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rmedge

Remove edge from graph

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Syntax

H = rmedge(G,s,t)
H = rmedge(G,idx)

Description

H = rmedge(G,s,t) removes the edges specified by the node pairs s and t from graph G. If there are multiple edges specified by s and t, then they are all removed.

example

H = rmedge(G,idx) specifies which edges to remove with edge indices idx. The edge indices are row numbers in the G.Edges table.

example

Examples

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Open Live Script

Create and plot a graph.

s = [1 1 1 2 2 3 3 4 5 5 6 7];
t = [2 4 5 3 6 4 7 8 6 8 7 8];
G = graph(s,t);
plot(G)

Figure contains an axes object. The axes object contains an object of type graphplot.

Remove several edges from the graph and plot the result.

G = rmedge(G,[1 2 3 4],[5 6 7 8]);
plot(G)

Figure contains an axes object. The axes object contains an object of type graphplot.

Open Live Script

Create a graph and view the edge list.

s = {'BOS' 'NYC' 'NYC' 'NYC' 'LAX'};
t = {'NYC' 'LAX' 'DEN' 'LAS' 'DCA'};
G = digraph(s,t);
G.Edges
ans=5×1 table
         EndNodes     
    __________________

    {'BOS'}    {'NYC'}
    {'NYC'}    {'LAX'}
    {'NYC'}    {'DEN'}
    {'NYC'}    {'LAS'}
    {'LAX'}    {'DCA'}

Remove the edge between nodes 'NYC' and 'DEN' using the edge index.

G = rmedge(G,3);
G.Edges
ans=4×1 table
         EndNodes     
    __________________

    {'BOS'}    {'NYC'}
    {'NYC'}    {'LAX'}
    {'NYC'}    {'LAS'}
    {'LAX'}    {'DCA'}
Open Live Script

This example shows how to remove all of the self-loops from a graph. Self-loops are edges that connect a node to itself.

Create a graph that has two self-loops.

G = graph([1 1 1 2],[1 2 3 2]);
plot(G)

Figure contains an axes object. The axes object contains an object of type graphplot.

Use rmedge to remove all self-loops from the graph. Even though G has only two self-loops, this technique removes all self-loops from any directed or undirected graph.

G = rmedge(G, 1:numnodes(G), 1:numnodes(G));
plot(G)

Figure contains an axes object. The axes object contains an object of type graphplot.

Input Arguments

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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])

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.

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

FormSingle NodeMultiple 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: G = rmedge(G,1,2) removes the edge between node 1 and node 2 from graph G.

Example: G = rmedge(G,{'a' 'b'},{'d' 'c'}) removes two edges from graph G, the first of which is between node 'a' and node 'd'.

Edge indices, specified as a scalar or vector. The edge indices are nonnegative integers that are row numbers in the G.Edges table.

Example: G = rmedge(G,[1 3 5]) removes the first, third, and fifth edges (rows) from G.Edges.

Output Arguments

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Output graph, returned as a graph or digraph object.

Extended Capabilities

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

Version History

Introduced in R2015b

See Also

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