line_graph

line_graph — graph with nodes corresponding to edges

Calling sequence

g1 = line_graph(g)  

Parameters

g : graph list of the old graph
g1 : graph list of the new graph

Description

line_graph returns the graph g1 with the nodes corresponding to the edges of the graph g. g1 is defined in the following way: - its nodes correspond to the edges of g - 2 nodes of the new graph are adjacent if and only if the corresponding edges of the graph g are adjacent.

The coordinates of the nodes of g1 are given by the middle points of the corresponding edges of g.

Examples



ta=[1 1 2 4 4 5 6 7 2 3 5 1];
he=[2 6 3 6 7 8 8 8 4 7 3 5];
g=make_graph('foo',0,8,ta,he);
g('node_x')=[281  284  360  185  405  182  118  45];
g('node_y')=[262  179  130  154  368  248  64  309];
show_graph(g);
g1=line_graph(g);
show_graph(g1,'new');
 
  

See also

arc_graph