<< graph_power Graphs - Nets graph_sum >>

metanet >> metanet > Graphs - Nets > graph_simp

graph_simp

converts a graph to a simple undirected graph

Calling Sequence

g1 = graph_simp(g)

Parameters

g

a graph_data_structure.

g1

graph data structure of the new graph

Description

graph_simp returns the simple undirected graph g1 corresponding to multigraph g. It deletes loops in g, replaces directed edges with undirected edges and replaces multiple edges with single edges.A simple graph is also called a strict graph.

Examples

ta=[1 1  1 2 2 2 3 4 4 4 5 5 6 7 7 8 8 9 9 10 10 10 10 10 11 12 12 13 13 13 14 15 16 16 17 17];
he=[1 2 10 3 5 7 4 2 9 9 4 6 6 8 2 6 9 7 4  7 11 13 13 15 12 11 13 9 10 14 11 16 1 17 14 15];
g=make_graph('foo',1,17,ta,he);
g.nodes.graphics.x=[283 163  63  98 164 162 273 235 267 384 504 493 409 573 601 627 642];
g.nodes.graphics.y=[ 59 133 223 311 227 299 221 288 384 141 209 299 398 383 187 121 301];
show_graph(g);
g1=graph_simp(g);
show_graph(g1,'new');
ta=[1 1  1 2 2 2 3 4 4 4 5 5 6 7 7 8 8 9 9 10 10 10 10 10 11 12 12 13 13 13 14 15 16 16 17 17];
he=[1 2 10 3 5 7 4 2 9 9 4 6 6 8 2 6 9 7 4  7 11 13 13 15 12 11 13 9 10 14 11 16 1 17 14 15];
g=make_graph('foo',1,17,ta,he);
g('node_x')=[283 163  63  98 164 162 273 235 267 384 504 493 409 573 601 627 642];
g('node_y')=[ 59 133 223 311 227 299 221 288 384 141 209 299 398 383 187 121 301];
g = add_node_data(g,'elevation',ones(1,17));
g = add_edge_data(g,'diameter',ones(size(ta,1),size(ta,2)));

show_graph(g);
g1=graph_simp(g);
show_graph(g1,'new');

// Because graph_simp doesn't remove nodes, the data at the nodes are kept
g.nodes.data
g1.nodes.data

// graph_simp performs simplifications on the edges. So, the data contained in
// g at the edges are lost in g1
g.edges.data
g1.edges.data

Bibliography

Bronshtein, I. N. and Semendyayev, K. A. Handbook of Mathematics, 4th ed. New York: Springer-Verlag, 2004.

Gibbons, A. Algorithmic Graph Theory. Cambridge, England: Cambridge University Press, 1985.

Harary, F. "The Number of Linear, Directed, Rooted, and Connected Graphs." Trans. Amer. Math. Soc. 78, 445-463, 1955.

Harary, F. "Enumeration of Graphs." In Graph Theory. Reading, MA: Addison-Wesley, pp. 185-187, 1994.

Steinbach, P. Field Guide to Simple Graphs. Albuquerque, NM: Design Lab, 1990.

Tutte, W. T. Graph Theory as I Have Known It. Oxford, England: Oxford University Press, 1998.

West, D. B. Introduction to Graph Theory, 2nd ed. Englewood Cliffs, NJ: Prentice-Hall, 2000.


Report an issue
<< graph_power Graphs - Nets graph_sum >>