net.scheinerman.graph
Class Graph<E>

java.lang.Object
  net.scheinerman.graph.Graph<E>

All Implemented Interfaces:

java.lang.Iterable<Vertex<E>>, java.util.Collection<Vertex<E>>

public class Graph<E>
extends java.lang.Object
implements java.util.Collection<Vertex<E>>

A Graph is a group of vertices, with edges between vertices. This implementation places vertices in a HashMap with the key being a Location and the value for a given key being a Vertex. Each vertex has an array of Edge objects. Each Edge has two vertices.
Graph can read files given in the simple graph format. The simple graph format consists of three parts:

The number of vertices and edges

All the edges given as two vertex numbers

The locations of each vertex

For example, given a graph with 4 vertices and 3 edges between vertices 1 and 3, 2 and 3, and 2 and 4, the file would look like this:

4 3
1 3
2 3
2 4
140 200
210 120
50 50
60 80

The first line is the number of vertices followed by the number of edges. The next three lines are all the edges each with one edge denoted by to vertex numbers. The following four lines are the locations of each of the vertices in order, in the form xLoc yLoc, (x,y).

Since:

1.6

Version:

1.0

Author:

Jonah Scheinerman

Constructor Summary

Graph()
Creates a new empty graph.

Method Summary

boolean	add(Vertex<E> v) Adds a vertex at its given location to this graph.
boolean	addAll(java.util.Collection<? extends Vertex<E>> arg0)
void	clear()
void	complete()
boolean	contains(java.lang.Object o)
boolean	containsAll(java.util.Collection<?> c)
static <E> Graph<E>	createInputGraph(java.io.File file) Creates a Graph object given a file in the Simple Graph Format.
java.io.File	createOutputFile(java.lang.String path) Creates an output file at the given location using the Simple Graph Format.
void	genMinSpanTree(Vertex<E> v)
Vertex<E>	get(Location loc) Returns the Vertex contained at Location loc.
java.util.Set<Vertex<E>>	getComponent(Vertex<E> v)
java.util.Set<Location>	getLocations() Retrieves the set of all vertex locations for this graph.
Vertex<E>	getVertexAt(Location l) Retrieves the vertex at a given location.
java.util.Collection<Vertex<E>>	getVertexCollection()
java.util.HashMap<Location,Vertex<E>>	getVertices() Returns the map of locations to vertices in this graph.
double	getWeight()
boolean	isEmpty()
java.util.Iterator<Vertex<E>>	iterator() Returns an iterator that iterates over the vertices in the graph.
Vertex<E>	remove(Location loc) Removes and returns the vertex at the given location.
boolean	remove(java.lang.Object arg0)
boolean	removeAll(java.util.Collection<?> arg0)
boolean	retainAll(java.util.Collection<?> arg0)
int	size()
java.lang.Object[]	toArray()
<T> T[]	toArray(T[] a)
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

equals, hashCode

Constructor Detail

Graph

public Graph()

Creates a new empty graph.

Method Detail

add

public boolean add(Vertex<E> v)

Adds a vertex at its given location to this graph.

Specified by:

add in interface java.util.Collection<Vertex<E>>

Parameters:

v - - a vertex

addAll

public boolean addAll(java.util.Collection<? extends Vertex<E>> arg0)

Specified by:

addAll in interface java.util.Collection<Vertex<E>>

clear

public void clear()

Specified by:

clear in interface java.util.Collection<Vertex<E>>

complete

public void complete()

createOutputFile

public java.io.File createOutputFile(java.lang.String path)
                              throws java.io.IOException

Creates an output file at the given location using the Simple Graph Format.

Parameters:

path - - a path for the file.

Returns:

a file which has been instantiated and written with the graph data.

Throws:

java.io.IOException - - if the file cannot be read or created.

createInputGraph

public static <E> Graph<E> createInputGraph(java.io.File file)
                                 throws java.io.FileNotFoundException

Creates a Graph object given a file in the Simple Graph Format.

Parameters:

file - - the file to be read

Returns:

a new graph created from the file data.

Throws:

java.io.FileNotFoundException - - if the file cannot be found.

contains

public boolean contains(java.lang.Object o)

Specified by:

contains in interface java.util.Collection<Vertex<E>>

containsAll

public boolean containsAll(java.util.Collection<?> c)

Specified by:

containsAll in interface java.util.Collection<Vertex<E>>

getComponent

public java.util.Set<Vertex<E>> getComponent(Vertex<E> v)

getLocations

public java.util.Set<Location> getLocations()

Retrieves the set of all vertex locations for this graph.

Returns:

a set of locations.

getVertexAt

public Vertex<E> getVertexAt(Location l)

Retrieves the vertex at a given location. This method guarantees that loc == getVertexAt(loc).getLocation() will always return true.

Parameters:

l - - a location

Returns:

the vertex at l.

getVertexCollection

public java.util.Collection<Vertex<E>> getVertexCollection()

getVertices

public java.util.HashMap<Location,Vertex<E>> getVertices()

Returns the map of locations to vertices in this graph.

Returns:

- the HashMap

getWeight

public double getWeight()

get

public Vertex<E> get(Location loc)

Returns the Vertex contained at Location loc. If no vertex exists at the given location, null will be returned.

Parameters:

loc - - a location

Returns:

the vertex at that location.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Collection<Vertex<E>>

genMinSpanTree

public void genMinSpanTree(Vertex<E> v)

remove

public Vertex<E> remove(Location loc)

Removes and returns the vertex at the given location. If this node has any edges connecting to other nodes, they will be removed from that vertex and its neighbors. If no node is at that location, null is returned.

Parameters:

loc - - a location

Returns:

the vertex at that location

remove

public boolean remove(java.lang.Object arg0)

Specified by:

remove in interface java.util.Collection<Vertex<E>>

removeAll

public boolean removeAll(java.util.Collection<?> arg0)

Specified by:

removeAll in interface java.util.Collection<Vertex<E>>

retainAll

public boolean retainAll(java.util.Collection<?> arg0)

Specified by:

retainAll in interface java.util.Collection<Vertex<E>>

size

public int size()

Specified by:

size in interface java.util.Collection<Vertex<E>>

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection<Vertex<E>>

toArray

public <T> T[] toArray(T[] a)

Specified by:

toArray in interface java.util.Collection<Vertex<E>>

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

iterator

public java.util.Iterator<Vertex<E>> iterator()

Returns an iterator that iterates over the vertices in the graph.

Specified by:

iterator in interface java.lang.Iterable<Vertex<E>>

Specified by:

iterator in interface java.util.Collection<Vertex<E>>

Returns:

a vertex iterator.