org.apache.mahout.cf.taste.hadoop

Class ToItemPrefsMapper

java.lang.Object

org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text,VarLongWritable,VarLongWritable>

org.apache.mahout.cf.taste.hadoop.ToEntityPrefsMapper

org.apache.mahout.cf.taste.hadoop.ToItemPrefsMapper

public final class ToItemPrefsMapper
extends ToEntityPrefsMapper

Input

Intended for use with TextInputFormat; accepts line number / line pairs as LongWritable/Text pairs.

Each line is assumed to be of the form userID,itemID,preference, or userID,itemID.

Output

Outputs the user ID as a VarLongWritable mapped to the item ID and preference as a EntityPrefWritable.

Nested Class Summary

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

org.apache.hadoop.mapreduce.Mapper.Context

Field Summary

Fields inherited from class org.apache.mahout.cf.taste.hadoop.ToEntityPrefsMapper

RATING_SHIFT, TRANSPOSE_USER_ITEM

Constructor Summary

Constructors

Constructor and Description
ToItemPrefsMapper()

Method Summary

Methods inherited from class org.apache.mahout.cf.taste.hadoop.ToEntityPrefsMapper

map, setup

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

ToItemPrefsMapper

public ToItemPrefsMapper()