# version 4.0.1

- Rewritten as.igraph to remove dependency on igraph's ability to read graphml files
- Modified is_directed_ml not to process pairs of layers that have not been initialised (it used to return a warning)

# version 4.0

- the multilayer network data structure has been re-implemented using multilayer cubes
- actors must exist on at least one layer
- removed actor Pucci from florentine data, not being present in any layer
- improved efficiency of functions returning dataframes
- removed functions deprecated since versions 3.0 and 3.1

# version 3.3.2

- new default behavior: loops are allowed
- added generate_communities_ml, to create simple community structures
- added flat_ec_ml, flat_nw_ml and mdlp_ml clustering algorithms
- added nmi_ml and omega_index_ml evaluation functions

# version 3.3.1

- no significant change (code fix for CRAN compatibility)

# version 3.3

- added some argument checks to plot_ml
- added option to print layer names inside each frame in plotting
- updated plot colors (default black for vertices) and added edge transparency
- added support for edge-by-edge style
- now add_vertices and add_edges automatically add actors and layers if they do not exist.  Layers are by default undirected.
- added a more efficient implementation of glouvain, now available as glouvain2.
- added back project_ml, only performing clique (i.e., unweighted) projections.
- fixed bug in write_ml (missing comma before "LOOP" keyword)

# version 3.2

- add_edges_ml now automatically adds the corresponding actors and vertices if they do not exist
- added support for global edge attributes in addition to local (layer-specific) edge attributes
- added support for loops in input files
- updated documentation for IO function: new Input/Output format version 3.0
- & in actor names and attribute values are escaped (&amp;) when saving to igraph objects.
  This prevents issues in the functions using igraph, such as summary()
- added support for igraph logical attributes, now stored as 0s (false) and 1s (true) in multinet
- removed unnecessary warning from add_igraph_layer function
- fixed bug in edges_ml, where for interlayer edges the two layers could get swapped
- fixed bug in get_values_ml, where for vertices the same layer was used even with multiple input layers
- fixed bug in clique_percolation_ml (returned different results for different executions)
- minor updates to the documentation

# version 3.1.0

- removed auto_ptr from the Infomap external library
- add_vertices_ml now automatically adds the corresponding actors if they do not exist
- minor updates to the documentation

# version 3.0.3

- added values2graphics to simplify the plotting of attribute values

# version 3.0.2

- added modularity_ml

# version 3.0.1

- minor code fix, to enable compilation on solaris (changed name to typedef ES)
- actor measures return as many values as the size of the "actors" input parameter
- fixed bug in reading directed edges from file (introduced in v3.0.0)

# version 3.0.0

- changed style, replacing . with _ in function names (except S3 methods)
- old functions deprecated, they will disappear from version 4.0.0
- changed colors in plotting function

# version 2.0.1

- minor fixes to the code

# version 2.0.0

- added infomap.ml algorithm
- significantly rewritten the underlying code
- some functions temporarily removed (pmm.ml, lart.ml, occupation.centrality.ml)
- custom attributes on interlayer edges temporarily disabled

# version 1.1.5

- introduced "vertex" as a synonim of "node", to later replace it
- added legend functionality to plotting function
- updated multiforce layout function (fixed frame borders)
- added summary and as.list functions

