Package org.apache.datasketches.quantiles

Class ClassicUtil

java.lang.Object

org.apache.datasketches.quantiles.ClassicUtil

public final class ClassicUtil
extends Object

Utilities for the classic quantiles sketches and independent of the type.

Author:

Lee Rhodes

Method Summary

Modifier and Type	Method	Description
static int	getKFromEpsilon(double epsilon, boolean pmf)	Used by Classic Quantiles.
static double	getNormalizedRankError(int k, boolean pmf)	Used by Classic Quantiles.

Methods inherited from class java.lang.Object

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

Method Detail

getNormalizedRankError

public static double getNormalizedRankError(int k,
                                            boolean pmf)

Used by Classic Quantiles. Gets the normalized rank error given k and pmf for the Quantiles DoubleSketch and ItemsSketch.

Parameters:

k - the configuration parameter

pmf - if true, returns the "double-sided" normalized rank error for the getPMF() function. Otherwise, it is the "single-sided" normalized rank error for all the other queries.

Returns:

if pmf is true, the normalized rank error for the getPMF() function. Otherwise, it is the "single-sided" normalized rank error for all the other queries.

getKFromEpsilon

public static int getKFromEpsilon(double epsilon,
                                  boolean pmf)

Used by Classic Quantiles. Gets the approximate k to use given epsilon, the normalized rank error for the Quantiles DoubleSketch and ItemsSketch.

Parameters:

epsilon - the normalized rank error between zero and one.

pmf - if true, this function returns k assuming the input epsilon is the desired "double-sided" epsilon for the getPMF() function. Otherwise, this function returns k assuming the input epsilon is the desired "single-sided" epsilon for all the other queries.

Returns:

k given epsilon.