## Class RandomRegularGraphGenerator<V,​E>

• Type Parameters:
V - graph node type
E - graph edge type
All Implemented Interfaces:
GraphGenerator<V,​E,​V>

public class RandomRegularGraphGenerator<V,​E>
extends Object
implements GraphGenerator<V,​E,​V>
Generate a random $d$-regular undirected graph with $n$ vertices. A regular graph is a graph where each vertex has the same degree, i.e. the same number of neighbors.

The algorithm for the simple case, proposed in [SW99] and extending the one for the non-simple case [W99], runs in expected $\mathcal{O}(nd^2)$ time. It has been proved in [KV03] to sample from the space of random d-regular graphs in a way which is asymptotically uniform at random when $d = \mathcal{O}(n^{1/3 - \epsilon})$.

[KV03] Kim, Jeong Han, and Van H. Vu. "Generating random regular graphs." Proceedings of the thirty-fifth annual ACM symposium on Theory of computing. ACM, 2003. [SW99] Steger, Angelika, and Nicholas C. Wormald. "Generating random regular graphs quickly." Combinatorics, Probability and Computing 8.4 (1999): 377-396. [W99] Wormald, Nicholas C. "Models of random regular graphs." London Mathematical Society Lecture Note Series (1999): 239-298.

Author:
Emilio Cruciani
• ### Constructor Summary

Constructors
Constructor Description
RandomRegularGraphGenerator​(int n, int d)
Construct a new RandomRegularGraphGenerator.
RandomRegularGraphGenerator​(int n, int d, long seed)
Construct a new RandomRegularGraphGenerator.
RandomRegularGraphGenerator​(int n, int d, Random rng)
Construct a new RandomRegularGraphGenerator.
• ### Method Summary

All Methods
Modifier and Type Method Description
void generateGraph​(Graph<V,​E> target, Map<String,​V> resultMap)
Generate a random regular graph.
• ### Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
• ### Methods inherited from interface org.jgrapht.generate.GraphGenerator

generateGraph
• ### Constructor Detail

• #### RandomRegularGraphGenerator

public RandomRegularGraphGenerator​(int n,
int d)
Construct a new RandomRegularGraphGenerator.
Parameters:
n - number of nodes
d - degree of nodes
Throws:
IllegalArgumentException - if number of nodes is negative
IllegalArgumentException - if degree is negative
IllegalArgumentException - if degree is greater than number of nodes
IllegalArgumentException - if the value "n * d" is odd
• #### RandomRegularGraphGenerator

public RandomRegularGraphGenerator​(int n,
int d,
long seed)
Construct a new RandomRegularGraphGenerator.
Parameters:
n - number of nodes
d - degree of nodes
seed - seed for the random number generator
Throws:
IllegalArgumentException - if number of nodes is negative
IllegalArgumentException - if degree is negative
IllegalArgumentException - if degree is greater than number of nodes
IllegalArgumentException - if the value "n * d" is odd
• #### RandomRegularGraphGenerator

public RandomRegularGraphGenerator​(int n,
int d,
Random rng)
Construct a new RandomRegularGraphGenerator.
Parameters:
n - number of nodes
d - degree of nodes
rng - the random number generator to use
Throws:
IllegalArgumentException - if number of nodes is negative
IllegalArgumentException - if degree is negative
IllegalArgumentException - if degree is greater than number of nodes
IllegalArgumentException - if the value "n * d" is odd
• ### Method Detail

• #### generateGraph

public void generateGraph​(Graph<V,​E> target,
Map<String,​V> resultMap)
Generate a random regular graph.
Specified by:
generateGraph in interface GraphGenerator<V,​E,​V>
Parameters:
target - the target graph
resultMap - the result map
Throws:
IllegalArgumentException - if target is not an undirected graph
IllegalArgumentException - if "n == d" and the graph is simple