ropi/cardinality-estimation

Cardinality estimation

v0.2.0 2022-03-29 20:35 UTC

Requires

• php: >=8.1.0
• ext-bcmath: *
• ext-fileinfo: *
• ext-mbstring: *

Requires (Dev)

• phpunit/phpunit: ^9.0

MIT

• Robert Piplica

• hyperloglog
• cardinality
• estimation
• estimator

README

This library is a PHP based implementation for estimating cardinalities.

Following cardinality estimators are implemented:

• HyperLogLog (approx. cardinality estimation but very low memory usage)
• Exact (exact cardinality estimation but very high memory usage)

Requirements

• PHP ^8.1

Installation

The library can be installed from a command line interface by using composer.

composer require ropi/cardinality-estimation

Basic usage

<?php
$estimator = new \Ropi\CardinalityEstimation\HyperLogLogCardinalityEstimator();

for ($i = 0; $i < 1000020; $i++) {
    $estimator->addValue((string) $i);
}

$estimator->estimate(); // Returns 995265 as approximated value