graph::unionfind(3pm) [debian man page]

Graph::UnionFind(3pm)					User Contributed Perl Documentation				     Graph::UnionFind(3pm)

NAME

       Graph::UnionFind - union-find data structures

SYNOPSIS

	   use Graph::UnionFind;
	   my $uf = Graph::UnionFind->new;

	   # Add the vertices to the data structure.
	   $uf->add($u);
	   $uf->add($v);

	   # Join the partitions of the vertices.
	   $uf->union( $u, $v );

	   # Find the partitions the vertices belong to
	   # in the union-find data structure.	If they
	   # are equal, they are in the same partition.
	   # If the vertex has not been seen,
	   # undef is returned.
	   my $pu = $uf->find( $u );
	   my $pv = $uf->find( $v );
	   $uf->same($u, $v) # Equal to $pu eq $pv.

	   # Has the union-find seen this vertex?
	   $uf->has( $v )

DESCRIPTION

       Union-find is a special data structure that can be used to track the partitioning of a set into subsets (a problem known also as disjoint
       sets).

       Graph::UnionFind() is used for Graph::connected_components(), Graph::connected_component(), and Graph::same_connected_components() if you
       specify a true "union_find" parameter when you create an undirected graph.

       Note that union-find is one way: you cannot (easily) 'ununion' vertices once you have 'unioned' them.  This means that if you delete edges
       from a "union_find" graph, you will get wrong results from the Graph::connected_components(), Graph::connected_component(), and
       Graph::same_connected_components().

   API
       add
	       $uf->add($v)

	   Add the vertex v to the union-find.

       union
	       $uf->union($u, $v)

	   Add the edge u-v to the union-find.	Also implicitly adds the vertices.

       has
	       $uf->has($v)

	   Return true if the vertex v has been added to the union-find, false otherwise.

       find
	       $uf->find($v)

	   Return the union-find partition the vertex v belongs to, or "undef" if it has not been added.

       new
	       $uf = Graph::UnionFind->new()

	   The constructor.

       same
	       $uf->same($u, $v)

	   Return true of the vertices belong to the same union-find partition the vertex v belongs to, false otherwise.

AUTHOR AND COPYRIGHT

       Jarkko Hietaniemi jhi@iki.fi

LICENSE

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

perl v5.10.0							    2008-11-27						     Graph::UnionFind(3pm)

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Graph::Easy::Layout::Repair(3pm)			User Contributed Perl Documentation			  Graph::Easy::Layout::Repair(3pm)

NAME

       Graph::Easy::Layout::Repair - Repair spliced layout with group cells

SYNOPSIS

	       use Graph::Easy;

	       my $graph = Graph::Easy->new();

	       my $bonn = Graph::Easy::Node->new(
		       name => 'Bonn',
	       );
	       my $berlin = Graph::Easy::Node->new(
		       name => 'Berlin',
	       );

	       $graph->add_edge ($bonn, $berlin);

	       $graph->layout();

	       print $graph->as_ascii( );

	       # prints:

	       # +------+     +--------+
	       # | Bonn | --> | Berlin |
	       # +------+     +--------+

DESCRIPTION

       "Graph::Easy::Layout::Repair" contains code that can splice in group cells into a layout, as well as repair the layout after that step.

       It is part of Graph::Easy and used automatically.

METHODS

       "Graph::Easy::Layout" injects the following methods into the "Graph::Easy" namespace:

   _edges_into_groups()
       Put the edges into the appropriate group and class.

   _assign_ranks()
	       $graph->_assign_ranks();

   _repair_nodes()
       Splicing the rows/columns to add filler cells will have torn holes into multi-edges nodes, so we insert additional filler cells to repair
       this.

   _splice_edges()
       Splicing the rows/columns to add filler cells might have torn holes into multi-celled edges, so we splice these together again.

   _repair_edges()
       Splicing the rows/columns to add filler cells might have put "holes" between an edge start/end and the node cell it points to. This routine
       fixes this problem by extending the edge by one cell if necessary.

   _fill_group_cells()
       After doing a "layout()", we need to add the group to each cell based on what group the nearest node is in.

       This routine will also find the label cell for each group, and repair edge/node damage done by the splicing.

EXPORT

       Exports nothing.

SEE ALSO

       Graph::Easy.

AUTHOR

       Copyright (C) 2004 - 2007 by Tels <http://bloodgate.com>

       See the LICENSE file for information.

perl v5.14.2							    2011-12-23					  Graph::Easy::Layout::Repair(3pm)

Linux and UNIX Man Pages

graph::unionfind(3pm) [debian man page]

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