ConditionalFrequencyDistribution (DKPro Core - Master Aggregator 1.7.0 API)

java.lang.Object
- de.tudarmstadt.ukp.dkpro.core.api.frequency.util.ConditionalFrequencyDistribution<C,V>

Type Parameters:
C - the type of the conditions
V - the type of the samples
```
public class ConditionalFrequencyDistribution<C,V>
extends Object
```
Inspired by nltk.probability.ConditionalFreqDist Maps a condition to a FrequencyDistribution.
This class could be used to learn how frequently a word collocates with another word. Suppose we want to know how frequently the word "of" appears after the word "because", then ConditionalFrequencyDistribution can be used as follows:
```
 ConditionalFrequencyDistribution<String, String> cfd =
     new ConditionalFrequencyDistribution<String, String>();

 cfd.addSample("because", "in");
 cfd.addSample("because", "of");
 cfd.addSample("despite", "in");
 cfd.addSample("because", "of");

 System.out.println(cfd.getCount("despite", "of"));
 
```
The last call to getCount(C, V) will yield 2, because given the condition that the first word in a two-word sequence is "because", the word "of" has appeared twice.

This class was inspired by NLTK's FreqDist.
Author:

zesch

See Also:
FrequencyDistribution

Constructor Summary

Constructors
Constructor and Description
`ConditionalFrequencyDistribution()` Creates a new empty `ConditionalFrequencyDistribution`.
`ConditionalFrequencyDistribution(Map<C,Iterable<V>> samples)` Creates a new `ConditionalFrequencyDistribution` and fills it with samples from a map.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addSample(C condition, V sample, long frequency)` Adds a sample with a certain frequency under a given `condition`.
`Set<C>`	`getConditions()` Returns all conditions for which samples have been recorded.
`long`	`getCount(C condition, V sample)` Returns the total number of samples which equal a given `sample` under a given `condition`.
`FrequencyDistribution<V>`	`getFrequencyDistribution(C condition)` Returns the `FrequencyDistribution` under a given `condition`, or `null` if this distribution contains no such `FrequencyDistribution` for this `condition`.
`long`	`getN()`
`boolean`	`hasCondition(C condition)` Indicates whether samples have been recorded under a given `condition`.
`void`	`inc(C condition, V sample)` Increases a sample under a given `condition`.
`void`	`incAll(C condition, Iterable<V> samples)` Increases all provided samples under a given `condition`.
`void`	`removeCondition(C condition)` Remove a previously registered condition
`void`	`setFrequencyDistribution(C condition, FrequencyDistribution<V> fd)` Directly set the frequency distribution for a given condition.
`String`	`toString()`

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

- Constructor Detail
  - ConditionalFrequencyDistribution
```
public ConditionalFrequencyDistribution()
```
    Creates a new empty ConditionalFrequencyDistribution.
  - ConditionalFrequencyDistribution
```
public ConditionalFrequencyDistribution(Map<C,Iterable<V>> samples)
```
    Creates a new ConditionalFrequencyDistribution and fills it with samples from a map.
    
    Parameters:
    samples - the Iterable to fill from
- Method Detail
  - getN
```
public long getN()
```
    Returns:
    The total number of sample outcomes that have been recorded by this ConditionalFreqDist.
  - getCount
```
public long getCount(C condition,
            V sample)
```
    Returns the total number of samples which equal a given sample under a given condition.
    If there are no samples for the condition in question on record, 0 will be returned.
    
    Parameters:
    condition - the condition
    sample - the sample under a given condition
    
    Returns:
    the number of all samples which equal sample
  - getFrequencyDistribution
```
public FrequencyDistribution<V> getFrequencyDistribution(C condition)
```
    Returns the FrequencyDistribution under a given condition, or null if this distribution contains no such FrequencyDistribution for this condition.
    
    Parameters:
    condition - the condition
    
    Returns:
    the distribution the condition maps to
  - setFrequencyDistribution
```
public void setFrequencyDistribution(C condition,
                            FrequencyDistribution<V> fd)
```
    Directly set the frequency distribution for a given condition.
    
    Parameters:
    condition - the condition.
    fd - the distribution.
  - getConditions
```
public Set<C> getConditions()
```
    Returns all conditions for which samples have been recorded.
    
    Returns:
    a Set of all recorded conditions
  - hasCondition
```
public boolean hasCondition(C condition)
```
    Indicates whether samples have been recorded under a given condition.
    
    Parameters:
    condition - the condition in question
    
    Returns:
    true if samples for condition exist
  - inc
```
public void inc(C condition,
       V sample)
```
    Increases a sample under a given condition.
    
    Parameters:
    condition - the condition for this sample
    sample - the sample to add
  - incAll
```
public void incAll(C condition,
          Iterable<V> samples)
```
    Increases all provided samples under a given condition.
    If there is no FrequencyDistribution present for the given condition, a new empty one will be created and populated from the given samples.
    
    Parameters:
    condition - the condition for the samples
    samples - the samples to add
  - addSample
```
public void addSample(C condition,
             V sample,
             long frequency)
```
    Adds a sample with a certain frequency under a given condition.
    
    Parameters:
    condition - the condition for this sample
    sample - the sample to add
    frequency - the frequenc of the sample
  - removeCondition
```
public void removeCondition(C condition)
```
    Remove a previously registered condition
    
    Parameters:
    condition - the condition to be removed
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class ConditionalFrequencyDistribution<C,V>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ConditionalFrequencyDistribution

ConditionalFrequencyDistribution

Method Detail

getN

getCount

getFrequencyDistribution

setFrequencyDistribution

getConditions

hasCondition

inc

incAll

addSample

removeCondition

toString