NetworkX 1.10
=============

Release date: 2 August 2015

Support for Python 2.6 is dropped in this release.

Highlights
~~~~~~~~~~

- Connected components now return generators
- new functions including

  + enumerate_all_cliques, greedy_coloring, edge_dfs, find_cycle
    immediate_dominators, harmonic_centrality
  + Hopcraft--Karp algorithm for maximum matchings
  + optimum branchings and arborescences.
  + all_simple_paths

- pyparsing dependence removed from GML reader/parser
- improve flow algorithms
- new generators related to expander graphs.
- new generators for multipartite graphs, nonisomorphic trees,
  circulant graphs
- allow graph subclasses to use dict-like objects in place of dicts
- added ordered graph subclasses
- pandas dataframe read/write added.
- data keyword in G.edges() allows requesting edge attribute directly
- expanded layout flexibility for node subsets
- Kanesky's algorithm for cut sets and k_components
- power function for graphs
- approximation of node connectivity
- transitive closure, triadic census and antichains
- quotient graphs and minors
- longest_path for DAGS
- modularity matrix routines

API changes
-----------
* [`#1501 <https://github.com/networkx/networkx/pull/1501>`_]
  ``connected_components``, ``weakly_connected_components``, and
  ``strongly_connected_components`` return now a generator of sets of
  nodes. Previously the generator was of lists of nodes. This PR also
  refactored the ``connected_components`` and ``weakly_connected_components``
  implementations making them faster, especially for large graphs.

* [`#1547 <https://github.com/networkx/networkx/pull/1547>`_]
  The ``func_iter`` functions in Di/Multi/Graphs classes are slated for
  removal in NetworkX 2.0 release. ``func`` will behave like ``func_iter``
  and return an iterator instead of list. These functions are deprecated in
  NetworkX 1.10 release.

New functionalities
-------------------

* [`#823 <https://github.com/networkx/networkx/pull/823>`_]
  A ``enumerate_all_cliques`` function is added in the clique package
  (``networkx.algorithms.clique``) for enumerating all cliques (including
  nonmaximal ones) of undirected graphs.

* [`#1105 <https://github.com/networkx/networkx/pull/1105>`_]
  A coloring package (``networkx.algorithms.coloring``) is created for
  graph coloring algorithms. Initially, a ``greedy_color`` function is
  provided for coloring graphs using various greedy heuristics.

* [`#1193 <https://github.com/networkx/networkx/pull/1193>`_]
  A new generator ``edge_dfs``, added to ``networkx.algorithms.traversal``,
  implements a depth-first traversal of the edges in a graph. This complements
  functionality provided by a depth-first traversal of the nodes in a graph.
  For multigraphs, it allows the user to know precisely which edges were
  followed in a traversal. All NetworkX graph types are supported. A traversal
  can also reverse edge orientations or ignore them.

* [`#1194 <https://github.com/networkx/networkx/pull/1194>`_]
  A ``find_cycle`` function is added to the ``networkx.algorithms.cycles``
  package to find a cycle in a graph. Edge orientations can be optionally
  reversed or ignored.

* [`#1210 <https://github.com/networkx/networkx/pull/1210>`_]
  Add a random generator for the duplication-divergence model.

* [`#1241 <https://github.com/networkx/networkx/pull/1241>`_]
  A new ``networkx.algorithms.dominance`` package is added for
  dominance/dominator algorithms on directed graphs. It contains a
  ``immediate_dominators`` function for computing immediate
  dominators/dominator trees and a ``dominance_frontiers`` function for
  computing dominance frontiers.

* [`#1269 <https://github.com/networkx/networkx/pull/1269>`_]
  The GML reader/parser and writer/generator are rewritten to remove the
  dependence on pyparsing and enable handling of arbitrary graph data.

* [`#1280 <https://github.com/networkx/networkx/pull/1280>`_]
  The network simplex method in the ``networkx.algorithms.flow`` package is
  rewritten to improve its performance and support multi- and disconnected
  networks. For some cases, the new implementation is two or three orders of
  magnitude faster than the old implementation.

* [`#1286 <https://github.com/networkx/networkx/pull/1286>`_]
  Added the Margulis--Gabber--Galil graph to ``networkx.generators``.

* [`#1306 <https://github.com/networkx/networkx/pull/1306>`_]
  Added the chordal p-cycle graph, a mildly explicit algebraic construction
  of a family of 3-regular expander graphs. Also, moves both the existing
  expander graph generator function (for the Margulis-Gabber-Galil
  expander) and the new chordal cycle graph function to a new module,
  ``networkx.generators.expanders``.

* [`#1314 <https://github.com/networkx/networkx/pull/1314>`_]
  Allow overwriting of base class dict with dict-like:
  OrderedGraph, ThinGraph, PrintGraph, etc.

* [`#1321 <https://github.com/networkx/networkx/pull/1321>`_]
  Added ``to_pandas_dataframe`` and ``from_pandas_dataframe``.

* [`#1322 <https://github.com/networkx/networkx/pull/1322>`_]
  Added the Hopcroft--Karp algorithm for finding a maximum cardinality
  matching in bipartite graphs.

* [`#1336 <https://github.com/networkx/networkx/pull/1336>`_]
  Expanded data keyword in G.edges and added default keyword.

* [`#1338 <https://github.com/networkx/networkx/pull/1338>`_]
  Added support for finding optimum branchings and arborescences.

* [`#1340 <https://github.com/networkx/networkx/pull/1340>`_]
  Added a ``from_pandas_dataframe`` function that accepts Pandas DataFrames
  and returns a new graph object. At a minimum, the DataFrame must have two
  columns, which define the nodes that make up an edge. However, the function
  can also process an arbitrary number of additional columns as edge
  attributes, such as 'weight'.

* [`#1354 <https://github.com/networkx/networkx/pull/1354>`_]
  Expanded layout functions to add flexibility for drawing subsets of nodes
  with distinct layouts and for centering each layout around given
  coordinates.

* [`#1356 <https://github.com/networkx/networkx/pull/1356>`_]
  Added ordered variants of default graph class.

* [`#1360 <https://github.com/networkx/networkx/pull/1360>`_]
  Added harmonic centrality to ``network.algorithms.centrality``.

* [`#1390 <https://github.com/networkx/networkx/pull/1390>`_]
  The ``generators.bipartite`` have been moved to
  ``algorithms.bipartite.generators``. The functions are not imported in the
  main  namespace, so to use it, the bipartite package has to be imported.

* [`#1391 <https://github.com/networkx/networkx/pull/1391>`_]
  Added Kanevsky's algorithm for finding all minimum-size separating
  node sets in an undirected graph. It is implemented as a generator
  of node cut sets.

* [`#1399 <https://github.com/networkx/networkx/pull/1399>`_]
  Added power function for simple graphs

* [`#1405 <https://github.com/networkx/networkx/pull/1405>`_]
  Added fast approximation for node connectivity based on White and
  Newman's approximation algorithm for finding node independent paths
  between two nodes.

* [`#1413 <https://github.com/networkx/networkx/pull/1413>`_]
  Added transitive closure and antichains function for directed acyclic
  graphs in ``algorithms.dag``. The antichains function was contributed
  by Peter Jipsen and Franco Saliola and originally developed for the
  SAGE project.

* [`#1425 <https://github.com/networkx/networkx/pull/1425>`_]
  Added generator function for the complete multipartite graph.

* [`#1427 <https://github.com/networkx/networkx/pull/1427>`_]
  Added nonisomorphic trees generator.

* [`#1436 <https://github.com/networkx/networkx/pull/1436>`_]
  Added a generator function for circulant graphs to the
  ``networkx.generators.classic`` module.

* [`#1437 <https://github.com/networkx/networkx/pull/1437>`_]
  Added function for computing quotient graphs; also created a new module,
  ``networkx.algorithms.minors``.

* [`#1438 <https://github.com/networkx/networkx/pull/1438>`_]
  Added longest_path and longest_path_length for DAG.

* [`#1439 <https://github.com/networkx/networkx/pull/1439>`_]
  Added node and edge contraction functions to
  ``networkx.algorithms.minors``.

* [`#1445 <https://github.com/networkx/networkx/pull/1448>`_]
  Added a new modularity matrix module to ``networkx.linalg``,
  and associated spectrum functions to the ``networkx.linalg.spectrum``
  module.

* [`#1447 <https://github.com/networkx/networkx/pull/1447>`_]
  Added function to generate all simple paths starting with the shortest
  ones based on Yen's algorithm for finding k shortest paths at
  ``algorithms.simple_paths``.

* [`#1455 <https://github.com/networkx/networkx/pull/1455>`_]
  Added the directed modularity matrix to the
  ``networkx.linalg.modularity_matrix`` module.

* [`#1474 <https://github.com/networkx/networkx/pull/1474>`_]
  Adds ``triadic_census`` function; also creates a new module,
  ``networkx.algorithms.triads``.

* [`#1476 <https://github.com/networkx/networkx/pull/1476>`_]
  Adds functions for testing if a graph has weighted or negatively weighted
  edges. Also adds a function for testing if a graph is empty. These are
  ``is_weighted``, ``is_negatively_weighted``, and ``is_empty``.

* [`#1481 <https://github.com/networkx/networkx/pull/1481>`_]
  Added Johnson's algorithm; one more algorithm for shortest paths. It
  solves all pairs shortest path problem. This is ``johnson`` at
  ``algorithms.shortest_paths``

* [`#1414 <https://github.com/networkx/networkx/pull/1414>`_]
  Added Moody and White algorithm for identifying ``k_components`` in a
  graph, which is based on Kanevsky's algorithm for finding all minimum-size
  node cut-sets (implemented in ``all_node_cuts`` #1391).

* [`#1415 <https://github.com/networkx/networkx/pull/1415>`_]
  Added fast approximation for ``k_components`` to the
  ``networkx.approximation`` package. This is based on White and Newman
  approximation algorithm for finding node independent paths between two
  nodes (see #1405).

Removed functionalities
-----------------------

* [`#1236 <https://github.com/networkx/networkx/pull/1236>`_]
  The legacy ``ford_fulkerson`` maximum flow function is removed. Use
  ``edmonds_karp`` instead.

Miscellaneous changes
---------------------

* [`#1192 <https://github.com/networkx/networkx/pull/1192>`_]
  Support for Python 2.6 is dropped.
