Graph::TransitiveClosure - create and query transitive closure of graph
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 automatically always on so this is a no-op.
my $tcg = Graph::TransitiveClosure->new($g, path_vertices => 1);
$tcg->path_vertices($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, $v)
You can use Graph::TransitiveClosure to compute the transitive
closure graph of a graph and optionally also the minimum paths
(lengths and vertices) between vertices, and after that query the
transitiveness between vertices by using the is_reachable() and
is_transitive() methods, and the paths by using the
path_length() and path_vertices() methods.
For further documentation, see the the Graph::TransitiveClosure::Matrix manpage.
- new($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.
These are only the methods 'native' to the class: see
the Graph::TransitiveClosure::Matrix manpage 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.
The transitive closure matrix is stored as an attribute of the graph
called _tcm , and any methods not found in the graph class are searched
in the transitive closure matrix class.
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