org.apache.hadoop.examples

Class PiEstimator.PiMapper

java.lang.Object

org.apache.hadoop.mapred.MapReduceBase

org.apache.hadoop.examples.PiEstimator.PiMapper

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, JobConfigurable, Mapper<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.BooleanWritable,org.apache.hadoop.io.LongWritable>

Enclosing class:

PiEstimator

public static class PiEstimator.PiMapper
extends MapReduceBase
implements Mapper<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.BooleanWritable,org.apache.hadoop.io.LongWritable>

Mapper class for Pi estimation. Generate points in a unit square and then count points inside/outside of the inscribed circle of the square.

Constructor Summary

Constructors

Constructor and Description
PiEstimator.PiMapper()

Method Summary

Methods

Modifier and Type	Method and Description
void	map(org.apache.hadoop.io.LongWritable offset, org.apache.hadoop.io.LongWritable size, OutputCollector<org.apache.hadoop.io.BooleanWritable,org.apache.hadoop.io.LongWritable> out, Reporter reporter) Map method.

Methods inherited from class org.apache.hadoop.mapred.MapReduceBase

close, configure

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.mapred.JobConfigurable

configure

Methods inherited from interface java.io.Closeable

close

Constructor Detail

PiEstimator.PiMapper

public PiEstimator.PiMapper()

Method Detail

map

public void map(org.apache.hadoop.io.LongWritable offset,
       org.apache.hadoop.io.LongWritable size,
       OutputCollector<org.apache.hadoop.io.BooleanWritable,org.apache.hadoop.io.LongWritable> out,
       Reporter reporter)
         throws java.io.IOException

Map method.

Specified by:

map in interface Mapper<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.BooleanWritable,org.apache.hadoop.io.LongWritable>

Parameters:

offset - samples starting from the (offset+1)th sample.

size - the number of samples for this map

out - output {ture->numInside, false->numOutside}

reporter -

Throws:

java.io.IOException