NAME¶

Graph::AdjacencyMatrix - create and query the adjacency matrix of graph G

SYNOPSIS¶

    use Graph::AdjacencyMatrix;
    use Graph::Directed; # or Undirected
    my $g  = Graph::Directed->new;
    $g->add_...(); # build $g
    my $am = Graph::AdjacencyMatrix->new($g);
    $am->is_adjacent($u, $v)
    my $am = Graph::AdjacencyMatrix->new($g, distance_matrix => 1);
    $am->distance($u, $v)
    my $am = Graph::AdjacencyMatrix->new($g, attribute_name => 'length');
    $am->distance($u, $v)
    my $am = Graph::AdjacencyMatrix->new($g, ...);
    my @V  = $am->vertices();

DESCRIPTION¶

You can use "Graph::AdjacencyMatrix" to compute the adjacency matrix and optionally also the distance matrix of a graph, and after that query the adjacencyness between vertices by using the "is_adjacent()" method, or query the distance between vertices by using the "distance()" method. By default the edge attribute used for distance is "w", but you can change that in new(), see below. If you modify the graph after creating the adjacency matrix of it, the adjacency matrix and the distance matrix may become invalid.

Methods¶

Class Methods¶

new($g)

Construct the adjacency matrix of the graph $g.

new($g, options)

Construct the adjacency matrix of the graph $g with options as a hash. The known options are

Object Methods¶

is_adjacent($u, $v)

Return true if the vertex $v is adjacent to vertex $u, or false if not.

distance($u, $v)

Return the distance between the vertices $u and $v, or "undef" if the vertices are not adjacent.

adjacency_matrix

Return the adjacency matrix itself (a list of bitvector scalars).

vertices

Return the list of vertices (useful for indexing the adjacency matrix).

ALGORITHM¶

The algorithm used to create the matrix is two nested loops, which is O(V**2) in time, and the returned matrices are O(V**2) in space.

SEE ALSO¶

Graph::TransitiveClosure, Graph::BitMatrix

AUTHOR AND COPYRIGHT¶

Jarkko Hietaniemi jhi@iki.fi

LICENSE¶

This module is licensed under the same terms as Perl itself.