NAME

Algorithm::HyperLogLog - Implementation of the HyperLogLog algorithm

SYNOPSIS

use Algorithm::HyperLogLog;

my $hll = Algorithm::HyperLogLog->new(14);

while(<>){
    $hll->add($_);
}

my $cardinality = $hll->estimate();

DESCRIPTION

This module is implementation of the HyperLogLog algorithm.

HyperLogLog is an algorithm for estimating the cardinality of a set.

METHODS

new($b)

Constructor.

`$b` is the parameter for determining register size. (The register size is 2^$b.)

`$b` must be a integer between 4 and 16.

add($data)

Adds element to the cardinality estimator.

estimate()

Returns estimated cardinality value in floation point number.

XS()

If using XS backend, this method return true value.

SEE ALSO

Philippe Flajolet, Éric Fusy, Olivier Gandouet and Frédéric Meunier. HyperLogLog: the analysis of a near-optimal cardinality estimation algorithm. 2007 Conference on Analysis of Algorithms, DMTCS proc. AH, pp. 127–146, 2007. http://algo.inria.fr/flajolet/Publications/FlFuGaMe07.pdf

AUTHOR

Hideaki Ohno <hide.o.j55 {at} gmail.com>

THANKS TO

MurmurHash3(https://github.com/PeterScott/murmur3)

Austin Appleby

Peter Scott

LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.