Package com.googlecode.javaewah32.symmetric

Class ThresholdFuncBitmap32

java.lang.Object

com.googlecode.javaewah32.symmetric.UpdateableBitmapFunction32

com.googlecode.javaewah32.symmetric.ThresholdFuncBitmap32

public final class ThresholdFuncBitmap32
extends UpdateableBitmapFunction32

A threshold Boolean function returns true if the number of true values exceed a threshold. It is a symmetric Boolean function. This class implements an algorithm described in the following paper: Owen Kaser and Daniel Lemire, Compressed bitmap indexes: beyond unions and intersections http://arxiv.org/abs/1402.4466 It is not thread safe: you should use one object per thread.

Since:

0.8.2

Author:

Daniel Lemire

See Also:

http://en.wikipedia.org/wiki/Symmetric_Boolean_function

Constructor Summary

Constructors

Constructor	Description
ThresholdFuncBitmap32(int min)	Construction a threshold function with a given threshold

Method Summary

Modifier and Type	Method	Description
void	dispatch(BitmapStorage32 out, int runBegin, int runend)	Writes out the answer.

Methods inherited from class com.googlecode.javaewah32.symmetric.UpdateableBitmapFunction32

clearLiteral, fillWithLiterals, getLiterals, getNumberOfLiterals, resize, setLiteral, setOne, setZero

Methods inherited from class java.lang.Object

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

Constructor Detail

ThresholdFuncBitmap32

public ThresholdFuncBitmap32(int min)

Construction a threshold function with a given threshold

Parameters:

min - threshold

Method Detail

dispatch

public void dispatch(BitmapStorage32 out,
                     int runBegin,
                     int runend)

Description copied from class: UpdateableBitmapFunction32

Writes out the answer.

Specified by:

dispatch in class UpdateableBitmapFunction32

Parameters:

out - output buffer

runBegin - beginning of the run

runend - end of the run