edgecount

Number of edges between two nodes

Syntax

C = edgecount(G,s,t)

Description

C = edgecount(G,s,t) returns the number of edges between the source and target node pairs s and t in graph G.

Examples

Number of Edges Between Nodes

Create a graph and display the edges table for reference. Find the number of edges between node 1 and node 2.

G = graph([1 1 1 1 2 2],[2 2 2 3 4 5]);
G.Edges

ans=6×1 table
    EndNodes
    ________

     1    2 
     1    2 
     1    2 
     1    3 
     2    4 
     2    5 

N = edgecount(G,1,2)

N = 
3

You also can specify a single source node and several target nodes. Find the number of edges between node 1 and all other nodes (including self-loops).

N = edgecount(G,1,1:numnodes(G))

N = 5×1

     0
     3
     1
     0
     0

Input Arguments

G — Input graph

graph object | digraph object

Input graph, specified as either a graph or digraph object. Use graph to create an undirected graph or digraph to create a directed graph.

Example: G = graph(1,2)

Example: G = digraph([1 2],[2 3])

s,t — Node pairs (as separate arguments)

node indices | node names

Node pairs, specified as separate arguments of node indices or node names. Similarly located elements in s and t specify the source and target nodes for edges in the graph. s and t must specify the same number of nodes, unless one of them specifies a single node.

This table shows the different ways to refer to one or more nodes either by their numeric node indices or by their node names.

Form	Single Node	Multiple Nodes
Node index	Scalar Example: 1	Vector Example: [1 2 3]
Node name	Character vector Example: 'A'	Cell array of character vectors Example: {'A' 'B' 'C'}
	String scalar Example: "A"	String array Example: ["A" "B" "C"]

Example: edgecount(G,1,2)

Example: edgecount(G,1,1:5)

Example: edgecount(G,{'a' 'b' 'c'},'a')

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• The node pairs s and t must be node indices of the input graph G. Node names are not supported.

Thread-Based Environment
Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

Version History

Introduced in R2018a