## org.apache.hadoop.examples
Class PiEstimator.PiMapper

    java.lang.Object
      org.apache.hadoop.mapred.MapReduceBase
          org.apache.hadoop.examples.PiEstimator.PiMapper

All Implemented Interfaces:
  Closeable, JobConfigurable, Mapper<LongWritable,LongWritable,BooleanWritable,LongWritable>

Enclosing class:
  PiEstimator

    public static class PiEstimator.PiMapper

extends MapReduceBase
implements Mapper<LongWritable,LongWritable,BooleanWritable,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
`PiEstimator.PiMapper()`

Method Summary
`void` `map(LongWritable offset, LongWritable size, OutputCollector<BooleanWritable,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(LongWritable offset,
                    LongWritable size,
                    OutputCollector<BooleanWritable,LongWritable> out,
                    Reporter reporter)
             throws IOException

  Map method.

  Specified by:
    `map` in interface `Mapper<LongWritable,LongWritable,BooleanWritable,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:
    `IOException`

Copyright © 2009 The Apache Software Foundation