Package org.apache.sysds.runtime.matrix.data.sketch

Interface MatrixSketch<T>

All Known Implementing Classes:

KMVSketch

public interface MatrixSketch<T>

Method Summary

Modifier and Type	Method	Description
CorrMatrixBlock	create(MatrixBlock blkIn)	Create a initial sketch of a given block.
MatrixBlock	getMatrixValue(CorrMatrixBlock blkIn)	Obtain matrix distinct count value from estimation Used for estimating distinct in rows or columns.
T	getScalarValue(MatrixBlock blkIn)	Get scalar distinct count from a input matrix block.
CorrMatrixBlock	intersection(CorrMatrixBlock arg0, CorrMatrixBlock arg1)	Intersect two sketches
CorrMatrixBlock	union(CorrMatrixBlock arg0, CorrMatrixBlock arg1)	Union two sketches together to from a combined sketch.

Method Detail

getScalarValue

T getScalarValue(MatrixBlock blkIn)

Get scalar distinct count from a input matrix block.

Parameters:

blkIn - A input block to estimate the number of distinct values in

Returns:

The distinct count estimate

getMatrixValue

MatrixBlock getMatrixValue(CorrMatrixBlock blkIn)

Obtain matrix distinct count value from estimation Used for estimating distinct in rows or columns.

Parameters:

blkIn - The sketch block to extract the count from

Returns:

The result matrix block

create

CorrMatrixBlock create(MatrixBlock blkIn)

Create a initial sketch of a given block.

Parameters:

blkIn - A block to process

Returns:

A sketch

union

CorrMatrixBlock union(CorrMatrixBlock arg0,
                      CorrMatrixBlock arg1)

Union two sketches together to from a combined sketch.

Parameters:

arg0 - Sketch one

arg1 - Sketch two

Returns:

The combined sketch

intersection

CorrMatrixBlock intersection(CorrMatrixBlock arg0,
                             CorrMatrixBlock arg1)

Intersect two sketches

Parameters:

arg0 - Sketch one

arg1 - Sketch two

Returns:

The intersected sketch