org.nongnu.multigraph.perturb

Class RandomRemove<N,E>

java.lang.Object

org.nongnu.multigraph.perturb.RandomRemove<N,E>

All Implemented Interfaces:

perturber<N,E>

public class RandomRemove<N,E>
extends java.lang.Object
implements perturber<N,E>

Perturb the graph by removing a randomly chosen set of edges from the graph. Methods are also given to restore removed edges, and clear the state kept for removed edges.

Author:

Paul Jakma

Constructor Summary

Constructors

Constructor and Description
RandomRemove(Graph<N,E> graph) Create new instance to randomly remove 1 edge on each call to
RandomRemove(Graph<N,E> graph, float remove_edges) Create new instance to iterate over the specified graph and remove then add up to remove_edges # of edges on each call to remove(),
RandomRemove(Graph<N,E> graph, float remove_edges, int max_perturbs) Create new instance to iterate over the specified graph and remove then add up to remove_edges # of edges on each call to remove(),

Method Summary

Modifier and Type	Method and Description
int	clear_removed_edges() Clear state held for the removed edges.
boolean	combine()
void	combine(boolean combine)
java.util.List<Edge<N,E>>	perturb() Carry out another iteration of random-removes by restoring any previously removed edges, clearing the removed_edge set, and then removing the next random set of edges.
java.util.List<Edge<N,E>>	remove() Randomly remove edges from the graph, up to the specified number of edges for the class.
java.util.List<Edge<N,E>>	removed_edges()
int	restore() Restore edges removed previously, up until the last call to clear_removed_edges().

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RandomRemove

public RandomRemove(Graph<N,E> graph)

Create new instance to randomly remove 1 edge on each call to

Parameters:

graph - The graph to act on.

RandomRemove

public RandomRemove(Graph<N,E> graph,
                    float remove_edges)

Create new instance to iterate over the specified graph and remove then add up to remove_edges # of edges on each call to remove(),

Parameters:

graph - The graph to act on

remove_edges - The number of edges to remove/add at a time, on each call to remove. This may be specified either as an absolute number of edges (> 1), or else as a proportion of the number of nodes, (0 < x < 1).

RandomRemove

public RandomRemove(Graph<N,E> graph,
                    float remove_edges,
                    int max_perturbs)

Create new instance to iterate over the specified graph and remove then add up to remove_edges # of edges on each call to remove(),

Parameters:

graph - The graph to act on

remove_edges - The number of edges to remove/add at a time, on each call to remove. This may be specified either as an absolute number of edges (> 1), or else as a proportion of the number of nodes, (0 < x < 1).

max_perturbs - Limit the number of times groups of edges will be removed. A value <= 0 means no limit.

Method Detail

combine

public void combine(boolean combine)

combine

public boolean combine()

remove

public java.util.List<Edge<N,E>> remove()

Randomly remove edges from the graph, up to the specified number of edges for the class.

Returns:

An unmodifiable list of the edges removed in this particular iteration.

restore

public int restore()

Restore edges removed previously, up until the last call to clear_removed_edges().

Specified by:

restore in interface perturber<N,E>

Returns:

The number of restored edges.

removed_edges

public java.util.List<Edge<N,E>> removed_edges()

Specified by:

removed_edges in interface perturber<N,E>

Returns:

An unmodifiable list view of the remembered, removed edges.

clear_removed_edges

public int clear_removed_edges()

Clear state held for the removed edges. Future restore() calls will not be able to add back any of the edges held before the call to this method.

Specified by:

clear_removed_edges in interface perturber<N,E>

Returns:

The number of edges cleared.

perturb

public java.util.List<Edge<N,E>> perturb()

Carry out another iteration of random-removes by restoring any previously removed edges, clearing the removed_edge set, and then removing the next random set of edges.

Specified by:

perturb in interface perturber<N,E>

Returns: