two version of R2R are here HEAD master

1 files changed, 57 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/networkx/algorithms/hierarchy.py b/.venv/lib/python3.12/site-packages/networkx/algorithms/hierarchy.py
new file mode 100644
index 00000000..d5a05525
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/networkx/algorithms/hierarchy.py
@@ -0,0 +1,57 @@
+"""
+Flow Hierarchy.
+"""
+
+import networkx as nx
+
+__all__ = ["flow_hierarchy"]
+
+
+@nx._dispatchable(edge_attrs="weight")
+def flow_hierarchy(G, weight=None):
+    """Returns the flow hierarchy of a directed network.
+
+    Flow hierarchy is defined as the fraction of edges not participating
+    in cycles in a directed graph [1]_.
+
+    Parameters
+    ----------
+    G : DiGraph or MultiDiGraph
+       A directed graph
+
+    weight : string, optional (default=None)
+       Attribute to use for edge weights. If None the weight defaults to 1.
+
+    Returns
+    -------
+    h : float
+       Flow hierarchy value
+
+    Raises
+    ------
+    NetworkXError
+       If `G` is not a directed graph or if `G` has no edges.
+
+    Notes
+    -----
+    The algorithm described in [1]_ computes the flow hierarchy through
+    exponentiation of the adjacency matrix.  This function implements an
+    alternative approach that finds strongly connected components.
+    An edge is in a cycle if and only if it is in a strongly connected
+    component, which can be found in $O(m)$ time using Tarjan's algorithm.
+
+    References
+    ----------
+    .. [1] Luo, J.; Magee, C.L. (2011),
+       Detecting evolving patterns of self-organizing networks by flow
+       hierarchy measurement, Complexity, Volume 16 Issue 6 53-61.
+       DOI: 10.1002/cplx.20368
+       http://web.mit.edu/~cmagee/www/documents/28-DetectingEvolvingPatterns_FlowHierarchy.pdf
+    """
+    # corner case: G has no edges
+    if nx.is_empty(G):
+        raise nx.NetworkXError("flow_hierarchy not applicable to empty graphs")
+    if not G.is_directed():
+        raise nx.NetworkXError("G must be a digraph in flow_hierarchy")
+    scc = nx.strongly_connected_components(G)
+    return 1 - sum(G.subgraph(c).size(weight) for c in scc) / G.size(weight)