plucky (3) Graph::TransitiveClosure.3pm.gz

NAME

       Graph::TransitiveClosure - create and query transitive closure of graph

SYNOPSIS

           use Graph::TransitiveClosure;
           use Graph::Directed; # or Undirected

           my $g  = Graph::Directed->new;
           $g->add_...(); # build $g

           # Compute the transitive closure graph.
           my $tcg = Graph::TransitiveClosure->new($g);
           $tcg->is_reachable($u, $v) # Identical to $tcg->has_edge($u, $v)

           # Being reflexive is the default, meaning that null transitions
           # (transitions from a vertex to the same vertex) are included.
           my $tcg = Graph::TransitiveClosure->new($g, reflexive => 1);
           my $tcg = Graph::TransitiveClosure->new($g, reflexive => 0);

           # is_reachable(u, v) is always reflexive.
           $tcg->is_reachable($u, $v)

           # You can check any graph for transitivity.
           $g->is_transitive()

           my $tcg = Graph::TransitiveClosure->new($g, path_length => 1);
           $tcg->path_length($u, $v)

           # path_vertices is on by default so this is a no-op.
           my $tcg = Graph::TransitiveClosure->new($g, path_vertices => 1);
           $tcg->path_vertices($u, $v)

           # see how many paths exist from $u to $v
           my $tcg = Graph::TransitiveClosure->new($g, path_count => 1);
           $tcg->path_length($u, $v)

           # Both path_length and path_vertices.
           my $tcg = Graph::TransitiveClosure->new($g, path => 1);
           $tcg->path_vertices($u, $v)
           $tcg->length($u, $v)

           my $tcg = Graph::TransitiveClosure->new($g, attribute_name => 'length');
           $tcg->path_length($u, $v)

DESCRIPTION

       You can use "Graph::TransitiveClosure" to compute the transitive closure graph of a graph and optionally
       also the minimum paths (lengths and vertices) between vertices, and after that query the transitiveness
       between vertices by using the is_reachable() and is_transitive() methods, and the paths by using the
       path_length() and path_vertices() methods.

       For further documentation, see the Graph::TransitiveClosure::Matrix.

   Class Methods
       new($g, %opt)
           Construct a new transitive closure object.  Note that strictly speaking the returned object is not a
           graph; it is a graph plus other stuff.  But you should be able to use it as a graph plus a couple of
           methods inherited from the Graph::TransitiveClosure::Matrix class.

   Object Methods
       These are only the methods 'native' to the class: see Graph::TransitiveClosure::Matrix for more.

       is_transitive($g)
           Return true if the Graph $g is transitive.

       transitive_closure_matrix
           Return the transitive closure matrix of the transitive closure object.