1 files changed, 55 insertions, 0 deletions
diff --git a/python/altgraph/doc/graphutil.rst b/python/altgraph/doc/graphutil.rst
new file mode 100644
index 000000000..c07836df8
--- /dev/null
+++ b/python/altgraph/doc/graphutil.rst
@@ -0,0 +1,55 @@
+:mod:`altgraph.GraphUtil` --- Utility functions
+================================================
+
+.. module:: altgraph.GraphUtil
+   :synopsis: Utility functions
+
+The module :mod:`altgraph.GraphUtil` performs a number of more
+or less useful utility functions.
+
+.. function:: generate_random_graph(node_num, edge_num[, self_loops[, multi_edges])
+
+   Generates and returns a :class:`Graph <altgraph.Graph.Graph>` instance
+   with *node_num* nodes randomly connected by *edge_num* edges.
+
+   When *self_loops* is present and True there can be edges that point from
+   a node to itself.
+
+   When *multi_edge* is present and True there can be duplicate edges.
+
+   This method raises :class:`GraphError <altgraph.GraphError` when
+   a graph with the requested configuration cannot be created.
+
+.. function:: generate_scale_free_graph(steps, growth_num[, self_loops[, multi_edges]])
+
+    Generates and returns a :py:class:`~altgraph.Graph.Graph` instance that 
+    will have *steps*growth_n um* nodes and a scale free (powerlaw) 
+    connectivity. 
+    
+    Starting with a fully connected graph with *growth_num* nodes
+    at every step *growth_num* nodes are added to the graph and are connected 
+    to existing nodes with a probability proportional to the degree of these 
+    existing nodes.
+
+    .. warning:: The current implementation is basically untested, although
+       code inspection seems to indicate an implementation that is consistent
+       with the description at 
+       `Wolfram MathWorld <http://mathworld.wolfram.com/Scale-FreeNetwork.html>`_
+
+.. function:: filter_stack(graph, head, filters)
+
+   Perform a depth-first oder walk of the graph starting at *head* and
+   apply all filter functions in *filters* on the node data of the nodes
+   found.
+
+   Returns (*visited*, *removes*, *orphans*), where
+
+   * *visited*: the set of visited nodes
+
+   * *removes*: the list of nodes where the node data doesn't match
+     all *filters*.
+
+   * *orphans*: list of tuples (*last_good*, *node*), where 
+     node is not in *removes* and one of the nodes that is connected
+     by an incoming edge is in *removes*. *Last_good* is the
+     closest upstream node that is not in *removes*.