edu.umd.cloud9.util
Class Histogram<T extends Comparable<T>>

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<K,V>
          edu.umd.cloud9.util.Scorekeeper<T,Integer>
              edu.umd.cloud9.util.Histogram<T>

Type Parameters:

T - type of object

All Implemented Interfaces:

Serializable, Cloneable, Map<T,Integer>

public class Histogram<T extends Comparable<T>>
extends Scorekeeper<T,Integer>

A class for keeping track of the number of times an object has been encountered. This is useful for counting things in a stream, e.g., POS tags, terms, etc. This object extends Scorekeeper.

Example usage:

 Histogram<String> h = new Histogram<String>();
 String[] terms = myString.split("\\s+");
 
 for (String term : terms) {
        h.count(term);
 }
 
 for (Map.Entry<String, Integer> e : h.entrySet()) {
        // do something with e.getKey()
        // do something with e.getValue()
 }
 

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Constructor Summary

Histogram()
Constructs an Histogram.

Method Summary

void	clear() Resets this histogram, purging all observations and counts.
void	count(T instance) Adds an instance to the set of observations.
int	getCount(T inst) Returns the number of times a particular instance has been observed.
int	getTotalCount() Returns the total number of observations.
void	printCounts() Prints each instance and how many times its been observed, sorted by the counts.

Methods inherited from class edu.umd.cloud9.util.Scorekeeper

getEntryByRank, getSortedEntries, getSortedEntries, getSortedKeys, getTopEntry

Methods inherited from class java.util.HashMap

clone, containsKey, containsValue, entrySet, get, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

Histogram

public Histogram()

Constructs an Histogram.

Method Detail

clear

public void clear()

Resets this histogram, purging all observations and counts.

Specified by:

clear in interface Map<T extends Comparable<T>,Integer>

Overrides:

clear in class HashMap<T extends Comparable<T>,Integer>

count

public void count(T instance)

Adds an instance to the set of observations.

Parameters:

instance - the instance observed

getCount

public int getCount(T inst)

Returns the number of times a particular instance has been observed.

Parameters:

inst - the instance

Returns:

the count of the instance

getTotalCount

public int getTotalCount()

Returns the total number of observations.

Returns:

the total number of observations

printCounts

public void printCounts()

Prints each instance and how many times its been observed, sorted by the counts.