IndexedCounter (S-Space Package 2.0.1 API)

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

All Implemented Interfaces:

Counter<T>, Serializable, Iterable<Map.Entry<T,Integer>>
```
public class IndexedCounter<T>
extends Object
implements Counter<T>, Serializable
```
A utility for counting unique instance of an object. Unlike an ObjectCounter, this class uses an Indexer to identify object equivalence and record the count. This class is intended for use when multiple Counter instances are needed to be run in parallel or to keep a record of the counters without storing references to the object instances in each of the Counter instances. This results in a linear space savings at the cost of some minor performance from needing to index the objects.
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

See Also:
Indexer, Serialized Form

Constructor Summary

Constructors
Constructor and Description
`IndexedCounter(Indexer<T> objectIndices)` Creates an empty `Counter` that uses the provided indexer to map countable values to corresponding indices.
`IndexedCounter(Indexer<T> objectIndices, boolean allowNewIndices)` Creates an empty `Counter` that uses the provided indexer to map countable values to corresponding indices.

Method Summary

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

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

- Constructor Detail
  - IndexedCounter
```
public IndexedCounter(Indexer<T> objectIndices)
```
    Creates an empty Counter that uses the provided indexer to map countable values to corresponding indices. Should an object be counted that was not in the indexer, a new index will be added for it.
  - IndexedCounter
```
public IndexedCounter(Indexer<T> objectIndices,
              boolean allowNewIndices)
```
    Creates an empty Counter that uses the provided indexer to map countable values to corresponding indices. Objects wth no corresponding indices will only be counted (and added to the Indexer) if allowNewIndices is true.
    
    Parameters:
    allowNewIndices - true if objects with new index should be added to objectIndices
- Method Detail
  - add
```
public void add(Counter<? extends T> counter)
```
    Adds the counts from the provided Counter to the current counts, adding new elements as needed.
    
    Specified by:
    
    add in interface Counter<T>
  - count
```
public int count(T obj)
```
    Counts the object, increasing its total count by 1.
    
    Specified by:
    
    count in interface Counter<T>
  - count
```
public int count(T obj,
        int count)
```
    Counts the object, increasing its total count by the specified positive amount.
    
    Specified by:
    
    count in interface Counter<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.
  - countAll
```
public void countAll(Collection<? extends T> c)
```
    Counts all the elements in the collection.
    
    Specified by:
    
    countAll in interface Counter<T>
    
    Parameters:
    c - a collection of elements to count
  - equals
```
public boolean equals(Object o)
```
    Specified by:
    
    equals in interface Counter<T>
    
    Overrides:
    
    equals in class Object
  - getCount
```
public int getCount(T obj)
```
    Returns the number of times the specified object has been seen by this counter.
    
    Specified by:
    
    getCount in interface Counter<T>
  - getFrequency
```
public double getFrequency(T obj)
```
    Returns the frequency of this object relative to the counts of all other objects. This value may also be interpreted as the probability of the instance of obj being seen in the items that have been counted.
    
    Specified by:
    
    getFrequency in interface Counter<T>
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface Counter<T>
    
    Overrides:
    
    hashCode in class Object
  - items
```
public Set<T> items()
```
    Returns a view of the items 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<T>
  - iterator
```
public Iterator<Map.Entry<T,Integer>> iterator()
```
    Returns an interator over the elements that have been counted thusfar and their respective counts.
    
    Specified by:
    
    iterator in interface Counter<T>
    
    Specified by:
    
    iterator in interface Iterable<Map.Entry<T,Integer>>
  - max
```
public T max()
```
    Returns the element that currently has the largest count. If no objects have been counted, null is returned. Ties in counts are arbitrarily broken.
    
    Specified by:
    
    max in interface Counter<T>
  - min
```
public T min()
```
    Returns the element that currently has the smallest count. If no objects have been counted, null is returned. Ties in counts are arbitrarily broken.
    
    Specified by:
    
    min in interface Counter<T>
  - reset
```
public void reset()
```
    Resets the counts for all objects. The size of Counter.items() will be 0 after this call. Note that this does not affect the object indices.
    
    Specified by:
    
    reset in interface Counter<T>
  - size
```
public int size()
```
    Returns the number of unique instances that are currently being counted.
    
    Specified by:
    
    size in interface Counter<T>
  - sum
```
public int sum()
```
    Returns the total number of instances that have been counted.
    
    Specified by:
    
    sum in interface Counter<T>
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class IndexedCounter<T>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

IndexedCounter

IndexedCounter

Method Detail

add

count

count

countAll

equals

getCount

getFrequency

hashCode

items

iterator

max

min

reset

size

sum

toString