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 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