NAME

Graph::Easy::Weighted - A weighted graph implementation

VERSION

version 0.0701

SYNOPSIS

 use Graph::Easy::Weighted;

 my $gw = Graph::Easy::Weighted->new();
 $gw->populate(
    [ [0,1,2,0,0], # Vertex 0 with 2 edges of weight 3
      [1,0,3,0,0], #    "   1      2 "               4
      [2,3,0,0,0], #    "   2      2 "               5
      [0,0,1,0,0], #    "   3      1 "               1
      [0,0,0,0,0], #    "   4      0 "               0
    ]
 );
 $gw->dump();

 my ($lightest, $heaviest) = $gw->vertex_span();
 ($lightest, $heaviest) = $gw->edge_span();

 my $weight = $gw->path_cost(\@vertices);

 my $attr = 'probability';
 $gw = Graph::Easy::Weighted->new();
 $gw->populate(
    {
        0 => { attributes => { title => 'A' }, 1=>0.4, 3=>0.6 },
        1 => { attributes => { title => 'B' }, 0=>0.3, 2=>0.7 },
        2 => { attributes => { title => 'C' }, 0=>0.5, 2=>0.5 },
        3 => { attributes => { title => 'D' }, 0=>0.2, 1=>0.8 },
    },
    $attr,
    '%0.2f'
 );
 $gw->dump();

DESCRIPTION

A Graph::Easy::Weighted object is a subclass of the Graph::Easy module with attribute handling. As such, all of the Graph::Easy methods may be used as documented, but with the addition of custom weighting.

METHODS

new()

  $gw = Graph::Easy::Weighted->new;

Return a new Graph::Easy::Weighted object.

Please see "new()" in Graph::Easy for the possible constructor arguments.

populate()

  $gw->populate($matrix);
  $gw->populate($matrix, $attribute);
  $gw->populate(\@vectors);
  $gw->populate(\@vectors, $attribute);
  $gw->populate(\%data);
  $gw->populate(\%data, $attribute);
  $gw->populate(\%data, $attribute, $format);

Populate a graph with weighted nodes.

The data can be an arrayref of numeric vectors, a Math::Matrix object, a Math::MatrixReal object, or a hashref of numeric edge values.

Data given as a hash reference may contain node attributes as shown in the SYNOPSIS. See Graph::Easy::Manual for the available attributes.

The optional edge attribute argument is a string, with the default "weight."

Multiple attributes may populate a single graph, thereby layering and increasing the overall dimension.

An optional sprintf format string may be provided for the edge label.

Examples of vertices in array reference form:

  []      1 vertex with no edges.
  [0]     1 vertex with no edges.
  [1]     1 vertex and 1 edge to itself, weight 1.
  [0,1]   2 vertices and 1 edge, weight 1.
  [1,0,9] 3 vertices and 2 edges having, weight 10.
  [1,2,3] 3 vertices and 3 edges having, weight 6.

get_cost()

  $c = $gw->get_cost($vertex);
  $c = $gw->get_cost($vertex, $attribute);
  $c = $gw->get_cost($edge);
  $c = $gw->get_cost($edge, $attribute);

Return the weight or named attribute value for the vertex or edge.

vertex_span()

 ($lightest, $heaviest) = $gw->vertex_span();
 ($lightest, $heaviest) = $gw->vertex_span($attr);

Return the lightest and heaviest vertices.

edge_span()

 ($lightest, $heaviest) = $gw->edge_span();
 ($lightest, $heaviest) = $gw->edge_span($attr);

Return the lightest to heaviest edges.

path_cost()

 $c = $gw->path_cost(\@named_vertices);
 $c = $gw->path_cost(\@named_vertices, $attr);

Return the summed weight (or given cost attribute) of the path edges.

For shortest paths and minimum spanning trees, please see "EXAMPLES" in Graph::Weighted.

dump()

  $gw->dump()
  $gw->dump($attr)

Print out the graph showing vertices, edges and costs.

SEE ALSO

Graph::Easy, the parent of this module

Graph::Weighted, the sibling

The eg/* and t/* file sources

AUTHOR

Gene Boggs <gene@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2022 by Gene Boggs.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm Graph::Easy::Weighted

perl -MCPAN -e shell
install Graph::Easy::Weighted