From 8f0341155ede981f4125fcf7ce5a9f448a0b64a3 Mon Sep 17 00:00:00 2001 From: Sultan Orazbayev Date: Mon, 26 Jun 2023 14:56:04 +0600 Subject: [PATCH 1/2] Allow isolate creation during export to networkx. Fixes #475. --- graphblas/io/_networkx.py | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/graphblas/io/_networkx.py b/graphblas/io/_networkx.py index 2324a11c2..3c62f27f2 100644 --- a/graphblas/io/_networkx.py +++ b/graphblas/io/_networkx.py @@ -31,7 +31,7 @@ def from_networkx(G, nodelist=None, dtype=None, weight="weight", name=None): # TODO: add parameters to allow different networkx classes and attribute names -def to_networkx(m, edge_attribute="weight"): +def to_networkx(m, edge_attribute="weight", create_isolates=False): """Create a networkx DiGraph from a square adjacency Matrix. Parameters @@ -41,6 +41,11 @@ def to_networkx(m, edge_attribute="weight"): edge_attribute : str, optional Name of edge attribute from values of Matrix. If None, values will be skipped. Default is "weight". + create_isolates : bool, optional + If row $i$ and column $i$ are both empty, then node $i$ is an isolate. By default, + these isolate nodes are ignored. If True, then the graph will also contain the + isolate nodes. Note that for very large adjacency matrices, creating isolates + will increase the memory footprint of the graph. Returns ------- @@ -56,4 +61,6 @@ def to_networkx(m, edge_attribute="weight"): G.add_edges_from(zip(rows, cols)) else: G.add_weighted_edges_from(zip(rows, cols, vals.tolist()), weight=edge_attribute) + if create_isolates: + G.add_nodes_from(range(max(m.shape))) return G From 423f82411f7fc4bd244460d8d4b6f895d9c3472b Mon Sep 17 00:00:00 2001 From: Sultan Orazbayev Date: Mon, 26 Jun 2023 15:20:16 +0600 Subject: [PATCH 2/2] Add test for `create_isolates`. --- graphblas/tests/test_io.py | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/graphblas/tests/test_io.py b/graphblas/tests/test_io.py index 671b12bd6..651fd89f9 100644 --- a/graphblas/tests/test_io.py +++ b/graphblas/tests/test_io.py @@ -161,6 +161,17 @@ def test_matrix_to_from_networkx(): assert M.nvals == 0 assert M.shape == (1, 1) + # test creation of isolates + M = gb.Matrix.from_edgelist([(0,1),(3,0)],nrows=5,ncols=5) + G = gb.io.to_networkx(M, create_isolates=True) + G_nx = nx.DiGraph() + G_nx.add_edges_from([(0,1),(3,0)]) + G_nx.add_nodes_from(range(5)) + assert G.number_of_edges() == G_nx.number_of_edges() == 2 + assert G.number_of_nodes() == G_nx.number_of_nodes() == 5 + from networkx.utils import graphs_equal + assert graphs_equal(G, G_nx) + @pytest.mark.skipif("not ss") @pytest.mark.parametrize("engine", ["auto", "scipy", "fmm"]) pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.

Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy