Package org.apache.datasketches.thetacommon

Class BoundsOnRatiosInThetaSketchedSets

java.lang.Object

org.apache.datasketches.thetacommon.BoundsOnRatiosInThetaSketchedSets

public final class BoundsOnRatiosInThetaSketchedSets
extends Object

This class is used to compute the bounds on the estimate of the ratio B / A, where:

• A is a Theta Sketch of population PopA.
• B is a Theta Sketch of population PopB that is a subset of A, obtained by an intersection of A with some other Theta Sketch C, which acts like a predicate or selection clause.
• The estimate of the ratio PopB/PopA is BoundsOnRatiosInThetaSketchedSets.getEstimateOfBoverA(A, B).
• The Upper Bound estimate on the ratio PopB/PopA is BoundsOnRatiosInThetaSketchedSets.getUpperBoundForBoverA(A, B).
• The Lower Bound estimate on the ratio PopB/PopA is BoundsOnRatiosInThetaSketchedSets.getLowerBoundForBoverA(A, B).

Note: The theta of A cannot be greater than the theta of B. If B is formed as an intersection of A and some other set C, then the theta of B is guaranteed to be less than or equal to the theta of B.

Author:

Kevin Lang, Lee Rhodes

Method Summary

Modifier and Type	Method	Description
static double	getEstimateOfBoverA(Sketch sketchA, Sketch sketchB)	Gets the estimate for B over A
static double	getLowerBoundForBoverA(Sketch sketchA, Sketch sketchB)	Gets the approximate lower bound for B over A based on a 95% confidence interval
static double	getUpperBoundForBoverA(Sketch sketchA, Sketch sketchB)	Gets the approximate upper bound for B over A based on a 95% confidence interval

Methods inherited from class java.lang.Object

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

Method Detail

getLowerBoundForBoverA

public static double getLowerBoundForBoverA(Sketch sketchA,
                                            Sketch sketchB)

Gets the approximate lower bound for B over A based on a 95% confidence interval

Parameters:

sketchA - the sketch A

sketchB - the sketch B

Returns:

the approximate lower bound for B over A

getUpperBoundForBoverA

public static double getUpperBoundForBoverA(Sketch sketchA,
                                            Sketch sketchB)

Gets the approximate upper bound for B over A based on a 95% confidence interval

Parameters:

sketchA - the sketch A

sketchB - the sketch B

Returns:

the approximate upper bound for B over A

getEstimateOfBoverA

public static double getEstimateOfBoverA(Sketch sketchA,
                                         Sketch sketchB)

Gets the estimate for B over A

Parameters:

sketchA - the sketch A

sketchB - the sketch B

Returns:

the estimate for B over A