PairCounter (S-Space Package 2.0.1 API)

java.lang.Object
- edu.ucla.sspace.util.PairCounter<T>

All Implemented Interfaces:

Counter<Pair<T>>, Serializable, Iterable<Map.Entry<Pair<T>,Integer>>
```
public class PairCounter<T>
extends Object
implements Counter<Pair<T>>, Serializable
```
A utility for counting unique instance of pairs of objects. This class provides several overloads for callers to provide the objects themselves without needing to explicitly create a Pair instance.
This class supports iterating over the set of instances being counted as well as the instances and counts together. All collections views that are returned are unmodifiable and will throw an exception if a mutating method is called.
This class is not thread-safe. Unless otherwise noted, all methods will throw a NullPointerException if passed a null element or a Pair with a null element.

See Also:
Serialized Form

Constructor Summary

Constructors
Constructor and Description
`PairCounter()` Creates an empty `Counter`.
`PairCounter(Collection<? extends Pair<T>> items)` Creates a `Counter` whose initial state has counted all of the specified items.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(Counter<? extends Pair<T>> counter)` Adds the counts from the provided `Counter` to the current counts, adding new elements as needed.
`int`	`count(Pair<T> obj)` Counts the pair of objects, increasing its total count by 1.
`int`	`count(Pair<T> obj, int count)` Counts the pair, increasing its total count by the specified positive amount.
`int`	`count(T x, T y)` Counts the pair of objects, increasing its total count by 1.
`int`	`count(T x, T y, int count)` Counts the pair, increasing its total count by the specified positive amount.
`void`	`countAll(Collection<? extends Pair<T>> c)` Counts all the elements in the collection.
`boolean`	`equals(Object o)`
`int`	`getCount(Pair<T> obj)` Returns the number of times the specified pair of objects has been seen by this counter.
`int`	`getCount(T x, T y)` Returns the number of times the specified pair of objects has been seen by this counter.
`double`	`getFrequency(Pair<T> p)` Returns the frequency of this object pair relative to the counts of all other object pair.
`int`	`hashCode()`
`Set<Pair<T>>`	`items()` Returns a view of the pairs currently being counted.
`Iterator<Map.Entry<Pair<T>,Integer>>`	`iterator()` Returns an iterator over the pairs that have been counted thusfar and their respective counts.
`Pair<T>`	`max()` Returns the pair that currently has the largest count.
`Pair<T>`	`min()` Returns the pair that currently has the smallest count.
`void`	`reset()` Resets the counts for all pairs.
`int`	`size()` Returns the number of pairs that are currently being counted.
`int`	`sum()` Returns the total number of pairs that have been counted.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - PairCounter
```
public PairCounter()
```
    Creates an empty Counter.
  - PairCounter
```
public PairCounter(Collection<? extends Pair<T>> items)
```
    Creates a Counter whose initial state has counted all of the specified items.
- Method Detail
  - add
```
public void add(Counter<? extends Pair<T>> counter)
```
    Adds the counts from the provided Counter to the current counts, adding new elements as needed.
    
    Specified by:
    
    add in interface Counter<Pair<T>>
  - count
```
public int count(Pair<T> obj)
```
    Counts the pair of objects, increasing its total count by 1.
    
    Specified by:
    
    count in interface Counter<Pair<T>>
  - count
```
public int count(T x,
        T y)
```
    Counts the pair of objects, increasing its total count by 1.
  - count
```
public int count(Pair<T> obj,
        int count)
```
    Counts the pair, increasing its total count by the specified positive amount.
    
    Specified by:
    
    count in interface Counter<Pair<T>>
    
    Parameters:
    count - a positive value for the number of times the object occurred
    
    Returns:
    the current count for the counted object
    
    Throws:
    
    IllegalArgumentException - if count is not a positive value.
  - count
```
public int count(T x,
        T y,
        int count)
```
    Counts the pair, increasing its total count by the specified positive amount.
    
    Parameters:
    count - a positive value for the number of times the object occurred
    
    Throws:
    
    IllegalArgumentException - if count is not a positive value.
  - countAll
```
public void countAll(Collection<? extends Pair<T>> c)
```
    Counts all the elements in the collection.
    
    Specified by:
    
    countAll in interface Counter<Pair<T>>
    
    Parameters:
    c - a collection of elements to count
  - equals
```
public boolean equals(Object o)
```
    Specified by:
    
    equals in interface Counter<Pair<T>>
    
    Overrides:
    
    equals in class Object
  - getCount
```
public int getCount(Pair<T> obj)
```
    Returns the number of times the specified pair of objects has been seen by this counter.
    
    Specified by:
    
    getCount in interface Counter<Pair<T>>
  - getCount
```
public int getCount(T x,
           T y)
```
    Returns the number of times the specified pair of objects has been seen by this counter.
  - getFrequency
```
public double getFrequency(Pair<T> p)
```
    Returns the frequency of this object pair relative to the counts of all other object pair. This value may also be interpreted as the probability of the instance of p being seen in the items that have been counted.
    
    Specified by:
    
    getFrequency in interface Counter<Pair<T>>
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface Counter<Pair<T>>
    
    Overrides:
    
    hashCode in class Object
  - items
```
public Set<Pair<T>> items()
```
    Returns a view of the pairs currently being counted. The returned view is read-only; any attempts to modify this view will throw an UnsupportedOperationException.
    
    Specified by:
    
    items in interface Counter<Pair<T>>
  - iterator
```
public Iterator<Map.Entry<Pair<T>,Integer>> iterator()
```
    Returns an iterator over the pairs that have been counted thusfar and their respective counts.
    
    Specified by:
    
    iterator in interface Counter<Pair<T>>
    
    Specified by:
    
    iterator in interface Iterable<Map.Entry<Pair<T>,Integer>>
  - max
```
public Pair<T> max()
```
    Returns the pair that currently has the largest count. If no pairs have been counted, null is returned. Ties in counts are arbitrarily broken.
    
    Specified by:
    
    max in interface Counter<Pair<T>>
  - min
```
public Pair<T> min()
```
    Returns the pair that currently has the smallest count. If no pairs have been counted, null is returned. Ties in counts are arbitrarily broken.
    
    Specified by:
    
    min in interface Counter<Pair<T>>
  - reset
```
public void reset()
```
    Resets the counts for all pairs. The size of items() will be 0 after this call.
    
    Specified by:
    
    reset in interface Counter<Pair<T>>
  - size
```
public int size()
```
    Returns the number of pairs that are currently being counted.
    
    Specified by:
    
    size in interface Counter<Pair<T>>
  - sum
```
public int sum()
```
    Returns the total number of pairs that have been counted.
    
    Specified by:
    
    sum in interface Counter<Pair<T>>
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class PairCounter<T>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

PairCounter

PairCounter

Method Detail

add

count

count

count

count

countAll

equals

getCount

getCount

getFrequency

hashCode

items

iterator

max

min

reset

size

sum

toString