Core Functions
LightGraphs.jl includes the following core functions:
LightGraphs.add_vertices!LightGraphs.all_neighborsLightGraphs.common_neighborsLightGraphs.degreeLightGraphs.degree_histogramLightGraphs.densityLightGraphs.has_self_loopsLightGraphs.indegreeLightGraphs.is_orderedLightGraphs.neighborsLightGraphs.num_self_loopsLightGraphs.outdegreeLightGraphs.squashLightGraphs.weightsLightGraphs.ΔLightGraphs.ΔinLightGraphs.ΔoutLightGraphs.δLightGraphs.δinLightGraphs.δout
Full Docs
LightGraphs.add_vertices! — Method.add_vertices!(g, n)Add n new vertices to the graph g. Return the number of vertices that were added successfully.
Examples
julia> using LightGraphs
julia> g = SimpleGraph()
{0, 0} undirected simple Int64 graph
julia> add_vertices!(g, 2)
2LightGraphs.all_neighbors — Function.all_neighbors(g, v)Return a list of all inbound and outbound neighbors of v in g. For undirected graphs, this is equivalent to both outneighbors and inneighbors.
Implementation Notes
Returns a reference to the current graph's internal structures, not a copy. Do not modify result. If the graph is modified, the behavior is undefined: the array behind this reference may be modified too, but this is not guaranteed.
Examples
```jldoctest julia> using LightGraphs
julia> g = DiGraph(3);
julia> add_edge!(g, 2, 3);
julia> add_edge!(g, 3, 1);
julia> all_neighbors(g, 1) 1-element Array{Int64,1}: 3
julia> all_neighbors(g, 2) 1-element Array{Int64,1}: 3
julia> all_neighbors(g, 3) 2-element Array{Int64,1}: 1 2 ```
LightGraphs.common_neighbors — Method.common_neighbors(g, u, v)Return the neighbors common to vertices u and v in g.
Implementation Notes
Returns a reference to the current graph's internal structures, not a copy. Do not modify result. If the graph is modified, the behavior is undefined: the array behind this reference may be modified too, but this is not guaranteed.
Examples
julia> using LightGraphs
julia> g = SimpleGraph(4);
julia> add_edge!(g, 1, 2);
julia> add_edge!(g, 2, 3);
julia> add_edge!(g, 3, 4);
julia> add_edge!(g, 4, 1);
julia> add_edge!(g, 1, 3);
julia> common_neighbors(g, 1, 3)
2-element Array{Int64,1}:
2
4
julia> common_neighbors(g, 1, 4)
1-element Array{Int64,1}:
3LightGraphs.degree — Function.degree(g[, v])Return a vector corresponding to the number of edges which start or end at each vertex in graph g. If v is specified, only return degrees for vertices in v. For directed graphs, this value equals the incoming plus outgoing edges. For undirected graphs, it equals the connected edges.
Examples
julia> using LightGraphs
julia> g = DiGraph(3);
julia> add_edge!(g, 2, 3);
julia> add_edge!(g, 3, 1);
julia> degree(g)
3-element Array{Int64,1}:
1
1
2LightGraphs.degree_histogram — Method.LightGraphs.density — Function.density(g)Return the density of g. Density is defined as the ratio of the number of actual edges to the number of possible edges ($|V|×(|V|-1)$ for directed graphs and $\frac{|V|×(|V|-1)}{2}$ for undirected graphs).
LightGraphs.has_self_loops — Method.has_self_loops(g)Return true if g has any self loops.
Examples
julia> using LightGraphs
julia> g = SimpleGraph(2);
julia> add_edge!(g, 1, 2);
julia> has_self_loops(g)
false
julia> add_edge!(g, 1, 1);
julia> has_self_loops(g)
trueLightGraphs.indegree — Method.indegree(g[, v])Return a vector corresponding to the number of edges which end at each vertex in graph g. If v is specified, only return degrees for vertices in v.
Examples
julia> using LightGraphs
julia> g = DiGraph(3);
julia> add_edge!(g, 2, 3);
julia> add_edge!(g, 3, 1);
julia> indegree(g)
3-element Array{Int64,1}:
1
0
1LightGraphs.is_ordered — Method.is_ordered(e)Return true if the source vertex of edge e is less than or equal to the destination vertex.
Examples
julia> using LightGraphs
julia> g = DiGraph(2);
julia> add_edge!(g, 2, 1);
julia> is_ordered(first(edges(g)))
falseLightGraphs.neighbors — Method.neighbors(g, v)Return a list of all neighbors reachable from vertex v in g. For directed graphs, the default is equivalent to outneighbors; use all_neighbors to list inbound and outbound neighbors.
Implementation Notes
Returns a reference to the current graph's internal structures, not a copy. Do not modify result. If the graph is modified, the behavior is undefined: the array behind this reference may be modified too, but this is not guaranteed.
Examples
julia> using LightGraphs
julia> g = DiGraph(3);
julia> add_edge!(g, 2, 3);
julia> add_edge!(g, 3, 1);
julia> neighbors(g, 1)
0-element Array{Int64,1}
julia> neighbors(g, 2)
1-element Array{Int64,1}:
3
julia> neighbors(g, 3)
1-element Array{Int64,1}:
1LightGraphs.num_self_loops — Method.num_self_loops(g)Return the number of self loops in g.
Examples
julia> using LightGraphs
julia> g = SimpleGraph(2);
julia> add_edge!(g, 1, 2);
julia> num_self_loops(g)
0
julia> add_edge!(g, 1, 1);
julia> num_self_loops(g)
1LightGraphs.outdegree — Method.outdegree(g[, v])Return a vector corresponding to the number of edges which start at each vertex in graph g. If v is specified, only return degrees for vertices in v.
Examples
julia> using LightGraphs
julia> g = DiGraph(3);
julia> add_edge!(g, 2, 3);
julia> add_edge!(g, 3, 1);
julia> outdegree(g)
3-element Array{Int64,1}:
0
1
1LightGraphs.squash — Method.squash(g)Return a copy of a graph with the smallest practical type that can accommodate all vertices.
LightGraphs.weights — Method.weights(g)Return the weights of the edges of a graph g as a matrix. Defaults to LightGraphs.DefaultDistance.
Implementation Notes
In general, referencing the weight of a nonexistent edge is undefined behavior. Do not rely on the weights matrix as a substitute for the graph's adjacency_matrix.
LightGraphs.Δ — Method.Δ(g)Return the maximum degree of vertices in g.
LightGraphs.Δin — Method.Δin(g)Return the maximum indegree of vertices in g.
LightGraphs.Δout — Method.Δout(g)Return the maximum outdegree of vertices in g.
LightGraphs.δ — Method.δ(g)Return the minimum degree of vertices in g.
LightGraphs.δin — Method.δin(g)Return the minimum indegree of vertices in g.
LightGraphs.δout — Method.δout(g)Return the minimum outdegree of vertices in g.