Package org.apache.sysds.runtime.compress.estim

Class ComEstSample

java.lang.Object

org.apache.sysds.runtime.compress.estim.AComEst

org.apache.sysds.runtime.compress.estim.ComEstSample

public class ComEstSample
extends AComEst

Estimate compression size based on subsample of data.

Constructor Summary

Constructors

Constructor	Description
ComEstSample(MatrixBlock data, CompressionSettings cs, int sampleSize, int k)	CompressedSizeEstimatorSample, samples from the input data and estimates the size of the compressed matrix.

Method Summary

Modifier and Type	Method	Description
CompressedSizeInfoColGroup	getColGroupInfo(IColIndex colIndexes, int estimate, int maxDistinct)	A method to extract the Compressed Size Info for a given list of columns, This method further limits the estimated number of unique values, since in some cases the estimated number of uniques is estimated higher than the number estimated in sub groups of the given colIndexes.
CompressedSizeInfoColGroup	getDeltaColGroupInfo(IColIndex colIndexes, int estimate, int maxDistinct)	A method to extract the Compressed Size Info for a given list of columns, This method further limits the estimated number of unique values, since in some cases the estimated number of uniques is estimated higher than the number estimated in sub groups of the given colIndexes.
static int[]	getSortedSample(int range, int sampleSize, long seed, int k)
String	toString()

Methods inherited from class org.apache.sysds.runtime.compress.estim.AComEst

clearNNZ, combine, combine, computeCompressedSizeInfos, getColGroupInfo, getDeltaColGroupInfo, getNumColumns, getNumRows

Methods inherited from class java.lang.Object

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

Constructor Detail

ComEstSample

public ComEstSample(MatrixBlock data,
                    CompressionSettings cs,
                    int sampleSize,
                    int k)

CompressedSizeEstimatorSample, samples from the input data and estimates the size of the compressed matrix.

Parameters:

data - The input data toSample from

cs - The Settings used for the sampling, and compression, contains information such as seed.

sampleSize - The size to sample from the data.

k - The parallelization degree allowed.

Method Detail

getColGroupInfo

public CompressedSizeInfoColGroup getColGroupInfo(IColIndex colIndexes,
                                                  int estimate,
                                                  int maxDistinct)

Description copied from class: AComEst

A method to extract the Compressed Size Info for a given list of columns, This method further limits the estimated number of unique values, since in some cases the estimated number of uniques is estimated higher than the number estimated in sub groups of the given colIndexes.

Specified by:

getColGroupInfo in class AComEst

Parameters:

colIndexes - The columns to extract compression information from

estimate - An estimate of number of unique elements in these columns

maxDistinct - The upper bound of unique elements allowed in the estimate, can be calculated from the number of unique elements estimated in sub columns multiplied together. This is flexible in the sense that if the sample is small then this unique can be manually edited like in CoCodeCostMatrixMult.

Returns:

The CompressedSizeInfoColGroup for the given column indexes.

getDeltaColGroupInfo

public CompressedSizeInfoColGroup getDeltaColGroupInfo(IColIndex colIndexes,
                                                       int estimate,
                                                       int maxDistinct)

Description copied from class: AComEst

A method to extract the Compressed Size Info for a given list of columns, This method further limits the estimated number of unique values, since in some cases the estimated number of uniques is estimated higher than the number estimated in sub groups of the given colIndexes. The Difference for this method is that it extract the values as delta values from the matrix block input.

Specified by:

getDeltaColGroupInfo in class AComEst

Parameters:

colIndexes - The columns to extract compression information from

estimate - An estimate of number of unique delta elements in these columns

maxDistinct - The upper bound of unique elements allowed in the estimate, can be calculated from the number of unique elements estimated in sub columns multiplied together. This is flexible in the sense that if the sample is small then this unique can be manually edited like in CoCodeCostMatrixMult.

Returns:

The CompressedSizeInfoColGroup for the given column indexes.

getSortedSample

public static int[] getSortedSample(int range,
                                    int sampleSize,
                                    long seed,
                                    int k)

toString

public String toString()

Overrides:

toString in class AComEst