org.apache.sysds.runtime.compress

Class CompressedMatrixBlockFactory

java.lang.Object

org.apache.sysds.runtime.compress.CompressedMatrixBlockFactory

public class CompressedMatrixBlockFactory
extends Object

Factory pattern to construct a CompressedMatrixBlock.

Constructor Summary

Constructors

Constructor and Description
CompressedMatrixBlockFactory()

Method Summary

Modifier and Type	Method and Description
static org.apache.commons.lang3.tuple.Pair<MatrixBlock,CompressionStatistics>	compress(MatrixBlock mb)
static org.apache.commons.lang3.tuple.Pair<MatrixBlock,CompressionStatistics>	compress(MatrixBlock mb, CompressionSettings customSettings)
static org.apache.commons.lang3.tuple.Pair<MatrixBlock,CompressionStatistics>	compress(MatrixBlock mb, int k)
static org.apache.commons.lang3.tuple.Pair<MatrixBlock,CompressionStatistics>	compress(MatrixBlock mb, int k, CompressionSettings compSettings) The main method for compressing the input matrix.

Methods inherited from class java.lang.Object

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

Constructor Detail

CompressedMatrixBlockFactory

public CompressedMatrixBlockFactory()

Method Detail

compress

public static org.apache.commons.lang3.tuple.Pair<MatrixBlock,CompressionStatistics> compress(MatrixBlock mb)

compress

public static org.apache.commons.lang3.tuple.Pair<MatrixBlock,CompressionStatistics> compress(MatrixBlock mb,
                                                                                              CompressionSettings customSettings)

compress

public static org.apache.commons.lang3.tuple.Pair<MatrixBlock,CompressionStatistics> compress(MatrixBlock mb,
                                                                                              int k)

compress

public static org.apache.commons.lang3.tuple.Pair<MatrixBlock,CompressionStatistics> compress(MatrixBlock mb,
                                                                                              int k,
                                                                                              CompressionSettings compSettings)

The main method for compressing the input matrix. SAMPLE-BASED DECISIONS: Decisions such as testing if a column is amenable to bitmap compression or evaluating co-coding potentials are made based on a subset of the rows. For large data sets, sampling might take a significant amount of time. So, we generate only one sample and use it for the entire compression process. Once the compression plan is selected based on sampling, the plan is verified and decisions are overwritten by full estimates.

Parameters:

mb - The matrix block to compress

k - The number of threads used to execute the compression

compSettings - The Compression settings used

Returns:

A compressed matrix block.