de.jungblut.writable

Class MatrixWritable

java.lang.Object

de.jungblut.writable.MatrixWritable

All Implemented Interfaces:

org.apache.hadoop.io.Writable

public final class MatrixWritable
extends Object
implements org.apache.hadoop.io.Writable

Writable class for dense and sparse matrices.

Field Summary

Fields

Modifier and Type	Field and Description
static byte	DENSE_DOUBLE_MATRIX
static byte	SPARSE_DOUBLE_ROW_MATRIX

Constructor Summary

Constructors

Constructor and Description
MatrixWritable()
MatrixWritable(de.jungblut.math.DoubleMatrix mat)

Method Summary

Modifier and Type	Method and Description
de.jungblut.math.DoubleMatrix	getMatrix()
static de.jungblut.math.dense.DenseDoubleMatrix	readDenseMatrix(DataInput in) Reads a dense matrix from the given input stream.
void	readFields(DataInput in)
static de.jungblut.math.sparse.SparseDoubleRowMatrix	readSparseMatrix(DataInput in) Reads a sparse matrix from the given input stream.
void	write(DataOutput out)
static void	writeDenseMatrix(de.jungblut.math.dense.DenseDoubleMatrix mat, DataOutput out) Writes a dense matrix to the given output stream.
static void	writeSparseMatrix(de.jungblut.math.sparse.SparseDoubleRowMatrix mat, DataOutput out) Writes a sparse matrix to the given output stream.

Methods inherited from class java.lang.Object

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

Field Detail

DENSE_DOUBLE_MATRIX

public static final byte DENSE_DOUBLE_MATRIX

See Also:

Constant Field Values

SPARSE_DOUBLE_ROW_MATRIX

public static final byte SPARSE_DOUBLE_ROW_MATRIX

See Also:

Constant Field Values

Constructor Detail

MatrixWritable

public MatrixWritable()

MatrixWritable

public MatrixWritable(de.jungblut.math.DoubleMatrix mat)

Method Detail

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

getMatrix

public de.jungblut.math.DoubleMatrix getMatrix()

writeSparseMatrix

public static void writeSparseMatrix(de.jungblut.math.sparse.SparseDoubleRowMatrix mat,
                                     DataOutput out)
                              throws IOException

Writes a sparse matrix to the given output stream. The layout is as simple as in memory, first the dimension is written (row count, column count as integer) then the number of non-zero row vectors are written (integer). Afterwards for each non-zero row vector the row index (integer) itself is written as well as the count of non-zero elements in the row vector. Then for each non-zero element an integer column index and a double value is following.

Parameters:

mat - the sparse matrix to serialize.

out - the output.

Throws:

IOException - in case of an IO error.

readSparseMatrix

public static de.jungblut.math.sparse.SparseDoubleRowMatrix readSparseMatrix(DataInput in)
                                                                      throws IOException

Reads a sparse matrix from the given input stream.

Parameters:

in - the input stream.

Returns:

a new sparse matrix from the stream.

Throws:

IOException - in case of an IO error.

writeDenseMatrix

public static void writeDenseMatrix(de.jungblut.math.dense.DenseDoubleMatrix mat,
                                    DataOutput out)
                             throws IOException

Writes a dense matrix to the given output stream. The layout is as simple as in memory, first the dimension is written (row count, column count as integer) afterwards there are following row*columns doubles in a row major fashion.

Parameters:

mat - the dense matrix to serialize.

out - the output.

Throws:

IOException - in case of an IO error.

readDenseMatrix

public static de.jungblut.math.dense.DenseDoubleMatrix readDenseMatrix(DataInput in)
                                                                throws IOException

Reads a dense matrix from the given input stream.

Parameters:

in - the input stream.

Returns:

a new dense matrix from the stream.

Throws:

IOException - in case of an IO error.