithms.operators.product import cartesian_product
|
| 128 |
+
|
| 129 |
+
if not dim:
|
| 130 |
+
return empty_graph(0)
|
| 131 |
+
|
| 132 |
+
try:
|
| 133 |
+
func = (cycle_graph if p else path_graph for p in periodic)
|
| 134 |
+
except TypeError:
|
| 135 |
+
func = repeat(cycle_graph if periodic else path_graph)
|
| 136 |
+
|
| 137 |
+
G = next(func)(dim[0])
|
| 138 |
+
for current_dim in dim[1:]:
|
| 139 |
+
Gnew = next(func)(current_dim)
|
| 140 |
+
G = cartesian_product(Gnew, G)
|
| 141 |
+
# graph G is done but has labels of the form (1, (2, (3, 1))) so relabel
|
| 142 |
+
H = relabel_nodes(G, flatten)
|
| 143 |
+
return H
|
| 144 |
+
|
| 145 |
+
|
| 146 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 147 |
+
def hypercube_graph(n):
|
| 148 |
+
"""Returns the *n*-dimensional hypercube graph.
|
| 149 |
+
|
| 150 |
+
The nodes are the integers between 0 and ``2 ** n - 1``, inclusive.
|
| 151 |
+
|
| 152 |
+
For more information on the hypercube graph, see the Wikipedia
|
| 153 |
+
article `Hypercube graph`_.
|
| 154 |
+
|
| 155 |
+
.. _Hypercube graph: https://en.wikipedia.org/wiki/Hypercube_graph
|
| 156 |
+
|
| 157 |
+
Parameters
|
| 158 |
+
----------
|
| 159 |
+
n : int
|
| 160 |
+
The dimension of the hypercube.
|
| 161 |
+
The number of nodes in the graph will be ``2 ** n``.
|
| 162 |
+
|
| 163 |
+
Returns
|
| 164 |
+
-------
|
| 165 |
+
NetworkX graph
|
| 166 |
+
The hypercube graph of dimension *n*.
|
| 167 |
+
"""
|
| 168 |
+
dim = n * [2]
|
| 169 |
+
G = grid_graph(dim)
|
| 170 |
+
return G
|
| 171 |
+
|
| 172 |
+
|
| 173 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 174 |
+
def triangular_lattice_graph(
|
| 175 |
+
m, n, periodic=False, with_positions=True, create_using=None
|
| 176 |
+
):
|
| 177 |
+
r"""Returns the $m$ by $n$ triangular lattice graph.
|
| 178 |
+
|
| 179 |
+
The `triangular lattice graph`_ is a two-dimensional `grid graph`_ in
|
| 180 |
+
which each square unit has a diagonal edge (each grid unit has a chord).
|
| 181 |
+
|
| 182 |
+
The returned graph has $m$ rows and $n$ columns of triangles. Rows and
|
| 183 |
+
columns include both triangles pointing up and down. Rows form a strip
|
| 184 |
+
of constant height. Columns form a series of diamond shapes, staggered
|
| 185 |
+
with the columns on either side. Another way to state the size is that
|
| 186 |
+
the nodes form a grid of `m+1` rows and `(n + 1) // 2` columns.
|
| 187 |
+
The odd row nodes are shifted horizontally relative to the even rows.
|
| 188 |
+
|
| 189 |
+
Directed graph types have edges pointed up or right.
|
| 190 |
+
|
| 191 |
+
Positions of nodes are computed by default or `with_positions is True`.
|
| 192 |
+
The position of each node (embedded in a euclidean plane) is stored in
|
| 193 |
+
the graph using equilateral triangles with sidelength 1.
|
| 194 |
+
The height between rows of nodes is thus $\sqrt(3)/2$.
|
| 195 |
+
Nodes lie in the first quadrant with the node $(0, 0)$ at the origin.
|
| 196 |
+
|
| 197 |
+
.. _triangular lattice graph: http://mathworld.wolfram.com/TriangularGrid.html
|
| 198 |
+
.. _grid graph: http://www-cs-students.stanford.edu/~amitp/game-programming/grids/
|
| 199 |
+
.. _Triangular Tiling: https://en.wikipedia.org/wiki/Triangular_tiling
|
| 200 |
+
|
| 201 |
+
Parameters
|
| 202 |
+
----------
|
| 203 |
+
m : int
|
| 204 |
+
The number of rows in the lattice.
|
| 205 |
+
|
| 206 |
+
n : int
|
| 207 |
+
The number of columns in the lattice.
|
| 208 |
+
|
| 209 |
+
periodic : bool (default: False)
|
| 210 |
+
If True, join the boundary vertices of the grid using periodic
|
| 211 |
+
boundary conditions. The join between boundaries is the final row
|
| 212 |
+
and column of triangles. This means there is one row and one column
|
| 213 |
+
fewer nodes for the periodic lattice. Periodic lattices require
|
| 214 |
+
`m >= 3`, `n >= 5` and are allowed but misaligned if `m` or `n` are odd
|
| 215 |
+
|
| 216 |
+
with_positions : bool (default: True)
|
| 217 |
+
Store the coordinates of each node in the graph node attribute 'pos'.
|
| 218 |
+
The coordinates provide a lattice with equilateral triangles.
|
| 219 |
+
Periodic positions shift the nodes vertically in a nonlinear way so
|
| 220 |
+
the edges don't overlap so much.
|
| 221 |
+
|
| 222 |
+
create_using : NetworkX graph constructor, optional (default=nx.Graph)
|
| 223 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 224 |
+
|
| 225 |
+
Returns
|
| 226 |
+
-------
|
| 227 |
+
NetworkX graph
|
| 228 |
+
The *m* by *n* triangular lattice graph.
|
| 229 |
+
"""
|
| 230 |
+
H = empty_graph(0, create_using)
|
| 231 |
+
if n == 0 or m == 0:
|
| 232 |
+
return H
|
| 233 |
+
if periodic:
|
| 234 |
+
if n < 5 or m < 3:
|
| 235 |
+
msg = f"m > 2 and n > 4 required for periodic. m={m}, n={n}"
|
| 236 |
+
raise NetworkXError(msg)
|
| 237 |
+
|
| 238 |
+
N = (n + 1) // 2 # number of nodes in row
|
| 239 |
+
rows = range(m + 1)
|
| 240 |
+
cols = range(N + 1)
|
| 241 |
+
# Make grid
|
| 242 |
+
H.add_edges_from(((i, j), (i + 1, j)) for j in rows for i in cols[:N])
|
| 243 |
+
H.add_edges_from(((i, j), (i, j + 1)) for j in rows[:m] for i in cols)
|
| 244 |
+
# add diagonals
|
| 245 |
+
H.add_edges_from(((i, j), (i + 1, j + 1)) for j in rows[1:m:2] for i in cols[:N])
|
| 246 |
+
H.add_edges_from(((i + 1, j), (i, j + 1)) for j in rows[:m:2] for i in cols[:N])
|
| 247 |
+
# identify boundary nodes if periodic
|
| 248 |
+
from networkx.algorithms.minors import contracted_nodes
|
| 249 |
+
|
| 250 |
+
if periodic is True:
|
| 251 |
+
for i in cols:
|
| 252 |
+
H = contracted_nodes(H, (i, 0), (i, m))
|
| 253 |
+
for j in rows[:m]:
|
| 254 |
+
H = contracted_nodes(H, (0, j), (N, j))
|
| 255 |
+
elif n % 2:
|
| 256 |
+
# remove extra nodes
|
| 257 |
+
H.remove_nodes_from((N, j) for j in rows[1::2])
|
| 258 |
+
|
| 259 |
+
# Add position node attributes
|
| 260 |
+
if with_positions:
|
| 261 |
+
ii = (i for i in cols for j in rows)
|
| 262 |
+
jj = (j for i in cols for j in rows)
|
| 263 |
+
xx = (0.5 * (j % 2) + i for i in cols for j in rows)
|
| 264 |
+
h = sqrt(3) / 2
|
| 265 |
+
if periodic:
|
| 266 |
+
yy = (h * j + 0.01 * i * i for i in cols for j in rows)
|
| 267 |
+
else:
|
| 268 |
+
yy = (h * j for i in cols for j in rows)
|
| 269 |
+
pos = {(i, j): (x, y) for i, j, x, y in zip(ii, jj, xx, yy) if (i, j) in H}
|
| 270 |
+
set_node_attributes(H, pos, "pos")
|
| 271 |
+
return H
|
| 272 |
+
|
| 273 |
+
|
| 274 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 275 |
+
def hexagonal_lattice_graph(
|
| 276 |
+
m, n, periodic=False, with_positions=True, create_using=None
|
| 277 |
+
):
|
| 278 |
+
"""Returns an `m` by `n` hexagonal lattice graph.
|
| 279 |
+
|
| 280 |
+
The *hexagonal lattice graph* is a graph whose nodes and edges are
|
| 281 |
+
the `hexagonal tiling`_ of the plane.
|
| 282 |
+
|
| 283 |
+
The returned graph will have `m` rows and `n` columns of hexagons.
|
| 284 |
+
`Odd numbered columns`_ are shifted up relative to even numbered columns.
|
| 285 |
+
|
| 286 |
+
Positions of nodes are computed by default or `with_positions is True`.
|
| 287 |
+
Node positions creating the standard embedding in the plane
|
| 288 |
+
with sidelength 1 and are stored in the node attribute 'pos'.
|
| 289 |
+
`pos = nx.get_node_attributes(G, 'pos')` creates a dict ready for drawing.
|
| 290 |
+
|
| 291 |
+
.. _hexagonal tiling: https://en.wikipedia.org/wiki/Hexagonal_tiling
|
| 292 |
+
.. _Odd numbered columns: http://www-cs-students.stanford.edu/~amitp/game-programming/grids/
|
| 293 |
+
|
| 294 |
+
Parameters
|
| 295 |
+
----------
|
| 296 |
+
m : int
|
| 297 |
+
The number of rows of hexagons in the lattice.
|
| 298 |
+
|
| 299 |
+
n : int
|
| 300 |
+
The number of columns of hexagons in the lattice.
|
| 301 |
+
|
| 302 |
+
periodic : bool
|
| 303 |
+
Whether to make a periodic grid by joining the boundary vertices.
|
| 304 |
+
For this to work `n` must be even and both `n > 1` and `m > 1`.
|
| 305 |
+
The periodic connections create another row and column of hexagons
|
| 306 |
+
so these graphs have fewer nodes as boundary nodes are identified.
|
| 307 |
+
|
| 308 |
+
with_positions : bool (default: True)
|
| 309 |
+
Store the coordinates of each node in the graph node attribute 'pos'.
|
| 310 |
+
The coordinates provide a lattice with vertical columns of hexagons
|
| 311 |
+
offset to interleave and cover the plane.
|
| 312 |
+
Periodic positions shift the nodes vertically in a nonlinear way so
|
| 313 |
+
the edges don't overlap so much.
|
| 314 |
+
|
| 315 |
+
create_using : NetworkX graph constructor, optional (default=nx.Graph)
|
| 316 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 317 |
+
If graph is directed, edges will point up or right.
|
| 318 |
+
|
| 319 |
+
Returns
|
| 320 |
+
-------
|
| 321 |
+
NetworkX graph
|
| 322 |
+
The *m* by *n* hexagonal lattice graph.
|
| 323 |
+
"""
|
| 324 |
+
G = empty_graph(0, create_using)
|
| 325 |
+
if m == 0 or n == 0:
|
| 326 |
+
return G
|
| 327 |
+
if periodic and (n % 2 == 1 or m < 2 or n < 2):
|
| 328 |
+
msg = "periodic hexagonal lattice needs m > 1, n > 1 and even n"
|
| 329 |
+
raise NetworkXError(msg)
|
| 330 |
+
|
| 331 |
+
M = 2 * m # twice as many nodes as hexagons vertically
|
| 332 |
+
rows = range(M + 2)
|
| 333 |
+
cols = range(n + 1)
|
| 334 |
+
# make lattice
|
| 335 |
+
col_edges = (((i, j), (i, j + 1)) for i in cols for j in rows[: M + 1])
|
| 336 |
+
row_edges = (((i, j), (i + 1, j)) for i in cols[:n] for j in rows if i % 2 == j % 2)
|
| 337 |
+
G.add_edges_from(col_edges)
|
| 338 |
+
G.add_edges_from(row_edges)
|
| 339 |
+
# Remove corner nodes with one edge
|
| 340 |
+
G.remove_node((0, M + 1))
|
| 341 |
+
G.remove_node((n, (M + 1) * (n % 2)))
|
| 342 |
+
|
| 343 |
+
# identify boundary nodes if periodic
|
| 344 |
+
from networkx.algorithms.minors import contracted_nodes
|
| 345 |
+
|
| 346 |
+
if periodic:
|
| 347 |
+
for i in cols[:n]:
|
| 348 |
+
G = contracted_nodes(G, (i, 0), (i, M))
|
| 349 |
+
for i in cols[1:]:
|
| 350 |
+
G = contracted_nodes(G, (i, 1), (i, M + 1))
|
| 351 |
+
for j in rows[1:M]:
|
| 352 |
+
G = contracted_nodes(G, (0, j), (n, j))
|
| 353 |
+
G.remove_node((n, M))
|
| 354 |
+
|
| 355 |
+
# calc position in embedded space
|
| 356 |
+
ii = (i for i in cols for j in rows)
|
| 357 |
+
jj = (j for i in cols for j in rows)
|
| 358 |
+
xx = (0.5 + i + i // 2 + (j % 2) * ((i % 2) - 0.5) for i in cols for j in rows)
|
| 359 |
+
h = sqrt(3) / 2
|
| 360 |
+
if periodic:
|
| 361 |
+
yy = (h * j + 0.01 * i * i for i in cols for j in rows)
|
| 362 |
+
else:
|
| 363 |
+
yy = (h * j for i in cols for j in rows)
|
| 364 |
+
# exclude nodes not in G
|
| 365 |
+
pos = {(i, j): (x, y) for i, j, x, y in zip(ii, jj, xx, yy) if (i, j) in G}
|
| 366 |
+
set_node_attributes(G, pos, "pos")
|
| 367 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/line.py
ADDED
|
@@ -0,0 +1,500 @@
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|
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|
|
|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
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|
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|
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|
|
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|
|
|
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|
|
|
|
|
|
|
|
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|
|
|
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|
|
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|
|
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|
|
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|
|
|
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|
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|
|
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|
|
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|
|
|
|
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|
|
|
|
|
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|
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|
|
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|
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|
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|
|
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|
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|
|
|
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|
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|
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|
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|
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|
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|
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|
|
|
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|
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|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
|
|
|
|
|
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|
|
|
|
|
|
|
|
|
|
|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
"""Functions for generating line graphs."""
|
| 2 |
+
|
| 3 |
+
from collections import defaultdict
|
| 4 |
+
from functools import partial
|
| 5 |
+
from itertools import combinations
|
| 6 |
+
|
| 7 |
+
import networkx as nx
|
| 8 |
+
from networkx.utils import arbitrary_element
|
| 9 |
+
from networkx.utils.decorators import not_implemented_for
|
| 10 |
+
|
| 11 |
+
__all__ = ["line_graph", "inverse_line_graph"]
|
| 12 |
+
|
| 13 |
+
|
| 14 |
+
@nx._dispatchable(returns_graph=True)
|
| 15 |
+
def line_graph(G, create_using=None):
|
| 16 |
+
r"""Returns the line graph of the graph or digraph `G`.
|
| 17 |
+
|
| 18 |
+
The line graph of a graph `G` has a node for each edge in `G` and an
|
| 19 |
+
edge joining those nodes if the two edges in `G` share a common node. For
|
| 20 |
+
directed graphs, nodes are adjacent exactly when the edges they represent
|
| 21 |
+
form a directed path of length two.
|
| 22 |
+
|
| 23 |
+
The nodes of the line graph are 2-tuples of nodes in the original graph (or
|
| 24 |
+
3-tuples for multigraphs, with the key of the edge as the third element).
|
| 25 |
+
|
| 26 |
+
For information about self-loops and more discussion, see the **Notes**
|
| 27 |
+
section below.
|
| 28 |
+
|
| 29 |
+
Parameters
|
| 30 |
+
----------
|
| 31 |
+
G : graph
|
| 32 |
+
A NetworkX Graph, DiGraph, MultiGraph, or MultiDigraph.
|
| 33 |
+
create_using : NetworkX graph constructor, optional (default=nx.Graph)
|
| 34 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 35 |
+
|
| 36 |
+
Returns
|
| 37 |
+
-------
|
| 38 |
+
L : graph
|
| 39 |
+
The line graph of G.
|
| 40 |
+
|
| 41 |
+
Examples
|
| 42 |
+
--------
|
| 43 |
+
>>> G = nx.star_graph(3)
|
| 44 |
+
>>> L = nx.line_graph(G)
|
| 45 |
+
>>> print(sorted(map(sorted, L.edges()))) # makes a 3-clique, K3
|
| 46 |
+
[[(0, 1), (0, 2)], [(0, 1), (0, 3)], [(0, 2), (0, 3)]]
|
| 47 |
+
|
| 48 |
+
Edge attributes from `G` are not copied over as node attributes in `L`, but
|
| 49 |
+
attributes can be copied manually:
|
| 50 |
+
|
| 51 |
+
>>> G = nx.path_graph(4)
|
| 52 |
+
>>> G.add_edges_from((u, v, {"tot": u + v}) for u, v in G.edges)
|
| 53 |
+
>>> G.edges(data=True)
|
| 54 |
+
EdgeDataView([(0, 1, {'tot': 1}), (1, 2, {'tot': 3}), (2, 3, {'tot': 5})])
|
| 55 |
+
>>> H = nx.line_graph(G)
|
| 56 |
+
>>> H.add_nodes_from((node, G.edges[node]) for node in H)
|
| 57 |
+
>>> H.nodes(data=True)
|
| 58 |
+
NodeDataView({(0, 1): {'tot': 1}, (2, 3): {'tot': 5}, (1, 2): {'tot': 3}})
|
| 59 |
+
|
| 60 |
+
Notes
|
| 61 |
+
-----
|
| 62 |
+
Graph, node, and edge data are not propagated to the new graph. For
|
| 63 |
+
undirected graphs, the nodes in G must be sortable, otherwise the
|
| 64 |
+
constructed line graph may not be correct.
|
| 65 |
+
|
| 66 |
+
*Self-loops in undirected graphs*
|
| 67 |
+
|
| 68 |
+
For an undirected graph `G` without multiple edges, each edge can be
|
| 69 |
+
written as a set `\{u, v\}`. Its line graph `L` has the edges of `G` as
|
| 70 |
+
its nodes. If `x` and `y` are two nodes in `L`, then `\{x, y\}` is an edge
|
| 71 |
+
in `L` if and only if the intersection of `x` and `y` is nonempty. Thus,
|
| 72 |
+
the set of all edges is determined by the set of all pairwise intersections
|
| 73 |
+
of edges in `G`.
|
| 74 |
+
|
| 75 |
+
Trivially, every edge in G would have a nonzero intersection with itself,
|
| 76 |
+
and so every node in `L` should have a self-loop. This is not so
|
| 77 |
+
interesting, and the original context of line graphs was with simple
|
| 78 |
+
graphs, which had no self-loops or multiple edges. The line graph was also
|
| 79 |
+
meant to be a simple graph and thus, self-loops in `L` are not part of the
|
| 80 |
+
standard definition of a line graph. In a pairwise intersection matrix,
|
| 81 |
+
this is analogous to excluding the diagonal entries from the line graph
|
| 82 |
+
definition.
|
| 83 |
+
|
| 84 |
+
Self-loops and multiple edges in `G` add nodes to `L` in a natural way, and
|
| 85 |
+
do not require any fundamental changes to the definition. It might be
|
| 86 |
+
argued that the self-loops we excluded before should now be included.
|
| 87 |
+
However, the self-loops are still "trivial" in some sense and thus, are
|
| 88 |
+
usually excluded.
|
| 89 |
+
|
| 90 |
+
*Self-loops in directed graphs*
|
| 91 |
+
|
| 92 |
+
For a directed graph `G` without multiple edges, each edge can be written
|
| 93 |
+
as a tuple `(u, v)`. Its line graph `L` has the edges of `G` as its
|
| 94 |
+
nodes. If `x` and `y` are two nodes in `L`, then `(x, y)` is an edge in `L`
|
| 95 |
+
if and only if the tail of `x` matches the head of `y`, for example, if `x
|
| 96 |
+
= (a, b)` and `y = (b, c)` for some vertices `a`, `b`, and `c` in `G`.
|
| 97 |
+
|
| 98 |
+
Due to the directed nature of the edges, it is no longer the case that
|
| 99 |
+
every edge in `G` should have a self-loop in `L`. Now, the only time
|
| 100 |
+
self-loops arise is if a node in `G` itself has a self-loop. So such
|
| 101 |
+
self-loops are no longer "trivial" but instead, represent essential
|
| 102 |
+
features of the topology of `G`. For this reason, the historical
|
| 103 |
+
development of line digraphs is such that self-loops are included. When the
|
| 104 |
+
graph `G` has multiple edges, once again only superficial changes are
|
| 105 |
+
required to the definition.
|
| 106 |
+
|
| 107 |
+
References
|
| 108 |
+
----------
|
| 109 |
+
* Harary, Frank, and Norman, Robert Z., "Some properties of line digraphs",
|
| 110 |
+
Rend. Circ. Mat. Palermo, II. Ser. 9 (1960), 161--168.
|
| 111 |
+
* Hemminger, R. L.; Beineke, L. W. (1978), "Line graphs and line digraphs",
|
| 112 |
+
in Beineke, L. W.; Wilson, R. J., Selected Topics in Graph Theory,
|
| 113 |
+
Academic Press Inc., pp. 271--305.
|
| 114 |
+
|
| 115 |
+
"""
|
| 116 |
+
if G.is_directed():
|
| 117 |
+
L = _lg_directed(G, create_using=create_using)
|
| 118 |
+
else:
|
| 119 |
+
L = _lg_undirected(G, selfloops=False, create_using=create_using)
|
| 120 |
+
return L
|
| 121 |
+
|
| 122 |
+
|
| 123 |
+
def _lg_directed(G, create_using=None):
|
| 124 |
+
"""Returns the line graph L of the (multi)digraph G.
|
| 125 |
+
|
| 126 |
+
Edges in G appear as nodes in L, represented as tuples of the form (u,v)
|
| 127 |
+
or (u,v,key) if G is a multidigraph. A node in L corresponding to the edge
|
| 128 |
+
(u,v) is connected to every node corresponding to an edge (v,w).
|
| 129 |
+
|
| 130 |
+
Parameters
|
| 131 |
+
----------
|
| 132 |
+
G : digraph
|
| 133 |
+
A directed graph or directed multigraph.
|
| 134 |
+
create_using : NetworkX graph constructor, optional
|
| 135 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 136 |
+
Default is to use the same graph class as `G`.
|
| 137 |
+
|
| 138 |
+
"""
|
| 139 |
+
L = nx.empty_graph(0, create_using, default=G.__class__)
|
| 140 |
+
|
| 141 |
+
# Create a graph specific edge function.
|
| 142 |
+
get_edges = partial(G.edges, keys=True) if G.is_multigraph() else G.edges
|
| 143 |
+
|
| 144 |
+
for from_node in get_edges():
|
| 145 |
+
# from_node is: (u,v) or (u,v,key)
|
| 146 |
+
L.add_node(from_node)
|
| 147 |
+
for to_node in get_edges(from_node[1]):
|
| 148 |
+
L.add_edge(from_node, to_node)
|
| 149 |
+
|
| 150 |
+
return L
|
| 151 |
+
|
| 152 |
+
|
| 153 |
+
def _lg_undirected(G, selfloops=False, create_using=None):
|
| 154 |
+
"""Returns the line graph L of the (multi)graph G.
|
| 155 |
+
|
| 156 |
+
Edges in G appear as nodes in L, represented as sorted tuples of the form
|
| 157 |
+
(u,v), or (u,v,key) if G is a multigraph. A node in L corresponding to
|
| 158 |
+
the edge {u,v} is connected to every node corresponding to an edge that
|
| 159 |
+
involves u or v.
|
| 160 |
+
|
| 161 |
+
Parameters
|
| 162 |
+
----------
|
| 163 |
+
G : graph
|
| 164 |
+
An undirected graph or multigraph.
|
| 165 |
+
selfloops : bool
|
| 166 |
+
If `True`, then self-loops are included in the line graph. If `False`,
|
| 167 |
+
they are excluded.
|
| 168 |
+
create_using : NetworkX graph constructor, optional (default=nx.Graph)
|
| 169 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 170 |
+
|
| 171 |
+
Notes
|
| 172 |
+
-----
|
| 173 |
+
The standard algorithm for line graphs of undirected graphs does not
|
| 174 |
+
produce self-loops.
|
| 175 |
+
|
| 176 |
+
"""
|
| 177 |
+
L = nx.empty_graph(0, create_using, default=G.__class__)
|
| 178 |
+
|
| 179 |
+
# Graph specific functions for edges.
|
| 180 |
+
get_edges = partial(G.edges, keys=True) if G.is_multigraph() else G.edges
|
| 181 |
+
|
| 182 |
+
# Determine if we include self-loops or not.
|
| 183 |
+
shift = 0 if selfloops else 1
|
| 184 |
+
|
| 185 |
+
# Introduce numbering of nodes
|
| 186 |
+
node_index = {n: i for i, n in enumerate(G)}
|
| 187 |
+
|
| 188 |
+
# Lift canonical representation of nodes to edges in line graph
|
| 189 |
+
edge_key_function = lambda edge: (node_index[edge[0]], node_index[edge[1]])
|
| 190 |
+
|
| 191 |
+
edges = set()
|
| 192 |
+
for u in G:
|
| 193 |
+
# Label nodes as a sorted tuple of nodes in original graph.
|
| 194 |
+
# Decide on representation of {u, v} as (u, v) or (v, u) depending on node_index.
|
| 195 |
+
# -> This ensures a canonical representation and avoids comparing values of different types.
|
| 196 |
+
nodes = [tuple(sorted(x[:2], key=node_index.get)) + x[2:] for x in get_edges(u)]
|
| 197 |
+
|
| 198 |
+
if len(nodes) == 1:
|
| 199 |
+
# Then the edge will be an isolated node in L.
|
| 200 |
+
L.add_node(nodes[0])
|
| 201 |
+
|
| 202 |
+
# Add a clique of `nodes` to graph. To prevent double adding edges,
|
| 203 |
+
# especially important for multigraphs, we store the edges in
|
| 204 |
+
# canonical form in a set.
|
| 205 |
+
for i, a in enumerate(nodes):
|
| 206 |
+
edges.update(
|
| 207 |
+
[
|
| 208 |
+
tuple(sorted((a, b), key=edge_key_function))
|
| 209 |
+
for b in nodes[i + shift :]
|
| 210 |
+
]
|
| 211 |
+
)
|
| 212 |
+
|
| 213 |
+
L.add_edges_from(edges)
|
| 214 |
+
return L
|
| 215 |
+
|
| 216 |
+
|
| 217 |
+
@not_implemented_for("directed")
|
| 218 |
+
@not_implemented_for("multigraph")
|
| 219 |
+
@nx._dispatchable(returns_graph=True)
|
| 220 |
+
def inverse_line_graph(G):
|
| 221 |
+
"""Returns the inverse line graph of graph G.
|
| 222 |
+
|
| 223 |
+
If H is a graph, and G is the line graph of H, such that G = L(H).
|
| 224 |
+
Then H is the inverse line graph of G.
|
| 225 |
+
|
| 226 |
+
Not all graphs are line graphs and these do not have an inverse line graph.
|
| 227 |
+
In these cases this function raises a NetworkXError.
|
| 228 |
+
|
| 229 |
+
Parameters
|
| 230 |
+
----------
|
| 231 |
+
G : graph
|
| 232 |
+
A NetworkX Graph
|
| 233 |
+
|
| 234 |
+
Returns
|
| 235 |
+
-------
|
| 236 |
+
H : graph
|
| 237 |
+
The inverse line graph of G.
|
| 238 |
+
|
| 239 |
+
Raises
|
| 240 |
+
------
|
| 241 |
+
NetworkXNotImplemented
|
| 242 |
+
If G is directed or a multigraph
|
| 243 |
+
|
| 244 |
+
NetworkXError
|
| 245 |
+
If G is not a line graph
|
| 246 |
+
|
| 247 |
+
Notes
|
| 248 |
+
-----
|
| 249 |
+
This is an implementation of the Roussopoulos algorithm[1]_.
|
| 250 |
+
|
| 251 |
+
If G consists of multiple components, then the algorithm doesn't work.
|
| 252 |
+
You should invert every component separately:
|
| 253 |
+
|
| 254 |
+
>>> K5 = nx.complete_graph(5)
|
| 255 |
+
>>> P4 = nx.Graph([("a", "b"), ("b", "c"), ("c", "d")])
|
| 256 |
+
>>> G = nx.union(K5, P4)
|
| 257 |
+
>>> root_graphs = []
|
| 258 |
+
>>> for comp in nx.connected_components(G):
|
| 259 |
+
... root_graphs.append(nx.inverse_line_graph(G.subgraph(comp)))
|
| 260 |
+
>>> len(root_graphs)
|
| 261 |
+
2
|
| 262 |
+
|
| 263 |
+
References
|
| 264 |
+
----------
|
| 265 |
+
.. [1] Roussopoulos, N.D. , "A max {m, n} algorithm for determining the graph H from
|
| 266 |
+
its line graph G", Information Processing Letters 2, (1973), 108--112, ISSN 0020-0190,
|
| 267 |
+
`DOI link <https://doi.org/10.1016/0020-0190(73)90029-X>`_
|
| 268 |
+
|
| 269 |
+
"""
|
| 270 |
+
if G.number_of_nodes() == 0:
|
| 271 |
+
return nx.empty_graph(1)
|
| 272 |
+
elif G.number_of_nodes() == 1:
|
| 273 |
+
v = arbitrary_element(G)
|
| 274 |
+
a = (v, 0)
|
| 275 |
+
b = (v, 1)
|
| 276 |
+
H = nx.Graph([(a, b)])
|
| 277 |
+
return H
|
| 278 |
+
elif G.number_of_nodes() > 1 and G.number_of_edges() == 0:
|
| 279 |
+
msg = (
|
| 280 |
+
"inverse_line_graph() doesn't work on an edgeless graph. "
|
| 281 |
+
"Please use this function on each component separately."
|
| 282 |
+
)
|
| 283 |
+
raise nx.NetworkXError(msg)
|
| 284 |
+
|
| 285 |
+
if nx.number_of_selfloops(G) != 0:
|
| 286 |
+
msg = (
|
| 287 |
+
"A line graph as generated by NetworkX has no selfloops, so G has no "
|
| 288 |
+
"inverse line graph. Please remove the selfloops from G and try again."
|
| 289 |
+
)
|
| 290 |
+
raise nx.NetworkXError(msg)
|
| 291 |
+
|
| 292 |
+
starting_cell = _select_starting_cell(G)
|
| 293 |
+
P = _find_partition(G, starting_cell)
|
| 294 |
+
# count how many times each vertex appears in the partition set
|
| 295 |
+
P_count = {u: 0 for u in G.nodes}
|
| 296 |
+
for p in P:
|
| 297 |
+
for u in p:
|
| 298 |
+
P_count[u] += 1
|
| 299 |
+
|
| 300 |
+
if max(P_count.values()) > 2:
|
| 301 |
+
msg = "G is not a line graph (vertex found in more than two partition cells)"
|
| 302 |
+
raise nx.NetworkXError(msg)
|
| 303 |
+
W = tuple((u,) for u in P_count if P_count[u] == 1)
|
| 304 |
+
H = nx.Graph()
|
| 305 |
+
H.add_nodes_from(P)
|
| 306 |
+
H.add_nodes_from(W)
|
| 307 |
+
for a, b in combinations(H.nodes, 2):
|
| 308 |
+
if any(a_bit in b for a_bit in a):
|
| 309 |
+
H.add_edge(a, b)
|
| 310 |
+
return H
|
| 311 |
+
|
| 312 |
+
|
| 313 |
+
def _triangles(G, e):
|
| 314 |
+
"""Return list of all triangles containing edge e"""
|
| 315 |
+
u, v = e
|
| 316 |
+
if u not in G:
|
| 317 |
+
raise nx.NetworkXError(f"Vertex {u} not in graph")
|
| 318 |
+
if v not in G[u]:
|
| 319 |
+
raise nx.NetworkXError(f"Edge ({u}, {v}) not in graph")
|
| 320 |
+
triangle_list = []
|
| 321 |
+
for x in G[u]:
|
| 322 |
+
if x in G[v]:
|
| 323 |
+
triangle_list.append((u, v, x))
|
| 324 |
+
return triangle_list
|
| 325 |
+
|
| 326 |
+
|
| 327 |
+
def _odd_triangle(G, T):
|
| 328 |
+
"""Test whether T is an odd triangle in G
|
| 329 |
+
|
| 330 |
+
Parameters
|
| 331 |
+
----------
|
| 332 |
+
G : NetworkX Graph
|
| 333 |
+
T : 3-tuple of vertices forming triangle in G
|
| 334 |
+
|
| 335 |
+
Returns
|
| 336 |
+
-------
|
| 337 |
+
True is T is an odd triangle
|
| 338 |
+
False otherwise
|
| 339 |
+
|
| 340 |
+
Raises
|
| 341 |
+
------
|
| 342 |
+
NetworkXError
|
| 343 |
+
T is not a triangle in G
|
| 344 |
+
|
| 345 |
+
Notes
|
| 346 |
+
-----
|
| 347 |
+
An odd triangle is one in which there exists another vertex in G which is
|
| 348 |
+
adjacent to either exactly one or exactly all three of the vertices in the
|
| 349 |
+
triangle.
|
| 350 |
+
|
| 351 |
+
"""
|
| 352 |
+
for u in T:
|
| 353 |
+
if u not in G.nodes():
|
| 354 |
+
raise nx.NetworkXError(f"Vertex {u} not in graph")
|
| 355 |
+
for e in list(combinations(T, 2)):
|
| 356 |
+
if e[0] not in G[e[1]]:
|
| 357 |
+
raise nx.NetworkXError(f"Edge ({e[0]}, {e[1]}) not in graph")
|
| 358 |
+
|
| 359 |
+
T_nbrs = defaultdict(int)
|
| 360 |
+
for t in T:
|
| 361 |
+
for v in G[t]:
|
| 362 |
+
if v not in T:
|
| 363 |
+
T_nbrs[v] += 1
|
| 364 |
+
return any(T_nbrs[v] in [1, 3] for v in T_nbrs)
|
| 365 |
+
|
| 366 |
+
|
| 367 |
+
def _find_partition(G, starting_cell):
|
| 368 |
+
"""Find a partition of the vertices of G into cells of complete graphs
|
| 369 |
+
|
| 370 |
+
Parameters
|
| 371 |
+
----------
|
| 372 |
+
G : NetworkX Graph
|
| 373 |
+
starting_cell : tuple of vertices in G which form a cell
|
| 374 |
+
|
| 375 |
+
Returns
|
| 376 |
+
-------
|
| 377 |
+
List of tuples of vertices of G
|
| 378 |
+
|
| 379 |
+
Raises
|
| 380 |
+
------
|
| 381 |
+
NetworkXError
|
| 382 |
+
If a cell is not a complete subgraph then G is not a line graph
|
| 383 |
+
"""
|
| 384 |
+
G_partition = G.copy()
|
| 385 |
+
P = [starting_cell] # partition set
|
| 386 |
+
G_partition.remove_edges_from(list(combinations(starting_cell, 2)))
|
| 387 |
+
# keep list of partitioned nodes which might have an edge in G_partition
|
| 388 |
+
partitioned_vertices = list(starting_cell)
|
| 389 |
+
while G_partition.number_of_edges() > 0:
|
| 390 |
+
# there are still edges left and so more cells to be made
|
| 391 |
+
u = partitioned_vertices.pop()
|
| 392 |
+
deg_u = len(G_partition[u])
|
| 393 |
+
if deg_u != 0:
|
| 394 |
+
# if u still has edges then we need to find its other cell
|
| 395 |
+
# this other cell must be a complete subgraph or else G is
|
| 396 |
+
# not a line graph
|
| 397 |
+
new_cell = [u] + list(G_partition[u])
|
| 398 |
+
for u in new_cell:
|
| 399 |
+
for v in new_cell:
|
| 400 |
+
if (u != v) and (v not in G_partition[u]):
|
| 401 |
+
msg = (
|
| 402 |
+
"G is not a line graph "
|
| 403 |
+
"(partition cell not a complete subgraph)"
|
| 404 |
+
)
|
| 405 |
+
raise nx.NetworkXError(msg)
|
| 406 |
+
P.append(tuple(new_cell))
|
| 407 |
+
G_partition.remove_edges_from(list(combinations(new_cell, 2)))
|
| 408 |
+
partitioned_vertices += new_cell
|
| 409 |
+
return P
|
| 410 |
+
|
| 411 |
+
|
| 412 |
+
def _select_starting_cell(G, starting_edge=None):
|
| 413 |
+
"""Select a cell to initiate _find_partition
|
| 414 |
+
|
| 415 |
+
Parameters
|
| 416 |
+
----------
|
| 417 |
+
G : NetworkX Graph
|
| 418 |
+
starting_edge: an edge to build the starting cell from
|
| 419 |
+
|
| 420 |
+
Returns
|
| 421 |
+
-------
|
| 422 |
+
Tuple of vertices in G
|
| 423 |
+
|
| 424 |
+
Raises
|
| 425 |
+
------
|
| 426 |
+
NetworkXError
|
| 427 |
+
If it is determined that G is not a line graph
|
| 428 |
+
|
| 429 |
+
Notes
|
| 430 |
+
-----
|
| 431 |
+
If starting edge not specified then pick an arbitrary edge - doesn't
|
| 432 |
+
matter which. However, this function may call itself requiring a
|
| 433 |
+
specific starting edge. Note that the r, s notation for counting
|
| 434 |
+
triangles is the same as in the Roussopoulos paper cited above.
|
| 435 |
+
"""
|
| 436 |
+
if starting_edge is None:
|
| 437 |
+
e = arbitrary_element(G.edges())
|
| 438 |
+
else:
|
| 439 |
+
e = starting_edge
|
| 440 |
+
if e[0] not in G.nodes():
|
| 441 |
+
raise nx.NetworkXError(f"Vertex {e[0]} not in graph")
|
| 442 |
+
if e[1] not in G[e[0]]:
|
| 443 |
+
msg = f"starting_edge ({e[0]}, {e[1]}) is not in the Graph"
|
| 444 |
+
raise nx.NetworkXError(msg)
|
| 445 |
+
e_triangles = _triangles(G, e)
|
| 446 |
+
r = len(e_triangles)
|
| 447 |
+
if r == 0:
|
| 448 |
+
# there are no triangles containing e, so the starting cell is just e
|
| 449 |
+
starting_cell = e
|
| 450 |
+
elif r == 1:
|
| 451 |
+
# there is exactly one triangle, T, containing e. If other 2 edges
|
| 452 |
+
# of T belong only to this triangle then T is starting cell
|
| 453 |
+
T = e_triangles[0]
|
| 454 |
+
a, b, c = T
|
| 455 |
+
# ab was original edge so check the other 2 edges
|
| 456 |
+
ac_edges = len(_triangles(G, (a, c)))
|
| 457 |
+
bc_edges = len(_triangles(G, (b, c)))
|
| 458 |
+
if ac_edges == 1:
|
| 459 |
+
if bc_edges == 1:
|
| 460 |
+
starting_cell = T
|
| 461 |
+
else:
|
| 462 |
+
return _select_starting_cell(G, starting_edge=(b, c))
|
| 463 |
+
else:
|
| 464 |
+
return _select_starting_cell(G, starting_edge=(a, c))
|
| 465 |
+
else:
|
| 466 |
+
# r >= 2 so we need to count the number of odd triangles, s
|
| 467 |
+
s = 0
|
| 468 |
+
odd_triangles = []
|
| 469 |
+
for T in e_triangles:
|
| 470 |
+
if _odd_triangle(G, T):
|
| 471 |
+
s += 1
|
| 472 |
+
odd_triangles.append(T)
|
| 473 |
+
if r == 2 and s == 0:
|
| 474 |
+
# in this case either triangle works, so just use T
|
| 475 |
+
starting_cell = T
|
| 476 |
+
elif r - 1 <= s <= r:
|
| 477 |
+
# check if odd triangles containing e form complete subgraph
|
| 478 |
+
triangle_nodes = set()
|
| 479 |
+
for T in odd_triangles:
|
| 480 |
+
for x in T:
|
| 481 |
+
triangle_nodes.add(x)
|
| 482 |
+
|
| 483 |
+
for u in triangle_nodes:
|
| 484 |
+
for v in triangle_nodes:
|
| 485 |
+
if u != v and (v not in G[u]):
|
| 486 |
+
msg = (
|
| 487 |
+
"G is not a line graph (odd triangles "
|
| 488 |
+
"do not form complete subgraph)"
|
| 489 |
+
)
|
| 490 |
+
raise nx.NetworkXError(msg)
|
| 491 |
+
# otherwise then we can use this as the starting cell
|
| 492 |
+
starting_cell = tuple(triangle_nodes)
|
| 493 |
+
|
| 494 |
+
else:
|
| 495 |
+
msg = (
|
| 496 |
+
"G is not a line graph (incorrect number of "
|
| 497 |
+
"odd triangles around starting edge)"
|
| 498 |
+
)
|
| 499 |
+
raise nx.NetworkXError(msg)
|
| 500 |
+
return starting_cell
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/mycielski.py
ADDED
|
@@ -0,0 +1,110 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
"""Functions related to the Mycielski Operation and the Mycielskian family
|
| 2 |
+
of graphs.
|
| 3 |
+
|
| 4 |
+
"""
|
| 5 |
+
|
| 6 |
+
import networkx as nx
|
| 7 |
+
from networkx.utils import not_implemented_for
|
| 8 |
+
|
| 9 |
+
__all__ = ["mycielskian", "mycielski_graph"]
|
| 10 |
+
|
| 11 |
+
|
| 12 |
+
@not_implemented_for("directed")
|
| 13 |
+
@not_implemented_for("multigraph")
|
| 14 |
+
@nx._dispatchable(returns_graph=True)
|
| 15 |
+
def mycielskian(G, iterations=1):
|
| 16 |
+
r"""Returns the Mycielskian of a simple, undirected graph G
|
| 17 |
+
|
| 18 |
+
The Mycielskian of graph preserves a graph's triangle free
|
| 19 |
+
property while increasing the chromatic number by 1.
|
| 20 |
+
|
| 21 |
+
The Mycielski Operation on a graph, :math:`G=(V, E)`, constructs a new
|
| 22 |
+
graph with :math:`2|V| + 1` nodes and :math:`3|E| + |V|` edges.
|
| 23 |
+
|
| 24 |
+
The construction is as follows:
|
| 25 |
+
|
| 26 |
+
Let :math:`V = {0, ..., n-1}`. Construct another vertex set
|
| 27 |
+
:math:`U = {n, ..., 2n}` and a vertex, `w`.
|
| 28 |
+
Construct a new graph, `M`, with vertices :math:`U \bigcup V \bigcup w`.
|
| 29 |
+
For edges, :math:`(u, v) \in E` add edges :math:`(u, v), (u, v + n)`, and
|
| 30 |
+
:math:`(u + n, v)` to M. Finally, for all vertices :math:`u \in U`, add
|
| 31 |
+
edge :math:`(u, w)` to M.
|
| 32 |
+
|
| 33 |
+
The Mycielski Operation can be done multiple times by repeating the above
|
| 34 |
+
process iteratively.
|
| 35 |
+
|
| 36 |
+
More information can be found at https://en.wikipedia.org/wiki/Mycielskian
|
| 37 |
+
|
| 38 |
+
Parameters
|
| 39 |
+
----------
|
| 40 |
+
G : graph
|
| 41 |
+
A simple, undirected NetworkX graph
|
| 42 |
+
iterations : int
|
| 43 |
+
The number of iterations of the Mycielski operation to
|
| 44 |
+
perform on G. Defaults to 1. Must be a non-negative integer.
|
| 45 |
+
|
| 46 |
+
Returns
|
| 47 |
+
-------
|
| 48 |
+
M : graph
|
| 49 |
+
The Mycielskian of G after the specified number of iterations.
|
| 50 |
+
|
| 51 |
+
Notes
|
| 52 |
+
-----
|
| 53 |
+
Graph, node, and edge data are not necessarily propagated to the new graph.
|
| 54 |
+
|
| 55 |
+
"""
|
| 56 |
+
|
| 57 |
+
M = nx.convert_node_labels_to_integers(G)
|
| 58 |
+
|
| 59 |
+
for i in range(iterations):
|
| 60 |
+
n = M.number_of_nodes()
|
| 61 |
+
M.add_nodes_from(range(n, 2 * n))
|
| 62 |
+
old_edges = list(M.edges())
|
| 63 |
+
M.add_edges_from((u, v + n) for u, v in old_edges)
|
| 64 |
+
M.add_edges_from((u + n, v) for u, v in old_edges)
|
| 65 |
+
M.add_node(2 * n)
|
| 66 |
+
M.add_edges_from((u + n, 2 * n) for u in range(n))
|
| 67 |
+
|
| 68 |
+
return M
|
| 69 |
+
|
| 70 |
+
|
| 71 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 72 |
+
def mycielski_graph(n):
|
| 73 |
+
"""Generator for the n_th Mycielski Graph.
|
| 74 |
+
|
| 75 |
+
The Mycielski family of graphs is an infinite set of graphs.
|
| 76 |
+
:math:`M_1` is the singleton graph, :math:`M_2` is two vertices with an
|
| 77 |
+
edge, and, for :math:`i > 2`, :math:`M_i` is the Mycielskian of
|
| 78 |
+
:math:`M_{i-1}`.
|
| 79 |
+
|
| 80 |
+
More information can be found at
|
| 81 |
+
http://mathworld.wolfram.com/MycielskiGraph.html
|
| 82 |
+
|
| 83 |
+
Parameters
|
| 84 |
+
----------
|
| 85 |
+
n : int
|
| 86 |
+
The desired Mycielski Graph.
|
| 87 |
+
|
| 88 |
+
Returns
|
| 89 |
+
-------
|
| 90 |
+
M : graph
|
| 91 |
+
The n_th Mycielski Graph
|
| 92 |
+
|
| 93 |
+
Notes
|
| 94 |
+
-----
|
| 95 |
+
The first graph in the Mycielski sequence is the singleton graph.
|
| 96 |
+
The Mycielskian of this graph is not the :math:`P_2` graph, but rather the
|
| 97 |
+
:math:`P_2` graph with an extra, isolated vertex. The second Mycielski
|
| 98 |
+
graph is the :math:`P_2` graph, so the first two are hard coded.
|
| 99 |
+
The remaining graphs are generated using the Mycielski operation.
|
| 100 |
+
|
| 101 |
+
"""
|
| 102 |
+
|
| 103 |
+
if n < 1:
|
| 104 |
+
raise nx.NetworkXError("must satisfy n >= 1")
|
| 105 |
+
|
| 106 |
+
if n == 1:
|
| 107 |
+
return nx.empty_graph(1)
|
| 108 |
+
|
| 109 |
+
else:
|
| 110 |
+
return mycielskian(nx.path_graph(2), n - 2)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/random_graphs.py
ADDED
|
@@ -0,0 +1,1400 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
| 1 |
+
"""
|
| 2 |
+
Generators for random graphs.
|
| 3 |
+
|
| 4 |
+
"""
|
| 5 |
+
|
| 6 |
+
import itertools
|
| 7 |
+
import math
|
| 8 |
+
from collections import defaultdict
|
| 9 |
+
|
| 10 |
+
import networkx as nx
|
| 11 |
+
from networkx.utils import py_random_state
|
| 12 |
+
|
| 13 |
+
from ..utils.misc import check_create_using
|
| 14 |
+
from .classic import complete_graph, empty_graph, path_graph, star_graph
|
| 15 |
+
from .degree_seq import degree_sequence_tree
|
| 16 |
+
|
| 17 |
+
__all__ = [
|
| 18 |
+
"fast_gnp_random_graph",
|
| 19 |
+
"gnp_random_graph",
|
| 20 |
+
"dense_gnm_random_graph",
|
| 21 |
+
"gnm_random_graph",
|
| 22 |
+
"erdos_renyi_graph",
|
| 23 |
+
"binomial_graph",
|
| 24 |
+
"newman_watts_strogatz_graph",
|
| 25 |
+
"watts_strogatz_graph",
|
| 26 |
+
"connected_watts_strogatz_graph",
|
| 27 |
+
"random_regular_graph",
|
| 28 |
+
"barabasi_albert_graph",
|
| 29 |
+
"dual_barabasi_albert_graph",
|
| 30 |
+
"extended_barabasi_albert_graph",
|
| 31 |
+
"powerlaw_cluster_graph",
|
| 32 |
+
"random_lobster",
|
| 33 |
+
"random_shell_graph",
|
| 34 |
+
"random_powerlaw_tree",
|
| 35 |
+
"random_powerlaw_tree_sequence",
|
| 36 |
+
"random_kernel_graph",
|
| 37 |
+
]
|
| 38 |
+
|
| 39 |
+
|
| 40 |
+
@py_random_state(2)
|
| 41 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 42 |
+
def fast_gnp_random_graph(n, p, seed=None, directed=False, *, create_using=None):
|
| 43 |
+
"""Returns a $G_{n,p}$ random graph, also known as an Erdős-Rényi graph or
|
| 44 |
+
a binomial graph.
|
| 45 |
+
|
| 46 |
+
Parameters
|
| 47 |
+
----------
|
| 48 |
+
n : int
|
| 49 |
+
The number of nodes.
|
| 50 |
+
p : float
|
| 51 |
+
Probability for edge creation.
|
| 52 |
+
seed : integer, random_state, or None (default)
|
| 53 |
+
Indicator of random number generation state.
|
| 54 |
+
See :ref:`Randomness<randomness>`.
|
| 55 |
+
directed : bool, optional (default=False)
|
| 56 |
+
If True, this function returns a directed graph.
|
| 57 |
+
create_using : Graph constructor, optional (default=nx.Graph or nx.DiGraph)
|
| 58 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 59 |
+
Multigraph types are not supported and raise a ``NetworkXError``.
|
| 60 |
+
By default NetworkX Graph or DiGraph are used depending on `directed`.
|
| 61 |
+
|
| 62 |
+
Notes
|
| 63 |
+
-----
|
| 64 |
+
The $G_{n,p}$ graph algorithm chooses each of the $[n (n - 1)] / 2$
|
| 65 |
+
(undirected) or $n (n - 1)$ (directed) possible edges with probability $p$.
|
| 66 |
+
|
| 67 |
+
This algorithm [1]_ runs in $O(n + m)$ time, where `m` is the expected number of
|
| 68 |
+
edges, which equals $p n (n - 1) / 2$. This should be faster than
|
| 69 |
+
:func:`gnp_random_graph` when $p$ is small and the expected number of edges
|
| 70 |
+
is small (that is, the graph is sparse).
|
| 71 |
+
|
| 72 |
+
See Also
|
| 73 |
+
--------
|
| 74 |
+
gnp_random_graph
|
| 75 |
+
|
| 76 |
+
References
|
| 77 |
+
----------
|
| 78 |
+
.. [1] Vladimir Batagelj and Ulrik Brandes,
|
| 79 |
+
"Efficient generation of large random networks",
|
| 80 |
+
Phys. Rev. E, 71, 036113, 2005.
|
| 81 |
+
"""
|
| 82 |
+
default = nx.DiGraph if directed else nx.Graph
|
| 83 |
+
create_using = check_create_using(
|
| 84 |
+
create_using, directed=directed, multigraph=False, default=default
|
| 85 |
+
)
|
| 86 |
+
if p <= 0 or p >= 1:
|
| 87 |
+
return nx.gnp_random_graph(
|
| 88 |
+
n, p, seed=seed, directed=directed, create_using=create_using
|
| 89 |
+
)
|
| 90 |
+
|
| 91 |
+
G = empty_graph(n, create_using=create_using)
|
| 92 |
+
|
| 93 |
+
lp = math.log(1.0 - p)
|
| 94 |
+
|
| 95 |
+
if directed:
|
| 96 |
+
v = 1
|
| 97 |
+
w = -1
|
| 98 |
+
while v < n:
|
| 99 |
+
lr = math.log(1.0 - seed.random())
|
| 100 |
+
w = w + 1 + int(lr / lp)
|
| 101 |
+
while w >= v and v < n:
|
| 102 |
+
w = w - v
|
| 103 |
+
v = v + 1
|
| 104 |
+
if v < n:
|
| 105 |
+
G.add_edge(w, v)
|
| 106 |
+
|
| 107 |
+
# Nodes in graph are from 0,n-1 (start with v as the second node index).
|
| 108 |
+
v = 1
|
| 109 |
+
w = -1
|
| 110 |
+
while v < n:
|
| 111 |
+
lr = math.log(1.0 - seed.random())
|
| 112 |
+
w = w + 1 + int(lr / lp)
|
| 113 |
+
while w >= v and v < n:
|
| 114 |
+
w = w - v
|
| 115 |
+
v = v + 1
|
| 116 |
+
if v < n:
|
| 117 |
+
G.add_edge(v, w)
|
| 118 |
+
return G
|
| 119 |
+
|
| 120 |
+
|
| 121 |
+
@py_random_state(2)
|
| 122 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 123 |
+
def gnp_random_graph(n, p, seed=None, directed=False, *, create_using=None):
|
| 124 |
+
"""Returns a $G_{n,p}$ random graph, also known as an Erdős-Rényi graph
|
| 125 |
+
or a binomial graph.
|
| 126 |
+
|
| 127 |
+
The $G_{n,p}$ model chooses each of the possible edges with probability $p$.
|
| 128 |
+
|
| 129 |
+
Parameters
|
| 130 |
+
----------
|
| 131 |
+
n : int
|
| 132 |
+
The number of nodes.
|
| 133 |
+
p : float
|
| 134 |
+
Probability for edge creation.
|
| 135 |
+
seed : integer, random_state, or None (default)
|
| 136 |
+
Indicator of random number generation state.
|
| 137 |
+
See :ref:`Randomness<randomness>`.
|
| 138 |
+
directed : bool, optional (default=False)
|
| 139 |
+
If True, this function returns a directed graph.
|
| 140 |
+
create_using : Graph constructor, optional (default=nx.Graph or nx.DiGraph)
|
| 141 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 142 |
+
Multigraph types are not supported and raise a ``NetworkXError``.
|
| 143 |
+
By default NetworkX Graph or DiGraph are used depending on `directed`.
|
| 144 |
+
|
| 145 |
+
See Also
|
| 146 |
+
--------
|
| 147 |
+
fast_gnp_random_graph
|
| 148 |
+
|
| 149 |
+
Notes
|
| 150 |
+
-----
|
| 151 |
+
This algorithm [2]_ runs in $O(n^2)$ time. For sparse graphs (that is, for
|
| 152 |
+
small values of $p$), :func:`fast_gnp_random_graph` is a faster algorithm.
|
| 153 |
+
|
| 154 |
+
:func:`binomial_graph` and :func:`erdos_renyi_graph` are
|
| 155 |
+
aliases for :func:`gnp_random_graph`.
|
| 156 |
+
|
| 157 |
+
>>> nx.binomial_graph is nx.gnp_random_graph
|
| 158 |
+
True
|
| 159 |
+
>>> nx.erdos_renyi_graph is nx.gnp_random_graph
|
| 160 |
+
True
|
| 161 |
+
|
| 162 |
+
References
|
| 163 |
+
----------
|
| 164 |
+
.. [1] P. Erdős and A. Rényi, On Random Graphs, Publ. Math. 6, 290 (1959).
|
| 165 |
+
.. [2] E. N. Gilbert, Random Graphs, Ann. Math. Stat., 30, 1141 (1959).
|
| 166 |
+
"""
|
| 167 |
+
default = nx.DiGraph if directed else nx.Graph
|
| 168 |
+
create_using = check_create_using(
|
| 169 |
+
create_using, directed=directed, multigraph=False, default=default
|
| 170 |
+
)
|
| 171 |
+
if p >= 1:
|
| 172 |
+
return complete_graph(n, create_using=create_using)
|
| 173 |
+
|
| 174 |
+
G = nx.empty_graph(n, create_using=create_using)
|
| 175 |
+
if p <= 0:
|
| 176 |
+
return G
|
| 177 |
+
|
| 178 |
+
edgetool = itertools.permutations if directed else itertools.combinations
|
| 179 |
+
for e in edgetool(range(n), 2):
|
| 180 |
+
if seed.random() < p:
|
| 181 |
+
G.add_edge(*e)
|
| 182 |
+
return G
|
| 183 |
+
|
| 184 |
+
|
| 185 |
+
# add some aliases to common names
|
| 186 |
+
binomial_graph = gnp_random_graph
|
| 187 |
+
erdos_renyi_graph = gnp_random_graph
|
| 188 |
+
|
| 189 |
+
|
| 190 |
+
@py_random_state(2)
|
| 191 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 192 |
+
def dense_gnm_random_graph(n, m, seed=None, *, create_using=None):
|
| 193 |
+
"""Returns a $G_{n,m}$ random graph.
|
| 194 |
+
|
| 195 |
+
In the $G_{n,m}$ model, a graph is chosen uniformly at random from the set
|
| 196 |
+
of all graphs with $n$ nodes and $m$ edges.
|
| 197 |
+
|
| 198 |
+
This algorithm should be faster than :func:`gnm_random_graph` for dense
|
| 199 |
+
graphs.
|
| 200 |
+
|
| 201 |
+
Parameters
|
| 202 |
+
----------
|
| 203 |
+
n : int
|
| 204 |
+
The number of nodes.
|
| 205 |
+
m : int
|
| 206 |
+
The number of edges.
|
| 207 |
+
seed : integer, random_state, or None (default)
|
| 208 |
+
Indicator of random number generation state.
|
| 209 |
+
See :ref:`Randomness<randomness>`.
|
| 210 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 211 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 212 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 213 |
+
|
| 214 |
+
See Also
|
| 215 |
+
--------
|
| 216 |
+
gnm_random_graph
|
| 217 |
+
|
| 218 |
+
Notes
|
| 219 |
+
-----
|
| 220 |
+
Algorithm by Keith M. Briggs Mar 31, 2006.
|
| 221 |
+
Inspired by Knuth's Algorithm S (Selection sampling technique),
|
| 222 |
+
in section 3.4.2 of [1]_.
|
| 223 |
+
|
| 224 |
+
References
|
| 225 |
+
----------
|
| 226 |
+
.. [1] Donald E. Knuth, The Art of Computer Programming,
|
| 227 |
+
Volume 2/Seminumerical algorithms, Third Edition, Addison-Wesley, 1997.
|
| 228 |
+
"""
|
| 229 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 230 |
+
mmax = n * (n - 1) // 2
|
| 231 |
+
if m >= mmax:
|
| 232 |
+
return complete_graph(n, create_using)
|
| 233 |
+
G = empty_graph(n, create_using)
|
| 234 |
+
|
| 235 |
+
if n == 1:
|
| 236 |
+
return G
|
| 237 |
+
|
| 238 |
+
u = 0
|
| 239 |
+
v = 1
|
| 240 |
+
t = 0
|
| 241 |
+
k = 0
|
| 242 |
+
while True:
|
| 243 |
+
if seed.randrange(mmax - t) < m - k:
|
| 244 |
+
G.add_edge(u, v)
|
| 245 |
+
k += 1
|
| 246 |
+
if k == m:
|
| 247 |
+
return G
|
| 248 |
+
t += 1
|
| 249 |
+
v += 1
|
| 250 |
+
if v == n: # go to next row of adjacency matrix
|
| 251 |
+
u += 1
|
| 252 |
+
v = u + 1
|
| 253 |
+
|
| 254 |
+
|
| 255 |
+
@py_random_state(2)
|
| 256 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 257 |
+
def gnm_random_graph(n, m, seed=None, directed=False, *, create_using=None):
|
| 258 |
+
"""Returns a $G_{n,m}$ random graph.
|
| 259 |
+
|
| 260 |
+
In the $G_{n,m}$ model, a graph is chosen uniformly at random from the set
|
| 261 |
+
of all graphs with $n$ nodes and $m$ edges.
|
| 262 |
+
|
| 263 |
+
This algorithm should be faster than :func:`dense_gnm_random_graph` for
|
| 264 |
+
sparse graphs.
|
| 265 |
+
|
| 266 |
+
Parameters
|
| 267 |
+
----------
|
| 268 |
+
n : int
|
| 269 |
+
The number of nodes.
|
| 270 |
+
m : int
|
| 271 |
+
The number of edges.
|
| 272 |
+
seed : integer, random_state, or None (default)
|
| 273 |
+
Indicator of random number generation state.
|
| 274 |
+
See :ref:`Randomness<randomness>`.
|
| 275 |
+
directed : bool, optional (default=False)
|
| 276 |
+
If True return a directed graph
|
| 277 |
+
create_using : Graph constructor, optional (default=nx.Graph or nx.DiGraph)
|
| 278 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 279 |
+
Multigraph types are not supported and raise a ``NetworkXError``.
|
| 280 |
+
By default NetworkX Graph or DiGraph are used depending on `directed`.
|
| 281 |
+
|
| 282 |
+
See also
|
| 283 |
+
--------
|
| 284 |
+
dense_gnm_random_graph
|
| 285 |
+
|
| 286 |
+
"""
|
| 287 |
+
default = nx.DiGraph if directed else nx.Graph
|
| 288 |
+
create_using = check_create_using(
|
| 289 |
+
create_using, directed=directed, multigraph=False, default=default
|
| 290 |
+
)
|
| 291 |
+
if n == 1:
|
| 292 |
+
return nx.empty_graph(n, create_using=create_using)
|
| 293 |
+
max_edges = n * (n - 1) if directed else n * (n - 1) / 2.0
|
| 294 |
+
if m >= max_edges:
|
| 295 |
+
return complete_graph(n, create_using=create_using)
|
| 296 |
+
|
| 297 |
+
G = nx.empty_graph(n, create_using=create_using)
|
| 298 |
+
nlist = list(G)
|
| 299 |
+
edge_count = 0
|
| 300 |
+
while edge_count < m:
|
| 301 |
+
# generate random edge,u,v
|
| 302 |
+
u = seed.choice(nlist)
|
| 303 |
+
v = seed.choice(nlist)
|
| 304 |
+
if u == v or G.has_edge(u, v):
|
| 305 |
+
continue
|
| 306 |
+
else:
|
| 307 |
+
G.add_edge(u, v)
|
| 308 |
+
edge_count = edge_count + 1
|
| 309 |
+
return G
|
| 310 |
+
|
| 311 |
+
|
| 312 |
+
@py_random_state(3)
|
| 313 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 314 |
+
def newman_watts_strogatz_graph(n, k, p, seed=None, *, create_using=None):
|
| 315 |
+
"""Returns a Newman–Watts–Strogatz small-world graph.
|
| 316 |
+
|
| 317 |
+
Parameters
|
| 318 |
+
----------
|
| 319 |
+
n : int
|
| 320 |
+
The number of nodes.
|
| 321 |
+
k : int
|
| 322 |
+
Each node is joined with its `k` nearest neighbors in a ring
|
| 323 |
+
topology.
|
| 324 |
+
p : float
|
| 325 |
+
The probability of adding a new edge for each edge.
|
| 326 |
+
seed : integer, random_state, or None (default)
|
| 327 |
+
Indicator of random number generation state.
|
| 328 |
+
See :ref:`Randomness<randomness>`.
|
| 329 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 330 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 331 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 332 |
+
|
| 333 |
+
Notes
|
| 334 |
+
-----
|
| 335 |
+
First create a ring over $n$ nodes [1]_. Then each node in the ring is
|
| 336 |
+
connected with its $k$ nearest neighbors (or $k - 1$ neighbors if $k$
|
| 337 |
+
is odd). Then shortcuts are created by adding new edges as follows: for
|
| 338 |
+
each edge $(u, v)$ in the underlying "$n$-ring with $k$ nearest
|
| 339 |
+
neighbors" with probability $p$ add a new edge $(u, w)$ with
|
| 340 |
+
randomly-chosen existing node $w$. In contrast with
|
| 341 |
+
:func:`watts_strogatz_graph`, no edges are removed.
|
| 342 |
+
|
| 343 |
+
See Also
|
| 344 |
+
--------
|
| 345 |
+
watts_strogatz_graph
|
| 346 |
+
|
| 347 |
+
References
|
| 348 |
+
----------
|
| 349 |
+
.. [1] M. E. J. Newman and D. J. Watts,
|
| 350 |
+
Renormalization group analysis of the small-world network model,
|
| 351 |
+
Physics Letters A, 263, 341, 1999.
|
| 352 |
+
https://doi.org/10.1016/S0375-9601(99)00757-4
|
| 353 |
+
"""
|
| 354 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 355 |
+
if k > n:
|
| 356 |
+
raise nx.NetworkXError("k>=n, choose smaller k or larger n")
|
| 357 |
+
|
| 358 |
+
# If k == n the graph return is a complete graph
|
| 359 |
+
if k == n:
|
| 360 |
+
return nx.complete_graph(n, create_using)
|
| 361 |
+
|
| 362 |
+
G = empty_graph(n, create_using)
|
| 363 |
+
nlist = list(G.nodes())
|
| 364 |
+
fromv = nlist
|
| 365 |
+
# connect the k/2 neighbors
|
| 366 |
+
for j in range(1, k // 2 + 1):
|
| 367 |
+
tov = fromv[j:] + fromv[0:j] # the first j are now last
|
| 368 |
+
for i in range(len(fromv)):
|
| 369 |
+
G.add_edge(fromv[i], tov[i])
|
| 370 |
+
# for each edge u-v, with probability p, randomly select existing
|
| 371 |
+
# node w and add new edge u-w
|
| 372 |
+
e = list(G.edges())
|
| 373 |
+
for u, v in e:
|
| 374 |
+
if seed.random() < p:
|
| 375 |
+
w = seed.choice(nlist)
|
| 376 |
+
# no self-loops and reject if edge u-w exists
|
| 377 |
+
# is that the correct NWS model?
|
| 378 |
+
while w == u or G.has_edge(u, w):
|
| 379 |
+
w = seed.choice(nlist)
|
| 380 |
+
if G.degree(u) >= n - 1:
|
| 381 |
+
break # skip this rewiring
|
| 382 |
+
else:
|
| 383 |
+
G.add_edge(u, w)
|
| 384 |
+
return G
|
| 385 |
+
|
| 386 |
+
|
| 387 |
+
@py_random_state(3)
|
| 388 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 389 |
+
def watts_strogatz_graph(n, k, p, seed=None, *, create_using=None):
|
| 390 |
+
"""Returns a Watts–Strogatz small-world graph.
|
| 391 |
+
|
| 392 |
+
Parameters
|
| 393 |
+
----------
|
| 394 |
+
n : int
|
| 395 |
+
The number of nodes
|
| 396 |
+
k : int
|
| 397 |
+
Each node is joined with its `k` nearest neighbors in a ring
|
| 398 |
+
topology.
|
| 399 |
+
p : float
|
| 400 |
+
The probability of rewiring each edge
|
| 401 |
+
seed : integer, random_state, or None (default)
|
| 402 |
+
Indicator of random number generation state.
|
| 403 |
+
See :ref:`Randomness<randomness>`.
|
| 404 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 405 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 406 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 407 |
+
|
| 408 |
+
See Also
|
| 409 |
+
--------
|
| 410 |
+
newman_watts_strogatz_graph
|
| 411 |
+
connected_watts_strogatz_graph
|
| 412 |
+
|
| 413 |
+
Notes
|
| 414 |
+
-----
|
| 415 |
+
First create a ring over $n$ nodes [1]_. Then each node in the ring is joined
|
| 416 |
+
to its $k$ nearest neighbors (or $k - 1$ neighbors if $k$ is odd).
|
| 417 |
+
Then shortcuts are created by replacing some edges as follows: for each
|
| 418 |
+
edge $(u, v)$ in the underlying "$n$-ring with $k$ nearest neighbors"
|
| 419 |
+
with probability $p$ replace it with a new edge $(u, w)$ with uniformly
|
| 420 |
+
random choice of existing node $w$.
|
| 421 |
+
|
| 422 |
+
In contrast with :func:`newman_watts_strogatz_graph`, the random rewiring
|
| 423 |
+
does not increase the number of edges. The rewired graph is not guaranteed
|
| 424 |
+
to be connected as in :func:`connected_watts_strogatz_graph`.
|
| 425 |
+
|
| 426 |
+
References
|
| 427 |
+
----------
|
| 428 |
+
.. [1] Duncan J. Watts and Steven H. Strogatz,
|
| 429 |
+
Collective dynamics of small-world networks,
|
| 430 |
+
Nature, 393, pp. 440--442, 1998.
|
| 431 |
+
"""
|
| 432 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 433 |
+
if k > n:
|
| 434 |
+
raise nx.NetworkXError("k>n, choose smaller k or larger n")
|
| 435 |
+
|
| 436 |
+
# If k == n, the graph is complete not Watts-Strogatz
|
| 437 |
+
if k == n:
|
| 438 |
+
G = nx.complete_graph(n, create_using)
|
| 439 |
+
return G
|
| 440 |
+
|
| 441 |
+
G = nx.empty_graph(n, create_using=create_using)
|
| 442 |
+
nodes = list(range(n)) # nodes are labeled 0 to n-1
|
| 443 |
+
# connect each node to k/2 neighbors
|
| 444 |
+
for j in range(1, k // 2 + 1):
|
| 445 |
+
targets = nodes[j:] + nodes[0:j] # first j nodes are now last in list
|
| 446 |
+
G.add_edges_from(zip(nodes, targets))
|
| 447 |
+
# rewire edges from each node
|
| 448 |
+
# loop over all nodes in order (label) and neighbors in order (distance)
|
| 449 |
+
# no self loops or multiple edges allowed
|
| 450 |
+
for j in range(1, k // 2 + 1): # outer loop is neighbors
|
| 451 |
+
targets = nodes[j:] + nodes[0:j] # first j nodes are now last in list
|
| 452 |
+
# inner loop in node order
|
| 453 |
+
for u, v in zip(nodes, targets):
|
| 454 |
+
if seed.random() < p:
|
| 455 |
+
w = seed.choice(nodes)
|
| 456 |
+
# Enforce no self-loops or multiple edges
|
| 457 |
+
while w == u or G.has_edge(u, w):
|
| 458 |
+
w = seed.choice(nodes)
|
| 459 |
+
if G.degree(u) >= n - 1:
|
| 460 |
+
break # skip this rewiring
|
| 461 |
+
else:
|
| 462 |
+
G.remove_edge(u, v)
|
| 463 |
+
G.add_edge(u, w)
|
| 464 |
+
return G
|
| 465 |
+
|
| 466 |
+
|
| 467 |
+
@py_random_state(4)
|
| 468 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 469 |
+
def connected_watts_strogatz_graph(n, k, p, tries=100, seed=None, *, create_using=None):
|
| 470 |
+
"""Returns a connected Watts–Strogatz small-world graph.
|
| 471 |
+
|
| 472 |
+
Attempts to generate a connected graph by repeated generation of
|
| 473 |
+
Watts–Strogatz small-world graphs. An exception is raised if the maximum
|
| 474 |
+
number of tries is exceeded.
|
| 475 |
+
|
| 476 |
+
Parameters
|
| 477 |
+
----------
|
| 478 |
+
n : int
|
| 479 |
+
The number of nodes
|
| 480 |
+
k : int
|
| 481 |
+
Each node is joined with its `k` nearest neighbors in a ring
|
| 482 |
+
topology.
|
| 483 |
+
p : float
|
| 484 |
+
The probability of rewiring each edge
|
| 485 |
+
tries : int
|
| 486 |
+
Number of attempts to generate a connected graph.
|
| 487 |
+
seed : integer, random_state, or None (default)
|
| 488 |
+
Indicator of random number generation state.
|
| 489 |
+
See :ref:`Randomness<randomness>`.
|
| 490 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 491 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 492 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 493 |
+
|
| 494 |
+
Notes
|
| 495 |
+
-----
|
| 496 |
+
First create a ring over $n$ nodes [1]_. Then each node in the ring is joined
|
| 497 |
+
to its $k$ nearest neighbors (or $k - 1$ neighbors if $k$ is odd).
|
| 498 |
+
Then shortcuts are created by replacing some edges as follows: for each
|
| 499 |
+
edge $(u, v)$ in the underlying "$n$-ring with $k$ nearest neighbors"
|
| 500 |
+
with probability $p$ replace it with a new edge $(u, w)$ with uniformly
|
| 501 |
+
random choice of existing node $w$.
|
| 502 |
+
The entire process is repeated until a connected graph results.
|
| 503 |
+
|
| 504 |
+
See Also
|
| 505 |
+
--------
|
| 506 |
+
newman_watts_strogatz_graph
|
| 507 |
+
watts_strogatz_graph
|
| 508 |
+
|
| 509 |
+
References
|
| 510 |
+
----------
|
| 511 |
+
.. [1] Duncan J. Watts and Steven H. Strogatz,
|
| 512 |
+
Collective dynamics of small-world networks,
|
| 513 |
+
Nature, 393, pp. 440--442, 1998.
|
| 514 |
+
"""
|
| 515 |
+
for i in range(tries):
|
| 516 |
+
# seed is an RNG so should change sequence each call
|
| 517 |
+
G = watts_strogatz_graph(n, k, p, seed, create_using=create_using)
|
| 518 |
+
if nx.is_connected(G):
|
| 519 |
+
return G
|
| 520 |
+
raise nx.NetworkXError("Maximum number of tries exceeded")
|
| 521 |
+
|
| 522 |
+
|
| 523 |
+
@py_random_state(2)
|
| 524 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 525 |
+
def random_regular_graph(d, n, seed=None, *, create_using=None):
|
| 526 |
+
r"""Returns a random $d$-regular graph on $n$ nodes.
|
| 527 |
+
|
| 528 |
+
A regular graph is a graph where each node has the same number of neighbors.
|
| 529 |
+
|
| 530 |
+
The resulting graph has no self-loops or parallel edges.
|
| 531 |
+
|
| 532 |
+
Parameters
|
| 533 |
+
----------
|
| 534 |
+
d : int
|
| 535 |
+
The degree of each node.
|
| 536 |
+
n : integer
|
| 537 |
+
The number of nodes. The value of $n \times d$ must be even.
|
| 538 |
+
seed : integer, random_state, or None (default)
|
| 539 |
+
Indicator of random number generation state.
|
| 540 |
+
See :ref:`Randomness<randomness>`.
|
| 541 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 542 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 543 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 544 |
+
|
| 545 |
+
Notes
|
| 546 |
+
-----
|
| 547 |
+
The nodes are numbered from $0$ to $n - 1$.
|
| 548 |
+
|
| 549 |
+
Kim and Vu's paper [2]_ shows that this algorithm samples in an
|
| 550 |
+
asymptotically uniform way from the space of random graphs when
|
| 551 |
+
$d = O(n^{1 / 3 - \epsilon})$.
|
| 552 |
+
|
| 553 |
+
Raises
|
| 554 |
+
------
|
| 555 |
+
|
| 556 |
+
NetworkXError
|
| 557 |
+
If $n \times d$ is odd or $d$ is greater than or equal to $n$.
|
| 558 |
+
|
| 559 |
+
References
|
| 560 |
+
----------
|
| 561 |
+
.. [1] A. Steger and N. Wormald,
|
| 562 |
+
Generating random regular graphs quickly,
|
| 563 |
+
Probability and Computing 8 (1999), 377-396, 1999.
|
| 564 |
+
https://doi.org/10.1017/S0963548399003867
|
| 565 |
+
|
| 566 |
+
.. [2] Jeong Han Kim and Van H. Vu,
|
| 567 |
+
Generating random regular graphs,
|
| 568 |
+
Proceedings of the thirty-fifth ACM symposium on Theory of computing,
|
| 569 |
+
San Diego, CA, USA, pp 213--222, 2003.
|
| 570 |
+
http://portal.acm.org/citation.cfm?id=780542.780576
|
| 571 |
+
"""
|
| 572 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 573 |
+
if (n * d) % 2 != 0:
|
| 574 |
+
raise nx.NetworkXError("n * d must be even")
|
| 575 |
+
|
| 576 |
+
if not 0 <= d < n:
|
| 577 |
+
raise nx.NetworkXError("the 0 <= d < n inequality must be satisfied")
|
| 578 |
+
|
| 579 |
+
G = nx.empty_graph(n, create_using=create_using)
|
| 580 |
+
|
| 581 |
+
if d == 0:
|
| 582 |
+
return G
|
| 583 |
+
|
| 584 |
+
def _suitable(edges, potential_edges):
|
| 585 |
+
# Helper subroutine to check if there are suitable edges remaining
|
| 586 |
+
# If False, the generation of the graph has failed
|
| 587 |
+
if not potential_edges:
|
| 588 |
+
return True
|
| 589 |
+
for s1 in potential_edges:
|
| 590 |
+
for s2 in potential_edges:
|
| 591 |
+
# Two iterators on the same dictionary are guaranteed
|
| 592 |
+
# to visit it in the same order if there are no
|
| 593 |
+
# intervening modifications.
|
| 594 |
+
if s1 == s2:
|
| 595 |
+
# Only need to consider s1-s2 pair one time
|
| 596 |
+
break
|
| 597 |
+
if s1 > s2:
|
| 598 |
+
s1, s2 = s2, s1
|
| 599 |
+
if (s1, s2) not in edges:
|
| 600 |
+
return True
|
| 601 |
+
return False
|
| 602 |
+
|
| 603 |
+
def _try_creation():
|
| 604 |
+
# Attempt to create an edge set
|
| 605 |
+
|
| 606 |
+
edges = set()
|
| 607 |
+
stubs = list(range(n)) * d
|
| 608 |
+
|
| 609 |
+
while stubs:
|
| 610 |
+
potential_edges = defaultdict(lambda: 0)
|
| 611 |
+
seed.shuffle(stubs)
|
| 612 |
+
stubiter = iter(stubs)
|
| 613 |
+
for s1, s2 in zip(stubiter, stubiter):
|
| 614 |
+
if s1 > s2:
|
| 615 |
+
s1, s2 = s2, s1
|
| 616 |
+
if s1 != s2 and ((s1, s2) not in edges):
|
| 617 |
+
edges.add((s1, s2))
|
| 618 |
+
else:
|
| 619 |
+
potential_edges[s1] += 1
|
| 620 |
+
potential_edges[s2] += 1
|
| 621 |
+
|
| 622 |
+
if not _suitable(edges, potential_edges):
|
| 623 |
+
return None # failed to find suitable edge set
|
| 624 |
+
|
| 625 |
+
stubs = [
|
| 626 |
+
node
|
| 627 |
+
for node, potential in potential_edges.items()
|
| 628 |
+
for _ in range(potential)
|
| 629 |
+
]
|
| 630 |
+
return edges
|
| 631 |
+
|
| 632 |
+
# Even though a suitable edge set exists,
|
| 633 |
+
# the generation of such a set is not guaranteed.
|
| 634 |
+
# Try repeatedly to find one.
|
| 635 |
+
edges = _try_creation()
|
| 636 |
+
while edges is None:
|
| 637 |
+
edges = _try_creation()
|
| 638 |
+
G.add_edges_from(edges)
|
| 639 |
+
|
| 640 |
+
return G
|
| 641 |
+
|
| 642 |
+
|
| 643 |
+
def _random_subset(seq, m, rng):
|
| 644 |
+
"""Return m unique elements from seq.
|
| 645 |
+
|
| 646 |
+
This differs from random.sample which can return repeated
|
| 647 |
+
elements if seq holds repeated elements.
|
| 648 |
+
|
| 649 |
+
Note: rng is a random.Random or numpy.random.RandomState instance.
|
| 650 |
+
"""
|
| 651 |
+
targets = set()
|
| 652 |
+
while len(targets) < m:
|
| 653 |
+
x = rng.choice(seq)
|
| 654 |
+
targets.add(x)
|
| 655 |
+
return targets
|
| 656 |
+
|
| 657 |
+
|
| 658 |
+
@py_random_state(2)
|
| 659 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 660 |
+
def barabasi_albert_graph(n, m, seed=None, initial_graph=None, *, create_using=None):
|
| 661 |
+
"""Returns a random graph using Barabási–Albert preferential attachment
|
| 662 |
+
|
| 663 |
+
A graph of $n$ nodes is grown by attaching new nodes each with $m$
|
| 664 |
+
edges that are preferentially attached to existing nodes with high degree.
|
| 665 |
+
|
| 666 |
+
Parameters
|
| 667 |
+
----------
|
| 668 |
+
n : int
|
| 669 |
+
Number of nodes
|
| 670 |
+
m : int
|
| 671 |
+
Number of edges to attach from a new node to existing nodes
|
| 672 |
+
seed : integer, random_state, or None (default)
|
| 673 |
+
Indicator of random number generation state.
|
| 674 |
+
See :ref:`Randomness<randomness>`.
|
| 675 |
+
initial_graph : Graph or None (default)
|
| 676 |
+
Initial network for Barabási–Albert algorithm.
|
| 677 |
+
It should be a connected graph for most use cases.
|
| 678 |
+
A copy of `initial_graph` is used.
|
| 679 |
+
If None, starts from a star graph on (m+1) nodes.
|
| 680 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 681 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 682 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 683 |
+
|
| 684 |
+
Returns
|
| 685 |
+
-------
|
| 686 |
+
G : Graph
|
| 687 |
+
|
| 688 |
+
Raises
|
| 689 |
+
------
|
| 690 |
+
NetworkXError
|
| 691 |
+
If `m` does not satisfy ``1 <= m < n``, or
|
| 692 |
+
the initial graph number of nodes m0 does not satisfy ``m <= m0 <= n``.
|
| 693 |
+
|
| 694 |
+
References
|
| 695 |
+
----------
|
| 696 |
+
.. [1] A. L. Barabási and R. Albert "Emergence of scaling in
|
| 697 |
+
random networks", Science 286, pp 509-512, 1999.
|
| 698 |
+
"""
|
| 699 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 700 |
+
if m < 1 or m >= n:
|
| 701 |
+
raise nx.NetworkXError(
|
| 702 |
+
f"Barabási–Albert network must have m >= 1 and m < n, m = {m}, n = {n}"
|
| 703 |
+
)
|
| 704 |
+
|
| 705 |
+
if initial_graph is None:
|
| 706 |
+
# Default initial graph : star graph on (m + 1) nodes
|
| 707 |
+
G = star_graph(m, create_using)
|
| 708 |
+
else:
|
| 709 |
+
if len(initial_graph) < m or len(initial_graph) > n:
|
| 710 |
+
raise nx.NetworkXError(
|
| 711 |
+
f"Barabási–Albert initial graph needs between m={m} and n={n} nodes"
|
| 712 |
+
)
|
| 713 |
+
G = initial_graph.copy()
|
| 714 |
+
|
| 715 |
+
# List of existing nodes, with nodes repeated once for each adjacent edge
|
| 716 |
+
repeated_nodes = [n for n, d in G.degree() for _ in range(d)]
|
| 717 |
+
# Start adding the other n - m0 nodes.
|
| 718 |
+
source = len(G)
|
| 719 |
+
while source < n:
|
| 720 |
+
# Now choose m unique nodes from the existing nodes
|
| 721 |
+
# Pick uniformly from repeated_nodes (preferential attachment)
|
| 722 |
+
targets = _random_subset(repeated_nodes, m, seed)
|
| 723 |
+
# Add edges to m nodes from the source.
|
| 724 |
+
G.add_edges_from(zip([source] * m, targets))
|
| 725 |
+
# Add one node to the list for each new edge just created.
|
| 726 |
+
repeated_nodes.extend(targets)
|
| 727 |
+
# And the new node "source" has m edges to add to the list.
|
| 728 |
+
repeated_nodes.extend([source] * m)
|
| 729 |
+
|
| 730 |
+
source += 1
|
| 731 |
+
return G
|
| 732 |
+
|
| 733 |
+
|
| 734 |
+
@py_random_state(4)
|
| 735 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 736 |
+
def dual_barabasi_albert_graph(
|
| 737 |
+
n, m1, m2, p, seed=None, initial_graph=None, *, create_using=None
|
| 738 |
+
):
|
| 739 |
+
"""Returns a random graph using dual Barabási–Albert preferential attachment
|
| 740 |
+
|
| 741 |
+
A graph of $n$ nodes is grown by attaching new nodes each with either $m_1$
|
| 742 |
+
edges (with probability $p$) or $m_2$ edges (with probability $1-p$) that
|
| 743 |
+
are preferentially attached to existing nodes with high degree.
|
| 744 |
+
|
| 745 |
+
Parameters
|
| 746 |
+
----------
|
| 747 |
+
n : int
|
| 748 |
+
Number of nodes
|
| 749 |
+
m1 : int
|
| 750 |
+
Number of edges to link each new node to existing nodes with probability $p$
|
| 751 |
+
m2 : int
|
| 752 |
+
Number of edges to link each new node to existing nodes with probability $1-p$
|
| 753 |
+
p : float
|
| 754 |
+
The probability of attaching $m_1$ edges (as opposed to $m_2$ edges)
|
| 755 |
+
seed : integer, random_state, or None (default)
|
| 756 |
+
Indicator of random number generation state.
|
| 757 |
+
See :ref:`Randomness<randomness>`.
|
| 758 |
+
initial_graph : Graph or None (default)
|
| 759 |
+
Initial network for Barabási–Albert algorithm.
|
| 760 |
+
A copy of `initial_graph` is used.
|
| 761 |
+
It should be connected for most use cases.
|
| 762 |
+
If None, starts from an star graph on max(m1, m2) + 1 nodes.
|
| 763 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 764 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 765 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 766 |
+
|
| 767 |
+
Returns
|
| 768 |
+
-------
|
| 769 |
+
G : Graph
|
| 770 |
+
|
| 771 |
+
Raises
|
| 772 |
+
------
|
| 773 |
+
NetworkXError
|
| 774 |
+
If `m1` and `m2` do not satisfy ``1 <= m1,m2 < n``, or
|
| 775 |
+
`p` does not satisfy ``0 <= p <= 1``, or
|
| 776 |
+
the initial graph number of nodes m0 does not satisfy m1, m2 <= m0 <= n.
|
| 777 |
+
|
| 778 |
+
References
|
| 779 |
+
----------
|
| 780 |
+
.. [1] N. Moshiri "The dual-Barabasi-Albert model", arXiv:1810.10538.
|
| 781 |
+
"""
|
| 782 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 783 |
+
if m1 < 1 or m1 >= n:
|
| 784 |
+
raise nx.NetworkXError(
|
| 785 |
+
f"Dual Barabási–Albert must have m1 >= 1 and m1 < n, m1 = {m1}, n = {n}"
|
| 786 |
+
)
|
| 787 |
+
if m2 < 1 or m2 >= n:
|
| 788 |
+
raise nx.NetworkXError(
|
| 789 |
+
f"Dual Barabási–Albert must have m2 >= 1 and m2 < n, m2 = {m2}, n = {n}"
|
| 790 |
+
)
|
| 791 |
+
if p < 0 or p > 1:
|
| 792 |
+
raise nx.NetworkXError(
|
| 793 |
+
f"Dual Barabási–Albert network must have 0 <= p <= 1, p = {p}"
|
| 794 |
+
)
|
| 795 |
+
|
| 796 |
+
# For simplicity, if p == 0 or 1, just return BA
|
| 797 |
+
if p == 1:
|
| 798 |
+
return barabasi_albert_graph(n, m1, seed, create_using=create_using)
|
| 799 |
+
elif p == 0:
|
| 800 |
+
return barabasi_albert_graph(n, m2, seed, create_using=create_using)
|
| 801 |
+
|
| 802 |
+
if initial_graph is None:
|
| 803 |
+
# Default initial graph : star graph on max(m1, m2) nodes
|
| 804 |
+
G = star_graph(max(m1, m2), create_using)
|
| 805 |
+
else:
|
| 806 |
+
if len(initial_graph) < max(m1, m2) or len(initial_graph) > n:
|
| 807 |
+
raise nx.NetworkXError(
|
| 808 |
+
f"Barabási–Albert initial graph must have between "
|
| 809 |
+
f"max(m1, m2) = {max(m1, m2)} and n = {n} nodes"
|
| 810 |
+
)
|
| 811 |
+
G = initial_graph.copy()
|
| 812 |
+
|
| 813 |
+
# Target nodes for new edges
|
| 814 |
+
targets = list(G)
|
| 815 |
+
# List of existing nodes, with nodes repeated once for each adjacent edge
|
| 816 |
+
repeated_nodes = [n for n, d in G.degree() for _ in range(d)]
|
| 817 |
+
# Start adding the remaining nodes.
|
| 818 |
+
source = len(G)
|
| 819 |
+
while source < n:
|
| 820 |
+
# Pick which m to use (m1 or m2)
|
| 821 |
+
if seed.random() < p:
|
| 822 |
+
m = m1
|
| 823 |
+
else:
|
| 824 |
+
m = m2
|
| 825 |
+
# Now choose m unique nodes from the existing nodes
|
| 826 |
+
# Pick uniformly from repeated_nodes (preferential attachment)
|
| 827 |
+
targets = _random_subset(repeated_nodes, m, seed)
|
| 828 |
+
# Add edges to m nodes from the source.
|
| 829 |
+
G.add_edges_from(zip([source] * m, targets))
|
| 830 |
+
# Add one node to the list for each new edge just created.
|
| 831 |
+
repeated_nodes.extend(targets)
|
| 832 |
+
# And the new node "source" has m edges to add to the list.
|
| 833 |
+
repeated_nodes.extend([source] * m)
|
| 834 |
+
|
| 835 |
+
source += 1
|
| 836 |
+
return G
|
| 837 |
+
|
| 838 |
+
|
| 839 |
+
@py_random_state(4)
|
| 840 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 841 |
+
def extended_barabasi_albert_graph(n, m, p, q, seed=None, *, create_using=None):
|
| 842 |
+
"""Returns an extended Barabási–Albert model graph.
|
| 843 |
+
|
| 844 |
+
An extended Barabási–Albert model graph is a random graph constructed
|
| 845 |
+
using preferential attachment. The extended model allows new edges,
|
| 846 |
+
rewired edges or new nodes. Based on the probabilities $p$ and $q$
|
| 847 |
+
with $p + q < 1$, the growing behavior of the graph is determined as:
|
| 848 |
+
|
| 849 |
+
1) With $p$ probability, $m$ new edges are added to the graph,
|
| 850 |
+
starting from randomly chosen existing nodes and attached preferentially at the
|
| 851 |
+
other end.
|
| 852 |
+
|
| 853 |
+
2) With $q$ probability, $m$ existing edges are rewired
|
| 854 |
+
by randomly choosing an edge and rewiring one end to a preferentially chosen node.
|
| 855 |
+
|
| 856 |
+
3) With $(1 - p - q)$ probability, $m$ new nodes are added to the graph
|
| 857 |
+
with edges attached preferentially.
|
| 858 |
+
|
| 859 |
+
When $p = q = 0$, the model behaves just like the Barabási–Alber model.
|
| 860 |
+
|
| 861 |
+
Parameters
|
| 862 |
+
----------
|
| 863 |
+
n : int
|
| 864 |
+
Number of nodes
|
| 865 |
+
m : int
|
| 866 |
+
Number of edges with which a new node attaches to existing nodes
|
| 867 |
+
p : float
|
| 868 |
+
Probability value for adding an edge between existing nodes. p + q < 1
|
| 869 |
+
q : float
|
| 870 |
+
Probability value of rewiring of existing edges. p + q < 1
|
| 871 |
+
seed : integer, random_state, or None (default)
|
| 872 |
+
Indicator of random number generation state.
|
| 873 |
+
See :ref:`Randomness<randomness>`.
|
| 874 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 875 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 876 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 877 |
+
|
| 878 |
+
Returns
|
| 879 |
+
-------
|
| 880 |
+
G : Graph
|
| 881 |
+
|
| 882 |
+
Raises
|
| 883 |
+
------
|
| 884 |
+
NetworkXError
|
| 885 |
+
If `m` does not satisfy ``1 <= m < n`` or ``1 >= p + q``
|
| 886 |
+
|
| 887 |
+
References
|
| 888 |
+
----------
|
| 889 |
+
.. [1] Albert, R., & Barabási, A. L. (2000)
|
| 890 |
+
Topology of evolving networks: local events and universality
|
| 891 |
+
Physical review letters, 85(24), 5234.
|
| 892 |
+
"""
|
| 893 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 894 |
+
if m < 1 or m >= n:
|
| 895 |
+
msg = f"Extended Barabasi-Albert network needs m>=1 and m<n, m={m}, n={n}"
|
| 896 |
+
raise nx.NetworkXError(msg)
|
| 897 |
+
if p + q >= 1:
|
| 898 |
+
msg = f"Extended Barabasi-Albert network needs p + q <= 1, p={p}, q={q}"
|
| 899 |
+
raise nx.NetworkXError(msg)
|
| 900 |
+
|
| 901 |
+
# Add m initial nodes (m0 in barabasi-speak)
|
| 902 |
+
G = empty_graph(m, create_using)
|
| 903 |
+
|
| 904 |
+
# List of nodes to represent the preferential attachment random selection.
|
| 905 |
+
# At the creation of the graph, all nodes are added to the list
|
| 906 |
+
# so that even nodes that are not connected have a chance to get selected,
|
| 907 |
+
# for rewiring and adding of edges.
|
| 908 |
+
# With each new edge, nodes at the ends of the edge are added to the list.
|
| 909 |
+
attachment_preference = []
|
| 910 |
+
attachment_preference.extend(range(m))
|
| 911 |
+
|
| 912 |
+
# Start adding the other n-m nodes. The first node is m.
|
| 913 |
+
new_node = m
|
| 914 |
+
while new_node < n:
|
| 915 |
+
a_probability = seed.random()
|
| 916 |
+
|
| 917 |
+
# Total number of edges of a Clique of all the nodes
|
| 918 |
+
clique_degree = len(G) - 1
|
| 919 |
+
clique_size = (len(G) * clique_degree) / 2
|
| 920 |
+
|
| 921 |
+
# Adding m new edges, if there is room to add them
|
| 922 |
+
if a_probability < p and G.size() <= clique_size - m:
|
| 923 |
+
# Select the nodes where an edge can be added
|
| 924 |
+
eligible_nodes = [nd for nd, deg in G.degree() if deg < clique_degree]
|
| 925 |
+
for i in range(m):
|
| 926 |
+
# Choosing a random source node from eligible_nodes
|
| 927 |
+
src_node = seed.choice(eligible_nodes)
|
| 928 |
+
|
| 929 |
+
# Picking a possible node that is not 'src_node' or
|
| 930 |
+
# neighbor with 'src_node', with preferential attachment
|
| 931 |
+
prohibited_nodes = list(G[src_node])
|
| 932 |
+
prohibited_nodes.append(src_node)
|
| 933 |
+
# This will raise an exception if the sequence is empty
|
| 934 |
+
dest_node = seed.choice(
|
| 935 |
+
[nd for nd in attachment_preference if nd not in prohibited_nodes]
|
| 936 |
+
)
|
| 937 |
+
# Adding the new edge
|
| 938 |
+
G.add_edge(src_node, dest_node)
|
| 939 |
+
|
| 940 |
+
# Appending both nodes to add to their preferential attachment
|
| 941 |
+
attachment_preference.append(src_node)
|
| 942 |
+
attachment_preference.append(dest_node)
|
| 943 |
+
|
| 944 |
+
# Adjusting the eligible nodes. Degree may be saturated.
|
| 945 |
+
if G.degree(src_node) == clique_degree:
|
| 946 |
+
eligible_nodes.remove(src_node)
|
| 947 |
+
if G.degree(dest_node) == clique_degree and dest_node in eligible_nodes:
|
| 948 |
+
eligible_nodes.remove(dest_node)
|
| 949 |
+
|
| 950 |
+
# Rewiring m edges, if there are enough edges
|
| 951 |
+
elif p <= a_probability < (p + q) and m <= G.size() < clique_size:
|
| 952 |
+
# Selecting nodes that have at least 1 edge but that are not
|
| 953 |
+
# fully connected to ALL other nodes (center of star).
|
| 954 |
+
# These nodes are the pivot nodes of the edges to rewire
|
| 955 |
+
eligible_nodes = [nd for nd, deg in G.degree() if 0 < deg < clique_degree]
|
| 956 |
+
for i in range(m):
|
| 957 |
+
# Choosing a random source node
|
| 958 |
+
node = seed.choice(eligible_nodes)
|
| 959 |
+
|
| 960 |
+
# The available nodes do have a neighbor at least.
|
| 961 |
+
nbr_nodes = list(G[node])
|
| 962 |
+
|
| 963 |
+
# Choosing the other end that will get detached
|
| 964 |
+
src_node = seed.choice(nbr_nodes)
|
| 965 |
+
|
| 966 |
+
# Picking a target node that is not 'node' or
|
| 967 |
+
# neighbor with 'node', with preferential attachment
|
| 968 |
+
nbr_nodes.append(node)
|
| 969 |
+
dest_node = seed.choice(
|
| 970 |
+
[nd for nd in attachment_preference if nd not in nbr_nodes]
|
| 971 |
+
)
|
| 972 |
+
# Rewire
|
| 973 |
+
G.remove_edge(node, src_node)
|
| 974 |
+
G.add_edge(node, dest_node)
|
| 975 |
+
|
| 976 |
+
# Adjusting the preferential attachment list
|
| 977 |
+
attachment_preference.remove(src_node)
|
| 978 |
+
attachment_preference.append(dest_node)
|
| 979 |
+
|
| 980 |
+
# Adjusting the eligible nodes.
|
| 981 |
+
# nodes may be saturated or isolated.
|
| 982 |
+
if G.degree(src_node) == 0 and src_node in eligible_nodes:
|
| 983 |
+
eligible_nodes.remove(src_node)
|
| 984 |
+
if dest_node in eligible_nodes:
|
| 985 |
+
if G.degree(dest_node) == clique_degree:
|
| 986 |
+
eligible_nodes.remove(dest_node)
|
| 987 |
+
else:
|
| 988 |
+
if G.degree(dest_node) == 1:
|
| 989 |
+
eligible_nodes.append(dest_node)
|
| 990 |
+
|
| 991 |
+
# Adding new node with m edges
|
| 992 |
+
else:
|
| 993 |
+
# Select the edges' nodes by preferential attachment
|
| 994 |
+
targets = _random_subset(attachment_preference, m, seed)
|
| 995 |
+
G.add_edges_from(zip([new_node] * m, targets))
|
| 996 |
+
|
| 997 |
+
# Add one node to the list for each new edge just created.
|
| 998 |
+
attachment_preference.extend(targets)
|
| 999 |
+
# The new node has m edges to it, plus itself: m + 1
|
| 1000 |
+
attachment_preference.extend([new_node] * (m + 1))
|
| 1001 |
+
new_node += 1
|
| 1002 |
+
return G
|
| 1003 |
+
|
| 1004 |
+
|
| 1005 |
+
@py_random_state(3)
|
| 1006 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 1007 |
+
def powerlaw_cluster_graph(n, m, p, seed=None, *, create_using=None):
|
| 1008 |
+
"""Holme and Kim algorithm for growing graphs with powerlaw
|
| 1009 |
+
degree distribution and approximate average clustering.
|
| 1010 |
+
|
| 1011 |
+
Parameters
|
| 1012 |
+
----------
|
| 1013 |
+
n : int
|
| 1014 |
+
the number of nodes
|
| 1015 |
+
m : int
|
| 1016 |
+
the number of random edges to add for each new node
|
| 1017 |
+
p : float,
|
| 1018 |
+
Probability of adding a triangle after adding a random edge
|
| 1019 |
+
seed : integer, random_state, or None (default)
|
| 1020 |
+
Indicator of random number generation state.
|
| 1021 |
+
See :ref:`Randomness<randomness>`.
|
| 1022 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 1023 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 1024 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 1025 |
+
|
| 1026 |
+
Notes
|
| 1027 |
+
-----
|
| 1028 |
+
The average clustering has a hard time getting above a certain
|
| 1029 |
+
cutoff that depends on `m`. This cutoff is often quite low. The
|
| 1030 |
+
transitivity (fraction of triangles to possible triangles) seems to
|
| 1031 |
+
decrease with network size.
|
| 1032 |
+
|
| 1033 |
+
It is essentially the Barabási–Albert (BA) growth model with an
|
| 1034 |
+
extra step that each random edge is followed by a chance of
|
| 1035 |
+
making an edge to one of its neighbors too (and thus a triangle).
|
| 1036 |
+
|
| 1037 |
+
This algorithm improves on BA in the sense that it enables a
|
| 1038 |
+
higher average clustering to be attained if desired.
|
| 1039 |
+
|
| 1040 |
+
It seems possible to have a disconnected graph with this algorithm
|
| 1041 |
+
since the initial `m` nodes may not be all linked to a new node
|
| 1042 |
+
on the first iteration like the BA model.
|
| 1043 |
+
|
| 1044 |
+
Raises
|
| 1045 |
+
------
|
| 1046 |
+
NetworkXError
|
| 1047 |
+
If `m` does not satisfy ``1 <= m <= n`` or `p` does not
|
| 1048 |
+
satisfy ``0 <= p <= 1``.
|
| 1049 |
+
|
| 1050 |
+
References
|
| 1051 |
+
----------
|
| 1052 |
+
.. [1] P. Holme and B. J. Kim,
|
| 1053 |
+
"Growing scale-free networks with tunable clustering",
|
| 1054 |
+
Phys. Rev. E, 65, 026107, 2002.
|
| 1055 |
+
"""
|
| 1056 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 1057 |
+
if m < 1 or n < m:
|
| 1058 |
+
raise nx.NetworkXError(f"NetworkXError must have m>1 and m<n, m={m},n={n}")
|
| 1059 |
+
|
| 1060 |
+
if p > 1 or p < 0:
|
| 1061 |
+
raise nx.NetworkXError(f"NetworkXError p must be in [0,1], p={p}")
|
| 1062 |
+
|
| 1063 |
+
G = empty_graph(m, create_using) # add m initial nodes (m0 in barabasi-speak)
|
| 1064 |
+
repeated_nodes = list(G) # list of existing nodes to sample from
|
| 1065 |
+
# with nodes repeated once for each adjacent edge
|
| 1066 |
+
source = m # next node is m
|
| 1067 |
+
while source < n: # Now add the other n-1 nodes
|
| 1068 |
+
possible_targets = _random_subset(repeated_nodes, m, seed)
|
| 1069 |
+
# do one preferential attachment for new node
|
| 1070 |
+
target = possible_targets.pop()
|
| 1071 |
+
G.add_edge(source, target)
|
| 1072 |
+
repeated_nodes.append(target) # add one node to list for each new link
|
| 1073 |
+
count = 1
|
| 1074 |
+
while count < m: # add m-1 more new links
|
| 1075 |
+
if seed.random() < p: # clustering step: add triangle
|
| 1076 |
+
neighborhood = [
|
| 1077 |
+
nbr
|
| 1078 |
+
for nbr in G.neighbors(target)
|
| 1079 |
+
if not G.has_edge(source, nbr) and nbr != source
|
| 1080 |
+
]
|
| 1081 |
+
if neighborhood: # if there is a neighbor without a link
|
| 1082 |
+
nbr = seed.choice(neighborhood)
|
| 1083 |
+
G.add_edge(source, nbr) # add triangle
|
| 1084 |
+
repeated_nodes.append(nbr)
|
| 1085 |
+
count = count + 1
|
| 1086 |
+
continue # go to top of while loop
|
| 1087 |
+
# else do preferential attachment step if above fails
|
| 1088 |
+
target = possible_targets.pop()
|
| 1089 |
+
G.add_edge(source, target)
|
| 1090 |
+
repeated_nodes.append(target)
|
| 1091 |
+
count = count + 1
|
| 1092 |
+
|
| 1093 |
+
repeated_nodes.extend([source] * m) # add source node to list m times
|
| 1094 |
+
source += 1
|
| 1095 |
+
return G
|
| 1096 |
+
|
| 1097 |
+
|
| 1098 |
+
@py_random_state(3)
|
| 1099 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 1100 |
+
def random_lobster(n, p1, p2, seed=None, *, create_using=None):
|
| 1101 |
+
"""Returns a random lobster graph.
|
| 1102 |
+
|
| 1103 |
+
A lobster is a tree that reduces to a caterpillar when pruning all
|
| 1104 |
+
leaf nodes. A caterpillar is a tree that reduces to a path graph
|
| 1105 |
+
when pruning all leaf nodes; setting `p2` to zero produces a caterpillar.
|
| 1106 |
+
|
| 1107 |
+
This implementation iterates on the probabilities `p1` and `p2` to add
|
| 1108 |
+
edges at levels 1 and 2, respectively. Graphs are therefore constructed
|
| 1109 |
+
iteratively with uniform randomness at each level rather than being selected
|
| 1110 |
+
uniformly at random from the set of all possible lobsters.
|
| 1111 |
+
|
| 1112 |
+
Parameters
|
| 1113 |
+
----------
|
| 1114 |
+
n : int
|
| 1115 |
+
The expected number of nodes in the backbone
|
| 1116 |
+
p1 : float
|
| 1117 |
+
Probability of adding an edge to the backbone
|
| 1118 |
+
p2 : float
|
| 1119 |
+
Probability of adding an edge one level beyond backbone
|
| 1120 |
+
seed : integer, random_state, or None (default)
|
| 1121 |
+
Indicator of random number generation state.
|
| 1122 |
+
See :ref:`Randomness<randomness>`.
|
| 1123 |
+
create_using : Graph constructor, optional (default=nx.Grap)
|
| 1124 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 1125 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 1126 |
+
|
| 1127 |
+
Raises
|
| 1128 |
+
------
|
| 1129 |
+
NetworkXError
|
| 1130 |
+
If `p1` or `p2` parameters are >= 1 because the while loops would never finish.
|
| 1131 |
+
"""
|
| 1132 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 1133 |
+
p1, p2 = abs(p1), abs(p2)
|
| 1134 |
+
if any(p >= 1 for p in [p1, p2]):
|
| 1135 |
+
raise nx.NetworkXError("Probability values for `p1` and `p2` must both be < 1.")
|
| 1136 |
+
|
| 1137 |
+
# a necessary ingredient in any self-respecting graph library
|
| 1138 |
+
llen = int(2 * seed.random() * n + 0.5)
|
| 1139 |
+
L = path_graph(llen, create_using)
|
| 1140 |
+
# build caterpillar: add edges to path graph with probability p1
|
| 1141 |
+
current_node = llen - 1
|
| 1142 |
+
for n in range(llen):
|
| 1143 |
+
while seed.random() < p1: # add fuzzy caterpillar parts
|
| 1144 |
+
current_node += 1
|
| 1145 |
+
L.add_edge(n, current_node)
|
| 1146 |
+
cat_node = current_node
|
| 1147 |
+
while seed.random() < p2: # add crunchy lobster bits
|
| 1148 |
+
current_node += 1
|
| 1149 |
+
L.add_edge(cat_node, current_node)
|
| 1150 |
+
return L # voila, un lobster!
|
| 1151 |
+
|
| 1152 |
+
|
| 1153 |
+
@py_random_state(1)
|
| 1154 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 1155 |
+
def random_shell_graph(constructor, seed=None, *, create_using=None):
|
| 1156 |
+
"""Returns a random shell graph for the constructor given.
|
| 1157 |
+
|
| 1158 |
+
Parameters
|
| 1159 |
+
----------
|
| 1160 |
+
constructor : list of three-tuples
|
| 1161 |
+
Represents the parameters for a shell, starting at the center
|
| 1162 |
+
shell. Each element of the list must be of the form `(n, m,
|
| 1163 |
+
d)`, where `n` is the number of nodes in the shell, `m` is
|
| 1164 |
+
the number of edges in the shell, and `d` is the ratio of
|
| 1165 |
+
inter-shell (next) edges to intra-shell edges. If `d` is zero,
|
| 1166 |
+
there will be no intra-shell edges, and if `d` is one there
|
| 1167 |
+
will be all possible intra-shell edges.
|
| 1168 |
+
seed : integer, random_state, or None (default)
|
| 1169 |
+
Indicator of random number generation state.
|
| 1170 |
+
See :ref:`Randomness<randomness>`.
|
| 1171 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 1172 |
+
Graph type to create. Graph instances are not supported.
|
| 1173 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 1174 |
+
|
| 1175 |
+
Examples
|
| 1176 |
+
--------
|
| 1177 |
+
>>> constructor = [(10, 20, 0.8), (20, 40, 0.8)]
|
| 1178 |
+
>>> G = nx.random_shell_graph(constructor)
|
| 1179 |
+
|
| 1180 |
+
"""
|
| 1181 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 1182 |
+
G = empty_graph(0, create_using)
|
| 1183 |
+
|
| 1184 |
+
glist = []
|
| 1185 |
+
intra_edges = []
|
| 1186 |
+
nnodes = 0
|
| 1187 |
+
# create gnm graphs for each shell
|
| 1188 |
+
for n, m, d in constructor:
|
| 1189 |
+
inter_edges = int(m * d)
|
| 1190 |
+
intra_edges.append(m - inter_edges)
|
| 1191 |
+
g = nx.convert_node_labels_to_integers(
|
| 1192 |
+
gnm_random_graph(n, inter_edges, seed=seed, create_using=G.__class__),
|
| 1193 |
+
first_label=nnodes,
|
| 1194 |
+
)
|
| 1195 |
+
glist.append(g)
|
| 1196 |
+
nnodes += n
|
| 1197 |
+
G = nx.operators.union(G, g)
|
| 1198 |
+
|
| 1199 |
+
# connect the shells randomly
|
| 1200 |
+
for gi in range(len(glist) - 1):
|
| 1201 |
+
nlist1 = list(glist[gi])
|
| 1202 |
+
nlist2 = list(glist[gi + 1])
|
| 1203 |
+
total_edges = intra_edges[gi]
|
| 1204 |
+
edge_count = 0
|
| 1205 |
+
while edge_count < total_edges:
|
| 1206 |
+
u = seed.choice(nlist1)
|
| 1207 |
+
v = seed.choice(nlist2)
|
| 1208 |
+
if u == v or G.has_edge(u, v):
|
| 1209 |
+
continue
|
| 1210 |
+
else:
|
| 1211 |
+
G.add_edge(u, v)
|
| 1212 |
+
edge_count = edge_count + 1
|
| 1213 |
+
return G
|
| 1214 |
+
|
| 1215 |
+
|
| 1216 |
+
@py_random_state(2)
|
| 1217 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 1218 |
+
def random_powerlaw_tree(n, gamma=3, seed=None, tries=100, *, create_using=None):
|
| 1219 |
+
"""Returns a tree with a power law degree distribution.
|
| 1220 |
+
|
| 1221 |
+
Parameters
|
| 1222 |
+
----------
|
| 1223 |
+
n : int
|
| 1224 |
+
The number of nodes.
|
| 1225 |
+
gamma : float
|
| 1226 |
+
Exponent of the power law.
|
| 1227 |
+
seed : integer, random_state, or None (default)
|
| 1228 |
+
Indicator of random number generation state.
|
| 1229 |
+
See :ref:`Randomness<randomness>`.
|
| 1230 |
+
tries : int
|
| 1231 |
+
Number of attempts to adjust the sequence to make it a tree.
|
| 1232 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 1233 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 1234 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 1235 |
+
|
| 1236 |
+
Raises
|
| 1237 |
+
------
|
| 1238 |
+
NetworkXError
|
| 1239 |
+
If no valid sequence is found within the maximum number of
|
| 1240 |
+
attempts.
|
| 1241 |
+
|
| 1242 |
+
Notes
|
| 1243 |
+
-----
|
| 1244 |
+
A trial power law degree sequence is chosen and then elements are
|
| 1245 |
+
swapped with new elements from a powerlaw distribution until the
|
| 1246 |
+
sequence makes a tree (by checking, for example, that the number of
|
| 1247 |
+
edges is one smaller than the number of nodes).
|
| 1248 |
+
|
| 1249 |
+
"""
|
| 1250 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 1251 |
+
# This call may raise a NetworkXError if the number of tries is succeeded.
|
| 1252 |
+
seq = random_powerlaw_tree_sequence(n, gamma=gamma, seed=seed, tries=tries)
|
| 1253 |
+
G = degree_sequence_tree(seq, create_using)
|
| 1254 |
+
return G
|
| 1255 |
+
|
| 1256 |
+
|
| 1257 |
+
@py_random_state(2)
|
| 1258 |
+
@nx._dispatchable(graphs=None)
|
| 1259 |
+
def random_powerlaw_tree_sequence(n, gamma=3, seed=None, tries=100):
|
| 1260 |
+
"""Returns a degree sequence for a tree with a power law distribution.
|
| 1261 |
+
|
| 1262 |
+
Parameters
|
| 1263 |
+
----------
|
| 1264 |
+
n : int,
|
| 1265 |
+
The number of nodes.
|
| 1266 |
+
gamma : float
|
| 1267 |
+
Exponent of the power law.
|
| 1268 |
+
seed : integer, random_state, or None (default)
|
| 1269 |
+
Indicator of random number generation state.
|
| 1270 |
+
See :ref:`Randomness<randomness>`.
|
| 1271 |
+
tries : int
|
| 1272 |
+
Number of attempts to adjust the sequence to make it a tree.
|
| 1273 |
+
|
| 1274 |
+
Raises
|
| 1275 |
+
------
|
| 1276 |
+
NetworkXError
|
| 1277 |
+
If no valid sequence is found within the maximum number of
|
| 1278 |
+
attempts.
|
| 1279 |
+
|
| 1280 |
+
Notes
|
| 1281 |
+
-----
|
| 1282 |
+
A trial power law degree sequence is chosen and then elements are
|
| 1283 |
+
swapped with new elements from a power law distribution until
|
| 1284 |
+
the sequence makes a tree (by checking, for example, that the number of
|
| 1285 |
+
edges is one smaller than the number of nodes).
|
| 1286 |
+
|
| 1287 |
+
"""
|
| 1288 |
+
# get trial sequence
|
| 1289 |
+
z = nx.utils.powerlaw_sequence(n, exponent=gamma, seed=seed)
|
| 1290 |
+
# round to integer values in the range [0,n]
|
| 1291 |
+
zseq = [min(n, max(round(s), 0)) for s in z]
|
| 1292 |
+
|
| 1293 |
+
# another sequence to swap values from
|
| 1294 |
+
z = nx.utils.powerlaw_sequence(tries, exponent=gamma, seed=seed)
|
| 1295 |
+
# round to integer values in the range [0,n]
|
| 1296 |
+
swap = [min(n, max(round(s), 0)) for s in z]
|
| 1297 |
+
|
| 1298 |
+
for deg in swap:
|
| 1299 |
+
# If this degree sequence can be the degree sequence of a tree, return
|
| 1300 |
+
# it. It can be a tree if the number of edges is one fewer than the
|
| 1301 |
+
# number of nodes, or in other words, `n - sum(zseq) / 2 == 1`. We
|
| 1302 |
+
# use an equivalent condition below that avoids floating point
|
| 1303 |
+
# operations.
|
| 1304 |
+
if 2 * n - sum(zseq) == 2:
|
| 1305 |
+
return zseq
|
| 1306 |
+
index = seed.randint(0, n - 1)
|
| 1307 |
+
zseq[index] = swap.pop()
|
| 1308 |
+
|
| 1309 |
+
raise nx.NetworkXError(
|
| 1310 |
+
f"Exceeded max ({tries}) attempts for a valid tree sequence."
|
| 1311 |
+
)
|
| 1312 |
+
|
| 1313 |
+
|
| 1314 |
+
@py_random_state(3)
|
| 1315 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 1316 |
+
def random_kernel_graph(
|
| 1317 |
+
n, kernel_integral, kernel_root=None, seed=None, *, create_using=None
|
| 1318 |
+
):
|
| 1319 |
+
r"""Returns an random graph based on the specified kernel.
|
| 1320 |
+
|
| 1321 |
+
The algorithm chooses each of the $[n(n-1)]/2$ possible edges with
|
| 1322 |
+
probability specified by a kernel $\kappa(x,y)$ [1]_. The kernel
|
| 1323 |
+
$\kappa(x,y)$ must be a symmetric (in $x,y$), non-negative,
|
| 1324 |
+
bounded function.
|
| 1325 |
+
|
| 1326 |
+
Parameters
|
| 1327 |
+
----------
|
| 1328 |
+
n : int
|
| 1329 |
+
The number of nodes
|
| 1330 |
+
kernel_integral : function
|
| 1331 |
+
Function that returns the definite integral of the kernel $\kappa(x,y)$,
|
| 1332 |
+
$F(y,a,b) := \int_a^b \kappa(x,y)dx$
|
| 1333 |
+
kernel_root: function (optional)
|
| 1334 |
+
Function that returns the root $b$ of the equation $F(y,a,b) = r$.
|
| 1335 |
+
If None, the root is found using :func:`scipy.optimize.brentq`
|
| 1336 |
+
(this requires SciPy).
|
| 1337 |
+
seed : integer, random_state, or None (default)
|
| 1338 |
+
Indicator of random number generation state.
|
| 1339 |
+
See :ref:`Randomness<randomness>`.
|
| 1340 |
+
create_using : Graph constructor, optional (default=nx.Graph)
|
| 1341 |
+
Graph type to create. If graph instance, then cleared before populated.
|
| 1342 |
+
Multigraph and directed types are not supported and raise a ``NetworkXError``.
|
| 1343 |
+
|
| 1344 |
+
Notes
|
| 1345 |
+
-----
|
| 1346 |
+
The kernel is specified through its definite integral which must be
|
| 1347 |
+
provided as one of the arguments. If the integral and root of the
|
| 1348 |
+
kernel integral can be found in $O(1)$ time then this algorithm runs in
|
| 1349 |
+
time $O(n+m)$ where m is the expected number of edges [2]_.
|
| 1350 |
+
|
| 1351 |
+
The nodes are set to integers from $0$ to $n-1$.
|
| 1352 |
+
|
| 1353 |
+
Examples
|
| 1354 |
+
--------
|
| 1355 |
+
Generate an Erdős–Rényi random graph $G(n,c/n)$, with kernel
|
| 1356 |
+
$\kappa(x,y)=c$ where $c$ is the mean expected degree.
|
| 1357 |
+
|
| 1358 |
+
>>> def integral(u, w, z):
|
| 1359 |
+
... return c * (z - w)
|
| 1360 |
+
>>> def root(u, w, r):
|
| 1361 |
+
... return r / c + w
|
| 1362 |
+
>>> c = 1
|
| 1363 |
+
>>> graph = nx.random_kernel_graph(1000, integral, root)
|
| 1364 |
+
|
| 1365 |
+
See Also
|
| 1366 |
+
--------
|
| 1367 |
+
gnp_random_graph
|
| 1368 |
+
expected_degree_graph
|
| 1369 |
+
|
| 1370 |
+
References
|
| 1371 |
+
----------
|
| 1372 |
+
.. [1] Bollobás, Béla, Janson, S. and Riordan, O.
|
| 1373 |
+
"The phase transition in inhomogeneous random graphs",
|
| 1374 |
+
*Random Structures Algorithms*, 31, 3--122, 2007.
|
| 1375 |
+
|
| 1376 |
+
.. [2] Hagberg A, Lemons N (2015),
|
| 1377 |
+
"Fast Generation of Sparse Random Kernel Graphs".
|
| 1378 |
+
PLoS ONE 10(9): e0135177, 2015. doi:10.1371/journal.pone.0135177
|
| 1379 |
+
"""
|
| 1380 |
+
create_using = check_create_using(create_using, directed=False, multigraph=False)
|
| 1381 |
+
if kernel_root is None:
|
| 1382 |
+
import scipy as sp
|
| 1383 |
+
|
| 1384 |
+
def kernel_root(y, a, r):
|
| 1385 |
+
def my_function(b):
|
| 1386 |
+
return kernel_integral(y, a, b) - r
|
| 1387 |
+
|
| 1388 |
+
return sp.optimize.brentq(my_function, a, 1)
|
| 1389 |
+
|
| 1390 |
+
graph = nx.empty_graph(create_using=create_using)
|
| 1391 |
+
graph.add_nodes_from(range(n))
|
| 1392 |
+
(i, j) = (1, 1)
|
| 1393 |
+
while i < n:
|
| 1394 |
+
r = -math.log(1 - seed.random()) # (1-seed.random()) in (0, 1]
|
| 1395 |
+
if kernel_integral(i / n, j / n, 1) <= r:
|
| 1396 |
+
i, j = i + 1, i + 1
|
| 1397 |
+
else:
|
| 1398 |
+
j = math.ceil(n * kernel_root(i / n, j / n, r))
|
| 1399 |
+
graph.add_edge(i - 1, j - 1)
|
| 1400 |
+
return graph
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/stochastic.py
ADDED
|
@@ -0,0 +1,54 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
"""Functions for generating stochastic graphs from a given weighted directed
|
| 2 |
+
graph.
|
| 3 |
+
|
| 4 |
+
"""
|
| 5 |
+
|
| 6 |
+
import networkx as nx
|
| 7 |
+
from networkx.classes import DiGraph, MultiDiGraph
|
| 8 |
+
from networkx.utils import not_implemented_for
|
| 9 |
+
|
| 10 |
+
__all__ = ["stochastic_graph"]
|
| 11 |
+
|
| 12 |
+
|
| 13 |
+
@not_implemented_for("undirected")
|
| 14 |
+
@nx._dispatchable(
|
| 15 |
+
edge_attrs="weight", mutates_input={"not copy": 1}, returns_graph=True
|
| 16 |
+
)
|
| 17 |
+
def stochastic_graph(G, copy=True, weight="weight"):
|
| 18 |
+
"""Returns a right-stochastic representation of directed graph `G`.
|
| 19 |
+
|
| 20 |
+
A right-stochastic graph is a weighted digraph in which for each
|
| 21 |
+
node, the sum of the weights of all the out-edges of that node is
|
| 22 |
+
1. If the graph is already weighted (for example, via a 'weight'
|
| 23 |
+
edge attribute), the reweighting takes that into account.
|
| 24 |
+
|
| 25 |
+
Parameters
|
| 26 |
+
----------
|
| 27 |
+
G : directed graph
|
| 28 |
+
A :class:`~networkx.DiGraph` or :class:`~networkx.MultiDiGraph`.
|
| 29 |
+
|
| 30 |
+
copy : boolean, optional
|
| 31 |
+
If this is True, then this function returns a new graph with
|
| 32 |
+
the stochastic reweighting. Otherwise, the original graph is
|
| 33 |
+
modified in-place (and also returned, for convenience).
|
| 34 |
+
|
| 35 |
+
weight : edge attribute key (optional, default='weight')
|
| 36 |
+
Edge attribute key used for reading the existing weight and
|
| 37 |
+
setting the new weight. If no attribute with this key is found
|
| 38 |
+
for an edge, then the edge weight is assumed to be 1. If an edge
|
| 39 |
+
has a weight, it must be a positive number.
|
| 40 |
+
|
| 41 |
+
"""
|
| 42 |
+
if copy:
|
| 43 |
+
G = MultiDiGraph(G) if G.is_multigraph() else DiGraph(G)
|
| 44 |
+
# There is a tradeoff here: the dictionary of node degrees may
|
| 45 |
+
# require a lot of memory, whereas making a call to `G.out_degree`
|
| 46 |
+
# inside the loop may be costly in computation time.
|
| 47 |
+
degree = dict(G.out_degree(weight=weight))
|
| 48 |
+
for u, v, d in G.edges(data=True):
|
| 49 |
+
if degree[u] == 0:
|
| 50 |
+
d[weight] = 0
|
| 51 |
+
else:
|
| 52 |
+
d[weight] = d.get(weight, 1) / degree[u]
|
| 53 |
+
nx._clear_cache(G)
|
| 54 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/__init__.py
ADDED
|
File without changes
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_atlas.py
ADDED
|
@@ -0,0 +1,75 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
from itertools import groupby
|
| 2 |
+
|
| 3 |
+
import pytest
|
| 4 |
+
|
| 5 |
+
import networkx as nx
|
| 6 |
+
from networkx import graph_atlas, graph_atlas_g
|
| 7 |
+
from networkx.generators.atlas import NUM_GRAPHS
|
| 8 |
+
from networkx.utils import edges_equal, nodes_equal, pairwise
|
| 9 |
+
|
| 10 |
+
|
| 11 |
+
class TestAtlasGraph:
|
| 12 |
+
"""Unit tests for the :func:`~networkx.graph_atlas` function."""
|
| 13 |
+
|
| 14 |
+
def test_index_too_small(self):
|
| 15 |
+
with pytest.raises(ValueError):
|
| 16 |
+
graph_atlas(-1)
|
| 17 |
+
|
| 18 |
+
def test_index_too_large(self):
|
| 19 |
+
with pytest.raises(ValueError):
|
| 20 |
+
graph_atlas(NUM_GRAPHS)
|
| 21 |
+
|
| 22 |
+
def test_graph(self):
|
| 23 |
+
G = graph_atlas(6)
|
| 24 |
+
assert nodes_equal(G.nodes(), range(3))
|
| 25 |
+
assert edges_equal(G.edges(), [(0, 1), (0, 2)])
|
| 26 |
+
|
| 27 |
+
|
| 28 |
+
class TestAtlasGraphG:
|
| 29 |
+
"""Unit tests for the :func:`~networkx.graph_atlas_g` function."""
|
| 30 |
+
|
| 31 |
+
@classmethod
|
| 32 |
+
def setup_class(cls):
|
| 33 |
+
cls.GAG = graph_atlas_g()
|
| 34 |
+
|
| 35 |
+
def test_sizes(self):
|
| 36 |
+
G = self.GAG[0]
|
| 37 |
+
assert G.number_of_nodes() == 0
|
| 38 |
+
assert G.number_of_edges() == 0
|
| 39 |
+
|
| 40 |
+
G = self.GAG[7]
|
| 41 |
+
assert G.number_of_nodes() == 3
|
| 42 |
+
assert G.number_of_edges() == 3
|
| 43 |
+
|
| 44 |
+
def test_names(self):
|
| 45 |
+
for i, G in enumerate(self.GAG):
|
| 46 |
+
assert int(G.name[1:]) == i
|
| 47 |
+
|
| 48 |
+
def test_nondecreasing_nodes(self):
|
| 49 |
+
# check for nondecreasing number of nodes
|
| 50 |
+
for n1, n2 in pairwise(map(len, self.GAG)):
|
| 51 |
+
assert n2 <= n1 + 1
|
| 52 |
+
|
| 53 |
+
def test_nondecreasing_edges(self):
|
| 54 |
+
# check for nondecreasing number of edges (for fixed number of
|
| 55 |
+
# nodes)
|
| 56 |
+
for n, group in groupby(self.GAG, key=nx.number_of_nodes):
|
| 57 |
+
for m1, m2 in pairwise(map(nx.number_of_edges, group)):
|
| 58 |
+
assert m2 <= m1 + 1
|
| 59 |
+
|
| 60 |
+
def test_nondecreasing_degree_sequence(self):
|
| 61 |
+
# Check for lexicographically nondecreasing degree sequences
|
| 62 |
+
# (for fixed number of nodes and edges).
|
| 63 |
+
#
|
| 64 |
+
# There are three exceptions to this rule in the order given in
|
| 65 |
+
# the "Atlas of Graphs" book, so we need to manually exclude
|
| 66 |
+
# those.
|
| 67 |
+
exceptions = [("G55", "G56"), ("G1007", "G1008"), ("G1012", "G1013")]
|
| 68 |
+
for n, group in groupby(self.GAG, key=nx.number_of_nodes):
|
| 69 |
+
for m, group in groupby(group, key=nx.number_of_edges):
|
| 70 |
+
for G1, G2 in pairwise(group):
|
| 71 |
+
if (G1.name, G2.name) in exceptions:
|
| 72 |
+
continue
|
| 73 |
+
d1 = sorted(d for v, d in G1.degree())
|
| 74 |
+
d2 = sorted(d for v, d in G2.degree())
|
| 75 |
+
assert d1 <= d2
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_cographs.py
ADDED
|
@@ -0,0 +1,18 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
"""Unit tests for the :mod:`networkx.generators.cographs` module."""
|
| 2 |
+
|
| 3 |
+
import networkx as nx
|
| 4 |
+
|
| 5 |
+
|
| 6 |
+
def test_random_cograph():
|
| 7 |
+
n = 3
|
| 8 |
+
G = nx.random_cograph(n)
|
| 9 |
+
|
| 10 |
+
assert len(G) == 2**n
|
| 11 |
+
|
| 12 |
+
# Every connected subgraph of G has diameter <= 2
|
| 13 |
+
if nx.is_connected(G):
|
| 14 |
+
assert nx.diameter(G) <= 2
|
| 15 |
+
else:
|
| 16 |
+
components = nx.connected_components(G)
|
| 17 |
+
for component in components:
|
| 18 |
+
assert nx.diameter(G.subgraph(component)) <= 2
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_community.py
ADDED
|
@@ -0,0 +1,362 @@
|
|
|
|
|
|
|
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|
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|
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|
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|
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|
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|
|
|
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|
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|
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|
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|
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|
|
|
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|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
|
|
|
|
|
|
|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
|
|
|
|
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|
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|
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|
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|
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|
|
|
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|
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|
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|
|
|
|
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|
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|
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|
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|
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|
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|
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|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
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|
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|
|
|
|
| 1 |
+
import pytest
|
| 2 |
+
|
| 3 |
+
import networkx as nx
|
| 4 |
+
|
| 5 |
+
|
| 6 |
+
def test_random_partition_graph():
|
| 7 |
+
G = nx.random_partition_graph([3, 3, 3], 1, 0, seed=42)
|
| 8 |
+
C = G.graph["partition"]
|
| 9 |
+
assert C == [{0, 1, 2}, {3, 4, 5}, {6, 7, 8}]
|
| 10 |
+
assert len(G) == 9
|
| 11 |
+
assert len(list(G.edges())) == 9
|
| 12 |
+
|
| 13 |
+
G = nx.random_partition_graph([3, 3, 3], 0, 1)
|
| 14 |
+
C = G.graph["partition"]
|
| 15 |
+
assert C == [{0, 1, 2}, {3, 4, 5}, {6, 7, 8}]
|
| 16 |
+
assert len(G) == 9
|
| 17 |
+
assert len(list(G.edges())) == 27
|
| 18 |
+
|
| 19 |
+
G = nx.random_partition_graph([3, 3, 3], 1, 0, directed=True)
|
| 20 |
+
C = G.graph["partition"]
|
| 21 |
+
assert C == [{0, 1, 2}, {3, 4, 5}, {6, 7, 8}]
|
| 22 |
+
assert len(G) == 9
|
| 23 |
+
assert len(list(G.edges())) == 18
|
| 24 |
+
|
| 25 |
+
G = nx.random_partition_graph([3, 3, 3], 0, 1, directed=True)
|
| 26 |
+
C = G.graph["partition"]
|
| 27 |
+
assert C == [{0, 1, 2}, {3, 4, 5}, {6, 7, 8}]
|
| 28 |
+
assert len(G) == 9
|
| 29 |
+
assert len(list(G.edges())) == 54
|
| 30 |
+
|
| 31 |
+
G = nx.random_partition_graph([1, 2, 3, 4, 5], 0.5, 0.1)
|
| 32 |
+
C = G.graph["partition"]
|
| 33 |
+
assert C == [{0}, {1, 2}, {3, 4, 5}, {6, 7, 8, 9}, {10, 11, 12, 13, 14}]
|
| 34 |
+
assert len(G) == 15
|
| 35 |
+
|
| 36 |
+
rpg = nx.random_partition_graph
|
| 37 |
+
pytest.raises(nx.NetworkXError, rpg, [1, 2, 3], 1.1, 0.1)
|
| 38 |
+
pytest.raises(nx.NetworkXError, rpg, [1, 2, 3], -0.1, 0.1)
|
| 39 |
+
pytest.raises(nx.NetworkXError, rpg, [1, 2, 3], 0.1, 1.1)
|
| 40 |
+
pytest.raises(nx.NetworkXError, rpg, [1, 2, 3], 0.1, -0.1)
|
| 41 |
+
|
| 42 |
+
|
| 43 |
+
def test_planted_partition_graph():
|
| 44 |
+
G = nx.planted_partition_graph(4, 3, 1, 0, seed=42)
|
| 45 |
+
C = G.graph["partition"]
|
| 46 |
+
assert len(C) == 4
|
| 47 |
+
assert len(G) == 12
|
| 48 |
+
assert len(list(G.edges())) == 12
|
| 49 |
+
|
| 50 |
+
G = nx.planted_partition_graph(4, 3, 0, 1)
|
| 51 |
+
C = G.graph["partition"]
|
| 52 |
+
assert len(C) == 4
|
| 53 |
+
assert len(G) == 12
|
| 54 |
+
assert len(list(G.edges())) == 54
|
| 55 |
+
|
| 56 |
+
G = nx.planted_partition_graph(10, 4, 0.5, 0.1, seed=42)
|
| 57 |
+
C = G.graph["partition"]
|
| 58 |
+
assert len(C) == 10
|
| 59 |
+
assert len(G) == 40
|
| 60 |
+
|
| 61 |
+
G = nx.planted_partition_graph(4, 3, 1, 0, directed=True)
|
| 62 |
+
C = G.graph["partition"]
|
| 63 |
+
assert len(C) == 4
|
| 64 |
+
assert len(G) == 12
|
| 65 |
+
assert len(list(G.edges())) == 24
|
| 66 |
+
|
| 67 |
+
G = nx.planted_partition_graph(4, 3, 0, 1, directed=True)
|
| 68 |
+
C = G.graph["partition"]
|
| 69 |
+
assert len(C) == 4
|
| 70 |
+
assert len(G) == 12
|
| 71 |
+
assert len(list(G.edges())) == 108
|
| 72 |
+
|
| 73 |
+
G = nx.planted_partition_graph(10, 4, 0.5, 0.1, seed=42, directed=True)
|
| 74 |
+
C = G.graph["partition"]
|
| 75 |
+
assert len(C) == 10
|
| 76 |
+
assert len(G) == 40
|
| 77 |
+
|
| 78 |
+
ppg = nx.planted_partition_graph
|
| 79 |
+
pytest.raises(nx.NetworkXError, ppg, 3, 3, 1.1, 0.1)
|
| 80 |
+
pytest.raises(nx.NetworkXError, ppg, 3, 3, -0.1, 0.1)
|
| 81 |
+
pytest.raises(nx.NetworkXError, ppg, 3, 3, 0.1, 1.1)
|
| 82 |
+
pytest.raises(nx.NetworkXError, ppg, 3, 3, 0.1, -0.1)
|
| 83 |
+
|
| 84 |
+
|
| 85 |
+
def test_relaxed_caveman_graph():
|
| 86 |
+
G = nx.relaxed_caveman_graph(4, 3, 0)
|
| 87 |
+
assert len(G) == 12
|
| 88 |
+
G = nx.relaxed_caveman_graph(4, 3, 1)
|
| 89 |
+
assert len(G) == 12
|
| 90 |
+
G = nx.relaxed_caveman_graph(4, 3, 0.5)
|
| 91 |
+
assert len(G) == 12
|
| 92 |
+
G = nx.relaxed_caveman_graph(4, 3, 0.5, seed=42)
|
| 93 |
+
assert len(G) == 12
|
| 94 |
+
|
| 95 |
+
|
| 96 |
+
def test_connected_caveman_graph():
|
| 97 |
+
G = nx.connected_caveman_graph(4, 3)
|
| 98 |
+
assert len(G) == 12
|
| 99 |
+
|
| 100 |
+
G = nx.connected_caveman_graph(1, 5)
|
| 101 |
+
K5 = nx.complete_graph(5)
|
| 102 |
+
K5.remove_edge(3, 4)
|
| 103 |
+
assert nx.is_isomorphic(G, K5)
|
| 104 |
+
|
| 105 |
+
# need at least 2 nodes in each clique
|
| 106 |
+
pytest.raises(nx.NetworkXError, nx.connected_caveman_graph, 4, 1)
|
| 107 |
+
|
| 108 |
+
|
| 109 |
+
def test_caveman_graph():
|
| 110 |
+
G = nx.caveman_graph(4, 3)
|
| 111 |
+
assert len(G) == 12
|
| 112 |
+
|
| 113 |
+
G = nx.caveman_graph(5, 1)
|
| 114 |
+
E5 = nx.empty_graph(5)
|
| 115 |
+
assert nx.is_isomorphic(G, E5)
|
| 116 |
+
|
| 117 |
+
G = nx.caveman_graph(1, 5)
|
| 118 |
+
K5 = nx.complete_graph(5)
|
| 119 |
+
assert nx.is_isomorphic(G, K5)
|
| 120 |
+
|
| 121 |
+
|
| 122 |
+
def test_gaussian_random_partition_graph():
|
| 123 |
+
G = nx.gaussian_random_partition_graph(100, 10, 10, 0.3, 0.01)
|
| 124 |
+
assert len(G) == 100
|
| 125 |
+
G = nx.gaussian_random_partition_graph(100, 10, 10, 0.3, 0.01, directed=True)
|
| 126 |
+
assert len(G) == 100
|
| 127 |
+
G = nx.gaussian_random_partition_graph(
|
| 128 |
+
100, 10, 10, 0.3, 0.01, directed=False, seed=42
|
| 129 |
+
)
|
| 130 |
+
assert len(G) == 100
|
| 131 |
+
assert not isinstance(G, nx.DiGraph)
|
| 132 |
+
G = nx.gaussian_random_partition_graph(
|
| 133 |
+
100, 10, 10, 0.3, 0.01, directed=True, seed=42
|
| 134 |
+
)
|
| 135 |
+
assert len(G) == 100
|
| 136 |
+
assert isinstance(G, nx.DiGraph)
|
| 137 |
+
pytest.raises(
|
| 138 |
+
nx.NetworkXError, nx.gaussian_random_partition_graph, 100, 101, 10, 1, 0
|
| 139 |
+
)
|
| 140 |
+
# Test when clusters are likely less than 1
|
| 141 |
+
G = nx.gaussian_random_partition_graph(10, 0.5, 0.5, 0.5, 0.5, seed=1)
|
| 142 |
+
assert len(G) == 10
|
| 143 |
+
|
| 144 |
+
|
| 145 |
+
def test_ring_of_cliques():
|
| 146 |
+
for i in range(2, 20, 3):
|
| 147 |
+
for j in range(2, 20, 3):
|
| 148 |
+
G = nx.ring_of_cliques(i, j)
|
| 149 |
+
assert G.number_of_nodes() == i * j
|
| 150 |
+
if i != 2 or j != 1:
|
| 151 |
+
expected_num_edges = i * (((j * (j - 1)) // 2) + 1)
|
| 152 |
+
else:
|
| 153 |
+
# the edge that already exists cannot be duplicated
|
| 154 |
+
expected_num_edges = i * (((j * (j - 1)) // 2) + 1) - 1
|
| 155 |
+
assert G.number_of_edges() == expected_num_edges
|
| 156 |
+
with pytest.raises(
|
| 157 |
+
nx.NetworkXError, match="A ring of cliques must have at least two cliques"
|
| 158 |
+
):
|
| 159 |
+
nx.ring_of_cliques(1, 5)
|
| 160 |
+
with pytest.raises(
|
| 161 |
+
nx.NetworkXError, match="The cliques must have at least two nodes"
|
| 162 |
+
):
|
| 163 |
+
nx.ring_of_cliques(3, 0)
|
| 164 |
+
|
| 165 |
+
|
| 166 |
+
def test_windmill_graph():
|
| 167 |
+
for n in range(2, 20, 3):
|
| 168 |
+
for k in range(2, 20, 3):
|
| 169 |
+
G = nx.windmill_graph(n, k)
|
| 170 |
+
assert G.number_of_nodes() == (k - 1) * n + 1
|
| 171 |
+
assert G.number_of_edges() == n * k * (k - 1) / 2
|
| 172 |
+
assert G.degree(0) == G.number_of_nodes() - 1
|
| 173 |
+
for i in range(1, G.number_of_nodes()):
|
| 174 |
+
assert G.degree(i) == k - 1
|
| 175 |
+
with pytest.raises(
|
| 176 |
+
nx.NetworkXError, match="A windmill graph must have at least two cliques"
|
| 177 |
+
):
|
| 178 |
+
nx.windmill_graph(1, 3)
|
| 179 |
+
with pytest.raises(
|
| 180 |
+
nx.NetworkXError, match="The cliques must have at least two nodes"
|
| 181 |
+
):
|
| 182 |
+
nx.windmill_graph(3, 0)
|
| 183 |
+
|
| 184 |
+
|
| 185 |
+
def test_stochastic_block_model():
|
| 186 |
+
sizes = [75, 75, 300]
|
| 187 |
+
probs = [[0.25, 0.05, 0.02], [0.05, 0.35, 0.07], [0.02, 0.07, 0.40]]
|
| 188 |
+
G = nx.stochastic_block_model(sizes, probs, seed=0)
|
| 189 |
+
C = G.graph["partition"]
|
| 190 |
+
assert len(C) == 3
|
| 191 |
+
assert len(G) == 450
|
| 192 |
+
assert G.size() == 22160
|
| 193 |
+
|
| 194 |
+
GG = nx.stochastic_block_model(sizes, probs, range(450), seed=0)
|
| 195 |
+
assert G.nodes == GG.nodes
|
| 196 |
+
|
| 197 |
+
# Test Exceptions
|
| 198 |
+
sbm = nx.stochastic_block_model
|
| 199 |
+
badnodelist = list(range(400)) # not enough nodes to match sizes
|
| 200 |
+
badprobs1 = [[0.25, 0.05, 1.02], [0.05, 0.35, 0.07], [0.02, 0.07, 0.40]]
|
| 201 |
+
badprobs2 = [[0.25, 0.05, 0.02], [0.05, -0.35, 0.07], [0.02, 0.07, 0.40]]
|
| 202 |
+
probs_rect1 = [[0.25, 0.05, 0.02], [0.05, -0.35, 0.07]]
|
| 203 |
+
probs_rect2 = [[0.25, 0.05], [0.05, -0.35], [0.02, 0.07]]
|
| 204 |
+
asymprobs = [[0.25, 0.05, 0.01], [0.05, -0.35, 0.07], [0.02, 0.07, 0.40]]
|
| 205 |
+
pytest.raises(nx.NetworkXException, sbm, sizes, badprobs1)
|
| 206 |
+
pytest.raises(nx.NetworkXException, sbm, sizes, badprobs2)
|
| 207 |
+
pytest.raises(nx.NetworkXException, sbm, sizes, probs_rect1, directed=True)
|
| 208 |
+
pytest.raises(nx.NetworkXException, sbm, sizes, probs_rect2, directed=True)
|
| 209 |
+
pytest.raises(nx.NetworkXException, sbm, sizes, asymprobs, directed=False)
|
| 210 |
+
pytest.raises(nx.NetworkXException, sbm, sizes, probs, badnodelist)
|
| 211 |
+
nodelist = [0] + list(range(449)) # repeated node name in nodelist
|
| 212 |
+
pytest.raises(nx.NetworkXException, sbm, sizes, probs, nodelist)
|
| 213 |
+
|
| 214 |
+
# Extra keyword arguments test
|
| 215 |
+
GG = nx.stochastic_block_model(sizes, probs, seed=0, selfloops=True)
|
| 216 |
+
assert G.nodes == GG.nodes
|
| 217 |
+
GG = nx.stochastic_block_model(sizes, probs, selfloops=True, directed=True)
|
| 218 |
+
assert G.nodes == GG.nodes
|
| 219 |
+
GG = nx.stochastic_block_model(sizes, probs, seed=0, sparse=False)
|
| 220 |
+
assert G.nodes == GG.nodes
|
| 221 |
+
|
| 222 |
+
|
| 223 |
+
def test_generator():
|
| 224 |
+
n = 250
|
| 225 |
+
tau1 = 3
|
| 226 |
+
tau2 = 1.5
|
| 227 |
+
mu = 0.1
|
| 228 |
+
G = nx.LFR_benchmark_graph(
|
| 229 |
+
n, tau1, tau2, mu, average_degree=5, min_community=20, seed=10
|
| 230 |
+
)
|
| 231 |
+
assert len(G) == 250
|
| 232 |
+
C = {frozenset(G.nodes[v]["community"]) for v in G}
|
| 233 |
+
assert nx.community.is_partition(G.nodes(), C)
|
| 234 |
+
|
| 235 |
+
|
| 236 |
+
def test_invalid_tau1():
|
| 237 |
+
with pytest.raises(nx.NetworkXError, match="tau2 must be greater than one"):
|
| 238 |
+
n = 100
|
| 239 |
+
tau1 = 2
|
| 240 |
+
tau2 = 1
|
| 241 |
+
mu = 0.1
|
| 242 |
+
nx.LFR_benchmark_graph(n, tau1, tau2, mu, min_degree=2)
|
| 243 |
+
|
| 244 |
+
|
| 245 |
+
def test_invalid_tau2():
|
| 246 |
+
with pytest.raises(nx.NetworkXError, match="tau1 must be greater than one"):
|
| 247 |
+
n = 100
|
| 248 |
+
tau1 = 1
|
| 249 |
+
tau2 = 2
|
| 250 |
+
mu = 0.1
|
| 251 |
+
nx.LFR_benchmark_graph(n, tau1, tau2, mu, min_degree=2)
|
| 252 |
+
|
| 253 |
+
|
| 254 |
+
def test_mu_too_large():
|
| 255 |
+
with pytest.raises(nx.NetworkXError, match="mu must be in the interval \\[0, 1\\]"):
|
| 256 |
+
n = 100
|
| 257 |
+
tau1 = 2
|
| 258 |
+
tau2 = 2
|
| 259 |
+
mu = 1.1
|
| 260 |
+
nx.LFR_benchmark_graph(n, tau1, tau2, mu, min_degree=2)
|
| 261 |
+
|
| 262 |
+
|
| 263 |
+
def test_mu_too_small():
|
| 264 |
+
with pytest.raises(nx.NetworkXError, match="mu must be in the interval \\[0, 1\\]"):
|
| 265 |
+
n = 100
|
| 266 |
+
tau1 = 2
|
| 267 |
+
tau2 = 2
|
| 268 |
+
mu = -1
|
| 269 |
+
nx.LFR_benchmark_graph(n, tau1, tau2, mu, min_degree=2)
|
| 270 |
+
|
| 271 |
+
|
| 272 |
+
def test_both_degrees_none():
|
| 273 |
+
with pytest.raises(
|
| 274 |
+
nx.NetworkXError,
|
| 275 |
+
match="Must assign exactly one of min_degree and average_degree",
|
| 276 |
+
):
|
| 277 |
+
n = 100
|
| 278 |
+
tau1 = 2
|
| 279 |
+
tau2 = 2
|
| 280 |
+
mu = 1
|
| 281 |
+
nx.LFR_benchmark_graph(n, tau1, tau2, mu)
|
| 282 |
+
|
| 283 |
+
|
| 284 |
+
def test_neither_degrees_none():
|
| 285 |
+
with pytest.raises(
|
| 286 |
+
nx.NetworkXError,
|
| 287 |
+
match="Must assign exactly one of min_degree and average_degree",
|
| 288 |
+
):
|
| 289 |
+
n = 100
|
| 290 |
+
tau1 = 2
|
| 291 |
+
tau2 = 2
|
| 292 |
+
mu = 1
|
| 293 |
+
nx.LFR_benchmark_graph(n, tau1, tau2, mu, min_degree=2, average_degree=5)
|
| 294 |
+
|
| 295 |
+
|
| 296 |
+
def test_max_iters_exceeded():
|
| 297 |
+
with pytest.raises(
|
| 298 |
+
nx.ExceededMaxIterations,
|
| 299 |
+
match="Could not assign communities; try increasing min_community",
|
| 300 |
+
):
|
| 301 |
+
n = 10
|
| 302 |
+
tau1 = 2
|
| 303 |
+
tau2 = 2
|
| 304 |
+
mu = 0.1
|
| 305 |
+
nx.LFR_benchmark_graph(n, tau1, tau2, mu, min_degree=2, max_iters=10, seed=1)
|
| 306 |
+
|
| 307 |
+
|
| 308 |
+
def test_max_deg_out_of_range():
|
| 309 |
+
with pytest.raises(
|
| 310 |
+
nx.NetworkXError, match="max_degree must be in the interval \\(0, n\\]"
|
| 311 |
+
):
|
| 312 |
+
n = 10
|
| 313 |
+
tau1 = 2
|
| 314 |
+
tau2 = 2
|
| 315 |
+
mu = 0.1
|
| 316 |
+
nx.LFR_benchmark_graph(
|
| 317 |
+
n, tau1, tau2, mu, max_degree=n + 1, max_iters=10, seed=1
|
| 318 |
+
)
|
| 319 |
+
|
| 320 |
+
|
| 321 |
+
def test_max_community():
|
| 322 |
+
n = 250
|
| 323 |
+
tau1 = 3
|
| 324 |
+
tau2 = 1.5
|
| 325 |
+
mu = 0.1
|
| 326 |
+
G = nx.LFR_benchmark_graph(
|
| 327 |
+
n,
|
| 328 |
+
tau1,
|
| 329 |
+
tau2,
|
| 330 |
+
mu,
|
| 331 |
+
average_degree=5,
|
| 332 |
+
max_degree=100,
|
| 333 |
+
min_community=50,
|
| 334 |
+
max_community=200,
|
| 335 |
+
seed=10,
|
| 336 |
+
)
|
| 337 |
+
assert len(G) == 250
|
| 338 |
+
C = {frozenset(G.nodes[v]["community"]) for v in G}
|
| 339 |
+
assert nx.community.is_partition(G.nodes(), C)
|
| 340 |
+
|
| 341 |
+
|
| 342 |
+
def test_powerlaw_iterations_exceeded():
|
| 343 |
+
with pytest.raises(
|
| 344 |
+
nx.ExceededMaxIterations, match="Could not create power law sequence"
|
| 345 |
+
):
|
| 346 |
+
n = 100
|
| 347 |
+
tau1 = 2
|
| 348 |
+
tau2 = 2
|
| 349 |
+
mu = 1
|
| 350 |
+
nx.LFR_benchmark_graph(n, tau1, tau2, mu, min_degree=2, max_iters=0)
|
| 351 |
+
|
| 352 |
+
|
| 353 |
+
def test_no_scipy_zeta():
|
| 354 |
+
zeta2 = 1.6449340668482264
|
| 355 |
+
assert abs(zeta2 - nx.generators.community._hurwitz_zeta(2, 1, 0.0001)) < 0.01
|
| 356 |
+
|
| 357 |
+
|
| 358 |
+
def test_generate_min_degree_itr():
|
| 359 |
+
with pytest.raises(
|
| 360 |
+
nx.ExceededMaxIterations, match="Could not match average_degree"
|
| 361 |
+
):
|
| 362 |
+
nx.generators.community._generate_min_degree(2, 2, 1, 0.01, 0)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_degree_seq.py
ADDED
|
@@ -0,0 +1,230 @@
|
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|
|
|
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|
|
|
|
|
|
|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
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|
| 1 |
+
import pytest
|
| 2 |
+
|
| 3 |
+
import networkx as nx
|
| 4 |
+
|
| 5 |
+
|
| 6 |
+
class TestConfigurationModel:
|
| 7 |
+
"""Unit tests for the :func:`~networkx.configuration_model`
|
| 8 |
+
function.
|
| 9 |
+
|
| 10 |
+
"""
|
| 11 |
+
|
| 12 |
+
def test_empty_degree_sequence(self):
|
| 13 |
+
"""Tests that an empty degree sequence yields the null graph."""
|
| 14 |
+
G = nx.configuration_model([])
|
| 15 |
+
assert len(G) == 0
|
| 16 |
+
|
| 17 |
+
def test_degree_zero(self):
|
| 18 |
+
"""Tests that a degree sequence of all zeros yields the empty
|
| 19 |
+
graph.
|
| 20 |
+
|
| 21 |
+
"""
|
| 22 |
+
G = nx.configuration_model([0, 0, 0])
|
| 23 |
+
assert len(G) == 3
|
| 24 |
+
assert G.number_of_edges() == 0
|
| 25 |
+
|
| 26 |
+
def test_degree_sequence(self):
|
| 27 |
+
"""Tests that the degree sequence of the generated graph matches
|
| 28 |
+
the input degree sequence.
|
| 29 |
+
|
| 30 |
+
"""
|
| 31 |
+
deg_seq = [5, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1]
|
| 32 |
+
G = nx.configuration_model(deg_seq, seed=12345678)
|
| 33 |
+
assert sorted((d for n, d in G.degree()), reverse=True) == [
|
| 34 |
+
5,
|
| 35 |
+
3,
|
| 36 |
+
3,
|
| 37 |
+
3,
|
| 38 |
+
3,
|
| 39 |
+
2,
|
| 40 |
+
2,
|
| 41 |
+
2,
|
| 42 |
+
1,
|
| 43 |
+
1,
|
| 44 |
+
1,
|
| 45 |
+
]
|
| 46 |
+
assert sorted((d for n, d in G.degree(range(len(deg_seq)))), reverse=True) == [
|
| 47 |
+
5,
|
| 48 |
+
3,
|
| 49 |
+
3,
|
| 50 |
+
3,
|
| 51 |
+
3,
|
| 52 |
+
2,
|
| 53 |
+
2,
|
| 54 |
+
2,
|
| 55 |
+
1,
|
| 56 |
+
1,
|
| 57 |
+
1,
|
| 58 |
+
]
|
| 59 |
+
|
| 60 |
+
def test_random_seed(self):
|
| 61 |
+
"""Tests that each call with the same random seed generates the
|
| 62 |
+
same graph.
|
| 63 |
+
|
| 64 |
+
"""
|
| 65 |
+
deg_seq = [3] * 12
|
| 66 |
+
G1 = nx.configuration_model(deg_seq, seed=1000)
|
| 67 |
+
G2 = nx.configuration_model(deg_seq, seed=1000)
|
| 68 |
+
assert nx.is_isomorphic(G1, G2)
|
| 69 |
+
G1 = nx.configuration_model(deg_seq, seed=10)
|
| 70 |
+
G2 = nx.configuration_model(deg_seq, seed=10)
|
| 71 |
+
assert nx.is_isomorphic(G1, G2)
|
| 72 |
+
|
| 73 |
+
def test_directed_disallowed(self):
|
| 74 |
+
"""Tests that attempting to create a configuration model graph
|
| 75 |
+
using a directed graph yields an exception.
|
| 76 |
+
|
| 77 |
+
"""
|
| 78 |
+
with pytest.raises(nx.NetworkXNotImplemented):
|
| 79 |
+
nx.configuration_model([], create_using=nx.DiGraph())
|
| 80 |
+
|
| 81 |
+
def test_odd_degree_sum(self):
|
| 82 |
+
"""Tests that a degree sequence whose sum is odd yields an
|
| 83 |
+
exception.
|
| 84 |
+
|
| 85 |
+
"""
|
| 86 |
+
with pytest.raises(nx.NetworkXError):
|
| 87 |
+
nx.configuration_model([1, 2])
|
| 88 |
+
|
| 89 |
+
|
| 90 |
+
def test_directed_configuration_raise_unequal():
|
| 91 |
+
with pytest.raises(nx.NetworkXError):
|
| 92 |
+
zin = [5, 3, 3, 3, 3, 2, 2, 2, 1, 1]
|
| 93 |
+
zout = [5, 3, 3, 3, 3, 2, 2, 2, 1, 2]
|
| 94 |
+
nx.directed_configuration_model(zin, zout)
|
| 95 |
+
|
| 96 |
+
|
| 97 |
+
def test_directed_configuration_model():
|
| 98 |
+
G = nx.directed_configuration_model([], [], seed=0)
|
| 99 |
+
assert len(G) == 0
|
| 100 |
+
|
| 101 |
+
|
| 102 |
+
def test_simple_directed_configuration_model():
|
| 103 |
+
G = nx.directed_configuration_model([1, 1], [1, 1], seed=0)
|
| 104 |
+
assert len(G) == 2
|
| 105 |
+
|
| 106 |
+
|
| 107 |
+
def test_expected_degree_graph_empty():
|
| 108 |
+
# empty graph has empty degree sequence
|
| 109 |
+
deg_seq = []
|
| 110 |
+
G = nx.expected_degree_graph(deg_seq)
|
| 111 |
+
assert dict(G.degree()) == {}
|
| 112 |
+
|
| 113 |
+
|
| 114 |
+
def test_expected_degree_graph():
|
| 115 |
+
# test that fixed seed delivers the same graph
|
| 116 |
+
deg_seq = [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3]
|
| 117 |
+
G1 = nx.expected_degree_graph(deg_seq, seed=1000)
|
| 118 |
+
assert len(G1) == 12
|
| 119 |
+
|
| 120 |
+
G2 = nx.expected_degree_graph(deg_seq, seed=1000)
|
| 121 |
+
assert nx.is_isomorphic(G1, G2)
|
| 122 |
+
|
| 123 |
+
G1 = nx.expected_degree_graph(deg_seq, seed=10)
|
| 124 |
+
G2 = nx.expected_degree_graph(deg_seq, seed=10)
|
| 125 |
+
assert nx.is_isomorphic(G1, G2)
|
| 126 |
+
|
| 127 |
+
|
| 128 |
+
def test_expected_degree_graph_selfloops():
|
| 129 |
+
deg_seq = [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3]
|
| 130 |
+
G1 = nx.expected_degree_graph(deg_seq, seed=1000, selfloops=False)
|
| 131 |
+
G2 = nx.expected_degree_graph(deg_seq, seed=1000, selfloops=False)
|
| 132 |
+
assert nx.is_isomorphic(G1, G2)
|
| 133 |
+
assert len(G1) == 12
|
| 134 |
+
|
| 135 |
+
|
| 136 |
+
def test_expected_degree_graph_skew():
|
| 137 |
+
deg_seq = [10, 2, 2, 2, 2]
|
| 138 |
+
G1 = nx.expected_degree_graph(deg_seq, seed=1000)
|
| 139 |
+
G2 = nx.expected_degree_graph(deg_seq, seed=1000)
|
| 140 |
+
assert nx.is_isomorphic(G1, G2)
|
| 141 |
+
assert len(G1) == 5
|
| 142 |
+
|
| 143 |
+
|
| 144 |
+
def test_havel_hakimi_construction():
|
| 145 |
+
G = nx.havel_hakimi_graph([])
|
| 146 |
+
assert len(G) == 0
|
| 147 |
+
|
| 148 |
+
z = [1000, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1]
|
| 149 |
+
pytest.raises(nx.NetworkXError, nx.havel_hakimi_graph, z)
|
| 150 |
+
z = ["A", 3, 3, 3, 3, 2, 2, 2, 1, 1, 1]
|
| 151 |
+
pytest.raises(nx.NetworkXError, nx.havel_hakimi_graph, z)
|
| 152 |
+
|
| 153 |
+
z = [5, 4, 3, 3, 3, 2, 2, 2]
|
| 154 |
+
G = nx.havel_hakimi_graph(z)
|
| 155 |
+
G = nx.configuration_model(z)
|
| 156 |
+
z = [6, 5, 4, 4, 2, 1, 1, 1]
|
| 157 |
+
pytest.raises(nx.NetworkXError, nx.havel_hakimi_graph, z)
|
| 158 |
+
|
| 159 |
+
z = [10, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2]
|
| 160 |
+
|
| 161 |
+
G = nx.havel_hakimi_graph(z)
|
| 162 |
+
|
| 163 |
+
pytest.raises(nx.NetworkXError, nx.havel_hakimi_graph, z, create_using=nx.DiGraph())
|
| 164 |
+
|
| 165 |
+
|
| 166 |
+
def test_directed_havel_hakimi():
|
| 167 |
+
# Test range of valid directed degree sequences
|
| 168 |
+
n, r = 100, 10
|
| 169 |
+
p = 1.0 / r
|
| 170 |
+
for i in range(r):
|
| 171 |
+
G1 = nx.erdos_renyi_graph(n, p * (i + 1), None, True)
|
| 172 |
+
din1 = [d for n, d in G1.in_degree()]
|
| 173 |
+
dout1 = [d for n, d in G1.out_degree()]
|
| 174 |
+
G2 = nx.directed_havel_hakimi_graph(din1, dout1)
|
| 175 |
+
din2 = [d for n, d in G2.in_degree()]
|
| 176 |
+
dout2 = [d for n, d in G2.out_degree()]
|
| 177 |
+
assert sorted(din1) == sorted(din2)
|
| 178 |
+
assert sorted(dout1) == sorted(dout2)
|
| 179 |
+
|
| 180 |
+
# Test non-graphical sequence
|
| 181 |
+
dout = [1000, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1]
|
| 182 |
+
din = [103, 102, 102, 102, 102, 102, 102, 102, 102, 102]
|
| 183 |
+
pytest.raises(nx.exception.NetworkXError, nx.directed_havel_hakimi_graph, din, dout)
|
| 184 |
+
# Test valid sequences
|
| 185 |
+
dout = [1, 1, 1, 1, 1, 2, 2, 2, 3, 4]
|
| 186 |
+
din = [2, 2, 2, 2, 2, 2, 2, 2, 0, 2]
|
| 187 |
+
G2 = nx.directed_havel_hakimi_graph(din, dout)
|
| 188 |
+
dout2 = (d for n, d in G2.out_degree())
|
| 189 |
+
din2 = (d for n, d in G2.in_degree())
|
| 190 |
+
assert sorted(dout) == sorted(dout2)
|
| 191 |
+
assert sorted(din) == sorted(din2)
|
| 192 |
+
# Test unequal sums
|
| 193 |
+
din = [2, 2, 2, 2, 2, 2, 2, 2, 2, 2]
|
| 194 |
+
pytest.raises(nx.exception.NetworkXError, nx.directed_havel_hakimi_graph, din, dout)
|
| 195 |
+
# Test for negative values
|
| 196 |
+
din = [2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -2]
|
| 197 |
+
pytest.raises(nx.exception.NetworkXError, nx.directed_havel_hakimi_graph, din, dout)
|
| 198 |
+
|
| 199 |
+
|
| 200 |
+
def test_degree_sequence_tree():
|
| 201 |
+
z = [1, 1, 1, 1, 1, 2, 2, 2, 3, 4]
|
| 202 |
+
G = nx.degree_sequence_tree(z)
|
| 203 |
+
assert len(G) == len(z)
|
| 204 |
+
assert len(list(G.edges())) == sum(z) / 2
|
| 205 |
+
|
| 206 |
+
pytest.raises(
|
| 207 |
+
nx.NetworkXError, nx.degree_sequence_tree, z, create_using=nx.DiGraph()
|
| 208 |
+
)
|
| 209 |
+
|
| 210 |
+
z = [1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 4]
|
| 211 |
+
pytest.raises(nx.NetworkXError, nx.degree_sequence_tree, z)
|
| 212 |
+
|
| 213 |
+
|
| 214 |
+
def test_random_degree_sequence_graph():
|
| 215 |
+
d = [1, 2, 2, 3]
|
| 216 |
+
G = nx.random_degree_sequence_graph(d, seed=42)
|
| 217 |
+
assert d == sorted(d for n, d in G.degree())
|
| 218 |
+
|
| 219 |
+
|
| 220 |
+
def test_random_degree_sequence_graph_raise():
|
| 221 |
+
z = [1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 4]
|
| 222 |
+
pytest.raises(nx.NetworkXUnfeasible, nx.random_degree_sequence_graph, z)
|
| 223 |
+
|
| 224 |
+
|
| 225 |
+
def test_random_degree_sequence_large():
|
| 226 |
+
G1 = nx.fast_gnp_random_graph(100, 0.1, seed=42)
|
| 227 |
+
d1 = (d for n, d in G1.degree())
|
| 228 |
+
G2 = nx.random_degree_sequence_graph(d1, seed=42)
|
| 229 |
+
d2 = (d for n, d in G2.degree())
|
| 230 |
+
assert sorted(d1) == sorted(d2)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_intersection.py
ADDED
|
@@ -0,0 +1,28 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
import pytest
|
| 2 |
+
|
| 3 |
+
import networkx as nx
|
| 4 |
+
|
| 5 |
+
|
| 6 |
+
class TestIntersectionGraph:
|
| 7 |
+
def test_random_intersection_graph(self):
|
| 8 |
+
G = nx.uniform_random_intersection_graph(10, 5, 0.5)
|
| 9 |
+
assert len(G) == 10
|
| 10 |
+
|
| 11 |
+
def test_k_random_intersection_graph(self):
|
| 12 |
+
G = nx.k_random_intersection_graph(10, 5, 2)
|
| 13 |
+
assert len(G) == 10
|
| 14 |
+
|
| 15 |
+
def test_k_random_intersection_graph_seeded(self):
|
| 16 |
+
G = nx.k_random_intersection_graph(10, 5, 2, seed=1234)
|
| 17 |
+
assert len(G) == 10
|
| 18 |
+
|
| 19 |
+
def test_general_random_intersection_graph(self):
|
| 20 |
+
G = nx.general_random_intersection_graph(10, 5, [0.1, 0.2, 0.2, 0.1, 0.1])
|
| 21 |
+
assert len(G) == 10
|
| 22 |
+
pytest.raises(
|
| 23 |
+
ValueError,
|
| 24 |
+
nx.general_random_intersection_graph,
|
| 25 |
+
10,
|
| 26 |
+
5,
|
| 27 |
+
[0.1, 0.2, 0.2, 0.1],
|
| 28 |
+
)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_mycielski.py
ADDED
|
@@ -0,0 +1,30 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
| 1 |
+
"""Unit tests for the :mod:`networkx.generators.mycielski` module."""
|
| 2 |
+
|
| 3 |
+
import pytest
|
| 4 |
+
|
| 5 |
+
import networkx as nx
|
| 6 |
+
|
| 7 |
+
|
| 8 |
+
class TestMycielski:
|
| 9 |
+
def test_construction(self):
|
| 10 |
+
G = nx.path_graph(2)
|
| 11 |
+
M = nx.mycielskian(G)
|
| 12 |
+
assert nx.is_isomorphic(M, nx.cycle_graph(5))
|
| 13 |
+
|
| 14 |
+
def test_size(self):
|
| 15 |
+
G = nx.path_graph(2)
|
| 16 |
+
M = nx.mycielskian(G, 2)
|
| 17 |
+
assert len(M) == 11
|
| 18 |
+
assert M.size() == 20
|
| 19 |
+
|
| 20 |
+
def test_mycielski_graph_generator(self):
|
| 21 |
+
G = nx.mycielski_graph(1)
|
| 22 |
+
assert nx.is_isomorphic(G, nx.empty_graph(1))
|
| 23 |
+
G = nx.mycielski_graph(2)
|
| 24 |
+
assert nx.is_isomorphic(G, nx.path_graph(2))
|
| 25 |
+
G = nx.mycielski_graph(3)
|
| 26 |
+
assert nx.is_isomorphic(G, nx.cycle_graph(5))
|
| 27 |
+
G = nx.mycielski_graph(4)
|
| 28 |
+
assert nx.is_isomorphic(G, nx.mycielskian(nx.cycle_graph(5)))
|
| 29 |
+
with pytest.raises(nx.NetworkXError, match="must satisfy n >= 1"):
|
| 30 |
+
nx.mycielski_graph(0)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_small.py
ADDED
|
@@ -0,0 +1,208 @@
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|
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|
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|
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|
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|
|
|
|
|
|
|
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|
|
|
|
|
|
|
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|
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|
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|
|
|
|
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|
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|
|
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|
|
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|
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|
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|
|
|
|
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|
|
|
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|
|
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|
|
|
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|
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|
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|
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|
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|
|
|
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|
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|
|
|
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|
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|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
import pytest
|
| 2 |
+
|
| 3 |
+
import networkx as nx
|
| 4 |
+
from networkx.algorithms.isomorphism.isomorph import graph_could_be_isomorphic
|
| 5 |
+
|
| 6 |
+
is_isomorphic = graph_could_be_isomorphic
|
| 7 |
+
|
| 8 |
+
"""Generators - Small
|
| 9 |
+
=====================
|
| 10 |
+
|
| 11 |
+
Some small graphs
|
| 12 |
+
"""
|
| 13 |
+
|
| 14 |
+
null = nx.null_graph()
|
| 15 |
+
|
| 16 |
+
|
| 17 |
+
class TestGeneratorsSmall:
|
| 18 |
+
def test__LCF_graph(self):
|
| 19 |
+
# If n<=0, then return the null_graph
|
| 20 |
+
G = nx.LCF_graph(-10, [1, 2], 100)
|
| 21 |
+
assert is_isomorphic(G, null)
|
| 22 |
+
G = nx.LCF_graph(0, [1, 2], 3)
|
| 23 |
+
assert is_isomorphic(G, null)
|
| 24 |
+
G = nx.LCF_graph(0, [1, 2], 10)
|
| 25 |
+
assert is_isomorphic(G, null)
|
| 26 |
+
|
| 27 |
+
# Test that LCF(n,[],0) == cycle_graph(n)
|
| 28 |
+
for a, b, c in [(5, [], 0), (10, [], 0), (5, [], 1), (10, [], 10)]:
|
| 29 |
+
G = nx.LCF_graph(a, b, c)
|
| 30 |
+
assert is_isomorphic(G, nx.cycle_graph(a))
|
| 31 |
+
|
| 32 |
+
# Generate the utility graph K_{3,3}
|
| 33 |
+
G = nx.LCF_graph(6, [3, -3], 3)
|
| 34 |
+
utility_graph = nx.complete_bipartite_graph(3, 3)
|
| 35 |
+
assert is_isomorphic(G, utility_graph)
|
| 36 |
+
|
| 37 |
+
with pytest.raises(nx.NetworkXError, match="Directed Graph not supported"):
|
| 38 |
+
G = nx.LCF_graph(6, [3, -3], 3, create_using=nx.DiGraph)
|
| 39 |
+
|
| 40 |
+
def test_properties_named_small_graphs(self):
|
| 41 |
+
G = nx.bull_graph()
|
| 42 |
+
assert sorted(G) == list(range(5))
|
| 43 |
+
assert G.number_of_edges() == 5
|
| 44 |
+
assert sorted(d for n, d in G.degree()) == [1, 1, 2, 3, 3]
|
| 45 |
+
assert nx.diameter(G) == 3
|
| 46 |
+
assert nx.radius(G) == 2
|
| 47 |
+
|
| 48 |
+
G = nx.chvatal_graph()
|
| 49 |
+
assert sorted(G) == list(range(12))
|
| 50 |
+
assert G.number_of_edges() == 24
|
| 51 |
+
assert [d for n, d in G.degree()] == 12 * [4]
|
| 52 |
+
assert nx.diameter(G) == 2
|
| 53 |
+
assert nx.radius(G) == 2
|
| 54 |
+
|
| 55 |
+
G = nx.cubical_graph()
|
| 56 |
+
assert sorted(G) == list(range(8))
|
| 57 |
+
assert G.number_of_edges() == 12
|
| 58 |
+
assert [d for n, d in G.degree()] == 8 * [3]
|
| 59 |
+
assert nx.diameter(G) == 3
|
| 60 |
+
assert nx.radius(G) == 3
|
| 61 |
+
|
| 62 |
+
G = nx.desargues_graph()
|
| 63 |
+
assert sorted(G) == list(range(20))
|
| 64 |
+
assert G.number_of_edges() == 30
|
| 65 |
+
assert [d for n, d in G.degree()] == 20 * [3]
|
| 66 |
+
|
| 67 |
+
G = nx.diamond_graph()
|
| 68 |
+
assert sorted(G) == list(range(4))
|
| 69 |
+
assert sorted(d for n, d in G.degree()) == [2, 2, 3, 3]
|
| 70 |
+
assert nx.diameter(G) == 2
|
| 71 |
+
assert nx.radius(G) == 1
|
| 72 |
+
|
| 73 |
+
G = nx.dodecahedral_graph()
|
| 74 |
+
assert sorted(G) == list(range(20))
|
| 75 |
+
assert G.number_of_edges() == 30
|
| 76 |
+
assert [d for n, d in G.degree()] == 20 * [3]
|
| 77 |
+
assert nx.diameter(G) == 5
|
| 78 |
+
assert nx.radius(G) == 5
|
| 79 |
+
|
| 80 |
+
G = nx.frucht_graph()
|
| 81 |
+
assert sorted(G) == list(range(12))
|
| 82 |
+
assert G.number_of_edges() == 18
|
| 83 |
+
assert [d for n, d in G.degree()] == 12 * [3]
|
| 84 |
+
assert nx.diameter(G) == 4
|
| 85 |
+
assert nx.radius(G) == 3
|
| 86 |
+
|
| 87 |
+
G = nx.heawood_graph()
|
| 88 |
+
assert sorted(G) == list(range(14))
|
| 89 |
+
assert G.number_of_edges() == 21
|
| 90 |
+
assert [d for n, d in G.degree()] == 14 * [3]
|
| 91 |
+
assert nx.diameter(G) == 3
|
| 92 |
+
assert nx.radius(G) == 3
|
| 93 |
+
|
| 94 |
+
G = nx.hoffman_singleton_graph()
|
| 95 |
+
assert sorted(G) == list(range(50))
|
| 96 |
+
assert G.number_of_edges() == 175
|
| 97 |
+
assert [d for n, d in G.degree()] == 50 * [7]
|
| 98 |
+
assert nx.diameter(G) == 2
|
| 99 |
+
assert nx.radius(G) == 2
|
| 100 |
+
|
| 101 |
+
G = nx.house_graph()
|
| 102 |
+
assert sorted(G) == list(range(5))
|
| 103 |
+
assert G.number_of_edges() == 6
|
| 104 |
+
assert sorted(d for n, d in G.degree()) == [2, 2, 2, 3, 3]
|
| 105 |
+
assert nx.diameter(G) == 2
|
| 106 |
+
assert nx.radius(G) == 2
|
| 107 |
+
|
| 108 |
+
G = nx.house_x_graph()
|
| 109 |
+
assert sorted(G) == list(range(5))
|
| 110 |
+
assert G.number_of_edges() == 8
|
| 111 |
+
assert sorted(d for n, d in G.degree()) == [2, 3, 3, 4, 4]
|
| 112 |
+
assert nx.diameter(G) == 2
|
| 113 |
+
assert nx.radius(G) == 1
|
| 114 |
+
|
| 115 |
+
G = nx.icosahedral_graph()
|
| 116 |
+
assert sorted(G) == list(range(12))
|
| 117 |
+
assert G.number_of_edges() == 30
|
| 118 |
+
assert [d for n, d in G.degree()] == [5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5]
|
| 119 |
+
assert nx.diameter(G) == 3
|
| 120 |
+
assert nx.radius(G) == 3
|
| 121 |
+
|
| 122 |
+
G = nx.krackhardt_kite_graph()
|
| 123 |
+
assert sorted(G) == list(range(10))
|
| 124 |
+
assert G.number_of_edges() == 18
|
| 125 |
+
assert sorted(d for n, d in G.degree()) == [1, 2, 3, 3, 3, 4, 4, 5, 5, 6]
|
| 126 |
+
|
| 127 |
+
G = nx.moebius_kantor_graph()
|
| 128 |
+
assert sorted(G) == list(range(16))
|
| 129 |
+
assert G.number_of_edges() == 24
|
| 130 |
+
assert [d for n, d in G.degree()] == 16 * [3]
|
| 131 |
+
assert nx.diameter(G) == 4
|
| 132 |
+
|
| 133 |
+
G = nx.octahedral_graph()
|
| 134 |
+
assert sorted(G) == list(range(6))
|
| 135 |
+
assert G.number_of_edges() == 12
|
| 136 |
+
assert [d for n, d in G.degree()] == 6 * [4]
|
| 137 |
+
assert nx.diameter(G) == 2
|
| 138 |
+
assert nx.radius(G) == 2
|
| 139 |
+
|
| 140 |
+
G = nx.pappus_graph()
|
| 141 |
+
assert sorted(G) == list(range(18))
|
| 142 |
+
assert G.number_of_edges() == 27
|
| 143 |
+
assert [d for n, d in G.degree()] == 18 * [3]
|
| 144 |
+
assert nx.diameter(G) == 4
|
| 145 |
+
|
| 146 |
+
G = nx.petersen_graph()
|
| 147 |
+
assert sorted(G) == list(range(10))
|
| 148 |
+
assert G.number_of_edges() == 15
|
| 149 |
+
assert [d for n, d in G.degree()] == 10 * [3]
|
| 150 |
+
assert nx.diameter(G) == 2
|
| 151 |
+
assert nx.radius(G) == 2
|
| 152 |
+
|
| 153 |
+
G = nx.sedgewick_maze_graph()
|
| 154 |
+
assert sorted(G) == list(range(8))
|
| 155 |
+
assert G.number_of_edges() == 10
|
| 156 |
+
assert sorted(d for n, d in G.degree()) == [1, 2, 2, 2, 3, 3, 3, 4]
|
| 157 |
+
|
| 158 |
+
G = nx.tetrahedral_graph()
|
| 159 |
+
assert sorted(G) == list(range(4))
|
| 160 |
+
assert G.number_of_edges() == 6
|
| 161 |
+
assert [d for n, d in G.degree()] == [3, 3, 3, 3]
|
| 162 |
+
assert nx.diameter(G) == 1
|
| 163 |
+
assert nx.radius(G) == 1
|
| 164 |
+
|
| 165 |
+
G = nx.truncated_cube_graph()
|
| 166 |
+
assert sorted(G) == list(range(24))
|
| 167 |
+
assert G.number_of_edges() == 36
|
| 168 |
+
assert [d for n, d in G.degree()] == 24 * [3]
|
| 169 |
+
|
| 170 |
+
G = nx.truncated_tetrahedron_graph()
|
| 171 |
+
assert sorted(G) == list(range(12))
|
| 172 |
+
assert G.number_of_edges() == 18
|
| 173 |
+
assert [d for n, d in G.degree()] == 12 * [3]
|
| 174 |
+
|
| 175 |
+
G = nx.tutte_graph()
|
| 176 |
+
assert sorted(G) == list(range(46))
|
| 177 |
+
assert G.number_of_edges() == 69
|
| 178 |
+
assert [d for n, d in G.degree()] == 46 * [3]
|
| 179 |
+
|
| 180 |
+
# Test create_using with directed or multigraphs on small graphs
|
| 181 |
+
pytest.raises(nx.NetworkXError, nx.tutte_graph, create_using=nx.DiGraph)
|
| 182 |
+
MG = nx.tutte_graph(create_using=nx.MultiGraph)
|
| 183 |
+
assert sorted(MG.edges()) == sorted(G.edges())
|
| 184 |
+
|
| 185 |
+
|
| 186 |
+
@pytest.mark.parametrize(
|
| 187 |
+
"fn",
|
| 188 |
+
(
|
| 189 |
+
nx.bull_graph,
|
| 190 |
+
nx.chvatal_graph,
|
| 191 |
+
nx.cubical_graph,
|
| 192 |
+
nx.diamond_graph,
|
| 193 |
+
nx.house_graph,
|
| 194 |
+
nx.house_x_graph,
|
| 195 |
+
nx.icosahedral_graph,
|
| 196 |
+
nx.krackhardt_kite_graph,
|
| 197 |
+
nx.octahedral_graph,
|
| 198 |
+
nx.petersen_graph,
|
| 199 |
+
nx.truncated_cube_graph,
|
| 200 |
+
nx.tutte_graph,
|
| 201 |
+
),
|
| 202 |
+
)
|
| 203 |
+
@pytest.mark.parametrize(
|
| 204 |
+
"create_using", (nx.DiGraph, nx.MultiDiGraph, nx.DiGraph([(0, 1)]))
|
| 205 |
+
)
|
| 206 |
+
def tests_raises_with_directed_create_using(fn, create_using):
|
| 207 |
+
with pytest.raises(nx.NetworkXError, match="Directed Graph not supported"):
|
| 208 |
+
fn(create_using=create_using)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_spectral_graph_forge.py
ADDED
|
@@ -0,0 +1,49 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
import pytest
|
| 2 |
+
|
| 3 |
+
pytest.importorskip("numpy")
|
| 4 |
+
pytest.importorskip("scipy")
|
| 5 |
+
|
| 6 |
+
|
| 7 |
+
from networkx import is_isomorphic
|
| 8 |
+
from networkx.exception import NetworkXError
|
| 9 |
+
from networkx.generators import karate_club_graph
|
| 10 |
+
from networkx.generators.spectral_graph_forge import spectral_graph_forge
|
| 11 |
+
from networkx.utils import nodes_equal
|
| 12 |
+
|
| 13 |
+
|
| 14 |
+
def test_spectral_graph_forge():
|
| 15 |
+
G = karate_club_graph()
|
| 16 |
+
|
| 17 |
+
seed = 54321
|
| 18 |
+
|
| 19 |
+
# common cases, just checking node number preserving and difference
|
| 20 |
+
# between identity and modularity cases
|
| 21 |
+
H = spectral_graph_forge(G, 0.1, transformation="identity", seed=seed)
|
| 22 |
+
assert nodes_equal(G, H)
|
| 23 |
+
|
| 24 |
+
I = spectral_graph_forge(G, 0.1, transformation="identity", seed=seed)
|
| 25 |
+
assert nodes_equal(G, H)
|
| 26 |
+
assert is_isomorphic(I, H)
|
| 27 |
+
|
| 28 |
+
I = spectral_graph_forge(G, 0.1, transformation="modularity", seed=seed)
|
| 29 |
+
assert nodes_equal(G, I)
|
| 30 |
+
|
| 31 |
+
assert not is_isomorphic(I, H)
|
| 32 |
+
|
| 33 |
+
# with all the eigenvectors, output graph is identical to the input one
|
| 34 |
+
H = spectral_graph_forge(G, 1, transformation="modularity", seed=seed)
|
| 35 |
+
assert nodes_equal(G, H)
|
| 36 |
+
assert is_isomorphic(G, H)
|
| 37 |
+
|
| 38 |
+
# invalid alpha input value, it is silently truncated in [0,1]
|
| 39 |
+
H = spectral_graph_forge(G, -1, transformation="identity", seed=seed)
|
| 40 |
+
assert nodes_equal(G, H)
|
| 41 |
+
|
| 42 |
+
H = spectral_graph_forge(G, 10, transformation="identity", seed=seed)
|
| 43 |
+
assert nodes_equal(G, H)
|
| 44 |
+
assert is_isomorphic(G, H)
|
| 45 |
+
|
| 46 |
+
# invalid transformation mode, checking the error raising
|
| 47 |
+
pytest.raises(
|
| 48 |
+
NetworkXError, spectral_graph_forge, G, 0.1, transformation="unknown", seed=seed
|
| 49 |
+
)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/tests/test_sudoku.py
ADDED
|
@@ -0,0 +1,92 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
"""Unit tests for the :mod:`networkx.generators.sudoku_graph` module."""
|
| 2 |
+
|
| 3 |
+
import pytest
|
| 4 |
+
|
| 5 |
+
import networkx as nx
|
| 6 |
+
|
| 7 |
+
|
| 8 |
+
def test_sudoku_negative():
|
| 9 |
+
"""Raise an error when generating a Sudoku graph of order -1."""
|
| 10 |
+
pytest.raises(nx.NetworkXError, nx.sudoku_graph, n=-1)
|
| 11 |
+
|
| 12 |
+
|
| 13 |
+
@pytest.mark.parametrize("n", [0, 1, 2, 3, 4])
|
| 14 |
+
def test_sudoku_generator(n):
|
| 15 |
+
"""Generate Sudoku graphs of various sizes and verify their properties."""
|
| 16 |
+
G = nx.sudoku_graph(n)
|
| 17 |
+
expected_nodes = n**4
|
| 18 |
+
expected_degree = (n - 1) * (3 * n + 1)
|
| 19 |
+
expected_edges = expected_nodes * expected_degree // 2
|
| 20 |
+
assert not G.is_directed()
|
| 21 |
+
assert not G.is_multigraph()
|
| 22 |
+
assert G.number_of_nodes() == expected_nodes
|
| 23 |
+
assert G.number_of_edges() == expected_edges
|
| 24 |
+
assert all(d == expected_degree for _, d in G.degree)
|
| 25 |
+
|
| 26 |
+
if n == 2:
|
| 27 |
+
assert sorted(G.neighbors(6)) == [2, 3, 4, 5, 7, 10, 14]
|
| 28 |
+
elif n == 3:
|
| 29 |
+
assert sorted(G.neighbors(42)) == [
|
| 30 |
+
6,
|
| 31 |
+
15,
|
| 32 |
+
24,
|
| 33 |
+
33,
|
| 34 |
+
34,
|
| 35 |
+
35,
|
| 36 |
+
36,
|
| 37 |
+
37,
|
| 38 |
+
38,
|
| 39 |
+
39,
|
| 40 |
+
40,
|
| 41 |
+
41,
|
| 42 |
+
43,
|
| 43 |
+
44,
|
| 44 |
+
51,
|
| 45 |
+
52,
|
| 46 |
+
53,
|
| 47 |
+
60,
|
| 48 |
+
69,
|
| 49 |
+
78,
|
| 50 |
+
]
|
| 51 |
+
elif n == 4:
|
| 52 |
+
assert sorted(G.neighbors(0)) == [
|
| 53 |
+
1,
|
| 54 |
+
2,
|
| 55 |
+
3,
|
| 56 |
+
4,
|
| 57 |
+
5,
|
| 58 |
+
6,
|
| 59 |
+
7,
|
| 60 |
+
8,
|
| 61 |
+
9,
|
| 62 |
+
10,
|
| 63 |
+
11,
|
| 64 |
+
12,
|
| 65 |
+
13,
|
| 66 |
+
14,
|
| 67 |
+
15,
|
| 68 |
+
16,
|
| 69 |
+
17,
|
| 70 |
+
18,
|
| 71 |
+
19,
|
| 72 |
+
32,
|
| 73 |
+
33,
|
| 74 |
+
34,
|
| 75 |
+
35,
|
| 76 |
+
48,
|
| 77 |
+
49,
|
| 78 |
+
50,
|
| 79 |
+
51,
|
| 80 |
+
64,
|
| 81 |
+
80,
|
| 82 |
+
96,
|
| 83 |
+
112,
|
| 84 |
+
128,
|
| 85 |
+
144,
|
| 86 |
+
160,
|
| 87 |
+
176,
|
| 88 |
+
192,
|
| 89 |
+
208,
|
| 90 |
+
224,
|
| 91 |
+
240,
|
| 92 |
+
]
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/time_series.py
ADDED
|
@@ -0,0 +1,74 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
"""
|
| 2 |
+
Time Series Graphs
|
| 3 |
+
"""
|
| 4 |
+
|
| 5 |
+
import itertools
|
| 6 |
+
|
| 7 |
+
import networkx as nx
|
| 8 |
+
|
| 9 |
+
__all__ = ["visibility_graph"]
|
| 10 |
+
|
| 11 |
+
|
| 12 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 13 |
+
def visibility_graph(series):
|
| 14 |
+
"""
|
| 15 |
+
Return a Visibility Graph of an input Time Series.
|
| 16 |
+
|
| 17 |
+
A visibility graph converts a time series into a graph. The constructed graph
|
| 18 |
+
uses integer nodes to indicate which event in the series the node represents.
|
| 19 |
+
Edges are formed as follows: consider a bar plot of the series and view that
|
| 20 |
+
as a side view of a landscape with a node at the top of each bar. An edge
|
| 21 |
+
means that the nodes can be connected by a straight "line-of-sight" without
|
| 22 |
+
being obscured by any bars between the nodes.
|
| 23 |
+
|
| 24 |
+
The resulting graph inherits several properties of the series in its structure.
|
| 25 |
+
Thereby, periodic series convert into regular graphs, random series convert
|
| 26 |
+
into random graphs, and fractal series convert into scale-free networks [1]_.
|
| 27 |
+
|
| 28 |
+
Parameters
|
| 29 |
+
----------
|
| 30 |
+
series : Sequence[Number]
|
| 31 |
+
A Time Series sequence (iterable and sliceable) of numeric values
|
| 32 |
+
representing times.
|
| 33 |
+
|
| 34 |
+
Returns
|
| 35 |
+
-------
|
| 36 |
+
NetworkX Graph
|
| 37 |
+
The Visibility Graph of the input series
|
| 38 |
+
|
| 39 |
+
Examples
|
| 40 |
+
--------
|
| 41 |
+
>>> series_list = [range(10), [2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3]]
|
| 42 |
+
>>> for s in series_list:
|
| 43 |
+
... g = nx.visibility_graph(s)
|
| 44 |
+
... print(g)
|
| 45 |
+
Graph with 10 nodes and 9 edges
|
| 46 |
+
Graph with 12 nodes and 18 edges
|
| 47 |
+
|
| 48 |
+
References
|
| 49 |
+
----------
|
| 50 |
+
.. [1] Lacasa, Lucas, Bartolo Luque, Fernando Ballesteros, Jordi Luque, and Juan Carlos Nuno.
|
| 51 |
+
"From time series to complex networks: The visibility graph." Proceedings of the
|
| 52 |
+
National Academy of Sciences 105, no. 13 (2008): 4972-4975.
|
| 53 |
+
https://www.pnas.org/doi/10.1073/pnas.0709247105
|
| 54 |
+
"""
|
| 55 |
+
|
| 56 |
+
# Sequential values are always connected
|
| 57 |
+
G = nx.path_graph(len(series))
|
| 58 |
+
nx.set_node_attributes(G, dict(enumerate(series)), "value")
|
| 59 |
+
|
| 60 |
+
# Check all combinations of nodes n series
|
| 61 |
+
for (n1, t1), (n2, t2) in itertools.combinations(enumerate(series), 2):
|
| 62 |
+
# check if any value between obstructs line of sight
|
| 63 |
+
slope = (t2 - t1) / (n2 - n1)
|
| 64 |
+
offset = t2 - slope * n2
|
| 65 |
+
|
| 66 |
+
obstructed = any(
|
| 67 |
+
t >= slope * n + offset
|
| 68 |
+
for n, t in enumerate(series[n1 + 1 : n2], start=n1 + 1)
|
| 69 |
+
)
|
| 70 |
+
|
| 71 |
+
if not obstructed:
|
| 72 |
+
G.add_edge(n1, n2)
|
| 73 |
+
|
| 74 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/trees.py
ADDED
|
@@ -0,0 +1,1071 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
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|
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|
|
|
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|
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|
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|
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|
| 1 |
+
"""Functions for generating trees.
|
| 2 |
+
|
| 3 |
+
The functions sampling trees at random in this module come
|
| 4 |
+
in two variants: labeled and unlabeled. The labeled variants
|
| 5 |
+
sample from every possible tree with the given number of nodes
|
| 6 |
+
uniformly at random. The unlabeled variants sample from every
|
| 7 |
+
possible *isomorphism class* of trees with the given number
|
| 8 |
+
of nodes uniformly at random.
|
| 9 |
+
|
| 10 |
+
To understand the difference, consider the following example.
|
| 11 |
+
There are two isomorphism classes of trees with four nodes.
|
| 12 |
+
One is that of the path graph, the other is that of the
|
| 13 |
+
star graph. The unlabeled variant will return a line graph or
|
| 14 |
+
a star graph with probability 1/2.
|
| 15 |
+
|
| 16 |
+
The labeled variant will return the line graph
|
| 17 |
+
with probability 3/4 and the star graph with probability 1/4,
|
| 18 |
+
because there are more labeled variants of the line graph
|
| 19 |
+
than of the star graph. More precisely, the line graph has
|
| 20 |
+
an automorphism group of order 2, whereas the star graph has
|
| 21 |
+
an automorphism group of order 6, so the line graph has three
|
| 22 |
+
times as many labeled variants as the star graph, and thus
|
| 23 |
+
three more chances to be drawn.
|
| 24 |
+
|
| 25 |
+
Additionally, some functions in this module can sample rooted
|
| 26 |
+
trees and forests uniformly at random. A rooted tree is a tree
|
| 27 |
+
with a designated root node. A rooted forest is a disjoint union
|
| 28 |
+
of rooted trees.
|
| 29 |
+
"""
|
| 30 |
+
|
| 31 |
+
import warnings
|
| 32 |
+
from collections import Counter, defaultdict
|
| 33 |
+
from math import comb, factorial
|
| 34 |
+
|
| 35 |
+
import networkx as nx
|
| 36 |
+
from networkx.utils import py_random_state
|
| 37 |
+
|
| 38 |
+
__all__ = [
|
| 39 |
+
"prefix_tree",
|
| 40 |
+
"prefix_tree_recursive",
|
| 41 |
+
"random_labeled_tree",
|
| 42 |
+
"random_labeled_rooted_tree",
|
| 43 |
+
"random_labeled_rooted_forest",
|
| 44 |
+
"random_unlabeled_tree",
|
| 45 |
+
"random_unlabeled_rooted_tree",
|
| 46 |
+
"random_unlabeled_rooted_forest",
|
| 47 |
+
]
|
| 48 |
+
|
| 49 |
+
|
| 50 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 51 |
+
def prefix_tree(paths):
|
| 52 |
+
"""Creates a directed prefix tree from a list of paths.
|
| 53 |
+
|
| 54 |
+
Usually the paths are described as strings or lists of integers.
|
| 55 |
+
|
| 56 |
+
A "prefix tree" represents the prefix structure of the strings.
|
| 57 |
+
Each node represents a prefix of some string. The root represents
|
| 58 |
+
the empty prefix with children for the single letter prefixes which
|
| 59 |
+
in turn have children for each double letter prefix starting with
|
| 60 |
+
the single letter corresponding to the parent node, and so on.
|
| 61 |
+
|
| 62 |
+
More generally the prefixes do not need to be strings. A prefix refers
|
| 63 |
+
to the start of a sequence. The root has children for each one element
|
| 64 |
+
prefix and they have children for each two element prefix that starts
|
| 65 |
+
with the one element sequence of the parent, and so on.
|
| 66 |
+
|
| 67 |
+
Note that this implementation uses integer nodes with an attribute.
|
| 68 |
+
Each node has an attribute "source" whose value is the original element
|
| 69 |
+
of the path to which this node corresponds. For example, suppose `paths`
|
| 70 |
+
consists of one path: "can". Then the nodes `[1, 2, 3]` which represent
|
| 71 |
+
this path have "source" values "c", "a" and "n".
|
| 72 |
+
|
| 73 |
+
All the descendants of a node have a common prefix in the sequence/path
|
| 74 |
+
associated with that node. From the returned tree, the prefix for each
|
| 75 |
+
node can be constructed by traversing the tree up to the root and
|
| 76 |
+
accumulating the "source" values along the way.
|
| 77 |
+
|
| 78 |
+
The root node is always `0` and has "source" attribute `None`.
|
| 79 |
+
The root is the only node with in-degree zero.
|
| 80 |
+
The nil node is always `-1` and has "source" attribute `"NIL"`.
|
| 81 |
+
The nil node is the only node with out-degree zero.
|
| 82 |
+
|
| 83 |
+
|
| 84 |
+
Parameters
|
| 85 |
+
----------
|
| 86 |
+
paths: iterable of paths
|
| 87 |
+
An iterable of paths which are themselves sequences.
|
| 88 |
+
Matching prefixes among these sequences are identified with
|
| 89 |
+
nodes of the prefix tree. One leaf of the tree is associated
|
| 90 |
+
with each path. (Identical paths are associated with the same
|
| 91 |
+
leaf of the tree.)
|
| 92 |
+
|
| 93 |
+
|
| 94 |
+
Returns
|
| 95 |
+
-------
|
| 96 |
+
tree: DiGraph
|
| 97 |
+
A directed graph representing an arborescence consisting of the
|
| 98 |
+
prefix tree generated by `paths`. Nodes are directed "downward",
|
| 99 |
+
from parent to child. A special "synthetic" root node is added
|
| 100 |
+
to be the parent of the first node in each path. A special
|
| 101 |
+
"synthetic" leaf node, the "nil" node `-1`, is added to be the child
|
| 102 |
+
of all nodes representing the last element in a path. (The
|
| 103 |
+
addition of this nil node technically makes this not an
|
| 104 |
+
arborescence but a directed acyclic graph; removing the nil node
|
| 105 |
+
makes it an arborescence.)
|
| 106 |
+
|
| 107 |
+
|
| 108 |
+
Notes
|
| 109 |
+
-----
|
| 110 |
+
The prefix tree is also known as a *trie*.
|
| 111 |
+
|
| 112 |
+
|
| 113 |
+
Examples
|
| 114 |
+
--------
|
| 115 |
+
Create a prefix tree from a list of strings with common prefixes::
|
| 116 |
+
|
| 117 |
+
>>> paths = ["ab", "abs", "ad"]
|
| 118 |
+
>>> T = nx.prefix_tree(paths)
|
| 119 |
+
>>> list(T.edges)
|
| 120 |
+
[(0, 1), (1, 2), (1, 4), (2, -1), (2, 3), (3, -1), (4, -1)]
|
| 121 |
+
|
| 122 |
+
The leaf nodes can be obtained as predecessors of the nil node::
|
| 123 |
+
|
| 124 |
+
>>> root, NIL = 0, -1
|
| 125 |
+
>>> list(T.predecessors(NIL))
|
| 126 |
+
[2, 3, 4]
|
| 127 |
+
|
| 128 |
+
To recover the original paths that generated the prefix tree,
|
| 129 |
+
traverse up the tree from the node `-1` to the node `0`::
|
| 130 |
+
|
| 131 |
+
>>> recovered = []
|
| 132 |
+
>>> for v in T.predecessors(NIL):
|
| 133 |
+
... prefix = ""
|
| 134 |
+
... while v != root:
|
| 135 |
+
... prefix = str(T.nodes[v]["source"]) + prefix
|
| 136 |
+
... v = next(T.predecessors(v)) # only one predecessor
|
| 137 |
+
... recovered.append(prefix)
|
| 138 |
+
>>> sorted(recovered)
|
| 139 |
+
['ab', 'abs', 'ad']
|
| 140 |
+
"""
|
| 141 |
+
|
| 142 |
+
def get_children(parent, paths):
|
| 143 |
+
children = defaultdict(list)
|
| 144 |
+
# Populate dictionary with key(s) as the child/children of the root and
|
| 145 |
+
# value(s) as the remaining paths of the corresponding child/children
|
| 146 |
+
for path in paths:
|
| 147 |
+
# If path is empty, we add an edge to the NIL node.
|
| 148 |
+
if not path:
|
| 149 |
+
tree.add_edge(parent, NIL)
|
| 150 |
+
continue
|
| 151 |
+
child, *rest = path
|
| 152 |
+
# `child` may exist as the head of more than one path in `paths`.
|
| 153 |
+
children[child].append(rest)
|
| 154 |
+
return children
|
| 155 |
+
|
| 156 |
+
# Initialize the prefix tree with a root node and a nil node.
|
| 157 |
+
tree = nx.DiGraph()
|
| 158 |
+
root = 0
|
| 159 |
+
tree.add_node(root, source=None)
|
| 160 |
+
NIL = -1
|
| 161 |
+
tree.add_node(NIL, source="NIL")
|
| 162 |
+
children = get_children(root, paths)
|
| 163 |
+
stack = [(root, iter(children.items()))]
|
| 164 |
+
while stack:
|
| 165 |
+
parent, remaining_children = stack[-1]
|
| 166 |
+
try:
|
| 167 |
+
child, remaining_paths = next(remaining_children)
|
| 168 |
+
# Pop item off stack if there are no remaining children
|
| 169 |
+
except StopIteration:
|
| 170 |
+
stack.pop()
|
| 171 |
+
continue
|
| 172 |
+
# We relabel each child with an unused name.
|
| 173 |
+
new_name = len(tree) - 1
|
| 174 |
+
# The "source" node attribute stores the original node name.
|
| 175 |
+
tree.add_node(new_name, source=child)
|
| 176 |
+
tree.add_edge(parent, new_name)
|
| 177 |
+
children = get_children(new_name, remaining_paths)
|
| 178 |
+
stack.append((new_name, iter(children.items())))
|
| 179 |
+
|
| 180 |
+
return tree
|
| 181 |
+
|
| 182 |
+
|
| 183 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 184 |
+
def prefix_tree_recursive(paths):
|
| 185 |
+
"""Recursively creates a directed prefix tree from a list of paths.
|
| 186 |
+
|
| 187 |
+
The original recursive version of prefix_tree for comparison. It is
|
| 188 |
+
the same algorithm but the recursion is unrolled onto a stack.
|
| 189 |
+
|
| 190 |
+
Usually the paths are described as strings or lists of integers.
|
| 191 |
+
|
| 192 |
+
A "prefix tree" represents the prefix structure of the strings.
|
| 193 |
+
Each node represents a prefix of some string. The root represents
|
| 194 |
+
the empty prefix with children for the single letter prefixes which
|
| 195 |
+
in turn have children for each double letter prefix starting with
|
| 196 |
+
the single letter corresponding to the parent node, and so on.
|
| 197 |
+
|
| 198 |
+
More generally the prefixes do not need to be strings. A prefix refers
|
| 199 |
+
to the start of a sequence. The root has children for each one element
|
| 200 |
+
prefix and they have children for each two element prefix that starts
|
| 201 |
+
with the one element sequence of the parent, and so on.
|
| 202 |
+
|
| 203 |
+
Note that this implementation uses integer nodes with an attribute.
|
| 204 |
+
Each node has an attribute "source" whose value is the original element
|
| 205 |
+
of the path to which this node corresponds. For example, suppose `paths`
|
| 206 |
+
consists of one path: "can". Then the nodes `[1, 2, 3]` which represent
|
| 207 |
+
this path have "source" values "c", "a" and "n".
|
| 208 |
+
|
| 209 |
+
All the descendants of a node have a common prefix in the sequence/path
|
| 210 |
+
associated with that node. From the returned tree, ehe prefix for each
|
| 211 |
+
node can be constructed by traversing the tree up to the root and
|
| 212 |
+
accumulating the "source" values along the way.
|
| 213 |
+
|
| 214 |
+
The root node is always `0` and has "source" attribute `None`.
|
| 215 |
+
The root is the only node with in-degree zero.
|
| 216 |
+
The nil node is always `-1` and has "source" attribute `"NIL"`.
|
| 217 |
+
The nil node is the only node with out-degree zero.
|
| 218 |
+
|
| 219 |
+
|
| 220 |
+
Parameters
|
| 221 |
+
----------
|
| 222 |
+
paths: iterable of paths
|
| 223 |
+
An iterable of paths which are themselves sequences.
|
| 224 |
+
Matching prefixes among these sequences are identified with
|
| 225 |
+
nodes of the prefix tree. One leaf of the tree is associated
|
| 226 |
+
with each path. (Identical paths are associated with the same
|
| 227 |
+
leaf of the tree.)
|
| 228 |
+
|
| 229 |
+
|
| 230 |
+
Returns
|
| 231 |
+
-------
|
| 232 |
+
tree: DiGraph
|
| 233 |
+
A directed graph representing an arborescence consisting of the
|
| 234 |
+
prefix tree generated by `paths`. Nodes are directed "downward",
|
| 235 |
+
from parent to child. A special "synthetic" root node is added
|
| 236 |
+
to be the parent of the first node in each path. A special
|
| 237 |
+
"synthetic" leaf node, the "nil" node `-1`, is added to be the child
|
| 238 |
+
of all nodes representing the last element in a path. (The
|
| 239 |
+
addition of this nil node technically makes this not an
|
| 240 |
+
arborescence but a directed acyclic graph; removing the nil node
|
| 241 |
+
makes it an arborescence.)
|
| 242 |
+
|
| 243 |
+
|
| 244 |
+
Notes
|
| 245 |
+
-----
|
| 246 |
+
The prefix tree is also known as a *trie*.
|
| 247 |
+
|
| 248 |
+
|
| 249 |
+
Examples
|
| 250 |
+
--------
|
| 251 |
+
Create a prefix tree from a list of strings with common prefixes::
|
| 252 |
+
|
| 253 |
+
>>> paths = ["ab", "abs", "ad"]
|
| 254 |
+
>>> T = nx.prefix_tree(paths)
|
| 255 |
+
>>> list(T.edges)
|
| 256 |
+
[(0, 1), (1, 2), (1, 4), (2, -1), (2, 3), (3, -1), (4, -1)]
|
| 257 |
+
|
| 258 |
+
The leaf nodes can be obtained as predecessors of the nil node.
|
| 259 |
+
|
| 260 |
+
>>> root, NIL = 0, -1
|
| 261 |
+
>>> list(T.predecessors(NIL))
|
| 262 |
+
[2, 3, 4]
|
| 263 |
+
|
| 264 |
+
To recover the original paths that generated the prefix tree,
|
| 265 |
+
traverse up the tree from the node `-1` to the node `0`::
|
| 266 |
+
|
| 267 |
+
>>> recovered = []
|
| 268 |
+
>>> for v in T.predecessors(NIL):
|
| 269 |
+
... prefix = ""
|
| 270 |
+
... while v != root:
|
| 271 |
+
... prefix = str(T.nodes[v]["source"]) + prefix
|
| 272 |
+
... v = next(T.predecessors(v)) # only one predecessor
|
| 273 |
+
... recovered.append(prefix)
|
| 274 |
+
>>> sorted(recovered)
|
| 275 |
+
['ab', 'abs', 'ad']
|
| 276 |
+
"""
|
| 277 |
+
|
| 278 |
+
def _helper(paths, root, tree):
|
| 279 |
+
"""Recursively create a trie from the given list of paths.
|
| 280 |
+
|
| 281 |
+
`paths` is a list of paths, each of which is itself a list of
|
| 282 |
+
nodes, relative to the given `root` (but not including it). This
|
| 283 |
+
list of paths will be interpreted as a tree-like structure, in
|
| 284 |
+
which two paths that share a prefix represent two branches of
|
| 285 |
+
the tree with the same initial segment.
|
| 286 |
+
|
| 287 |
+
`root` is the parent of the node at index 0 in each path.
|
| 288 |
+
|
| 289 |
+
`tree` is the "accumulator", the :class:`networkx.DiGraph`
|
| 290 |
+
representing the branching to which the new nodes and edges will
|
| 291 |
+
be added.
|
| 292 |
+
|
| 293 |
+
"""
|
| 294 |
+
# For each path, remove the first node and make it a child of root.
|
| 295 |
+
# Any remaining paths then get processed recursively.
|
| 296 |
+
children = defaultdict(list)
|
| 297 |
+
for path in paths:
|
| 298 |
+
# If path is empty, we add an edge to the NIL node.
|
| 299 |
+
if not path:
|
| 300 |
+
tree.add_edge(root, NIL)
|
| 301 |
+
continue
|
| 302 |
+
child, *rest = path
|
| 303 |
+
# `child` may exist as the head of more than one path in `paths`.
|
| 304 |
+
children[child].append(rest)
|
| 305 |
+
# Add a node for each child, connect root, recurse to remaining paths
|
| 306 |
+
for child, remaining_paths in children.items():
|
| 307 |
+
# We relabel each child with an unused name.
|
| 308 |
+
new_name = len(tree) - 1
|
| 309 |
+
# The "source" node attribute stores the original node name.
|
| 310 |
+
tree.add_node(new_name, source=child)
|
| 311 |
+
tree.add_edge(root, new_name)
|
| 312 |
+
_helper(remaining_paths, new_name, tree)
|
| 313 |
+
|
| 314 |
+
# Initialize the prefix tree with a root node and a nil node.
|
| 315 |
+
tree = nx.DiGraph()
|
| 316 |
+
root = 0
|
| 317 |
+
tree.add_node(root, source=None)
|
| 318 |
+
NIL = -1
|
| 319 |
+
tree.add_node(NIL, source="NIL")
|
| 320 |
+
# Populate the tree.
|
| 321 |
+
_helper(paths, root, tree)
|
| 322 |
+
return tree
|
| 323 |
+
|
| 324 |
+
|
| 325 |
+
@py_random_state("seed")
|
| 326 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 327 |
+
def random_labeled_tree(n, *, seed=None):
|
| 328 |
+
"""Returns a labeled tree on `n` nodes chosen uniformly at random.
|
| 329 |
+
|
| 330 |
+
Generating uniformly distributed random Prüfer sequences and
|
| 331 |
+
converting them into the corresponding trees is a straightforward
|
| 332 |
+
method of generating uniformly distributed random labeled trees.
|
| 333 |
+
This function implements this method.
|
| 334 |
+
|
| 335 |
+
Parameters
|
| 336 |
+
----------
|
| 337 |
+
n : int
|
| 338 |
+
The number of nodes, greater than zero.
|
| 339 |
+
seed : random_state
|
| 340 |
+
Indicator of random number generation state.
|
| 341 |
+
See :ref:`Randomness<randomness>`
|
| 342 |
+
|
| 343 |
+
Returns
|
| 344 |
+
-------
|
| 345 |
+
:class:`networkx.Graph`
|
| 346 |
+
A `networkx.Graph` with nodes in the set {0, …, *n* - 1}.
|
| 347 |
+
|
| 348 |
+
Raises
|
| 349 |
+
------
|
| 350 |
+
NetworkXPointlessConcept
|
| 351 |
+
If `n` is zero (because the null graph is not a tree).
|
| 352 |
+
|
| 353 |
+
Examples
|
| 354 |
+
--------
|
| 355 |
+
>>> G = nx.random_labeled_tree(5, seed=42)
|
| 356 |
+
>>> nx.is_tree(G)
|
| 357 |
+
True
|
| 358 |
+
>>> G.edges
|
| 359 |
+
EdgeView([(0, 1), (0, 3), (0, 2), (2, 4)])
|
| 360 |
+
|
| 361 |
+
A tree with *arbitrarily directed* edges can be created by assigning
|
| 362 |
+
generated edges to a ``DiGraph``:
|
| 363 |
+
|
| 364 |
+
>>> DG = nx.DiGraph()
|
| 365 |
+
>>> DG.add_edges_from(G.edges)
|
| 366 |
+
>>> nx.is_tree(DG)
|
| 367 |
+
True
|
| 368 |
+
>>> DG.edges
|
| 369 |
+
OutEdgeView([(0, 1), (0, 3), (0, 2), (2, 4)])
|
| 370 |
+
"""
|
| 371 |
+
# Cannot create a Prüfer sequence unless `n` is at least two.
|
| 372 |
+
if n == 0:
|
| 373 |
+
raise nx.NetworkXPointlessConcept("the null graph is not a tree")
|
| 374 |
+
if n == 1:
|
| 375 |
+
return nx.empty_graph(1)
|
| 376 |
+
return nx.from_prufer_sequence([seed.choice(range(n)) for i in range(n - 2)])
|
| 377 |
+
|
| 378 |
+
|
| 379 |
+
@py_random_state("seed")
|
| 380 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 381 |
+
def random_labeled_rooted_tree(n, *, seed=None):
|
| 382 |
+
"""Returns a labeled rooted tree with `n` nodes.
|
| 383 |
+
|
| 384 |
+
The returned tree is chosen uniformly at random from all labeled rooted trees.
|
| 385 |
+
|
| 386 |
+
Parameters
|
| 387 |
+
----------
|
| 388 |
+
n : int
|
| 389 |
+
The number of nodes
|
| 390 |
+
seed : integer, random_state, or None (default)
|
| 391 |
+
Indicator of random number generation state.
|
| 392 |
+
See :ref:`Randomness<randomness>`.
|
| 393 |
+
|
| 394 |
+
Returns
|
| 395 |
+
-------
|
| 396 |
+
:class:`networkx.Graph`
|
| 397 |
+
A `networkx.Graph` with integer nodes 0 <= node <= `n` - 1.
|
| 398 |
+
The root of the tree is selected uniformly from the nodes.
|
| 399 |
+
The "root" graph attribute identifies the root of the tree.
|
| 400 |
+
|
| 401 |
+
Notes
|
| 402 |
+
-----
|
| 403 |
+
This function returns the result of :func:`random_labeled_tree`
|
| 404 |
+
with a randomly selected root.
|
| 405 |
+
|
| 406 |
+
Raises
|
| 407 |
+
------
|
| 408 |
+
NetworkXPointlessConcept
|
| 409 |
+
If `n` is zero (because the null graph is not a tree).
|
| 410 |
+
"""
|
| 411 |
+
t = random_labeled_tree(n, seed=seed)
|
| 412 |
+
t.graph["root"] = seed.randint(0, n - 1)
|
| 413 |
+
return t
|
| 414 |
+
|
| 415 |
+
|
| 416 |
+
@py_random_state("seed")
|
| 417 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 418 |
+
def random_labeled_rooted_forest(n, *, seed=None):
|
| 419 |
+
"""Returns a labeled rooted forest with `n` nodes.
|
| 420 |
+
|
| 421 |
+
The returned forest is chosen uniformly at random using a
|
| 422 |
+
generalization of Prüfer sequences [1]_ in the form described in [2]_.
|
| 423 |
+
|
| 424 |
+
Parameters
|
| 425 |
+
----------
|
| 426 |
+
n : int
|
| 427 |
+
The number of nodes.
|
| 428 |
+
seed : random_state
|
| 429 |
+
See :ref:`Randomness<randomness>`.
|
| 430 |
+
|
| 431 |
+
Returns
|
| 432 |
+
-------
|
| 433 |
+
:class:`networkx.Graph`
|
| 434 |
+
A `networkx.Graph` with integer nodes 0 <= node <= `n` - 1.
|
| 435 |
+
The "roots" graph attribute is a set of integers containing the roots.
|
| 436 |
+
|
| 437 |
+
References
|
| 438 |
+
----------
|
| 439 |
+
.. [1] Knuth, Donald E. "Another Enumeration of Trees."
|
| 440 |
+
Canadian Journal of Mathematics, 20 (1968): 1077-1086.
|
| 441 |
+
https://doi.org/10.4153/CJM-1968-104-8
|
| 442 |
+
.. [2] Rubey, Martin. "Counting Spanning Trees". Diplomarbeit
|
| 443 |
+
zur Erlangung des akademischen Grades Magister der
|
| 444 |
+
Naturwissenschaften an der Formal- und Naturwissenschaftlichen
|
| 445 |
+
Fakultät der Universität Wien. Wien, May 2000.
|
| 446 |
+
"""
|
| 447 |
+
|
| 448 |
+
# Select the number of roots by iterating over the cumulative count of trees
|
| 449 |
+
# with at most k roots
|
| 450 |
+
def _select_k(n, seed):
|
| 451 |
+
r = seed.randint(0, (n + 1) ** (n - 1) - 1)
|
| 452 |
+
cum_sum = 0
|
| 453 |
+
for k in range(1, n):
|
| 454 |
+
cum_sum += (factorial(n - 1) * n ** (n - k)) // (
|
| 455 |
+
factorial(k - 1) * factorial(n - k)
|
| 456 |
+
)
|
| 457 |
+
if r < cum_sum:
|
| 458 |
+
return k
|
| 459 |
+
|
| 460 |
+
return n
|
| 461 |
+
|
| 462 |
+
F = nx.empty_graph(n)
|
| 463 |
+
if n == 0:
|
| 464 |
+
F.graph["roots"] = {}
|
| 465 |
+
return F
|
| 466 |
+
# Select the number of roots k
|
| 467 |
+
k = _select_k(n, seed)
|
| 468 |
+
if k == n:
|
| 469 |
+
F.graph["roots"] = set(range(n))
|
| 470 |
+
return F # Nothing to do
|
| 471 |
+
# Select the roots
|
| 472 |
+
roots = seed.sample(range(n), k)
|
| 473 |
+
# Nonroots
|
| 474 |
+
p = set(range(n)).difference(roots)
|
| 475 |
+
# Coding sequence
|
| 476 |
+
N = [seed.randint(0, n - 1) for i in range(n - k - 1)]
|
| 477 |
+
# Multiset of elements in N also in p
|
| 478 |
+
degree = Counter([x for x in N if x in p])
|
| 479 |
+
# Iterator over the elements of p with degree zero
|
| 480 |
+
iterator = iter(x for x in p if degree[x] == 0)
|
| 481 |
+
u = last = next(iterator)
|
| 482 |
+
# This loop is identical to that for Prüfer sequences,
|
| 483 |
+
# except that we can draw nodes only from p
|
| 484 |
+
for v in N:
|
| 485 |
+
F.add_edge(u, v)
|
| 486 |
+
degree[v] -= 1
|
| 487 |
+
if v < last and degree[v] == 0:
|
| 488 |
+
u = v
|
| 489 |
+
else:
|
| 490 |
+
last = u = next(iterator)
|
| 491 |
+
|
| 492 |
+
F.add_edge(u, roots[0])
|
| 493 |
+
F.graph["roots"] = set(roots)
|
| 494 |
+
return F
|
| 495 |
+
|
| 496 |
+
|
| 497 |
+
# The following functions support generation of unlabeled trees and forests.
|
| 498 |
+
|
| 499 |
+
|
| 500 |
+
def _to_nx(edges, n_nodes, root=None, roots=None):
|
| 501 |
+
"""
|
| 502 |
+
Converts the (edges, n_nodes) input to a :class:`networkx.Graph`.
|
| 503 |
+
The (edges, n_nodes) input is a list of even length, where each pair
|
| 504 |
+
of consecutive integers represents an edge, and an integer `n_nodes`.
|
| 505 |
+
Integers in the list are elements of `range(n_nodes)`.
|
| 506 |
+
|
| 507 |
+
Parameters
|
| 508 |
+
----------
|
| 509 |
+
edges : list of ints
|
| 510 |
+
The flattened list of edges of the graph.
|
| 511 |
+
n_nodes : int
|
| 512 |
+
The number of nodes of the graph.
|
| 513 |
+
root: int (default=None)
|
| 514 |
+
If not None, the "root" attribute of the graph will be set to this value.
|
| 515 |
+
roots: collection of ints (default=None)
|
| 516 |
+
If not None, he "roots" attribute of the graph will be set to this value.
|
| 517 |
+
|
| 518 |
+
Returns
|
| 519 |
+
-------
|
| 520 |
+
:class:`networkx.Graph`
|
| 521 |
+
The graph with `n_nodes` nodes and edges given by `edges`.
|
| 522 |
+
"""
|
| 523 |
+
G = nx.empty_graph(n_nodes)
|
| 524 |
+
G.add_edges_from(edges)
|
| 525 |
+
if root is not None:
|
| 526 |
+
G.graph["root"] = root
|
| 527 |
+
if roots is not None:
|
| 528 |
+
G.graph["roots"] = roots
|
| 529 |
+
return G
|
| 530 |
+
|
| 531 |
+
|
| 532 |
+
def _num_rooted_trees(n, cache_trees):
|
| 533 |
+
"""Returns the number of unlabeled rooted trees with `n` nodes.
|
| 534 |
+
|
| 535 |
+
See also https://oeis.org/A000081.
|
| 536 |
+
|
| 537 |
+
Parameters
|
| 538 |
+
----------
|
| 539 |
+
n : int
|
| 540 |
+
The number of nodes
|
| 541 |
+
cache_trees : list of ints
|
| 542 |
+
The $i$-th element is the number of unlabeled rooted trees with $i$ nodes,
|
| 543 |
+
which is used as a cache (and is extended to length $n+1$ if needed)
|
| 544 |
+
|
| 545 |
+
Returns
|
| 546 |
+
-------
|
| 547 |
+
int
|
| 548 |
+
The number of unlabeled rooted trees with `n` nodes.
|
| 549 |
+
"""
|
| 550 |
+
for n_i in range(len(cache_trees), n + 1):
|
| 551 |
+
cache_trees.append(
|
| 552 |
+
sum(
|
| 553 |
+
[
|
| 554 |
+
d * cache_trees[n_i - j * d] * cache_trees[d]
|
| 555 |
+
for d in range(1, n_i)
|
| 556 |
+
for j in range(1, (n_i - 1) // d + 1)
|
| 557 |
+
]
|
| 558 |
+
)
|
| 559 |
+
// (n_i - 1)
|
| 560 |
+
)
|
| 561 |
+
return cache_trees[n]
|
| 562 |
+
|
| 563 |
+
|
| 564 |
+
def _select_jd_trees(n, cache_trees, seed):
|
| 565 |
+
"""Returns a pair $(j,d)$ with a specific probability
|
| 566 |
+
|
| 567 |
+
Given $n$, returns a pair of positive integers $(j,d)$ with the probability
|
| 568 |
+
specified in formula (5) of Chapter 29 of [1]_.
|
| 569 |
+
|
| 570 |
+
Parameters
|
| 571 |
+
----------
|
| 572 |
+
n : int
|
| 573 |
+
The number of nodes
|
| 574 |
+
cache_trees : list of ints
|
| 575 |
+
Cache for :func:`_num_rooted_trees`.
|
| 576 |
+
seed : random_state
|
| 577 |
+
See :ref:`Randomness<randomness>`.
|
| 578 |
+
|
| 579 |
+
Returns
|
| 580 |
+
-------
|
| 581 |
+
(int, int)
|
| 582 |
+
A pair of positive integers $(j,d)$ satisfying formula (5) of
|
| 583 |
+
Chapter 29 of [1]_.
|
| 584 |
+
|
| 585 |
+
References
|
| 586 |
+
----------
|
| 587 |
+
.. [1] Nijenhuis, Albert, and Wilf, Herbert S.
|
| 588 |
+
"Combinatorial algorithms: for computers and calculators."
|
| 589 |
+
Academic Press, 1978.
|
| 590 |
+
https://doi.org/10.1016/C2013-0-11243-3
|
| 591 |
+
"""
|
| 592 |
+
p = seed.randint(0, _num_rooted_trees(n, cache_trees) * (n - 1) - 1)
|
| 593 |
+
cumsum = 0
|
| 594 |
+
for d in range(n - 1, 0, -1):
|
| 595 |
+
for j in range(1, (n - 1) // d + 1):
|
| 596 |
+
cumsum += (
|
| 597 |
+
d
|
| 598 |
+
* _num_rooted_trees(n - j * d, cache_trees)
|
| 599 |
+
* _num_rooted_trees(d, cache_trees)
|
| 600 |
+
)
|
| 601 |
+
if p < cumsum:
|
| 602 |
+
return (j, d)
|
| 603 |
+
|
| 604 |
+
|
| 605 |
+
def _random_unlabeled_rooted_tree(n, cache_trees, seed):
|
| 606 |
+
"""Returns an unlabeled rooted tree with `n` nodes.
|
| 607 |
+
|
| 608 |
+
Returns an unlabeled rooted tree with `n` nodes chosen uniformly
|
| 609 |
+
at random using the "RANRUT" algorithm from [1]_.
|
| 610 |
+
The tree is returned in the form: (list_of_edges, number_of_nodes)
|
| 611 |
+
|
| 612 |
+
Parameters
|
| 613 |
+
----------
|
| 614 |
+
n : int
|
| 615 |
+
The number of nodes, greater than zero.
|
| 616 |
+
cache_trees : list ints
|
| 617 |
+
Cache for :func:`_num_rooted_trees`.
|
| 618 |
+
seed : random_state
|
| 619 |
+
See :ref:`Randomness<randomness>`.
|
| 620 |
+
|
| 621 |
+
Returns
|
| 622 |
+
-------
|
| 623 |
+
(list_of_edges, number_of_nodes) : list, int
|
| 624 |
+
A random unlabeled rooted tree with `n` nodes as a 2-tuple
|
| 625 |
+
``(list_of_edges, number_of_nodes)``.
|
| 626 |
+
The root is node 0.
|
| 627 |
+
|
| 628 |
+
References
|
| 629 |
+
----------
|
| 630 |
+
.. [1] Nijenhuis, Albert, and Wilf, Herbert S.
|
| 631 |
+
"Combinatorial algorithms: for computers and calculators."
|
| 632 |
+
Academic Press, 1978.
|
| 633 |
+
https://doi.org/10.1016/C2013-0-11243-3
|
| 634 |
+
"""
|
| 635 |
+
if n == 1:
|
| 636 |
+
edges, n_nodes = [], 1
|
| 637 |
+
return edges, n_nodes
|
| 638 |
+
if n == 2:
|
| 639 |
+
edges, n_nodes = [(0, 1)], 2
|
| 640 |
+
return edges, n_nodes
|
| 641 |
+
|
| 642 |
+
j, d = _select_jd_trees(n, cache_trees, seed)
|
| 643 |
+
t1, t1_nodes = _random_unlabeled_rooted_tree(n - j * d, cache_trees, seed)
|
| 644 |
+
t2, t2_nodes = _random_unlabeled_rooted_tree(d, cache_trees, seed)
|
| 645 |
+
t12 = [(0, t2_nodes * i + t1_nodes) for i in range(j)]
|
| 646 |
+
t1.extend(t12)
|
| 647 |
+
for _ in range(j):
|
| 648 |
+
t1.extend((n1 + t1_nodes, n2 + t1_nodes) for n1, n2 in t2)
|
| 649 |
+
t1_nodes += t2_nodes
|
| 650 |
+
|
| 651 |
+
return t1, t1_nodes
|
| 652 |
+
|
| 653 |
+
|
| 654 |
+
@py_random_state("seed")
|
| 655 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 656 |
+
def random_unlabeled_rooted_tree(n, *, number_of_trees=None, seed=None):
|
| 657 |
+
"""Returns a number of unlabeled rooted trees uniformly at random
|
| 658 |
+
|
| 659 |
+
Returns one or more (depending on `number_of_trees`)
|
| 660 |
+
unlabeled rooted trees with `n` nodes drawn uniformly
|
| 661 |
+
at random.
|
| 662 |
+
|
| 663 |
+
Parameters
|
| 664 |
+
----------
|
| 665 |
+
n : int
|
| 666 |
+
The number of nodes
|
| 667 |
+
number_of_trees : int or None (default)
|
| 668 |
+
If not None, this number of trees is generated and returned.
|
| 669 |
+
seed : integer, random_state, or None (default)
|
| 670 |
+
Indicator of random number generation state.
|
| 671 |
+
See :ref:`Randomness<randomness>`.
|
| 672 |
+
|
| 673 |
+
Returns
|
| 674 |
+
-------
|
| 675 |
+
:class:`networkx.Graph` or list of :class:`networkx.Graph`
|
| 676 |
+
A single `networkx.Graph` (or a list thereof, if `number_of_trees`
|
| 677 |
+
is specified) with nodes in the set {0, …, *n* - 1}.
|
| 678 |
+
The "root" graph attribute identifies the root of the tree.
|
| 679 |
+
|
| 680 |
+
Notes
|
| 681 |
+
-----
|
| 682 |
+
The trees are generated using the "RANRUT" algorithm from [1]_.
|
| 683 |
+
The algorithm needs to compute some counting functions
|
| 684 |
+
that are relatively expensive: in case several trees are needed,
|
| 685 |
+
it is advisable to use the `number_of_trees` optional argument
|
| 686 |
+
to reuse the counting functions.
|
| 687 |
+
|
| 688 |
+
Raises
|
| 689 |
+
------
|
| 690 |
+
NetworkXPointlessConcept
|
| 691 |
+
If `n` is zero (because the null graph is not a tree).
|
| 692 |
+
|
| 693 |
+
References
|
| 694 |
+
----------
|
| 695 |
+
.. [1] Nijenhuis, Albert, and Wilf, Herbert S.
|
| 696 |
+
"Combinatorial algorithms: for computers and calculators."
|
| 697 |
+
Academic Press, 1978.
|
| 698 |
+
https://doi.org/10.1016/C2013-0-11243-3
|
| 699 |
+
"""
|
| 700 |
+
if n == 0:
|
| 701 |
+
raise nx.NetworkXPointlessConcept("the null graph is not a tree")
|
| 702 |
+
cache_trees = [0, 1] # initial cache of number of rooted trees
|
| 703 |
+
if number_of_trees is None:
|
| 704 |
+
return _to_nx(*_random_unlabeled_rooted_tree(n, cache_trees, seed), root=0)
|
| 705 |
+
return [
|
| 706 |
+
_to_nx(*_random_unlabeled_rooted_tree(n, cache_trees, seed), root=0)
|
| 707 |
+
for i in range(number_of_trees)
|
| 708 |
+
]
|
| 709 |
+
|
| 710 |
+
|
| 711 |
+
def _num_rooted_forests(n, q, cache_forests):
|
| 712 |
+
"""Returns the number of unlabeled rooted forests with `n` nodes, and with
|
| 713 |
+
no more than `q` nodes per tree. A recursive formula for this is (2) in
|
| 714 |
+
[1]_. This function is implemented using dynamic programming instead of
|
| 715 |
+
recursion.
|
| 716 |
+
|
| 717 |
+
Parameters
|
| 718 |
+
----------
|
| 719 |
+
n : int
|
| 720 |
+
The number of nodes.
|
| 721 |
+
q : int
|
| 722 |
+
The maximum number of nodes for each tree of the forest.
|
| 723 |
+
cache_forests : list of ints
|
| 724 |
+
The $i$-th element is the number of unlabeled rooted forests with
|
| 725 |
+
$i$ nodes, and with no more than `q` nodes per tree; this is used
|
| 726 |
+
as a cache (and is extended to length `n` + 1 if needed).
|
| 727 |
+
|
| 728 |
+
Returns
|
| 729 |
+
-------
|
| 730 |
+
int
|
| 731 |
+
The number of unlabeled rooted forests with `n` nodes with no more than
|
| 732 |
+
`q` nodes per tree.
|
| 733 |
+
|
| 734 |
+
References
|
| 735 |
+
----------
|
| 736 |
+
.. [1] Wilf, Herbert S. "The uniform selection of free trees."
|
| 737 |
+
Journal of Algorithms 2.2 (1981): 204-207.
|
| 738 |
+
https://doi.org/10.1016/0196-6774(81)90021-3
|
| 739 |
+
"""
|
| 740 |
+
for n_i in range(len(cache_forests), n + 1):
|
| 741 |
+
q_i = min(n_i, q)
|
| 742 |
+
cache_forests.append(
|
| 743 |
+
sum(
|
| 744 |
+
[
|
| 745 |
+
d * cache_forests[n_i - j * d] * cache_forests[d - 1]
|
| 746 |
+
for d in range(1, q_i + 1)
|
| 747 |
+
for j in range(1, n_i // d + 1)
|
| 748 |
+
]
|
| 749 |
+
)
|
| 750 |
+
// n_i
|
| 751 |
+
)
|
| 752 |
+
|
| 753 |
+
return cache_forests[n]
|
| 754 |
+
|
| 755 |
+
|
| 756 |
+
def _select_jd_forests(n, q, cache_forests, seed):
|
| 757 |
+
"""Given `n` and `q`, returns a pair of positive integers $(j,d)$
|
| 758 |
+
such that $j\\leq d$, with probability satisfying (F1) of [1]_.
|
| 759 |
+
|
| 760 |
+
Parameters
|
| 761 |
+
----------
|
| 762 |
+
n : int
|
| 763 |
+
The number of nodes.
|
| 764 |
+
q : int
|
| 765 |
+
The maximum number of nodes for each tree of the forest.
|
| 766 |
+
cache_forests : list of ints
|
| 767 |
+
Cache for :func:`_num_rooted_forests`.
|
| 768 |
+
seed : random_state
|
| 769 |
+
See :ref:`Randomness<randomness>`.
|
| 770 |
+
|
| 771 |
+
Returns
|
| 772 |
+
-------
|
| 773 |
+
(int, int)
|
| 774 |
+
A pair of positive integers $(j,d)$
|
| 775 |
+
|
| 776 |
+
References
|
| 777 |
+
----------
|
| 778 |
+
.. [1] Wilf, Herbert S. "The uniform selection of free trees."
|
| 779 |
+
Journal of Algorithms 2.2 (1981): 204-207.
|
| 780 |
+
https://doi.org/10.1016/0196-6774(81)90021-3
|
| 781 |
+
"""
|
| 782 |
+
p = seed.randint(0, _num_rooted_forests(n, q, cache_forests) * n - 1)
|
| 783 |
+
cumsum = 0
|
| 784 |
+
for d in range(q, 0, -1):
|
| 785 |
+
for j in range(1, n // d + 1):
|
| 786 |
+
cumsum += (
|
| 787 |
+
d
|
| 788 |
+
* _num_rooted_forests(n - j * d, q, cache_forests)
|
| 789 |
+
* _num_rooted_forests(d - 1, q, cache_forests)
|
| 790 |
+
)
|
| 791 |
+
if p < cumsum:
|
| 792 |
+
return (j, d)
|
| 793 |
+
|
| 794 |
+
|
| 795 |
+
def _random_unlabeled_rooted_forest(n, q, cache_trees, cache_forests, seed):
|
| 796 |
+
"""Returns an unlabeled rooted forest with `n` nodes, and with no more
|
| 797 |
+
than `q` nodes per tree, drawn uniformly at random. It is an implementation
|
| 798 |
+
of the algorithm "Forest" of [1]_.
|
| 799 |
+
|
| 800 |
+
Parameters
|
| 801 |
+
----------
|
| 802 |
+
n : int
|
| 803 |
+
The number of nodes.
|
| 804 |
+
q : int
|
| 805 |
+
The maximum number of nodes per tree.
|
| 806 |
+
cache_trees :
|
| 807 |
+
Cache for :func:`_num_rooted_trees`.
|
| 808 |
+
cache_forests :
|
| 809 |
+
Cache for :func:`_num_rooted_forests`.
|
| 810 |
+
seed : random_state
|
| 811 |
+
See :ref:`Randomness<randomness>`.
|
| 812 |
+
|
| 813 |
+
Returns
|
| 814 |
+
-------
|
| 815 |
+
(edges, n, r) : (list, int, list)
|
| 816 |
+
The forest (edges, n) and a list r of root nodes.
|
| 817 |
+
|
| 818 |
+
References
|
| 819 |
+
----------
|
| 820 |
+
.. [1] Wilf, Herbert S. "The uniform selection of free trees."
|
| 821 |
+
Journal of Algorithms 2.2 (1981): 204-207.
|
| 822 |
+
https://doi.org/10.1016/0196-6774(81)90021-3
|
| 823 |
+
"""
|
| 824 |
+
if n == 0:
|
| 825 |
+
return ([], 0, [])
|
| 826 |
+
|
| 827 |
+
j, d = _select_jd_forests(n, q, cache_forests, seed)
|
| 828 |
+
t1, t1_nodes, r1 = _random_unlabeled_rooted_forest(
|
| 829 |
+
n - j * d, q, cache_trees, cache_forests, seed
|
| 830 |
+
)
|
| 831 |
+
t2, t2_nodes = _random_unlabeled_rooted_tree(d, cache_trees, seed)
|
| 832 |
+
for _ in range(j):
|
| 833 |
+
r1.append(t1_nodes)
|
| 834 |
+
t1.extend((n1 + t1_nodes, n2 + t1_nodes) for n1, n2 in t2)
|
| 835 |
+
t1_nodes += t2_nodes
|
| 836 |
+
return t1, t1_nodes, r1
|
| 837 |
+
|
| 838 |
+
|
| 839 |
+
@py_random_state("seed")
|
| 840 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 841 |
+
def random_unlabeled_rooted_forest(n, *, q=None, number_of_forests=None, seed=None):
|
| 842 |
+
"""Returns a forest or list of forests selected at random.
|
| 843 |
+
|
| 844 |
+
Returns one or more (depending on `number_of_forests`)
|
| 845 |
+
unlabeled rooted forests with `n` nodes, and with no more than
|
| 846 |
+
`q` nodes per tree, drawn uniformly at random.
|
| 847 |
+
The "roots" graph attribute identifies the roots of the forest.
|
| 848 |
+
|
| 849 |
+
Parameters
|
| 850 |
+
----------
|
| 851 |
+
n : int
|
| 852 |
+
The number of nodes
|
| 853 |
+
q : int or None (default)
|
| 854 |
+
The maximum number of nodes per tree.
|
| 855 |
+
number_of_forests : int or None (default)
|
| 856 |
+
If not None, this number of forests is generated and returned.
|
| 857 |
+
seed : integer, random_state, or None (default)
|
| 858 |
+
Indicator of random number generation state.
|
| 859 |
+
See :ref:`Randomness<randomness>`.
|
| 860 |
+
|
| 861 |
+
Returns
|
| 862 |
+
-------
|
| 863 |
+
:class:`networkx.Graph` or list of :class:`networkx.Graph`
|
| 864 |
+
A single `networkx.Graph` (or a list thereof, if `number_of_forests`
|
| 865 |
+
is specified) with nodes in the set {0, …, *n* - 1}.
|
| 866 |
+
The "roots" graph attribute is a set containing the roots
|
| 867 |
+
of the trees in the forest.
|
| 868 |
+
|
| 869 |
+
Notes
|
| 870 |
+
-----
|
| 871 |
+
This function implements the algorithm "Forest" of [1]_.
|
| 872 |
+
The algorithm needs to compute some counting functions
|
| 873 |
+
that are relatively expensive: in case several trees are needed,
|
| 874 |
+
it is advisable to use the `number_of_forests` optional argument
|
| 875 |
+
to reuse the counting functions.
|
| 876 |
+
|
| 877 |
+
Raises
|
| 878 |
+
------
|
| 879 |
+
ValueError
|
| 880 |
+
If `n` is non-zero but `q` is zero.
|
| 881 |
+
|
| 882 |
+
References
|
| 883 |
+
----------
|
| 884 |
+
.. [1] Wilf, Herbert S. "The uniform selection of free trees."
|
| 885 |
+
Journal of Algorithms 2.2 (1981): 204-207.
|
| 886 |
+
https://doi.org/10.1016/0196-6774(81)90021-3
|
| 887 |
+
"""
|
| 888 |
+
if q is None:
|
| 889 |
+
q = n
|
| 890 |
+
if q == 0 and n != 0:
|
| 891 |
+
raise ValueError("q must be a positive integer if n is positive.")
|
| 892 |
+
|
| 893 |
+
cache_trees = [0, 1] # initial cache of number of rooted trees
|
| 894 |
+
cache_forests = [1] # initial cache of number of rooted forests
|
| 895 |
+
|
| 896 |
+
if number_of_forests is None:
|
| 897 |
+
g, nodes, rs = _random_unlabeled_rooted_forest(
|
| 898 |
+
n, q, cache_trees, cache_forests, seed
|
| 899 |
+
)
|
| 900 |
+
return _to_nx(g, nodes, roots=set(rs))
|
| 901 |
+
|
| 902 |
+
res = []
|
| 903 |
+
for i in range(number_of_forests):
|
| 904 |
+
g, nodes, rs = _random_unlabeled_rooted_forest(
|
| 905 |
+
n, q, cache_trees, cache_forests, seed
|
| 906 |
+
)
|
| 907 |
+
res.append(_to_nx(g, nodes, roots=set(rs)))
|
| 908 |
+
return res
|
| 909 |
+
|
| 910 |
+
|
| 911 |
+
def _num_trees(n, cache_trees):
|
| 912 |
+
"""Returns the number of unlabeled trees with `n` nodes.
|
| 913 |
+
|
| 914 |
+
See also https://oeis.org/A000055.
|
| 915 |
+
|
| 916 |
+
Parameters
|
| 917 |
+
----------
|
| 918 |
+
n : int
|
| 919 |
+
The number of nodes.
|
| 920 |
+
cache_trees : list of ints
|
| 921 |
+
Cache for :func:`_num_rooted_trees`.
|
| 922 |
+
|
| 923 |
+
Returns
|
| 924 |
+
-------
|
| 925 |
+
int
|
| 926 |
+
The number of unlabeled trees with `n` nodes.
|
| 927 |
+
"""
|
| 928 |
+
r = _num_rooted_trees(n, cache_trees) - sum(
|
| 929 |
+
[
|
| 930 |
+
_num_rooted_trees(j, cache_trees) * _num_rooted_trees(n - j, cache_trees)
|
| 931 |
+
for j in range(1, n // 2 + 1)
|
| 932 |
+
]
|
| 933 |
+
)
|
| 934 |
+
if n % 2 == 0:
|
| 935 |
+
r += comb(_num_rooted_trees(n // 2, cache_trees) + 1, 2)
|
| 936 |
+
return r
|
| 937 |
+
|
| 938 |
+
|
| 939 |
+
def _bicenter(n, cache, seed):
|
| 940 |
+
"""Returns a bi-centroidal tree on `n` nodes drawn uniformly at random.
|
| 941 |
+
|
| 942 |
+
This function implements the algorithm Bicenter of [1]_.
|
| 943 |
+
|
| 944 |
+
Parameters
|
| 945 |
+
----------
|
| 946 |
+
n : int
|
| 947 |
+
The number of nodes (must be even).
|
| 948 |
+
cache : list of ints.
|
| 949 |
+
Cache for :func:`_num_rooted_trees`.
|
| 950 |
+
seed : random_state
|
| 951 |
+
See :ref:`Randomness<randomness>`
|
| 952 |
+
|
| 953 |
+
Returns
|
| 954 |
+
-------
|
| 955 |
+
(edges, n)
|
| 956 |
+
The tree as a list of edges and number of nodes.
|
| 957 |
+
|
| 958 |
+
References
|
| 959 |
+
----------
|
| 960 |
+
.. [1] Wilf, Herbert S. "The uniform selection of free trees."
|
| 961 |
+
Journal of Algorithms 2.2 (1981): 204-207.
|
| 962 |
+
https://doi.org/10.1016/0196-6774(81)90021-3
|
| 963 |
+
"""
|
| 964 |
+
t, t_nodes = _random_unlabeled_rooted_tree(n // 2, cache, seed)
|
| 965 |
+
if seed.randint(0, _num_rooted_trees(n // 2, cache)) == 0:
|
| 966 |
+
t2, t2_nodes = t, t_nodes
|
| 967 |
+
else:
|
| 968 |
+
t2, t2_nodes = _random_unlabeled_rooted_tree(n // 2, cache, seed)
|
| 969 |
+
t.extend([(n1 + (n // 2), n2 + (n // 2)) for n1, n2 in t2])
|
| 970 |
+
t.append((0, n // 2))
|
| 971 |
+
return t, t_nodes + t2_nodes
|
| 972 |
+
|
| 973 |
+
|
| 974 |
+
def _random_unlabeled_tree(n, cache_trees, cache_forests, seed):
|
| 975 |
+
"""Returns a tree on `n` nodes drawn uniformly at random.
|
| 976 |
+
It implements the Wilf's algorithm "Free" of [1]_.
|
| 977 |
+
|
| 978 |
+
Parameters
|
| 979 |
+
----------
|
| 980 |
+
n : int
|
| 981 |
+
The number of nodes, greater than zero.
|
| 982 |
+
cache_trees : list of ints
|
| 983 |
+
Cache for :func:`_num_rooted_trees`.
|
| 984 |
+
cache_forests : list of ints
|
| 985 |
+
Cache for :func:`_num_rooted_forests`.
|
| 986 |
+
seed : random_state
|
| 987 |
+
Indicator of random number generation state.
|
| 988 |
+
See :ref:`Randomness<randomness>`
|
| 989 |
+
|
| 990 |
+
Returns
|
| 991 |
+
-------
|
| 992 |
+
(edges, n)
|
| 993 |
+
The tree as a list of edges and number of nodes.
|
| 994 |
+
|
| 995 |
+
References
|
| 996 |
+
----------
|
| 997 |
+
.. [1] Wilf, Herbert S. "The uniform selection of free trees."
|
| 998 |
+
Journal of Algorithms 2.2 (1981): 204-207.
|
| 999 |
+
https://doi.org/10.1016/0196-6774(81)90021-3
|
| 1000 |
+
"""
|
| 1001 |
+
if n % 2 == 1:
|
| 1002 |
+
p = 0
|
| 1003 |
+
else:
|
| 1004 |
+
p = comb(_num_rooted_trees(n // 2, cache_trees) + 1, 2)
|
| 1005 |
+
if seed.randint(0, _num_trees(n, cache_trees) - 1) < p:
|
| 1006 |
+
return _bicenter(n, cache_trees, seed)
|
| 1007 |
+
else:
|
| 1008 |
+
f, n_f, r = _random_unlabeled_rooted_forest(
|
| 1009 |
+
n - 1, (n - 1) // 2, cache_trees, cache_forests, seed
|
| 1010 |
+
)
|
| 1011 |
+
for i in r:
|
| 1012 |
+
f.append((i, n_f))
|
| 1013 |
+
return f, n_f + 1
|
| 1014 |
+
|
| 1015 |
+
|
| 1016 |
+
@py_random_state("seed")
|
| 1017 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 1018 |
+
def random_unlabeled_tree(n, *, number_of_trees=None, seed=None):
|
| 1019 |
+
"""Returns a tree or list of trees chosen randomly.
|
| 1020 |
+
|
| 1021 |
+
Returns one or more (depending on `number_of_trees`)
|
| 1022 |
+
unlabeled trees with `n` nodes drawn uniformly at random.
|
| 1023 |
+
|
| 1024 |
+
Parameters
|
| 1025 |
+
----------
|
| 1026 |
+
n : int
|
| 1027 |
+
The number of nodes
|
| 1028 |
+
number_of_trees : int or None (default)
|
| 1029 |
+
If not None, this number of trees is generated and returned.
|
| 1030 |
+
seed : integer, random_state, or None (default)
|
| 1031 |
+
Indicator of random number generation state.
|
| 1032 |
+
See :ref:`Randomness<randomness>`.
|
| 1033 |
+
|
| 1034 |
+
Returns
|
| 1035 |
+
-------
|
| 1036 |
+
:class:`networkx.Graph` or list of :class:`networkx.Graph`
|
| 1037 |
+
A single `networkx.Graph` (or a list thereof, if
|
| 1038 |
+
`number_of_trees` is specified) with nodes in the set {0, …, *n* - 1}.
|
| 1039 |
+
|
| 1040 |
+
Raises
|
| 1041 |
+
------
|
| 1042 |
+
NetworkXPointlessConcept
|
| 1043 |
+
If `n` is zero (because the null graph is not a tree).
|
| 1044 |
+
|
| 1045 |
+
Notes
|
| 1046 |
+
-----
|
| 1047 |
+
This function generates an unlabeled tree uniformly at random using
|
| 1048 |
+
Wilf's algorithm "Free" of [1]_. The algorithm needs to
|
| 1049 |
+
compute some counting functions that are relatively expensive:
|
| 1050 |
+
in case several trees are needed, it is advisable to use the
|
| 1051 |
+
`number_of_trees` optional argument to reuse the counting
|
| 1052 |
+
functions.
|
| 1053 |
+
|
| 1054 |
+
References
|
| 1055 |
+
----------
|
| 1056 |
+
.. [1] Wilf, Herbert S. "The uniform selection of free trees."
|
| 1057 |
+
Journal of Algorithms 2.2 (1981): 204-207.
|
| 1058 |
+
https://doi.org/10.1016/0196-6774(81)90021-3
|
| 1059 |
+
"""
|
| 1060 |
+
if n == 0:
|
| 1061 |
+
raise nx.NetworkXPointlessConcept("the null graph is not a tree")
|
| 1062 |
+
|
| 1063 |
+
cache_trees = [0, 1] # initial cache of number of rooted trees
|
| 1064 |
+
cache_forests = [1] # initial cache of number of rooted forests
|
| 1065 |
+
if number_of_trees is None:
|
| 1066 |
+
return _to_nx(*_random_unlabeled_tree(n, cache_trees, cache_forests, seed))
|
| 1067 |
+
else:
|
| 1068 |
+
return [
|
| 1069 |
+
_to_nx(*_random_unlabeled_tree(n, cache_trees, cache_forests, seed))
|
| 1070 |
+
for i in range(number_of_trees)
|
| 1071 |
+
]
|
evalkit_tf446/lib/python3.10/site-packages/networkx/generators/triads.py
ADDED
|
@@ -0,0 +1,94 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
# See https://github.com/networkx/networkx/pull/1474
|
| 2 |
+
# Copyright 2011 Reya Group <http://www.reyagroup.com>
|
| 3 |
+
# Copyright 2011 Alex Levenson <alex@isnotinvain.com>
|
| 4 |
+
# Copyright 2011 Diederik van Liere <diederik.vanliere@rotman.utoronto.ca>
|
| 5 |
+
"""Functions that generate the triad graphs, that is, the possible
|
| 6 |
+
digraphs on three nodes.
|
| 7 |
+
|
| 8 |
+
"""
|
| 9 |
+
|
| 10 |
+
import networkx as nx
|
| 11 |
+
from networkx.classes import DiGraph
|
| 12 |
+
|
| 13 |
+
__all__ = ["triad_graph"]
|
| 14 |
+
|
| 15 |
+
#: Dictionary mapping triad name to list of directed edges in the
|
| 16 |
+
#: digraph representation of that triad (with nodes 'a', 'b', and 'c').
|
| 17 |
+
TRIAD_EDGES = {
|
| 18 |
+
"003": [],
|
| 19 |
+
"012": ["ab"],
|
| 20 |
+
"102": ["ab", "ba"],
|
| 21 |
+
"021D": ["ba", "bc"],
|
| 22 |
+
"021U": ["ab", "cb"],
|
| 23 |
+
"021C": ["ab", "bc"],
|
| 24 |
+
"111D": ["ac", "ca", "bc"],
|
| 25 |
+
"111U": ["ac", "ca", "cb"],
|
| 26 |
+
"030T": ["ab", "cb", "ac"],
|
| 27 |
+
"030C": ["ba", "cb", "ac"],
|
| 28 |
+
"201": ["ab", "ba", "ac", "ca"],
|
| 29 |
+
"120D": ["bc", "ba", "ac", "ca"],
|
| 30 |
+
"120U": ["ab", "cb", "ac", "ca"],
|
| 31 |
+
"120C": ["ab", "bc", "ac", "ca"],
|
| 32 |
+
"210": ["ab", "bc", "cb", "ac", "ca"],
|
| 33 |
+
"300": ["ab", "ba", "bc", "cb", "ac", "ca"],
|
| 34 |
+
}
|
| 35 |
+
|
| 36 |
+
|
| 37 |
+
@nx._dispatchable(graphs=None, returns_graph=True)
|
| 38 |
+
def triad_graph(triad_name):
|
| 39 |
+
"""Returns the triad graph with the given name.
|
| 40 |
+
|
| 41 |
+
Each string in the following tuple is a valid triad name::
|
| 42 |
+
|
| 43 |
+
(
|
| 44 |
+
"003",
|
| 45 |
+
"012",
|
| 46 |
+
"102",
|
| 47 |
+
"021D",
|
| 48 |
+
"021U",
|
| 49 |
+
"021C",
|
| 50 |
+
"111D",
|
| 51 |
+
"111U",
|
| 52 |
+
"030T",
|
| 53 |
+
"030C",
|
| 54 |
+
"201",
|
| 55 |
+
"120D",
|
| 56 |
+
"120U",
|
| 57 |
+
"120C",
|
| 58 |
+
"210",
|
| 59 |
+
"300",
|
| 60 |
+
)
|
| 61 |
+
|
| 62 |
+
Each triad name corresponds to one of the possible valid digraph on
|
| 63 |
+
three nodes.
|
| 64 |
+
|
| 65 |
+
Parameters
|
| 66 |
+
----------
|
| 67 |
+
triad_name : string
|
| 68 |
+
The name of a triad, as described above.
|
| 69 |
+
|
| 70 |
+
Returns
|
| 71 |
+
-------
|
| 72 |
+
:class:`~networkx.DiGraph`
|
| 73 |
+
The digraph on three nodes with the given name. The nodes of the
|
| 74 |
+
graph are the single-character strings 'a', 'b', and 'c'.
|
| 75 |
+
|
| 76 |
+
Raises
|
| 77 |
+
------
|
| 78 |
+
ValueError
|
| 79 |
+
If `triad_name` is not the name of a triad.
|
| 80 |
+
|
| 81 |
+
See also
|
| 82 |
+
--------
|
| 83 |
+
triadic_census
|
| 84 |
+
|
| 85 |
+
"""
|
| 86 |
+
if triad_name not in TRIAD_EDGES:
|
| 87 |
+
raise ValueError(
|
| 88 |
+
f'unknown triad name "{triad_name}"; use one of the triad names'
|
| 89 |
+
" in the TRIAD_NAMES constant"
|
| 90 |
+
)
|
| 91 |
+
G = DiGraph()
|
| 92 |
+
G.add_nodes_from("abc")
|
| 93 |
+
G.add_edges_from(TRIAD_EDGES[triad_name])
|
| 94 |
+
return G
|
evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/__init__.cpython-310.pyc
ADDED
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_all_random_functions.cpython-310.pyc
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_convert.cpython-310.pyc
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_convert_numpy.cpython-310.pyc
ADDED
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_convert_pandas.cpython-310.pyc
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_convert_scipy.cpython-310.pyc
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_exceptions.cpython-310.pyc
ADDED
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_import.cpython-310.pyc
ADDED
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_lazy_imports.cpython-310.pyc
ADDED
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/__pycache__/test_relabel.cpython-310.pyc
ADDED
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evalkit_tf446/lib/python3.10/site-packages/networkx/tests/test_convert_numpy.py
ADDED
|
@@ -0,0 +1,532 @@
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|
| 1 |
+
import itertools
|
| 2 |
+
|
| 3 |
+
import pytest
|
| 4 |
+
|
| 5 |
+
np = pytest.importorskip("numpy")
|
| 6 |
+
npt = pytest.importorskip("numpy.testing")
|
| 7 |
+
|
| 8 |
+
import networkx as nx
|
| 9 |
+
from networkx.generators.classic import barbell_graph, cycle_graph, path_graph
|
| 10 |
+
from networkx.utils import graphs_equal
|
| 11 |
+
|
| 12 |
+
|
| 13 |
+
class TestConvertNumpyArray:
|
| 14 |
+
def setup_method(self):
|
| 15 |
+
self.G1 = barbell_graph(10, 3)
|
| 16 |
+
self.G2 = cycle_graph(10, create_using=nx.DiGraph)
|
| 17 |
+
self.G3 = self.create_weighted(nx.Graph())
|
| 18 |
+
self.G4 = self.create_weighted(nx.DiGraph())
|
| 19 |
+
|
| 20 |
+
def create_weighted(self, G):
|
| 21 |
+
g = cycle_graph(4)
|
| 22 |
+
G.add_nodes_from(g)
|
| 23 |
+
G.add_weighted_edges_from((u, v, 10 + u) for u, v in g.edges())
|
| 24 |
+
return G
|
| 25 |
+
|
| 26 |
+
def assert_equal(self, G1, G2):
|
| 27 |
+
assert sorted(G1.nodes()) == sorted(G2.nodes())
|
| 28 |
+
assert sorted(G1.edges()) == sorted(G2.edges())
|
| 29 |
+
|
| 30 |
+
def identity_conversion(self, G, A, create_using):
|
| 31 |
+
assert A.sum() > 0
|
| 32 |
+
GG = nx.from_numpy_array(A, create_using=create_using)
|
| 33 |
+
self.assert_equal(G, GG)
|
| 34 |
+
GW = nx.to_networkx_graph(A, create_using=create_using)
|
| 35 |
+
self.assert_equal(G, GW)
|
| 36 |
+
GI = nx.empty_graph(0, create_using).__class__(A)
|
| 37 |
+
self.assert_equal(G, GI)
|
| 38 |
+
|
| 39 |
+
def test_shape(self):
|
| 40 |
+
"Conversion from non-square array."
|
| 41 |
+
A = np.array([[1, 2, 3], [4, 5, 6]])
|
| 42 |
+
pytest.raises(nx.NetworkXError, nx.from_numpy_array, A)
|
| 43 |
+
|
| 44 |
+
def test_identity_graph_array(self):
|
| 45 |
+
"Conversion from graph to array to graph."
|
| 46 |
+
A = nx.to_numpy_array(self.G1)
|
| 47 |
+
self.identity_conversion(self.G1, A, nx.Graph())
|
| 48 |
+
|
| 49 |
+
def test_identity_digraph_array(self):
|
| 50 |
+
"""Conversion from digraph to array to digraph."""
|
| 51 |
+
A = nx.to_numpy_array(self.G2)
|
| 52 |
+
self.identity_conversion(self.G2, A, nx.DiGraph())
|
| 53 |
+
|
| 54 |
+
def test_identity_weighted_graph_array(self):
|
| 55 |
+
"""Conversion from weighted graph to array to weighted graph."""
|
| 56 |
+
A = nx.to_numpy_array(self.G3)
|
| 57 |
+
self.identity_conversion(self.G3, A, nx.Graph())
|
| 58 |
+
|
| 59 |
+
def test_identity_weighted_digraph_array(self):
|
| 60 |
+
"""Conversion from weighted digraph to array to weighted digraph."""
|
| 61 |
+
A = nx.to_numpy_array(self.G4)
|
| 62 |
+
self.identity_conversion(self.G4, A, nx.DiGraph())
|
| 63 |
+
|
| 64 |
+
def test_nodelist(self):
|
| 65 |
+
"""Conversion from graph to array to graph with nodelist."""
|
| 66 |
+
P4 = path_graph(4)
|
| 67 |
+
P3 = path_graph(3)
|
| 68 |
+
nodelist = list(P3)
|
| 69 |
+
A = nx.to_numpy_array(P4, nodelist=nodelist)
|
| 70 |
+
GA = nx.Graph(A)
|
| 71 |
+
self.assert_equal(GA, P3)
|
| 72 |
+
|
| 73 |
+
# Make nodelist ambiguous by containing duplicates.
|
| 74 |
+
nodelist += [nodelist[0]]
|
| 75 |
+
pytest.raises(nx.NetworkXError, nx.to_numpy_array, P3, nodelist=nodelist)
|
| 76 |
+
|
| 77 |
+
# Make nodelist invalid by including nonexistent nodes
|
| 78 |
+
nodelist = [-1, 0, 1]
|
| 79 |
+
with pytest.raises(
|
| 80 |
+
nx.NetworkXError,
|
| 81 |
+
match=f"Nodes {nodelist - P3.nodes} in nodelist is not in G",
|
| 82 |
+
):
|
| 83 |
+
nx.to_numpy_array(P3, nodelist=nodelist)
|
| 84 |
+
|
| 85 |
+
def test_weight_keyword(self):
|
| 86 |
+
WP4 = nx.Graph()
|
| 87 |
+
WP4.add_edges_from((n, n + 1, {"weight": 0.5, "other": 0.3}) for n in range(3))
|
| 88 |
+
P4 = path_graph(4)
|
| 89 |
+
A = nx.to_numpy_array(P4)
|
| 90 |
+
np.testing.assert_equal(A, nx.to_numpy_array(WP4, weight=None))
|
| 91 |
+
np.testing.assert_equal(0.5 * A, nx.to_numpy_array(WP4))
|
| 92 |
+
np.testing.assert_equal(0.3 * A, nx.to_numpy_array(WP4, weight="other"))
|
| 93 |
+
|
| 94 |
+
def test_from_numpy_array_type(self):
|
| 95 |
+
A = np.array([[1]])
|
| 96 |
+
G = nx.from_numpy_array(A)
|
| 97 |
+
assert type(G[0][0]["weight"]) == int
|
| 98 |
+
|
| 99 |
+
A = np.array([[1]]).astype(float)
|
| 100 |
+
G = nx.from_numpy_array(A)
|
| 101 |
+
assert type(G[0][0]["weight"]) == float
|
| 102 |
+
|
| 103 |
+
A = np.array([[1]]).astype(str)
|
| 104 |
+
G = nx.from_numpy_array(A)
|
| 105 |
+
assert type(G[0][0]["weight"]) == str
|
| 106 |
+
|
| 107 |
+
A = np.array([[1]]).astype(bool)
|
| 108 |
+
G = nx.from_numpy_array(A)
|
| 109 |
+
assert type(G[0][0]["weight"]) == bool
|
| 110 |
+
|
| 111 |
+
A = np.array([[1]]).astype(complex)
|
| 112 |
+
G = nx.from_numpy_array(A)
|
| 113 |
+
assert type(G[0][0]["weight"]) == complex
|
| 114 |
+
|
| 115 |
+
A = np.array([[1]]).astype(object)
|
| 116 |
+
pytest.raises(TypeError, nx.from_numpy_array, A)
|
| 117 |
+
|
| 118 |
+
A = np.array([[[1, 1, 1], [1, 1, 1]], [[1, 1, 1], [1, 1, 1]]])
|
| 119 |
+
with pytest.raises(
|
| 120 |
+
nx.NetworkXError, match=f"Input array must be 2D, not {A.ndim}"
|
| 121 |
+
):
|
| 122 |
+
g = nx.from_numpy_array(A)
|
| 123 |
+
|
| 124 |
+
def test_from_numpy_array_dtype(self):
|
| 125 |
+
dt = [("weight", float), ("cost", int)]
|
| 126 |
+
A = np.array([[(1.0, 2)]], dtype=dt)
|
| 127 |
+
G = nx.from_numpy_array(A)
|
| 128 |
+
assert type(G[0][0]["weight"]) == float
|
| 129 |
+
assert type(G[0][0]["cost"]) == int
|
| 130 |
+
assert G[0][0]["cost"] == 2
|
| 131 |
+
assert G[0][0]["weight"] == 1.0
|
| 132 |
+
|
| 133 |
+
def test_from_numpy_array_parallel_edges(self):
|
| 134 |
+
"""Tests that the :func:`networkx.from_numpy_array` function
|
| 135 |
+
interprets integer weights as the number of parallel edges when
|
| 136 |
+
creating a multigraph.
|
| 137 |
+
|
| 138 |
+
"""
|
| 139 |
+
A = np.array([[1, 1], [1, 2]])
|
| 140 |
+
# First, with a simple graph, each integer entry in the adjacency
|
| 141 |
+
# matrix is interpreted as the weight of a single edge in the graph.
|
| 142 |
+
expected = nx.DiGraph()
|
| 143 |
+
edges = [(0, 0), (0, 1), (1, 0)]
|
| 144 |
+
expected.add_weighted_edges_from([(u, v, 1) for (u, v) in edges])
|
| 145 |
+
expected.add_edge(1, 1, weight=2)
|
| 146 |
+
actual = nx.from_numpy_array(A, parallel_edges=True, create_using=nx.DiGraph)
|
| 147 |
+
assert graphs_equal(actual, expected)
|
| 148 |
+
actual = nx.from_numpy_array(A, parallel_edges=False, create_using=nx.DiGraph)
|
| 149 |
+
assert graphs_equal(actual, expected)
|
| 150 |
+
# Now each integer entry in the adjacency matrix is interpreted as the
|
| 151 |
+
# number of parallel edges in the graph if the appropriate keyword
|
| 152 |
+
# argument is specified.
|
| 153 |
+
edges = [(0, 0), (0, 1), (1, 0), (1, 1), (1, 1)]
|
| 154 |
+
expected = nx.MultiDiGraph()
|
| 155 |
+
expected.add_weighted_edges_from([(u, v, 1) for (u, v) in edges])
|
| 156 |
+
actual = nx.from_numpy_array(
|
| 157 |
+
A, parallel_edges=True, create_using=nx.MultiDiGraph
|
| 158 |
+
)
|
| 159 |
+
assert graphs_equal(actual, expected)
|
| 160 |
+
expected = nx.MultiDiGraph()
|
| 161 |
+
expected.add_edges_from(set(edges), weight=1)
|
| 162 |
+
# The sole self-loop (edge 0) on vertex 1 should have weight 2.
|
| 163 |
+
expected[1][1][0]["weight"] = 2
|
| 164 |
+
actual = nx.from_numpy_array(
|
| 165 |
+
A, parallel_edges=False, create_using=nx.MultiDiGraph
|
| 166 |
+
)
|
| 167 |
+
assert graphs_equal(actual, expected)
|
| 168 |
+
|
| 169 |
+
@pytest.mark.parametrize(
|
| 170 |
+
"dt",
|
| 171 |
+
(
|
| 172 |
+
None, # default
|
| 173 |
+
int, # integer dtype
|
| 174 |
+
np.dtype(
|
| 175 |
+
[("weight", "f8"), ("color", "i1")]
|
| 176 |
+
), # Structured dtype with named fields
|
| 177 |
+
),
|
| 178 |
+
)
|
| 179 |
+
def test_from_numpy_array_no_edge_attr(self, dt):
|
| 180 |
+
A = np.array([[0, 1], [1, 0]], dtype=dt)
|
| 181 |
+
G = nx.from_numpy_array(A, edge_attr=None)
|
| 182 |
+
assert "weight" not in G.edges[0, 1]
|
| 183 |
+
assert len(G.edges[0, 1]) == 0
|
| 184 |
+
|
| 185 |
+
def test_from_numpy_array_multiedge_no_edge_attr(self):
|
| 186 |
+
A = np.array([[0, 2], [2, 0]])
|
| 187 |
+
G = nx.from_numpy_array(A, create_using=nx.MultiDiGraph, edge_attr=None)
|
| 188 |
+
assert all("weight" not in e for _, e in G[0][1].items())
|
| 189 |
+
assert len(G[0][1][0]) == 0
|
| 190 |
+
|
| 191 |
+
def test_from_numpy_array_custom_edge_attr(self):
|
| 192 |
+
A = np.array([[0, 2], [3, 0]])
|
| 193 |
+
G = nx.from_numpy_array(A, edge_attr="cost")
|
| 194 |
+
assert "weight" not in G.edges[0, 1]
|
| 195 |
+
assert G.edges[0, 1]["cost"] == 3
|
| 196 |
+
|
| 197 |
+
def test_symmetric(self):
|
| 198 |
+
"""Tests that a symmetric array has edges added only once to an
|
| 199 |
+
undirected multigraph when using :func:`networkx.from_numpy_array`.
|
| 200 |
+
|
| 201 |
+
"""
|
| 202 |
+
A = np.array([[0, 1], [1, 0]])
|
| 203 |
+
G = nx.from_numpy_array(A, create_using=nx.MultiGraph)
|
| 204 |
+
expected = nx.MultiGraph()
|
| 205 |
+
expected.add_edge(0, 1, weight=1)
|
| 206 |
+
assert graphs_equal(G, expected)
|
| 207 |
+
|
| 208 |
+
def test_dtype_int_graph(self):
|
| 209 |
+
"""Test that setting dtype int actually gives an integer array.
|
| 210 |
+
|
| 211 |
+
For more information, see GitHub pull request #1363.
|
| 212 |
+
|
| 213 |
+
"""
|
| 214 |
+
G = nx.complete_graph(3)
|
| 215 |
+
A = nx.to_numpy_array(G, dtype=int)
|
| 216 |
+
assert A.dtype == int
|
| 217 |
+
|
| 218 |
+
def test_dtype_int_multigraph(self):
|
| 219 |
+
"""Test that setting dtype int actually gives an integer array.
|
| 220 |
+
|
| 221 |
+
For more information, see GitHub pull request #1363.
|
| 222 |
+
|
| 223 |
+
"""
|
| 224 |
+
G = nx.MultiGraph(nx.complete_graph(3))
|
| 225 |
+
A = nx.to_numpy_array(G, dtype=int)
|
| 226 |
+
assert A.dtype == int
|
| 227 |
+
|
| 228 |
+
|
| 229 |
+
@pytest.fixture
|
| 230 |
+
def multigraph_test_graph():
|
| 231 |
+
G = nx.MultiGraph()
|
| 232 |
+
G.add_edge(1, 2, weight=7)
|
| 233 |
+
G.add_edge(1, 2, weight=70)
|
| 234 |
+
return G
|
| 235 |
+
|
| 236 |
+
|
| 237 |
+
@pytest.mark.parametrize(("operator", "expected"), ((sum, 77), (min, 7), (max, 70)))
|
| 238 |
+
def test_numpy_multigraph(multigraph_test_graph, operator, expected):
|
| 239 |
+
A = nx.to_numpy_array(multigraph_test_graph, multigraph_weight=operator)
|
| 240 |
+
assert A[1, 0] == expected
|
| 241 |
+
|
| 242 |
+
|
| 243 |
+
def test_to_numpy_array_multigraph_nodelist(multigraph_test_graph):
|
| 244 |
+
G = multigraph_test_graph
|
| 245 |
+
G.add_edge(0, 1, weight=3)
|
| 246 |
+
A = nx.to_numpy_array(G, nodelist=[1, 2])
|
| 247 |
+
assert A.shape == (2, 2)
|
| 248 |
+
assert A[1, 0] == 77
|
| 249 |
+
|
| 250 |
+
|
| 251 |
+
@pytest.mark.parametrize(
|
| 252 |
+
"G, expected",
|
| 253 |
+
[
|
| 254 |
+
(nx.Graph(), np.array([[0, 1 + 2j], [1 + 2j, 0]], dtype=complex)),
|
| 255 |
+
(nx.DiGraph(), np.array([[0, 1 + 2j], [0, 0]], dtype=complex)),
|
| 256 |
+
],
|
| 257 |
+
)
|
| 258 |
+
def test_to_numpy_array_complex_weights(G, expected):
|
| 259 |
+
G.add_edge(0, 1, weight=1 + 2j)
|
| 260 |
+
A = nx.to_numpy_array(G, dtype=complex)
|
| 261 |
+
npt.assert_array_equal(A, expected)
|
| 262 |
+
|
| 263 |
+
|
| 264 |
+
def test_to_numpy_array_arbitrary_weights():
|
| 265 |
+
G = nx.DiGraph()
|
| 266 |
+
w = 922337203685477580102 # Out of range for int64
|
| 267 |
+
G.add_edge(0, 1, weight=922337203685477580102) # val not representable by int64
|
| 268 |
+
A = nx.to_numpy_array(G, dtype=object)
|
| 269 |
+
expected = np.array([[0, w], [0, 0]], dtype=object)
|
| 270 |
+
npt.assert_array_equal(A, expected)
|
| 271 |
+
|
| 272 |
+
# Undirected
|
| 273 |
+
A = nx.to_numpy_array(G.to_undirected(), dtype=object)
|
| 274 |
+
expected = np.array([[0, w], [w, 0]], dtype=object)
|
| 275 |
+
npt.assert_array_equal(A, expected)
|
| 276 |
+
|
| 277 |
+
|
| 278 |
+
@pytest.mark.parametrize(
|
| 279 |
+
"func, expected",
|
| 280 |
+
((min, -1), (max, 10), (sum, 11), (np.mean, 11 / 3), (np.median, 2)),
|
| 281 |
+
)
|
| 282 |
+
def test_to_numpy_array_multiweight_reduction(func, expected):
|
| 283 |
+
"""Test various functions for reducing multiedge weights."""
|
| 284 |
+
G = nx.MultiDiGraph()
|
| 285 |
+
weights = [-1, 2, 10.0]
|
| 286 |
+
for w in weights:
|
| 287 |
+
G.add_edge(0, 1, weight=w)
|
| 288 |
+
A = nx.to_numpy_array(G, multigraph_weight=func, dtype=float)
|
| 289 |
+
assert np.allclose(A, [[0, expected], [0, 0]])
|
| 290 |
+
|
| 291 |
+
# Undirected case
|
| 292 |
+
A = nx.to_numpy_array(G.to_undirected(), multigraph_weight=func, dtype=float)
|
| 293 |
+
assert np.allclose(A, [[0, expected], [expected, 0]])
|
| 294 |
+
|
| 295 |
+
|
| 296 |
+
@pytest.mark.parametrize(
|
| 297 |
+
("G, expected"),
|
| 298 |
+
[
|
| 299 |
+
(nx.Graph(), [[(0, 0), (10, 5)], [(10, 5), (0, 0)]]),
|
| 300 |
+
(nx.DiGraph(), [[(0, 0), (10, 5)], [(0, 0), (0, 0)]]),
|
| 301 |
+
],
|
| 302 |
+
)
|
| 303 |
+
def test_to_numpy_array_structured_dtype_attrs_from_fields(G, expected):
|
| 304 |
+
"""When `dtype` is structured (i.e. has names) and `weight` is None, use
|
| 305 |
+
the named fields of the dtype to look up edge attributes."""
|
| 306 |
+
G.add_edge(0, 1, weight=10, cost=5.0)
|
| 307 |
+
dtype = np.dtype([("weight", int), ("cost", int)])
|
| 308 |
+
A = nx.to_numpy_array(G, dtype=dtype, weight=None)
|
| 309 |
+
expected = np.asarray(expected, dtype=dtype)
|
| 310 |
+
npt.assert_array_equal(A, expected)
|
| 311 |
+
|
| 312 |
+
|
| 313 |
+
def test_to_numpy_array_structured_dtype_single_attr_default():
|
| 314 |
+
G = nx.path_graph(3)
|
| 315 |
+
dtype = np.dtype([("weight", float)]) # A single named field
|
| 316 |
+
A = nx.to_numpy_array(G, dtype=dtype, weight=None)
|
| 317 |
+
expected = np.array([[0, 1, 0], [1, 0, 1], [0, 1, 0]], dtype=float)
|
| 318 |
+
npt.assert_array_equal(A["weight"], expected)
|
| 319 |
+
|
| 320 |
+
|
| 321 |
+
@pytest.mark.parametrize(
|
| 322 |
+
("field_name", "expected_attr_val"),
|
| 323 |
+
[
|
| 324 |
+
("weight", 1),
|
| 325 |
+
("cost", 3),
|
| 326 |
+
],
|
| 327 |
+
)
|
| 328 |
+
def test_to_numpy_array_structured_dtype_single_attr(field_name, expected_attr_val):
|
| 329 |
+
G = nx.Graph()
|
| 330 |
+
G.add_edge(0, 1, cost=3)
|
| 331 |
+
dtype = np.dtype([(field_name, float)])
|
| 332 |
+
A = nx.to_numpy_array(G, dtype=dtype, weight=None)
|
| 333 |
+
expected = np.array([[0, expected_attr_val], [expected_attr_val, 0]], dtype=float)
|
| 334 |
+
npt.assert_array_equal(A[field_name], expected)
|
| 335 |
+
|
| 336 |
+
|
| 337 |
+
@pytest.mark.parametrize("graph_type", (nx.Graph, nx.DiGraph))
|
| 338 |
+
@pytest.mark.parametrize(
|
| 339 |
+
"edge",
|
| 340 |
+
[
|
| 341 |
+
(0, 1), # No edge attributes
|
| 342 |
+
(0, 1, {"weight": 10}), # One edge attr
|
| 343 |
+
(0, 1, {"weight": 5, "flow": -4}), # Multiple but not all edge attrs
|
| 344 |
+
(0, 1, {"weight": 2.0, "cost": 10, "flow": -45}), # All attrs
|
| 345 |
+
],
|
| 346 |
+
)
|
| 347 |
+
def test_to_numpy_array_structured_dtype_multiple_fields(graph_type, edge):
|
| 348 |
+
G = graph_type([edge])
|
| 349 |
+
dtype = np.dtype([("weight", float), ("cost", float), ("flow", float)])
|
| 350 |
+
A = nx.to_numpy_array(G, dtype=dtype, weight=None)
|
| 351 |
+
for attr in dtype.names:
|
| 352 |
+
expected = nx.to_numpy_array(G, dtype=float, weight=attr)
|
| 353 |
+
npt.assert_array_equal(A[attr], expected)
|
| 354 |
+
|
| 355 |
+
|
| 356 |
+
@pytest.mark.parametrize("G", (nx.Graph(), nx.DiGraph()))
|
| 357 |
+
def test_to_numpy_array_structured_dtype_scalar_nonedge(G):
|
| 358 |
+
G.add_edge(0, 1, weight=10)
|
| 359 |
+
dtype = np.dtype([("weight", float), ("cost", float)])
|
| 360 |
+
A = nx.to_numpy_array(G, dtype=dtype, weight=None, nonedge=np.nan)
|
| 361 |
+
for attr in dtype.names:
|
| 362 |
+
expected = nx.to_numpy_array(G, dtype=float, weight=attr, nonedge=np.nan)
|
| 363 |
+
npt.assert_array_equal(A[attr], expected)
|
| 364 |
+
|
| 365 |
+
|
| 366 |
+
@pytest.mark.parametrize("G", (nx.Graph(), nx.DiGraph()))
|
| 367 |
+
def test_to_numpy_array_structured_dtype_nonedge_ary(G):
|
| 368 |
+
"""Similar to the scalar case, except has a different non-edge value for
|
| 369 |
+
each named field."""
|
| 370 |
+
G.add_edge(0, 1, weight=10)
|
| 371 |
+
dtype = np.dtype([("weight", float), ("cost", float)])
|
| 372 |
+
nonedges = np.array([(0, np.inf)], dtype=dtype)
|
| 373 |
+
A = nx.to_numpy_array(G, dtype=dtype, weight=None, nonedge=nonedges)
|
| 374 |
+
for attr in dtype.names:
|
| 375 |
+
nonedge = nonedges[attr]
|
| 376 |
+
expected = nx.to_numpy_array(G, dtype=float, weight=attr, nonedge=nonedge)
|
| 377 |
+
npt.assert_array_equal(A[attr], expected)
|
| 378 |
+
|
| 379 |
+
|
| 380 |
+
def test_to_numpy_array_structured_dtype_with_weight_raises():
|
| 381 |
+
"""Using both a structured dtype (with named fields) and specifying a `weight`
|
| 382 |
+
parameter is ambiguous."""
|
| 383 |
+
G = nx.path_graph(3)
|
| 384 |
+
dtype = np.dtype([("weight", int), ("cost", int)])
|
| 385 |
+
exception_msg = "Specifying `weight` not supported for structured dtypes"
|
| 386 |
+
with pytest.raises(ValueError, match=exception_msg):
|
| 387 |
+
nx.to_numpy_array(G, dtype=dtype) # Default is weight="weight"
|
| 388 |
+
with pytest.raises(ValueError, match=exception_msg):
|
| 389 |
+
nx.to_numpy_array(G, dtype=dtype, weight="cost")
|
| 390 |
+
|
| 391 |
+
|
| 392 |
+
@pytest.mark.parametrize("graph_type", (nx.MultiGraph, nx.MultiDiGraph))
|
| 393 |
+
def test_to_numpy_array_structured_multigraph_raises(graph_type):
|
| 394 |
+
G = nx.path_graph(3, create_using=graph_type)
|
| 395 |
+
dtype = np.dtype([("weight", int), ("cost", int)])
|
| 396 |
+
with pytest.raises(nx.NetworkXError, match="Structured arrays are not supported"):
|
| 397 |
+
nx.to_numpy_array(G, dtype=dtype, weight=None)
|
| 398 |
+
|
| 399 |
+
|
| 400 |
+
def test_from_numpy_array_nodelist_bad_size():
|
| 401 |
+
"""An exception is raised when `len(nodelist) != A.shape[0]`."""
|
| 402 |
+
n = 5 # Number of nodes
|
| 403 |
+
A = np.diag(np.ones(n - 1), k=1) # Adj. matrix for P_n
|
| 404 |
+
expected = nx.path_graph(n)
|
| 405 |
+
|
| 406 |
+
assert graphs_equal(nx.from_numpy_array(A, edge_attr=None), expected)
|
| 407 |
+
nodes = list(range(n))
|
| 408 |
+
assert graphs_equal(
|
| 409 |
+
nx.from_numpy_array(A, edge_attr=None, nodelist=nodes), expected
|
| 410 |
+
)
|
| 411 |
+
|
| 412 |
+
# Too many node labels
|
| 413 |
+
nodes = list(range(n + 1))
|
| 414 |
+
with pytest.raises(ValueError, match="nodelist must have the same length as A"):
|
| 415 |
+
nx.from_numpy_array(A, nodelist=nodes)
|
| 416 |
+
|
| 417 |
+
# Too few node labels
|
| 418 |
+
nodes = list(range(n - 1))
|
| 419 |
+
with pytest.raises(ValueError, match="nodelist must have the same length as A"):
|
| 420 |
+
nx.from_numpy_array(A, nodelist=nodes)
|
| 421 |
+
|
| 422 |
+
|
| 423 |
+
@pytest.mark.parametrize(
|
| 424 |
+
"nodes",
|
| 425 |
+
(
|
| 426 |
+
[4, 3, 2, 1, 0],
|
| 427 |
+
[9, 7, 1, 2, 8],
|
| 428 |
+
["a", "b", "c", "d", "e"],
|
| 429 |
+
[(0, 0), (1, 1), (2, 3), (0, 2), (3, 1)],
|
| 430 |
+
["A", 2, 7, "spam", (1, 3)],
|
| 431 |
+
),
|
| 432 |
+
)
|
| 433 |
+
def test_from_numpy_array_nodelist(nodes):
|
| 434 |
+
A = np.diag(np.ones(4), k=1)
|
| 435 |
+
# Without edge attributes
|
| 436 |
+
expected = nx.relabel_nodes(
|
| 437 |
+
nx.path_graph(5), mapping=dict(enumerate(nodes)), copy=True
|
| 438 |
+
)
|
| 439 |
+
G = nx.from_numpy_array(A, edge_attr=None, nodelist=nodes)
|
| 440 |
+
assert graphs_equal(G, expected)
|
| 441 |
+
|
| 442 |
+
# With edge attributes
|
| 443 |
+
nx.set_edge_attributes(expected, 1.0, name="weight")
|
| 444 |
+
G = nx.from_numpy_array(A, nodelist=nodes)
|
| 445 |
+
assert graphs_equal(G, expected)
|
| 446 |
+
|
| 447 |
+
|
| 448 |
+
@pytest.mark.parametrize(
|
| 449 |
+
"nodes",
|
| 450 |
+
(
|
| 451 |
+
[4, 3, 2, 1, 0],
|
| 452 |
+
[9, 7, 1, 2, 8],
|
| 453 |
+
["a", "b", "c", "d", "e"],
|
| 454 |
+
[(0, 0), (1, 1), (2, 3), (0, 2), (3, 1)],
|
| 455 |
+
["A", 2, 7, "spam", (1, 3)],
|
| 456 |
+
),
|
| 457 |
+
)
|
| 458 |
+
def test_from_numpy_array_nodelist_directed(nodes):
|
| 459 |
+
A = np.diag(np.ones(4), k=1)
|
| 460 |
+
# Without edge attributes
|
| 461 |
+
H = nx.DiGraph([(0, 1), (1, 2), (2, 3), (3, 4)])
|
| 462 |
+
expected = nx.relabel_nodes(H, mapping=dict(enumerate(nodes)), copy=True)
|
| 463 |
+
G = nx.from_numpy_array(A, create_using=nx.DiGraph, edge_attr=None, nodelist=nodes)
|
| 464 |
+
assert graphs_equal(G, expected)
|
| 465 |
+
|
| 466 |
+
# With edge attributes
|
| 467 |
+
nx.set_edge_attributes(expected, 1.0, name="weight")
|
| 468 |
+
G = nx.from_numpy_array(A, create_using=nx.DiGraph, nodelist=nodes)
|
| 469 |
+
assert graphs_equal(G, expected)
|
| 470 |
+
|
| 471 |
+
|
| 472 |
+
@pytest.mark.parametrize(
|
| 473 |
+
"nodes",
|
| 474 |
+
(
|
| 475 |
+
[4, 3, 2, 1, 0],
|
| 476 |
+
[9, 7, 1, 2, 8],
|
| 477 |
+
["a", "b", "c", "d", "e"],
|
| 478 |
+
[(0, 0), (1, 1), (2, 3), (0, 2), (3, 1)],
|
| 479 |
+
["A", 2, 7, "spam", (1, 3)],
|
| 480 |
+
),
|
| 481 |
+
)
|
| 482 |
+
def test_from_numpy_array_nodelist_multigraph(nodes):
|
| 483 |
+
A = np.array(
|
| 484 |
+
[
|
| 485 |
+
[0, 1, 0, 0, 0],
|
| 486 |
+
[1, 0, 2, 0, 0],
|
| 487 |
+
[0, 2, 0, 3, 0],
|
| 488 |
+
[0, 0, 3, 0, 4],
|
| 489 |
+
[0, 0, 0, 4, 0],
|
| 490 |
+
]
|
| 491 |
+
)
|
| 492 |
+
|
| 493 |
+
H = nx.MultiGraph()
|
| 494 |
+
for i, edge in enumerate(((0, 1), (1, 2), (2, 3), (3, 4))):
|
| 495 |
+
H.add_edges_from(itertools.repeat(edge, i + 1))
|
| 496 |
+
expected = nx.relabel_nodes(H, mapping=dict(enumerate(nodes)), copy=True)
|
| 497 |
+
|
| 498 |
+
G = nx.from_numpy_array(
|
| 499 |
+
A,
|
| 500 |
+
parallel_edges=True,
|
| 501 |
+
create_using=nx.MultiGraph,
|
| 502 |
+
edge_attr=None,
|
| 503 |
+
nodelist=nodes,
|
| 504 |
+
)
|
| 505 |
+
assert graphs_equal(G, expected)
|
| 506 |
+
|
| 507 |
+
|
| 508 |
+
@pytest.mark.parametrize(
|
| 509 |
+
"nodes",
|
| 510 |
+
(
|
| 511 |
+
[4, 3, 2, 1, 0],
|
| 512 |
+
[9, 7, 1, 2, 8],
|
| 513 |
+
["a", "b", "c", "d", "e"],
|
| 514 |
+
[(0, 0), (1, 1), (2, 3), (0, 2), (3, 1)],
|
| 515 |
+
["A", 2, 7, "spam", (1, 3)],
|
| 516 |
+
),
|
| 517 |
+
)
|
| 518 |
+
@pytest.mark.parametrize("graph", (nx.complete_graph, nx.cycle_graph, nx.wheel_graph))
|
| 519 |
+
def test_from_numpy_array_nodelist_rountrip(graph, nodes):
|
| 520 |
+
G = graph(5)
|
| 521 |
+
A = nx.to_numpy_array(G)
|
| 522 |
+
expected = nx.relabel_nodes(G, mapping=dict(enumerate(nodes)), copy=True)
|
| 523 |
+
H = nx.from_numpy_array(A, edge_attr=None, nodelist=nodes)
|
| 524 |
+
assert graphs_equal(H, expected)
|
| 525 |
+
|
| 526 |
+
# With an isolated node
|
| 527 |
+
G = graph(4)
|
| 528 |
+
G.add_node("foo")
|
| 529 |
+
A = nx.to_numpy_array(G)
|
| 530 |
+
expected = nx.relabel_nodes(G, mapping=dict(zip(G.nodes, nodes)), copy=True)
|
| 531 |
+
H = nx.from_numpy_array(A, edge_attr=None, nodelist=nodes)
|
| 532 |
+
assert graphs_equal(H, expected)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/tests/test_convert_pandas.py
ADDED
|
@@ -0,0 +1,349 @@
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|
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|
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|
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|
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|
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|
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|
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|
|
|
|
|
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
import pytest
|
| 2 |
+
|
| 3 |
+
import networkx as nx
|
| 4 |
+
from networkx.utils import edges_equal, graphs_equal, nodes_equal
|
| 5 |
+
|
| 6 |
+
np = pytest.importorskip("numpy")
|
| 7 |
+
pd = pytest.importorskip("pandas")
|
| 8 |
+
|
| 9 |
+
|
| 10 |
+
class TestConvertPandas:
|
| 11 |
+
def setup_method(self):
|
| 12 |
+
self.rng = np.random.RandomState(seed=5)
|
| 13 |
+
ints = self.rng.randint(1, 11, size=(3, 2))
|
| 14 |
+
a = ["A", "B", "C"]
|
| 15 |
+
b = ["D", "A", "E"]
|
| 16 |
+
df = pd.DataFrame(ints, columns=["weight", "cost"])
|
| 17 |
+
df[0] = a # Column label 0 (int)
|
| 18 |
+
df["b"] = b # Column label 'b' (str)
|
| 19 |
+
self.df = df
|
| 20 |
+
|
| 21 |
+
mdf = pd.DataFrame([[4, 16, "A", "D"]], columns=["weight", "cost", 0, "b"])
|
| 22 |
+
self.mdf = pd.concat([df, mdf])
|
| 23 |
+
|
| 24 |
+
def test_exceptions(self):
|
| 25 |
+
G = pd.DataFrame(["a"]) # adj
|
| 26 |
+
pytest.raises(nx.NetworkXError, nx.to_networkx_graph, G)
|
| 27 |
+
G = pd.DataFrame(["a", 0.0]) # elist
|
| 28 |
+
pytest.raises(nx.NetworkXError, nx.to_networkx_graph, G)
|
| 29 |
+
df = pd.DataFrame([[1, 1], [1, 0]], dtype=int, index=[1, 2], columns=["a", "b"])
|
| 30 |
+
pytest.raises(nx.NetworkXError, nx.from_pandas_adjacency, df)
|
| 31 |
+
|
| 32 |
+
def test_from_edgelist_all_attr(self):
|
| 33 |
+
Gtrue = nx.Graph(
|
| 34 |
+
[
|
| 35 |
+
("E", "C", {"cost": 9, "weight": 10}),
|
| 36 |
+
("B", "A", {"cost": 1, "weight": 7}),
|
| 37 |
+
("A", "D", {"cost": 7, "weight": 4}),
|
| 38 |
+
]
|
| 39 |
+
)
|
| 40 |
+
G = nx.from_pandas_edgelist(self.df, 0, "b", True)
|
| 41 |
+
assert graphs_equal(G, Gtrue)
|
| 42 |
+
# MultiGraph
|
| 43 |
+
MGtrue = nx.MultiGraph(Gtrue)
|
| 44 |
+
MGtrue.add_edge("A", "D", cost=16, weight=4)
|
| 45 |
+
MG = nx.from_pandas_edgelist(self.mdf, 0, "b", True, nx.MultiGraph())
|
| 46 |
+
assert graphs_equal(MG, MGtrue)
|
| 47 |
+
|
| 48 |
+
def test_from_edgelist_multi_attr(self):
|
| 49 |
+
Gtrue = nx.Graph(
|
| 50 |
+
[
|
| 51 |
+
("E", "C", {"cost": 9, "weight": 10}),
|
| 52 |
+
("B", "A", {"cost": 1, "weight": 7}),
|
| 53 |
+
("A", "D", {"cost": 7, "weight": 4}),
|
| 54 |
+
]
|
| 55 |
+
)
|
| 56 |
+
G = nx.from_pandas_edgelist(self.df, 0, "b", ["weight", "cost"])
|
| 57 |
+
assert graphs_equal(G, Gtrue)
|
| 58 |
+
|
| 59 |
+
def test_from_edgelist_multi_attr_incl_target(self):
|
| 60 |
+
Gtrue = nx.Graph(
|
| 61 |
+
[
|
| 62 |
+
("E", "C", {0: "C", "b": "E", "weight": 10}),
|
| 63 |
+
("B", "A", {0: "B", "b": "A", "weight": 7}),
|
| 64 |
+
("A", "D", {0: "A", "b": "D", "weight": 4}),
|
| 65 |
+
]
|
| 66 |
+
)
|
| 67 |
+
G = nx.from_pandas_edgelist(self.df, 0, "b", [0, "b", "weight"])
|
| 68 |
+
assert graphs_equal(G, Gtrue)
|
| 69 |
+
|
| 70 |
+
def test_from_edgelist_multidigraph_and_edge_attr(self):
|
| 71 |
+
# example from issue #2374
|
| 72 |
+
edges = [
|
| 73 |
+
("X1", "X4", {"Co": "zA", "Mi": 0, "St": "X1"}),
|
| 74 |
+
("X1", "X4", {"Co": "zB", "Mi": 54, "St": "X2"}),
|
| 75 |
+
("X1", "X4", {"Co": "zB", "Mi": 49, "St": "X3"}),
|
| 76 |
+
("X1", "X4", {"Co": "zB", "Mi": 44, "St": "X4"}),
|
| 77 |
+
("Y1", "Y3", {"Co": "zC", "Mi": 0, "St": "Y1"}),
|
| 78 |
+
("Y1", "Y3", {"Co": "zC", "Mi": 34, "St": "Y2"}),
|
| 79 |
+
("Y1", "Y3", {"Co": "zC", "Mi": 29, "St": "X2"}),
|
| 80 |
+
("Y1", "Y3", {"Co": "zC", "Mi": 24, "St": "Y3"}),
|
| 81 |
+
("Z1", "Z3", {"Co": "zD", "Mi": 0, "St": "Z1"}),
|
| 82 |
+
("Z1", "Z3", {"Co": "zD", "Mi": 14, "St": "X3"}),
|
| 83 |
+
]
|
| 84 |
+
Gtrue = nx.MultiDiGraph(edges)
|
| 85 |
+
data = {
|
| 86 |
+
"O": ["X1", "X1", "X1", "X1", "Y1", "Y1", "Y1", "Y1", "Z1", "Z1"],
|
| 87 |
+
"D": ["X4", "X4", "X4", "X4", "Y3", "Y3", "Y3", "Y3", "Z3", "Z3"],
|
| 88 |
+
"St": ["X1", "X2", "X3", "X4", "Y1", "Y2", "X2", "Y3", "Z1", "X3"],
|
| 89 |
+
"Co": ["zA", "zB", "zB", "zB", "zC", "zC", "zC", "zC", "zD", "zD"],
|
| 90 |
+
"Mi": [0, 54, 49, 44, 0, 34, 29, 24, 0, 14],
|
| 91 |
+
}
|
| 92 |
+
df = pd.DataFrame.from_dict(data)
|
| 93 |
+
G1 = nx.from_pandas_edgelist(
|
| 94 |
+
df, source="O", target="D", edge_attr=True, create_using=nx.MultiDiGraph
|
| 95 |
+
)
|
| 96 |
+
G2 = nx.from_pandas_edgelist(
|
| 97 |
+
df,
|
| 98 |
+
source="O",
|
| 99 |
+
target="D",
|
| 100 |
+
edge_attr=["St", "Co", "Mi"],
|
| 101 |
+
create_using=nx.MultiDiGraph,
|
| 102 |
+
)
|
| 103 |
+
assert graphs_equal(G1, Gtrue)
|
| 104 |
+
assert graphs_equal(G2, Gtrue)
|
| 105 |
+
|
| 106 |
+
def test_from_edgelist_one_attr(self):
|
| 107 |
+
Gtrue = nx.Graph(
|
| 108 |
+
[
|
| 109 |
+
("E", "C", {"weight": 10}),
|
| 110 |
+
("B", "A", {"weight": 7}),
|
| 111 |
+
("A", "D", {"weight": 4}),
|
| 112 |
+
]
|
| 113 |
+
)
|
| 114 |
+
G = nx.from_pandas_edgelist(self.df, 0, "b", "weight")
|
| 115 |
+
assert graphs_equal(G, Gtrue)
|
| 116 |
+
|
| 117 |
+
def test_from_edgelist_int_attr_name(self):
|
| 118 |
+
# note: this also tests that edge_attr can be `source`
|
| 119 |
+
Gtrue = nx.Graph(
|
| 120 |
+
[("E", "C", {0: "C"}), ("B", "A", {0: "B"}), ("A", "D", {0: "A"})]
|
| 121 |
+
)
|
| 122 |
+
G = nx.from_pandas_edgelist(self.df, 0, "b", 0)
|
| 123 |
+
assert graphs_equal(G, Gtrue)
|
| 124 |
+
|
| 125 |
+
def test_from_edgelist_invalid_attr(self):
|
| 126 |
+
pytest.raises(
|
| 127 |
+
nx.NetworkXError, nx.from_pandas_edgelist, self.df, 0, "b", "misspell"
|
| 128 |
+
)
|
| 129 |
+
pytest.raises(nx.NetworkXError, nx.from_pandas_edgelist, self.df, 0, "b", 1)
|
| 130 |
+
# see Issue #3562
|
| 131 |
+
edgeframe = pd.DataFrame([[0, 1], [1, 2], [2, 0]], columns=["s", "t"])
|
| 132 |
+
pytest.raises(
|
| 133 |
+
nx.NetworkXError, nx.from_pandas_edgelist, edgeframe, "s", "t", True
|
| 134 |
+
)
|
| 135 |
+
pytest.raises(
|
| 136 |
+
nx.NetworkXError, nx.from_pandas_edgelist, edgeframe, "s", "t", "weight"
|
| 137 |
+
)
|
| 138 |
+
pytest.raises(
|
| 139 |
+
nx.NetworkXError,
|
| 140 |
+
nx.from_pandas_edgelist,
|
| 141 |
+
edgeframe,
|
| 142 |
+
"s",
|
| 143 |
+
"t",
|
| 144 |
+
["weight", "size"],
|
| 145 |
+
)
|
| 146 |
+
|
| 147 |
+
def test_from_edgelist_no_attr(self):
|
| 148 |
+
Gtrue = nx.Graph([("E", "C", {}), ("B", "A", {}), ("A", "D", {})])
|
| 149 |
+
G = nx.from_pandas_edgelist(self.df, 0, "b")
|
| 150 |
+
assert graphs_equal(G, Gtrue)
|
| 151 |
+
|
| 152 |
+
def test_from_edgelist(self):
|
| 153 |
+
# Pandas DataFrame
|
| 154 |
+
G = nx.cycle_graph(10)
|
| 155 |
+
G.add_weighted_edges_from((u, v, u) for u, v in list(G.edges))
|
| 156 |
+
|
| 157 |
+
edgelist = nx.to_edgelist(G)
|
| 158 |
+
source = [s for s, t, d in edgelist]
|
| 159 |
+
target = [t for s, t, d in edgelist]
|
| 160 |
+
weight = [d["weight"] for s, t, d in edgelist]
|
| 161 |
+
edges = pd.DataFrame({"source": source, "target": target, "weight": weight})
|
| 162 |
+
|
| 163 |
+
GG = nx.from_pandas_edgelist(edges, edge_attr="weight")
|
| 164 |
+
assert nodes_equal(G.nodes(), GG.nodes())
|
| 165 |
+
assert edges_equal(G.edges(), GG.edges())
|
| 166 |
+
GW = nx.to_networkx_graph(edges, create_using=nx.Graph)
|
| 167 |
+
assert nodes_equal(G.nodes(), GW.nodes())
|
| 168 |
+
assert edges_equal(G.edges(), GW.edges())
|
| 169 |
+
|
| 170 |
+
def test_to_edgelist_default_source_or_target_col_exists(self):
|
| 171 |
+
G = nx.path_graph(10)
|
| 172 |
+
G.add_weighted_edges_from((u, v, u) for u, v in list(G.edges))
|
| 173 |
+
nx.set_edge_attributes(G, 0, name="source")
|
| 174 |
+
pytest.raises(nx.NetworkXError, nx.to_pandas_edgelist, G)
|
| 175 |
+
|
| 176 |
+
# drop source column to test an exception raised for the target column
|
| 177 |
+
for u, v, d in G.edges(data=True):
|
| 178 |
+
d.pop("source", None)
|
| 179 |
+
|
| 180 |
+
nx.set_edge_attributes(G, 0, name="target")
|
| 181 |
+
pytest.raises(nx.NetworkXError, nx.to_pandas_edgelist, G)
|
| 182 |
+
|
| 183 |
+
def test_to_edgelist_custom_source_or_target_col_exists(self):
|
| 184 |
+
G = nx.path_graph(10)
|
| 185 |
+
G.add_weighted_edges_from((u, v, u) for u, v in list(G.edges))
|
| 186 |
+
nx.set_edge_attributes(G, 0, name="source_col_name")
|
| 187 |
+
pytest.raises(
|
| 188 |
+
nx.NetworkXError, nx.to_pandas_edgelist, G, source="source_col_name"
|
| 189 |
+
)
|
| 190 |
+
|
| 191 |
+
# drop source column to test an exception raised for the target column
|
| 192 |
+
for u, v, d in G.edges(data=True):
|
| 193 |
+
d.pop("source_col_name", None)
|
| 194 |
+
|
| 195 |
+
nx.set_edge_attributes(G, 0, name="target_col_name")
|
| 196 |
+
pytest.raises(
|
| 197 |
+
nx.NetworkXError, nx.to_pandas_edgelist, G, target="target_col_name"
|
| 198 |
+
)
|
| 199 |
+
|
| 200 |
+
def test_to_edgelist_edge_key_col_exists(self):
|
| 201 |
+
G = nx.path_graph(10, create_using=nx.MultiGraph)
|
| 202 |
+
G.add_weighted_edges_from((u, v, u) for u, v in list(G.edges()))
|
| 203 |
+
nx.set_edge_attributes(G, 0, name="edge_key_name")
|
| 204 |
+
pytest.raises(
|
| 205 |
+
nx.NetworkXError, nx.to_pandas_edgelist, G, edge_key="edge_key_name"
|
| 206 |
+
)
|
| 207 |
+
|
| 208 |
+
def test_from_adjacency(self):
|
| 209 |
+
nodelist = [1, 2]
|
| 210 |
+
dftrue = pd.DataFrame(
|
| 211 |
+
[[1, 1], [1, 0]], dtype=int, index=nodelist, columns=nodelist
|
| 212 |
+
)
|
| 213 |
+
G = nx.Graph([(1, 1), (1, 2)])
|
| 214 |
+
df = nx.to_pandas_adjacency(G, dtype=int)
|
| 215 |
+
pd.testing.assert_frame_equal(df, dftrue)
|
| 216 |
+
|
| 217 |
+
@pytest.mark.parametrize("graph", [nx.Graph, nx.MultiGraph])
|
| 218 |
+
def test_roundtrip(self, graph):
|
| 219 |
+
# edgelist
|
| 220 |
+
Gtrue = graph([(1, 1), (1, 2)])
|
| 221 |
+
df = nx.to_pandas_edgelist(Gtrue)
|
| 222 |
+
G = nx.from_pandas_edgelist(df, create_using=graph)
|
| 223 |
+
assert graphs_equal(Gtrue, G)
|
| 224 |
+
# adjacency
|
| 225 |
+
adj = {1: {1: {"weight": 1}, 2: {"weight": 1}}, 2: {1: {"weight": 1}}}
|
| 226 |
+
Gtrue = graph(adj)
|
| 227 |
+
df = nx.to_pandas_adjacency(Gtrue, dtype=int)
|
| 228 |
+
G = nx.from_pandas_adjacency(df, create_using=graph)
|
| 229 |
+
assert graphs_equal(Gtrue, G)
|
| 230 |
+
|
| 231 |
+
def test_from_adjacency_named(self):
|
| 232 |
+
# example from issue #3105
|
| 233 |
+
data = {
|
| 234 |
+
"A": {"A": 0, "B": 0, "C": 0},
|
| 235 |
+
"B": {"A": 1, "B": 0, "C": 0},
|
| 236 |
+
"C": {"A": 0, "B": 1, "C": 0},
|
| 237 |
+
}
|
| 238 |
+
dftrue = pd.DataFrame(data, dtype=np.intp)
|
| 239 |
+
df = dftrue[["A", "C", "B"]]
|
| 240 |
+
G = nx.from_pandas_adjacency(df, create_using=nx.DiGraph())
|
| 241 |
+
df = nx.to_pandas_adjacency(G, dtype=np.intp)
|
| 242 |
+
pd.testing.assert_frame_equal(df, dftrue)
|
| 243 |
+
|
| 244 |
+
@pytest.mark.parametrize("edge_attr", [["attr2", "attr3"], True])
|
| 245 |
+
def test_edgekey_with_multigraph(self, edge_attr):
|
| 246 |
+
df = pd.DataFrame(
|
| 247 |
+
{
|
| 248 |
+
"source": {"A": "N1", "B": "N2", "C": "N1", "D": "N1"},
|
| 249 |
+
"target": {"A": "N2", "B": "N3", "C": "N1", "D": "N2"},
|
| 250 |
+
"attr1": {"A": "F1", "B": "F2", "C": "F3", "D": "F4"},
|
| 251 |
+
"attr2": {"A": 1, "B": 0, "C": 0, "D": 0},
|
| 252 |
+
"attr3": {"A": 0, "B": 1, "C": 0, "D": 1},
|
| 253 |
+
}
|
| 254 |
+
)
|
| 255 |
+
Gtrue = nx.MultiGraph(
|
| 256 |
+
[
|
| 257 |
+
("N1", "N2", "F1", {"attr2": 1, "attr3": 0}),
|
| 258 |
+
("N2", "N3", "F2", {"attr2": 0, "attr3": 1}),
|
| 259 |
+
("N1", "N1", "F3", {"attr2": 0, "attr3": 0}),
|
| 260 |
+
("N1", "N2", "F4", {"attr2": 0, "attr3": 1}),
|
| 261 |
+
]
|
| 262 |
+
)
|
| 263 |
+
# example from issue #4065
|
| 264 |
+
G = nx.from_pandas_edgelist(
|
| 265 |
+
df,
|
| 266 |
+
source="source",
|
| 267 |
+
target="target",
|
| 268 |
+
edge_attr=edge_attr,
|
| 269 |
+
edge_key="attr1",
|
| 270 |
+
create_using=nx.MultiGraph(),
|
| 271 |
+
)
|
| 272 |
+
assert graphs_equal(G, Gtrue)
|
| 273 |
+
|
| 274 |
+
df_roundtrip = nx.to_pandas_edgelist(G, edge_key="attr1")
|
| 275 |
+
df_roundtrip = df_roundtrip.sort_values("attr1")
|
| 276 |
+
df_roundtrip.index = ["A", "B", "C", "D"]
|
| 277 |
+
pd.testing.assert_frame_equal(
|
| 278 |
+
df, df_roundtrip[["source", "target", "attr1", "attr2", "attr3"]]
|
| 279 |
+
)
|
| 280 |
+
|
| 281 |
+
def test_edgekey_with_normal_graph_no_action(self):
|
| 282 |
+
Gtrue = nx.Graph(
|
| 283 |
+
[
|
| 284 |
+
("E", "C", {"cost": 9, "weight": 10}),
|
| 285 |
+
("B", "A", {"cost": 1, "weight": 7}),
|
| 286 |
+
("A", "D", {"cost": 7, "weight": 4}),
|
| 287 |
+
]
|
| 288 |
+
)
|
| 289 |
+
G = nx.from_pandas_edgelist(self.df, 0, "b", True, edge_key="weight")
|
| 290 |
+
assert graphs_equal(G, Gtrue)
|
| 291 |
+
|
| 292 |
+
def test_nonexisting_edgekey_raises(self):
|
| 293 |
+
with pytest.raises(nx.exception.NetworkXError):
|
| 294 |
+
nx.from_pandas_edgelist(
|
| 295 |
+
self.df,
|
| 296 |
+
source="source",
|
| 297 |
+
target="target",
|
| 298 |
+
edge_key="Not_real",
|
| 299 |
+
edge_attr=True,
|
| 300 |
+
create_using=nx.MultiGraph(),
|
| 301 |
+
)
|
| 302 |
+
|
| 303 |
+
def test_multigraph_with_edgekey_no_edgeattrs(self):
|
| 304 |
+
Gtrue = nx.MultiGraph()
|
| 305 |
+
Gtrue.add_edge(0, 1, key=0)
|
| 306 |
+
Gtrue.add_edge(0, 1, key=3)
|
| 307 |
+
df = nx.to_pandas_edgelist(Gtrue, edge_key="key")
|
| 308 |
+
expected = pd.DataFrame({"source": [0, 0], "target": [1, 1], "key": [0, 3]})
|
| 309 |
+
pd.testing.assert_frame_equal(expected, df)
|
| 310 |
+
G = nx.from_pandas_edgelist(df, edge_key="key", create_using=nx.MultiGraph)
|
| 311 |
+
assert graphs_equal(Gtrue, G)
|
| 312 |
+
|
| 313 |
+
|
| 314 |
+
def test_to_pandas_adjacency_with_nodelist():
|
| 315 |
+
G = nx.complete_graph(5)
|
| 316 |
+
nodelist = [1, 4]
|
| 317 |
+
expected = pd.DataFrame(
|
| 318 |
+
[[0, 1], [1, 0]], dtype=int, index=nodelist, columns=nodelist
|
| 319 |
+
)
|
| 320 |
+
pd.testing.assert_frame_equal(
|
| 321 |
+
expected, nx.to_pandas_adjacency(G, nodelist, dtype=int)
|
| 322 |
+
)
|
| 323 |
+
|
| 324 |
+
|
| 325 |
+
def test_to_pandas_edgelist_with_nodelist():
|
| 326 |
+
G = nx.Graph()
|
| 327 |
+
G.add_edges_from([(0, 1), (1, 2), (1, 3)], weight=2.0)
|
| 328 |
+
G.add_edge(0, 5, weight=100)
|
| 329 |
+
df = nx.to_pandas_edgelist(G, nodelist=[1, 2])
|
| 330 |
+
assert 0 not in df["source"].to_numpy()
|
| 331 |
+
assert 100 not in df["weight"].to_numpy()
|
| 332 |
+
|
| 333 |
+
|
| 334 |
+
def test_from_pandas_adjacency_with_index_collisions():
|
| 335 |
+
"""See gh-7407"""
|
| 336 |
+
df = pd.DataFrame(
|
| 337 |
+
[
|
| 338 |
+
[0, 1, 0, 0],
|
| 339 |
+
[0, 0, 1, 0],
|
| 340 |
+
[0, 0, 0, 1],
|
| 341 |
+
[0, 0, 0, 0],
|
| 342 |
+
],
|
| 343 |
+
index=[1010001, 2, 1, 1010002],
|
| 344 |
+
columns=[1010001, 2, 1, 1010002],
|
| 345 |
+
)
|
| 346 |
+
G = nx.from_pandas_adjacency(df, create_using=nx.DiGraph)
|
| 347 |
+
expected = nx.DiGraph([(1010001, 2), (2, 1), (1, 1010002)])
|
| 348 |
+
assert nodes_equal(G.nodes, expected.nodes)
|
| 349 |
+
assert edges_equal(G.edges, expected.edges)
|
evalkit_tf446/lib/python3.10/site-packages/networkx/tests/test_convert_scipy.py
ADDED
|
@@ -0,0 +1,282 @@
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|
|
| 1 |
+
import pytest
|
| 2 |
+
|
| 3 |
+
np = pytest.importorskip("numpy")
|
| 4 |
+
sp = pytest.importorskip("scipy")
|
| 5 |
+
|
| 6 |
+
import networkx as nx
|
| 7 |
+
from networkx.generators.classic import barbell_graph, cycle_graph, path_graph
|
| 8 |
+
from networkx.utils import graphs_equal
|
| 9 |
+
|
| 10 |
+
|
| 11 |
+
class TestConvertScipy:
|
| 12 |
+
def setup_method(self):
|
| 13 |
+
self.G1 = barbell_graph(10, 3)
|
| 14 |
+
self.G2 = cycle_graph(10, create_using=nx.DiGraph)
|
| 15 |
+
|
| 16 |
+
self.G3 = self.create_weighted(nx.Graph())
|
| 17 |
+
self.G4 = self.create_weighted(nx.DiGraph())
|
| 18 |
+
|
| 19 |
+
def test_exceptions(self):
|
| 20 |
+
class G:
|
| 21 |
+
format = None
|
| 22 |
+
|
| 23 |
+
pytest.raises(nx.NetworkXError, nx.to_networkx_graph, G)
|
| 24 |
+
|
| 25 |
+
def create_weighted(self, G):
|
| 26 |
+
g = cycle_graph(4)
|
| 27 |
+
e = list(g.edges())
|
| 28 |
+
source = [u for u, v in e]
|
| 29 |
+
dest = [v for u, v in e]
|
| 30 |
+
weight = [s + 10 for s in source]
|
| 31 |
+
ex = zip(source, dest, weight)
|
| 32 |
+
G.add_weighted_edges_from(ex)
|
| 33 |
+
return G
|
| 34 |
+
|
| 35 |
+
def identity_conversion(self, G, A, create_using):
|
| 36 |
+
GG = nx.from_scipy_sparse_array(A, create_using=create_using)
|
| 37 |
+
assert nx.is_isomorphic(G, GG)
|
| 38 |
+
|
| 39 |
+
GW = nx.to_networkx_graph(A, create_using=create_using)
|
| 40 |
+
assert nx.is_isomorphic(G, GW)
|
| 41 |
+
|
| 42 |
+
GI = nx.empty_graph(0, create_using).__class__(A)
|
| 43 |
+
assert nx.is_isomorphic(G, GI)
|
| 44 |
+
|
| 45 |
+
ACSR = A.tocsr()
|
| 46 |
+
GI = nx.empty_graph(0, create_using).__class__(ACSR)
|
| 47 |
+
assert nx.is_isomorphic(G, GI)
|
| 48 |
+
|
| 49 |
+
ACOO = A.tocoo()
|
| 50 |
+
GI = nx.empty_graph(0, create_using).__class__(ACOO)
|
| 51 |
+
assert nx.is_isomorphic(G, GI)
|
| 52 |
+
|
| 53 |
+
ACSC = A.tocsc()
|
| 54 |
+
GI = nx.empty_graph(0, create_using).__class__(ACSC)
|
| 55 |
+
assert nx.is_isomorphic(G, GI)
|
| 56 |
+
|
| 57 |
+
AD = A.todense()
|
| 58 |
+
GI = nx.empty_graph(0, create_using).__class__(AD)
|
| 59 |
+
assert nx.is_isomorphic(G, GI)
|
| 60 |
+
|
| 61 |
+
AA = A.toarray()
|
| 62 |
+
GI = nx.empty_graph(0, create_using).__class__(AA)
|
| 63 |
+
assert nx.is_isomorphic(G, GI)
|
| 64 |
+
|
| 65 |
+
def test_shape(self):
|
| 66 |
+
"Conversion from non-square sparse array."
|
| 67 |
+
A = sp.sparse.lil_array([[1, 2, 3], [4, 5, 6]])
|
| 68 |
+
pytest.raises(nx.NetworkXError, nx.from_scipy_sparse_array, A)
|
| 69 |
+
|
| 70 |
+
def test_identity_graph_matrix(self):
|
| 71 |
+
"Conversion from graph to sparse matrix to graph."
|
| 72 |
+
A = nx.to_scipy_sparse_array(self.G1)
|
| 73 |
+
self.identity_conversion(self.G1, A, nx.Graph())
|
| 74 |
+
|
| 75 |
+
def test_identity_digraph_matrix(self):
|
| 76 |
+
"Conversion from digraph to sparse matrix to digraph."
|
| 77 |
+
A = nx.to_scipy_sparse_array(self.G2)
|
| 78 |
+
self.identity_conversion(self.G2, A, nx.DiGraph())
|
| 79 |
+
|
| 80 |
+
def test_identity_weighted_graph_matrix(self):
|
| 81 |
+
"""Conversion from weighted graph to sparse matrix to weighted graph."""
|
| 82 |
+
A = nx.to_scipy_sparse_array(self.G3)
|
| 83 |
+
self.identity_conversion(self.G3, A, nx.Graph())
|
| 84 |
+
|
| 85 |
+
def test_identity_weighted_digraph_matrix(self):
|
| 86 |
+
"""Conversion from weighted digraph to sparse matrix to weighted digraph."""
|
| 87 |
+
A = nx.to_scipy_sparse_array(self.G4)
|
| 88 |
+
self.identity_conversion(self.G4, A, nx.DiGraph())
|
| 89 |
+
|
| 90 |
+
def test_nodelist(self):
|
| 91 |
+
"""Conversion from graph to sparse matrix to graph with nodelist."""
|
| 92 |
+
P4 = path_graph(4)
|
| 93 |
+
P3 = path_graph(3)
|
| 94 |
+
nodelist = list(P3.nodes())
|
| 95 |
+
A = nx.to_scipy_sparse_array(P4, nodelist=nodelist)
|
| 96 |
+
GA = nx.Graph(A)
|
| 97 |
+
assert nx.is_isomorphic(GA, P3)
|
| 98 |
+
|
| 99 |
+
pytest.raises(nx.NetworkXError, nx.to_scipy_sparse_array, P3, nodelist=[])
|
| 100 |
+
# Test nodelist duplicates.
|
| 101 |
+
long_nl = nodelist + [0]
|
| 102 |
+
pytest.raises(nx.NetworkXError, nx.to_scipy_sparse_array, P3, nodelist=long_nl)
|
| 103 |
+
|
| 104 |
+
# Test nodelist contains non-nodes
|
| 105 |
+
non_nl = [-1, 0, 1, 2]
|
| 106 |
+
pytest.raises(nx.NetworkXError, nx.to_scipy_sparse_array, P3, nodelist=non_nl)
|
| 107 |
+
|
| 108 |
+
def test_weight_keyword(self):
|
| 109 |
+
WP4 = nx.Graph()
|
| 110 |
+
WP4.add_edges_from((n, n + 1, {"weight": 0.5, "other": 0.3}) for n in range(3))
|
| 111 |
+
P4 = path_graph(4)
|
| 112 |
+
A = nx.to_scipy_sparse_array(P4)
|
| 113 |
+
np.testing.assert_equal(
|
| 114 |
+
A.todense(), nx.to_scipy_sparse_array(WP4, weight=None).todense()
|
| 115 |
+
)
|
| 116 |
+
np.testing.assert_equal(
|
| 117 |
+
0.5 * A.todense(), nx.to_scipy_sparse_array(WP4).todense()
|
| 118 |
+
)
|
| 119 |
+
np.testing.assert_equal(
|
| 120 |
+
0.3 * A.todense(), nx.to_scipy_sparse_array(WP4, weight="other").todense()
|
| 121 |
+
)
|
| 122 |
+
|
| 123 |
+
def test_format_keyword(self):
|
| 124 |
+
WP4 = nx.Graph()
|
| 125 |
+
WP4.add_edges_from((n, n + 1, {"weight": 0.5, "other": 0.3}) for n in range(3))
|
| 126 |
+
P4 = path_graph(4)
|
| 127 |
+
A = nx.to_scipy_sparse_array(P4, format="csr")
|
| 128 |
+
np.testing.assert_equal(
|
| 129 |
+
A.todense(), nx.to_scipy_sparse_array(WP4, weight=None).todense()
|
| 130 |
+
)
|
| 131 |
+
|
| 132 |
+
A = nx.to_scipy_sparse_array(P4, format="csc")
|
| 133 |
+
np.testing.assert_equal(
|
| 134 |
+
A.todense(), nx.to_scipy_sparse_array(WP4, weight=None).todense()
|
| 135 |
+
)
|
| 136 |
+
|
| 137 |
+
A = nx.to_scipy_sparse_array(P4, format="coo")
|
| 138 |
+
np.testing.assert_equal(
|
| 139 |
+
A.todense(), nx.to_scipy_sparse_array(WP4, weight=None).todense()
|
| 140 |
+
)
|
| 141 |
+
|
| 142 |
+
A = nx.to_scipy_sparse_array(P4, format="bsr")
|
| 143 |
+
np.testing.assert_equal(
|
| 144 |
+
A.todense(), nx.to_scipy_sparse_array(WP4, weight=None).todense()
|
| 145 |
+
)
|
| 146 |
+
|
| 147 |
+
A = nx.to_scipy_sparse_array(P4, format="lil")
|
| 148 |
+
np.testing.assert_equal(
|
| 149 |
+
A.todense(), nx.to_scipy_sparse_array(WP4, weight=None).todense()
|
| 150 |
+
)
|
| 151 |
+
|
| 152 |
+
A = nx.to_scipy_sparse_array(P4, format="dia")
|
| 153 |
+
np.testing.assert_equal(
|
| 154 |
+
A.todense(), nx.to_scipy_sparse_array(WP4, weight=None).todense()
|
| 155 |
+
)
|
| 156 |
+
|
| 157 |
+
A = nx.to_scipy_sparse_array(P4, format="dok")
|
| 158 |
+
np.testing.assert_equal(
|
| 159 |
+
A.todense(), nx.to_scipy_sparse_array(WP4, weight=None).todense()
|
| 160 |
+
)
|
| 161 |
+
|
| 162 |
+
def test_format_keyword_raise(self):
|
| 163 |
+
with pytest.raises(nx.NetworkXError):
|
| 164 |
+
WP4 = nx.Graph()
|
| 165 |
+
WP4.add_edges_from(
|
| 166 |
+
(n, n + 1, {"weight": 0.5, "other": 0.3}) for n in range(3)
|
| 167 |
+
)
|
| 168 |
+
P4 = path_graph(4)
|
| 169 |
+
nx.to_scipy_sparse_array(P4, format="any_other")
|
| 170 |
+
|
| 171 |
+
def test_null_raise(self):
|
| 172 |
+
with pytest.raises(nx.NetworkXError):
|
| 173 |
+
nx.to_scipy_sparse_array(nx.Graph())
|
| 174 |
+
|
| 175 |
+
def test_empty(self):
|
| 176 |
+
G = nx.Graph()
|
| 177 |
+
G.add_node(1)
|
| 178 |
+
M = nx.to_scipy_sparse_array(G)
|
| 179 |
+
np.testing.assert_equal(M.toarray(), np.array([[0]]))
|
| 180 |
+
|
| 181 |
+
def test_ordering(self):
|
| 182 |
+
G = nx.DiGraph()
|
| 183 |
+
G.add_edge(1, 2)
|
| 184 |
+
G.add_edge(2, 3)
|
| 185 |
+
G.add_edge(3, 1)
|
| 186 |
+
M = nx.to_scipy_sparse_array(G, nodelist=[3, 2, 1])
|
| 187 |
+
np.testing.assert_equal(
|
| 188 |
+
M.toarray(), np.array([[0, 0, 1], [1, 0, 0], [0, 1, 0]])
|
| 189 |
+
)
|
| 190 |
+
|
| 191 |
+
def test_selfloop_graph(self):
|
| 192 |
+
G = nx.Graph([(1, 1)])
|
| 193 |
+
M = nx.to_scipy_sparse_array(G)
|
| 194 |
+
np.testing.assert_equal(M.toarray(), np.array([[1]]))
|
| 195 |
+
|
| 196 |
+
G.add_edges_from([(2, 3), (3, 4)])
|
| 197 |
+
M = nx.to_scipy_sparse_array(G, nodelist=[2, 3, 4])
|
| 198 |
+
np.testing.assert_equal(
|
| 199 |
+
M.toarray(), np.array([[0, 1, 0], [1, 0, 1], [0, 1, 0]])
|
| 200 |
+
)
|
| 201 |
+
|
| 202 |
+
def test_selfloop_digraph(self):
|
| 203 |
+
G = nx.DiGraph([(1, 1)])
|
| 204 |
+
M = nx.to_scipy_sparse_array(G)
|
| 205 |
+
np.testing.assert_equal(M.toarray(), np.array([[1]]))
|
| 206 |
+
|
| 207 |
+
G.add_edges_from([(2, 3), (3, 4)])
|
| 208 |
+
M = nx.to_scipy_sparse_array(G, nodelist=[2, 3, 4])
|
| 209 |
+
np.testing.assert_equal(
|
| 210 |
+
M.toarray(), np.array([[0, 1, 0], [0, 0, 1], [0, 0, 0]])
|
| 211 |
+
)
|
| 212 |
+
|
| 213 |
+
def test_from_scipy_sparse_array_parallel_edges(self):
|
| 214 |
+
"""Tests that the :func:`networkx.from_scipy_sparse_array` function
|
| 215 |
+
interprets integer weights as the number of parallel edges when
|
| 216 |
+
creating a multigraph.
|
| 217 |
+
|
| 218 |
+
"""
|
| 219 |
+
A = sp.sparse.csr_array([[1, 1], [1, 2]])
|
| 220 |
+
# First, with a simple graph, each integer entry in the adjacency
|
| 221 |
+
# matrix is interpreted as the weight of a single edge in the graph.
|
| 222 |
+
expected = nx.DiGraph()
|
| 223 |
+
edges = [(0, 0), (0, 1), (1, 0)]
|
| 224 |
+
expected.add_weighted_edges_from([(u, v, 1) for (u, v) in edges])
|
| 225 |
+
expected.add_edge(1, 1, weight=2)
|
| 226 |
+
actual = nx.from_scipy_sparse_array(
|
| 227 |
+
A, parallel_edges=True, create_using=nx.DiGraph
|
| 228 |
+
)
|
| 229 |
+
assert graphs_equal(actual, expected)
|
| 230 |
+
actual = nx.from_scipy_sparse_array(
|
| 231 |
+
A, parallel_edges=False, create_using=nx.DiGraph
|
| 232 |
+
)
|
| 233 |
+
assert graphs_equal(actual, expected)
|
| 234 |
+
# Now each integer entry in the adjacency matrix is interpreted as the
|
| 235 |
+
# number of parallel edges in the graph if the appropriate keyword
|
| 236 |
+
# argument is specified.
|
| 237 |
+
edges = [(0, 0), (0, 1), (1, 0), (1, 1), (1, 1)]
|
| 238 |
+
expected = nx.MultiDiGraph()
|
| 239 |
+
expected.add_weighted_edges_from([(u, v, 1) for (u, v) in edges])
|
| 240 |
+
actual = nx.from_scipy_sparse_array(
|
| 241 |
+
A, parallel_edges=True, create_using=nx.MultiDiGraph
|
| 242 |
+
)
|
| 243 |
+
assert graphs_equal(actual, expected)
|
| 244 |
+
expected = nx.MultiDiGraph()
|
| 245 |
+
expected.add_edges_from(set(edges), weight=1)
|
| 246 |
+
# The sole self-loop (edge 0) on vertex 1 should have weight 2.
|
| 247 |
+
expected[1][1][0]["weight"] = 2
|
| 248 |
+
actual = nx.from_scipy_sparse_array(
|
| 249 |
+
A, parallel_edges=False, create_using=nx.MultiDiGraph
|
| 250 |
+
)
|
| 251 |
+
assert graphs_equal(actual, expected)
|
| 252 |
+
|
| 253 |
+
def test_symmetric(self):
|
| 254 |
+
"""Tests that a symmetric matrix has edges added only once to an
|
| 255 |
+
undirected multigraph when using
|
| 256 |
+
:func:`networkx.from_scipy_sparse_array`.
|
| 257 |
+
|
| 258 |
+
"""
|
| 259 |
+
A = sp.sparse.csr_array([[0, 1], [1, 0]])
|
| 260 |
+
G = nx.from_scipy_sparse_array(A, create_using=nx.MultiGraph)
|
| 261 |
+
expected = nx.MultiGraph()
|
| 262 |
+
expected.add_edge(0, 1, weight=1)
|
| 263 |
+
assert graphs_equal(G, expected)
|
| 264 |
+
|
| 265 |
+
|
| 266 |
+
@pytest.mark.parametrize("sparse_format", ("csr", "csc", "dok"))
|
| 267 |
+
def test_from_scipy_sparse_array_formats(sparse_format):
|
| 268 |
+
"""Test all formats supported by _generate_weighted_edges."""
|
| 269 |
+
# trinode complete graph with non-uniform edge weights
|
| 270 |
+
expected = nx.Graph()
|
| 271 |
+
expected.add_edges_from(
|
| 272 |
+
[
|
| 273 |
+
(0, 1, {"weight": 3}),
|
| 274 |
+
(0, 2, {"weight": 2}),
|
| 275 |
+
(1, 0, {"weight": 3}),
|
| 276 |
+
(1, 2, {"weight": 1}),
|
| 277 |
+
(2, 0, {"weight": 2}),
|
| 278 |
+
(2, 1, {"weight": 1}),
|
| 279 |
+
]
|
| 280 |
+
)
|
| 281 |
+
A = sp.sparse.coo_array([[0, 3, 2], [3, 0, 1], [2, 1, 0]]).asformat(sparse_format)
|
| 282 |
+
assert graphs_equal(expected, nx.from_scipy_sparse_array(A))
|
evalkit_tf446/lib/python3.10/site-packages/networkx/tests/test_import.py
ADDED
|
@@ -0,0 +1,11 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
import pytest
|
| 2 |
+
|
| 3 |
+
|
| 4 |
+
def test_namespace_alias():
|
| 5 |
+
with pytest.raises(ImportError):
|
| 6 |
+
from networkx import nx
|
| 7 |
+
|
| 8 |
+
|
| 9 |
+
def test_namespace_nesting():
|
| 10 |
+
with pytest.raises(ImportError):
|
| 11 |
+
from networkx import networkx
|
evalkit_tf446/lib/python3.10/site-packages/networkx/utils/__init__.py
ADDED
|
@@ -0,0 +1,8 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
from networkx.utils.misc import *
|
| 2 |
+
from networkx.utils.decorators import *
|
| 3 |
+
from networkx.utils.random_sequence import *
|
| 4 |
+
from networkx.utils.union_find import *
|
| 5 |
+
from networkx.utils.rcm import *
|
| 6 |
+
from networkx.utils.heaps import *
|
| 7 |
+
from networkx.utils.configs import *
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| 8 |
+
from networkx.utils.backends import *
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evalkit_tf446/lib/python3.10/site-packages/networkx/utils/__pycache__/__init__.cpython-310.pyc
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