MATLAB Examples

Coloring graphs in Matgraph

We illustrate how to find colorings of graphs and display the results.

Contents

Use the Buckyball graph

We set g to be the Bucky graph.

g = graph;
bucky(g)

Greedy coloring

First we find a greedy coloring of the graph and display the results. Notice that this coloring uses four colors.

c = color(g); % uses algorithm 'greedy' by default
disp(['This coloring uses ', int2str(np(c)),' colors']);
cdraw(g,c);
This coloring uses 4 colors

Optimal coloring

An optimal coloring is slower (and may be intolerable on large graphs). However, for the Bucky graph, it uses fewer colors than the greedy algorithm.

tic; c = color(g,'optimal'); toc
disp(['This coloring uses ', int2str(np(c)),' colors']);
cdraw(g,c);
Elapsed time is 0.598491 seconds.
This coloring uses 3 colors

Release the graph

free(g);