I am trying to write a map reduce function which takes take the following types
of <key,value> pairs
Map function -- should read floating point values (i dont really care about
key)
it should output <null,floatwritable>
reduce -- input- <null,floatwritable>
output <null,floatwritable>
I Have set the input format to be TextInputFormat.class (is this right?)
Please tell me what signature am I supposed to use for the Map/ reduce methods?
as of now I am trying to write the Map function as
public static class Map extends MapReduceBase implements Mapper<LongWritable,
FloatWritable, Text, FloatWritable>
{
public void map(LongWritable key, FloatWritable value,
OutputCollector<Text, FloatWritable> output, Reporter reporter) throws
IOException
{ ...........
..........
}
}
But I am getting an error saying text cannot be cast to longwritable.
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