org.apache.flink.streaming.api.functions.windowing.delta

Class CosineDistance<DATA>

java.lang.Object

org.apache.flink.streaming.api.functions.windowing.delta.ExtractionAwareDeltaFunction<DATA,double[]>

org.apache.flink.streaming.api.functions.windowing.delta.CosineDistance<DATA>

Type Parameters:

DATA - The input data type. This delta function works with a double[], but can extract/convert to it from any other given object in case the respective extractor has been set. See ExtractionAwareDeltaFunction for more information.

All Implemented Interfaces:

Serializable, DeltaFunction<DATA>

@PublicEvolving
public class CosineDistance<DATA>
extends ExtractionAwareDeltaFunction<DATA,double[]>

This delta function calculates the cosine distance between two given vectors. The cosine distance is defined as: cosineDistance=1-cosineSimilarity

Cosine similarity: http://en.wikipedia.org/wiki/Cosine_similarity

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CosineDistance()
CosineDistance(Extractor<DATA,double[]> converter)

Method Summary

Modifier and Type	Method and Description
double	getNestedDelta(double[] oldDataPoint, double[] newDataPoint) This method is exactly the same as DeltaFunction.getDelta(Object, Object) except that it gets the result of the previously done extractions as input.

Methods inherited from class org.apache.flink.streaming.api.functions.windowing.delta.ExtractionAwareDeltaFunction

getDelta

Methods inherited from class java.lang.Object

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

Constructor Detail

CosineDistance

public CosineDistance()

CosineDistance

public CosineDistance(Extractor<DATA,double[]> converter)

Method Detail

getNestedDelta

public double getNestedDelta(double[] oldDataPoint,
                             double[] newDataPoint)

Description copied from class: ExtractionAwareDeltaFunction

This method is exactly the same as DeltaFunction.getDelta(Object, Object) except that it gets the result of the previously done extractions as input. Therefore, this method only does the actual calculation of the delta but no data extraction or conversion.

Specified by:

getNestedDelta in class ExtractionAwareDeltaFunction<DATA,double[]>

Parameters:

oldDataPoint - the older data point.

newDataPoint - the new data point.

Returns:

the delta between the two points.