org.apache.mahout.cf.taste.hadoop.als

Class PredictionMapper

java.lang.Object

org.apache.hadoop.mapreduce.Mapper<K1,V1,K2,V2>

org.apache.mahout.cf.taste.hadoop.als.SharingMapper<org.apache.hadoop.io.IntWritable,VectorWritable,org.apache.hadoop.io.LongWritable,RecommendedItemsWritable,Pair<OpenIntObjectHashMap<Vector>,OpenIntObjectHashMap<Vector>>>

org.apache.mahout.cf.taste.hadoop.als.PredictionMapper

public class PredictionMapper
extends SharingMapper<org.apache.hadoop.io.IntWritable,VectorWritable,org.apache.hadoop.io.LongWritable,RecommendedItemsWritable,Pair<OpenIntObjectHashMap<Vector>,OpenIntObjectHashMap<Vector>>>

a multithreaded mapper that loads the feature matrices U and M into memory. Afterwards it computes recommendations from these. Can be executed by a MultithreadedSharingMapper.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Mapper

org.apache.hadoop.mapreduce.Mapper.Context

Constructor Summary

Constructors

Constructor and Description
PredictionMapper()

Method Summary

Modifier and Type	Method and Description
protected void	map(org.apache.hadoop.io.IntWritable userIndexWritable, VectorWritable ratingsWritable, org.apache.hadoop.mapreduce.Mapper.Context ctx)
protected void	setup(org.apache.hadoop.mapreduce.Mapper.Context ctx)

Methods inherited from class org.apache.hadoop.mapreduce.Mapper

cleanup, run

Methods inherited from class java.lang.Object

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

Constructor Detail

PredictionMapper

public PredictionMapper()

Method Detail

setup

protected void setup(org.apache.hadoop.mapreduce.Mapper.Context ctx)
              throws IOException,
                     InterruptedException

Overrides:

setup in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.IntWritable,VectorWritable,org.apache.hadoop.io.LongWritable,RecommendedItemsWritable>

Throws:

IOException

InterruptedException

map

protected void map(org.apache.hadoop.io.IntWritable userIndexWritable,
                   VectorWritable ratingsWritable,
                   org.apache.hadoop.mapreduce.Mapper.Context ctx)
            throws IOException,
                   InterruptedException

Overrides:

map in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.IntWritable,VectorWritable,org.apache.hadoop.io.LongWritable,RecommendedItemsWritable>

Throws:

IOException

InterruptedException