diff env/lib/python3.9/site-packages/networkx/generators/intersection.py @ 0:4f3585e2f14b draft default tip

"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.9/site-packages/networkx/generators/intersection.py	Mon Mar 22 18:12:50 2021 +0000
@@ -0,0 +1,120 @@
+"""
+Generators for random intersection graphs.
+"""
+import networkx as nx
+from networkx.algorithms import bipartite
+from networkx.utils import py_random_state
+
+__all__ = [
+    "uniform_random_intersection_graph",
+    "k_random_intersection_graph",
+    "general_random_intersection_graph",
+]
+
+
+@py_random_state(3)
+def uniform_random_intersection_graph(n, m, p, seed=None):
+    """Returns a uniform random intersection graph.
+
+    Parameters
+    ----------
+    n : int
+        The number of nodes in the first bipartite set (nodes)
+    m : int
+        The number of nodes in the second bipartite set (attributes)
+    p : float
+        Probability of connecting nodes between bipartite sets
+    seed : integer, random_state, or None (default)
+        Indicator of random number generation state.
+        See :ref:`Randomness<randomness>`.
+
+    See Also
+    --------
+    gnp_random_graph
+
+    References
+    ----------
+    .. [1] K.B. Singer-Cohen, Random Intersection Graphs, 1995,
+       PhD thesis, Johns Hopkins University
+    .. [2] Fill, J. A., Scheinerman, E. R., and Singer-Cohen, K. B.,
+       Random intersection graphs when m = !(n):
+       An equivalence theorem relating the evolution of the g(n, m, p)
+       and g(n, p) models. Random Struct. Algorithms 16, 2 (2000), 156–176.
+    """
+    G = bipartite.random_graph(n, m, p, seed)
+    return nx.projected_graph(G, range(n))
+
+
+@py_random_state(3)
+def k_random_intersection_graph(n, m, k, seed=None):
+    """Returns a intersection graph with randomly chosen attribute sets for
+    each node that are of equal size (k).
+
+    Parameters
+    ----------
+    n : int
+        The number of nodes in the first bipartite set (nodes)
+    m : int
+        The number of nodes in the second bipartite set (attributes)
+    k : float
+        Size of attribute set to assign to each node.
+    seed : integer, random_state, or None (default)
+        Indicator of random number generation state.
+        See :ref:`Randomness<randomness>`.
+
+    See Also
+    --------
+    gnp_random_graph, uniform_random_intersection_graph
+
+    References
+    ----------
+    .. [1] Godehardt, E., and Jaworski, J.
+       Two models of random intersection graphs and their applications.
+       Electronic Notes in Discrete Mathematics 10 (2001), 129--132.
+    """
+    G = nx.empty_graph(n + m)
+    mset = range(n, n + m)
+    for v in range(n):
+        targets = seed.sample(mset, k)
+        G.add_edges_from(zip([v] * len(targets), targets))
+    return nx.projected_graph(G, range(n))
+
+
+@py_random_state(3)
+def general_random_intersection_graph(n, m, p, seed=None):
+    """Returns a random intersection graph with independent probabilities
+    for connections between node and attribute sets.
+
+    Parameters
+    ----------
+    n : int
+        The number of nodes in the first bipartite set (nodes)
+    m : int
+        The number of nodes in the second bipartite set (attributes)
+    p : list of floats of length m
+        Probabilities for connecting nodes to each attribute
+    seed : integer, random_state, or None (default)
+        Indicator of random number generation state.
+        See :ref:`Randomness<randomness>`.
+
+    See Also
+    --------
+    gnp_random_graph, uniform_random_intersection_graph
+
+    References
+    ----------
+    .. [1] Nikoletseas, S. E., Raptopoulos, C., and Spirakis, P. G.
+       The existence and efficient construction of large independent sets
+       in general random intersection graphs. In ICALP (2004), J. D´ıaz,
+       J. Karhum¨aki, A. Lepist¨o, and D. Sannella, Eds., vol. 3142
+       of Lecture Notes in Computer Science, Springer, pp. 1029–1040.
+    """
+    if len(p) != m:
+        raise ValueError("Probability list p must have m elements.")
+    G = nx.empty_graph(n + m)
+    mset = range(n, n + m)
+    for u in range(n):
+        for v, q in zip(mset, p):
+            if seed.random() < q:
+                G.add_edge(u, v)
+    return nx.projected_graph(G, range(n))