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

NAME

       Graph::MoreUtils - utilities for graphs

SYNOPSIS

           use Graph::MoreUtils qw( line );
           use Graph::Undirected;

           my $G = Graph::Undirected->new;

           # Greate graph here

           # Get line graph for $G:
           my $L = line( $G );

   "SSSR( $graph, $max_depth )"
       Finds the Smallest Set of Smallest Rings (SSSR) in Graph objects.  Thus it should work with any
       Graph::Undirected object.  The code is largely taken from the "cod-tools" package
       (<https://wiki.crystallography.net/cod-tools/>).

       The algorithm returns a superset of minimum cycle basis of a graph in order to produce deterministic
       results.  As a result it does not succumb to the counterexample of oxabicyclo[2.2.2]octane
       (<https://depth-first.com/articles/2020/08/31/a-smallest-set-of-smallest-rings/>, section "SSSR and
       Uniqueness").  The algorithm has means to control the maximum size of rings included in the SSSR to
       reduce its complexity.  The default value of "undef" stands for no limit.

   "graph_replace( $graph, $new, @old )"
       Replaces one or more vertices (@old) in the graph with a given one ($new).  All edges between the
       replaced vertices are removed and all edges with other vertices become a reconnected to the new one.

   line( $graph )
       Generates line graphs for Graph objects.  Line graph is constructed nondestructively and returned from
       the call.  Both simple and multiedged, undirected and directed graphs are supported.

       Call accepts additional options hash.  Currently only one option is supported, "loop_end_vertices", which
       treats the input graph as having self-loops on pendant vertices, that is, increasing the degrees of
       vertices having degrees of 1.  Thus they are not "lost" during line graph construction.  In the resulting
       line graph these self-loops are represented as instances of Graph::MoreUtils::Line::SelfLoopVertex.  This
       does not work with directed graphs yet.

   smooth( $graph )
       Smooths the given graph by collating vertices of degree 2.

SEE ALSO

       perl(1)

AUTHORS

       Andrius Merkys, <merkys@cpan.org>