org.apache.mahout.math.hadoop.stochasticsvd
Class DenseBlockWritable

java.lang.Object
  extended by org.apache.mahout.math.hadoop.stochasticsvd.DenseBlockWritable
All Implemented Interfaces:
org.apache.hadoop.io.Writable

public class DenseBlockWritable
extends Object
implements org.apache.hadoop.io.Writable

Ad-hoc substitution for MatrixWritable. Perhaps more useful for situations with mostly dense data (such as Q-blocks) but reduces GC by reusing the same block memory between loads and writes.

in case of Q blocks, it doesn't even matter if they this data is dense cause we need to unpack it into dense for fast access in computations anyway and even if it is not so dense the block compressor in sequence files will take care of it for the serialized size.


Constructor Summary
DenseBlockWritable()
           
 
Method Summary
 double[][] getBlock()
           
 void readFields(DataInput in)
           
 void setBlock(double[][] block)
           
 void write(DataOutput out)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DenseBlockWritable

public DenseBlockWritable()
Method Detail

setBlock

public void setBlock(double[][] block)

getBlock

public double[][] getBlock()

readFields

public void readFields(DataInput in)
                throws IOException
Specified by:
readFields in interface org.apache.hadoop.io.Writable
Throws:
IOException

write

public void write(DataOutput out)
           throws IOException
Specified by:
write in interface org.apache.hadoop.io.Writable
Throws:
IOException


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