com.datadoghq.sketch

Interface QuantileSketch<QS extends QuantileSketch<QS>>

All Superinterfaces:

java.util.function.DoubleConsumer

All Known Implementing Classes:

DDSketch, DDSketchWithExactSummaryStatistics, WithExactSummaryStatistics

public interface QuantileSketch<QS extends QuantileSketch<QS>>
extends java.util.function.DoubleConsumer

A data structure that consumes double values and can compute quantiles over the ingested values.

Quantile values are usually computed with an approximation error that depends on the sketch implementation.

Method Summary

Modifier and Type	Method and Description
void	accept(double value) Adds a value to the sketch.
void	accept(double value, double count) Adds a value to the sketch with a floating-point count.
void	clear() Sets all counts in the sketch to zero.
QS	copy()
default double	getAverage()
double	getCount()
default double	getMaxValue()
default double	getMinValue()
double	getSum()
double	getValueAtQuantile(double quantile)
double[]	getValuesAtQuantiles(double[] quantiles)
default boolean	isEmpty()
void	mergeWith(QS other) Merges the other sketch into this one.

Methods inherited from interface java.util.function.DoubleConsumer

andThen

Method Detail

accept

void accept(double value)

Adds a value to the sketch.

Specified by:

accept in interface java.util.function.DoubleConsumer

Parameters:

value - the value to be added

accept

void accept(double value,
            double count)

Adds a value to the sketch with a floating-point count.

If count is an integer, calling accept(value, count) is equivalent to calling accept(value) count times.

Parameters:

value - the value to be added

count - the weight associated with the value to be added

Throws:

java.lang.IllegalArgumentException - if count is negative

mergeWith

void mergeWith(QS other)

Merges the other sketch into this one. After this operation, this sketch encodes the values that were added to both this and the other sketches.

Parameters:

other - the sketch to be merged into this one

Throws:

java.lang.NullPointerException - if other is null

copy

QS copy()

Returns:

a (deep) copy of this sketch

isEmpty

default boolean isEmpty()

Returns:

iff no value has been added to this sketch

clear

void clear()

Sets all counts in the sketch to zero. The sketch behaves as if it were empty after this call, but any allocated memory is not released.

getCount

double getCount()

Returns:

the total number of values that have been added to this sketch

getSum

double getSum()

Returns:

the sum of values that have been added to this sketch (specifically, zero if none has been added)

getMinValue

default double getMinValue()

Returns:

the minimum value that has been added to this sketch

Throws:

java.util.NoSuchElementException - if the sketch is empty

getMaxValue

default double getMaxValue()

Returns:

the maximum value that has been added to this sketch

Throws:

java.util.NoSuchElementException - if the sketch is empty

getValueAtQuantile

double getValueAtQuantile(double quantile)

Parameters:

quantile - a number between 0 and 1 (both included)

Returns:

the value at the specified quantile

Throws:

java.util.NoSuchElementException - if the sketch is empty

getValuesAtQuantiles

double[] getValuesAtQuantiles(double[] quantiles)

Parameters:

quantiles - number between 0 and 1 (both included)

Returns:

the values at the respective specified quantiles

Throws:

java.util.NoSuchElementException - if the sketch is empty

getAverage

default double getAverage()

Returns:

the arithmetic mean of values that have been added to this sketch

Throws:

java.util.NoSuchElementException - if the sketch is empty