Class AliasElementSampler<T>

java.lang.Object

io.nosqlbench.virtdata.library.basics.core.stathelpers.AliasElementSampler<T>

All Implemented Interfaces:

DoubleFunction<T>

public class AliasElementSampler<T>
extends Object
implements DoubleFunction<T>

Uses the alias sampling method to encode and sample from discrete probabilities, even over large sets of data. This form requires a unit interval sample value between 0.0 and 1.0. Assuming the maximal amount of memory is used for distinct outcomes N, a memory buffer of N*16 bytes is required for this implementation, requiring 32MB of memory for 1M entries. This sampler should be shared between threads, and will be by default, in order to avoid many instances of a 32MB buffer on heap.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	AliasElementSampler.Weighted

Constructor Summary

Constructors

Constructor	Description
AliasElementSampler(List<ElemProbD<T>> events)

Method Summary

Modifier and Type	Method	Description
T	apply(double value)

Methods inherited from class java.lang.Object

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

Constructor Details

AliasElementSampler

public AliasElementSampler(List<ElemProbD<T>> events)

Method Details

apply

public T apply(double value)

Specified by:

apply in interface DoubleFunction<T>