burlap.datastructures

Class HashedAggregator<K>

java.lang.Object

burlap.datastructures.HashedAggregator<K>

Type Parameters:

K - the key, which must be hashable.

public class HashedAggregator<K>
extends java.lang.Object

Datasturcutre for maintaining numeric aggregated values for different keys. If the value has never been queried or added to before, then it assumes an initial value (zero by default). The values are backed by a HashMap.

Author:

James MacGlashan

Field Summary

Fields

Modifier and Type	Field and Description
protected double	initialValue The initial value for each key
protected java.util.HashMap<K,java.lang.Double>	storage The backing hash map

Constructor Summary

Constructors

Constructor and Description
HashedAggregator() Initializes with initial value for each key being 0.0.
HashedAggregator(double initialValue) Initializes with the given initial value for each key.
HashedAggregator(double initialValue, int capacity) Initializes with the given initial value for each key and the initial capacity for the table.

Method Summary

Modifier and Type	Method and Description
void	add(K ind, double v) Adds a specified value to a key.
boolean	containsKey(K key) Returns true if this object has a value associated with the specified key, false otherwise.
java.util.Set<java.util.Map.Entry<K,java.lang.Double>>	entrySet() The entry set for stored keys and values.
java.util.Map<K,java.lang.Double>	getHashMap() Returns the HashMap that backs this object.
java.util.Set<K>	keySet() The set of keys stored.
int	size() Returns the number of keys stored.
double	v(K ind) The current value associated with key ind.
java.util.Collection<java.lang.Double>	valueSet() The set of values stored.

Methods inherited from class java.lang.Object

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

Field Detail

storage

protected java.util.HashMap<K,java.lang.Double> storage

The backing hash map

initialValue

protected double initialValue

The initial value for each key

Constructor Detail

HashedAggregator

public HashedAggregator()

Initializes with initial value for each key being 0.0.

HashedAggregator

public HashedAggregator(double initialValue)

Initializes with the given initial value for each key.

Parameters:

initialValue - the initial value associated with each key.

HashedAggregator

public HashedAggregator(double initialValue,
                        int capacity)

Initializes with the given initial value for each key and the initial capacity for the table.

Parameters:

initialValue - the initial value associated with each key.

capacity - the initial memory capacity of the storing table

Method Detail

add

public void add(K ind,
                double v)

Adds a specified value to a key. If the key has not been index previously, its new value is this object's initialValue datamember + v.

Parameters:

ind - the key index

v - the value to add to the value associated with ind.

v

public double v(K ind)

The current value associated with key ind. This object's initialValue datamember is returned if nothing has been added to this value previously.

Parameters:

ind - the key index

Returns:

the value associated with the key index.

size

public int size()

Returns the number of keys stored.

Returns:

the number of keys stored.

keySet

public java.util.Set<K> keySet()

The set of keys stored.

Returns:

The set of keys stored.

valueSet

public java.util.Collection<java.lang.Double> valueSet()

The set of values stored.

Returns:

The set of values stored.

entrySet

public java.util.Set<java.util.Map.Entry<K,java.lang.Double>> entrySet()

The entry set for stored keys and values.

Returns:

The entry set for stored keys and values.

getHashMap

public java.util.Map<K,java.lang.Double> getHashMap()

Returns the HashMap that backs this object.

Returns:

the HashMap that backs this object.

containsKey

public boolean containsKey(K key)

Returns true if this object has a value associated with the specified key, false otherwise.

Parameters:

key - the key to check

Returns:

true if this object has a value associated with the specified key, false otherwise.