README.md

MetaGraphs

Project Status: As of 8 October 2021 MetaGraphs is no longer under active development. It will remain available on Github at sbromberger/MetaGraphs.jl. The JuliaGraphs organization will continue to maintain packages that use MetaGraphs and transition development over the long term.

LightGraphs.jl graphs with arbitrary metadata.

Documentation

Full documentation is available at GitHub Pages. Documentation for methods is also available via the Julia REPL help system.

Installation

Installation is straightforward: from the Julia pkg prompt,

add MetaGraphs

Example Usage

julia> using LightGraphs, MetaGraphs

# create a standard simplegraph
julia> g = path_graph(5)
{5, 4} undirected simple Int64 graph

# create a metagraph based on the simplegraph, with optional default edgeweight
julia> mg = MetaGraph(g, 3.0)
{5, 4} undirected Int64 metagraph with Float64 weights defined by :weight (default weight 3.0)

# create a directed metagraph based on the simplegraph, with optional default edgeweight
julia> mdg = MetaDiGraph(g, 3.0)
{5, 8} directed Int64 metagraph with Float64 weights defined by :weight (default weight 3.0)

# set some properties for the graph itself
julia> set_prop!(mg, :description, "This is a metagraph.")
Dict{Symbol,Any} with 1 entry:
  :description => "This is a metagraph."

# set properties on a vertex in bulk
julia> set_props!(mg, 1, Dict(:name=>"Susan", :id => 123))
true

# set individual properties
julia> set_prop!(mg, 2, :name, "John")
true

# set a property on an edge
julia> set_prop!(mg, Edge(1, 2), :action, "knows")
true

julia> using Dates: Date

# set another property on an edge by specifying source and destination
julia> set_prop!(mg, 1, 2, :since, Date("20170501", "yyyymmdd"))
Dict{Symbol,Any} with 2 entries:
  :since   => 2017-05-01
  :action => "knows"

# get all the properties for an element
julia> props(mg, 1)
Dict{Symbol,Any} with 2 entries:
  :id   => 123
  :name => "Susan"

# get a specific property by name
julia> get_prop(mg, 2, :name)
"John"

# delete a specific property
julia> rem_prop!(mg, 1, :name)
Dict{Symbol,Any} with 1 entry:
  :id => 123

# clear all properties for vertex 2
julia> clear_props!(mg, 2)
Dict{Symbol,Any} with 0 entries

# confirm there are no properties set for vertex 2
julia> props(mg, 2)
Dict{Symbol,Any} with 0 entries

# all LightGraphs analytics work
julia> betweenness_centrality(mg)
5-element Array{Float64,1}:
 0.0
 0.5
 0.666667
 0.5
 0.0

# using weights
julia> mg = MetaGraph(complete_graph(3))
{3, 3} undirected Int64 metagraph with Float64 weights defined by :weight (default weight 1.0)

julia> enumerate_paths(dijkstra_shortest_paths(mg, 1), 3)
2-element Array{Int64,1}:
 1
 3

julia> set_prop!(mg, 1, 2, :weight, 0.2)
true

julia> set_prop!(mg, 2, 3, :weight, 0.6)
true

julia> enumerate_paths(dijkstra_shortest_paths(mg, 1), 3)
3-element Array{Int64,1}:
 1
 2
 3

# use vertex values as indices
julia> G = MetaGraph(100)
{100, 0} undirected Int64 metagraph with Float64 weights defined by :weight (default weight 1.0)

julia> for i in 1:100
           set_prop!(G, i, :name, "node$i")
       end

julia> set_indexing_prop!(G, :name)
Set(Symbol[:name])

# nodes can now be found by the value in the index
julia> G["node4", :name]
4

# You can also find the value of an index by the vertex number (note, this behavior will dominate if index values are also integers)
julia> G[4, :name]
"node4"

julia> set_prop!(G, 3, :name, "name3") # or set_indexing_prop!(G, 3, :name, "name3")
Set(Symbol[:name])