org.apache.mahout.math.hadoop.stochasticsvd

Class ABtJob.ABtMapper

java.lang.Object

org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Writable,VectorWritable,SplitPartitionedWritable,SparseRowBlockWritable>

org.apache.mahout.math.hadoop.stochasticsvd.ABtJob.ABtMapper

Enclosing class:

ABtJob

public static class ABtJob.ABtMapper
extends org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Writable,VectorWritable,SplitPartitionedWritable,SparseRowBlockWritable>

So, here, i preload A block into memory.

A sparse matrix seems to be ideal for that but there are two reasons why i am not using it:

• 1) I don't know the full block height. so i may need to reallocate it from time to time. Although this probably not a showstopper.
• 2) I found that RandomAccessSparseVectors seem to take much more memory than the SequentialAccessSparseVectors.

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
ABtMapper()

Method Summary

Modifier and Type	Method and Description
protected void	cleanup(org.apache.hadoop.mapreduce.Mapper.Context context)
protected void	map(org.apache.hadoop.io.Writable key, VectorWritable value, org.apache.hadoop.mapreduce.Mapper.Context context)
protected void	setup(org.apache.hadoop.mapreduce.Mapper.Context context)

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

run

Methods inherited from class java.lang.Object

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

Constructor Detail

ABtMapper

public ABtMapper()

Method Detail

map

protected void map(org.apache.hadoop.io.Writable key,
                   VectorWritable value,
                   org.apache.hadoop.mapreduce.Mapper.Context context)
            throws IOException,
                   InterruptedException

Overrides:

map in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Writable,VectorWritable,SplitPartitionedWritable,SparseRowBlockWritable>

Throws:

IOException

InterruptedException

cleanup

protected void cleanup(org.apache.hadoop.mapreduce.Mapper.Context context)
                throws IOException,
                       InterruptedException

Overrides:

cleanup in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Writable,VectorWritable,SplitPartitionedWritable,SparseRowBlockWritable>

Throws:

IOException

InterruptedException

setup

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

Overrides:

setup in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Writable,VectorWritable,SplitPartitionedWritable,SparseRowBlockWritable>

Throws:

IOException

InterruptedException