Package org.apache.sysds.runtime.compress.cost

Class ComputationCostEstimator

java.lang.Object

org.apache.sysds.runtime.compress.cost.ACostEstimate

org.apache.sysds.runtime.compress.cost.ComputationCostEstimator

All Implemented Interfaces:

Serializable

public class ComputationCostEstimator
extends ACostEstimate

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
ComputationCostEstimator(int scans, int decompressions, int overlappingDecompressions, int leftMultiplications, int rightMultiplications, int compressedMultiplication, int dictOps, int indexing, boolean isDensifying)

Method Summary

Modifier and Type	Method	Description
double	getCost(int nRows, int nRowsScanned, int nCols, int nVals, double sparsity)	Get the cost of a column group.
double	getCost(AColGroup cg, int nRows)	Get the cost of a compressed columnGroup.
double	getCost(MatrixBlock mb)	Get the cost of a matrix block.
boolean	isDense()
boolean	shouldSparsify()	Ask the cost estimator if it is a good idea to try to sparsify a column group.
String	toString()

Methods inherited from class org.apache.sysds.runtime.compress.cost.ACostEstimate

getCost, getCost, getCost, getCost

Methods inherited from class java.lang.Object

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

Constructor Details

ComputationCostEstimator

public ComputationCostEstimator(int scans,
 int decompressions,
 int overlappingDecompressions,
 int leftMultiplications,
 int rightMultiplications,
 int compressedMultiplication,
 int dictOps,
 int indexing,
 boolean isDensifying)

Method Details

getCost

public double getCost(int nRows,
 int nRowsScanned,
 int nCols,
 int nVals,
 double sparsity)

Get the cost of a column group.

Parameters:

nRows - The total number of rows

nRowsScanned - Number of rows to process in this specific group

nCols - Number of columns in the column group

nVals - Number of unique tuples contained in the group

sparsity - The sparsity of the unique tuples stored

Returns:

A cost

isDense

public boolean isDense()

getCost

public double getCost(MatrixBlock mb)

Description copied from class: ACostEstimate

Get the cost of a matrix block.

Specified by:

getCost in class ACostEstimate

Parameters:

mb - A MatrixBlock

Returns:

The cost subject to the internal cost functions

getCost

public double getCost(AColGroup cg,
 int nRows)

Description copied from class: ACostEstimate

Get the cost of a compressed columnGroup.

Specified by:

getCost in class ACostEstimate

Parameters:

cg - A ColumnGroup

nRows - The number of rows in the column group

Returns:

The cost subject to the internal cost functions

shouldSparsify

public boolean shouldSparsify()

Description copied from class: ACostEstimate

Ask the cost estimator if it is a good idea to try to sparsify a column group. It is the same as asking if it is a good idea to make FOR on top of the column group.

Specified by:

shouldSparsify in class ACostEstimate

Returns:

true if yes

toString

public String toString()

Overrides:

toString in class ACostEstimate