Description of union

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union

PURPOSE

union(g,h1,h2) --- set g equal to the union of h1 and h2.

SYNOPSIS

function union(g,h1,h2)

DESCRIPTION

 union(g,h1,h2) --- set g equal to the union of h1 and h2.
 The vertices of g are the union of the vertex sets of h1 and h2, and the
 edge set of g is the union of the edge sets of h1 and h2.

CROSS-REFERENCE INFORMATION

This function calls:

• copy copy(g,h) --- overwrite g with a copy of h
• free free(g) --- free the graph from the system
• graph graph: constructor for the graph class
• matrix matrix(g) --- return (a copy of) the adjacency matrix of g
• nv nv(g) --- number of vertices in g
• resize resize(g,n) --- change the number of vertices in g to n

This function is called by:

• bipmatch bipmatch --- maximum matching in a bipartite graph

SOURCE CODE

0001 function union(g,h1,h2)
0002 % union(g,h1,h2) --- set g equal to the union of h1 and h2.
0003 % The vertices of g are the union of the vertex sets of h1 and h2, and the
0004 % edge set of g is the union of the edge sets of h1 and h2.
0005 
0006 global GRAPH_MAGIC
0007 
0008 n1 = nv(h1);
0009 n2 = nv(h2);
0010 
0011 g1 = graph;
0012 g2 = graph;
0013 
0014 copy(g1,h1);
0015 copy(g2,h2);
0016 
0017 if n1 < n2
0018     resize(g1,n2)
0019 else
0020     resize(g2,n1)
0021 end
0022 
0023 GRAPH_MAGIC.graphs{g.idx}.array = ...
0024     double(matrix(g1) | matrix(g2));
0025 
0026 free(g1);
0027 free(g2);

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